Chapter 18 with our Microbiology MCQs and explanations! Test your knowledge and understanding of key concepts with our complete set of multiple choice questions with detailed explanations for each answer. Increase your confidence and understanding of the fascinating world of microorganisms!
MCQs:
Microbiology is the study of living organisms that are not visible to the naked eye. All microorganisms such as amoebae, protozoa, viruses, bacteria are studied in microbiology. Microbes play a major role in nutrient cycling, decomposition, food spoilage, disease control and causation, and biotechnology. Due to their versatile nature, they can be used for different purposes.
Below is a set of microbiology MCQs along with the answers for your reference. These will help students improve their conceptual knowledge.
Microbiology MCQs 851 to 900
- one of the standard cloning vector widely used in gene cloning is?
- Ti pasmid
- EMBL 3
- pBR 322
- EMBL 4
Answer and Explanation
Answer: pBR 322
pBR322 is a plasmid vector that has been widely used in molecular biology and genetic engineering for gene cloning. It was one of the first plasmids to be used extensively for this purpose. pBR322 contains multiple restriction sites, allowing the insertion of foreign DNA, and it also carries genes for antibiotic resistance, making it easy to select for cells that have taken up the vector.
The other options are incorrect:
- Ti plasmid: The Ti (tumor-inducing) plasmid is commonly used in plant genetic engineering, particularly for the introduction of genes into plants. It is not as widely used in gene cloning in bacterial systems.
- EMBL3: EMBL3 and EMBL4 are bacteriophage lambda-based vectors used for cloning larger fragments of DNA. They are not as commonly used as pBR322 for routine gene cloning.
- EMBL4: EMBL4, like EMBL3, is a bacteriophage lambda-based vector used for cloning larger DNA fragments. It is not as commonly used as pBR322 for routine gene cloning.
- In alchoholic fermentation, CO2 is evolved during?
- Decarboxylatin of pyruvic acid
- Formation of acetaldehyde
- Oxidation of acetaldehyde
- Both Decarboxylatin of pyruvic acid and Formation of acetaldehyde
Answer and Explanation
Answer: Both Decarboxylatin of pyruvic acid and Formation of acetaldehyde
During alcoholic fermentation, pyruvic acid undergoes decarboxylation to form acetaldehyde and carbon dioxide. This is a key step in the conversion of pyruvic acid to ethanol. The overall reaction can be summarized as follows:
Pyruvic acid→Acetaldehyde+CO₂
The other options are incorrect:
- Decarboxylation of pyruvic acid: This is the correct answer. CO₂ is evolved during the decarboxylation of pyruvic acid in alcoholic fermentation.
- Formation of acetaldehyde: While acetaldehyde is an intermediate in the fermentation process, CO₂ is not evolved during its formation.
- Oxidation of acetaldehyde: The oxidation of acetaldehyde to ethanol is the next step in alcoholic fermentation, but CO₂ is not evolved during this specific step.
- In the industrial production of streptomycin, the secondary metabolite or byproducts is?
- Vitamin – B12
- Vitamin – C
- Vitamin – B6
- Ethanol
Answer and Explanation
Answer: Vitamin – B12
n the industrial production of streptomycin, the secondary metabolite or byproduct is Vitamin B12. This is because the bacterium Streptomyces griseus, which produces streptomycin, also produces vitamin B12 as a secondary metabolite. Vitamin B12 is an essential nutrient for humans and animals, and it is used in a variety of foods and supplements.
The other options are incorrect:
- Vitamin C is produced by plants and some animals, but it is not produced by bacteria.
- Vitamin B6 is produced by plants, bacteria, and fungi.
- Ethanol is produced by yeast and some bacteria, but it is not produced by Streptomyces griseus.
- Tobacco and tea leaves are fermented to give flavour and taste. This type of fermentation is known as?
- Alcohol fermentation
- Curing
- Degradation
- Lactic acid fermentation
Answer and Explanation
Answer: Curing
The type of fermentation used to process tobacco and tea leaves is called curing. Curing is a process that involves drying and enzymatically oxidizing the leaves, which changes their flavor, aroma, and color. It is a complex process that requires careful control of temperature, humidity, and oxygen levels.
The other options are incorrect:
- Alcohol fermentation is a process that produces ethanol from sugars. It is not typically used for tobacco or tea leaves.
- Degradation is a process that breaks down organic matter into simpler compounds. It is not typically used to improve the flavor or aroma of tobacco or tea leaves.
- Lactic acid fermentation is a process that produces lactic acid from sugars. It is typically used for preserving foods, such as yogurt and sauerkraut.
- Vinegar fermentation involves?
- Yeasts only
- Yeasts with lactic bacteria
- Yeasts with acetic acid bacteria
- Yeasts with butric acid bacteria
Answer and Explanation
Answer: Yeasts with acetic acid bacteria
Vinegar fermentation involves yeasts with acetic acid bacteria. The process starts with yeasts converting sugars into ethanol, and then acetic acid bacteria convert the ethanol into acetic acid, which is the main component of vinegar. Lactic acid bacteria and butric acid bacteria are not typically involved in vinegar fermentation.
The other options are incorrect:
- Yeasts: Yeasts are single-celled microorganisms that ferment sugars into ethanol and carbon dioxide. In vinegar fermentation, the yeasts first convert the sugars in the starting material (such as fruit juice or wine) into ethanol.
- Acetic acid bacteria: Acetic acid bacteria are also single-celled microorganisms that can oxidize ethanol into acetic acid. They thrive in an acidic environment, which is why vinegar fermentation is typically successful when the starting material is already slightly acidic.
- Carcinoma refers to?
- Malignant tumours of the connective tissue
- Malignant tumors of the skin or mucous membrane
- Malignant tumours of the colon
- Malignant tumors of the connective tissue
Answer and Explanation
Answer: Malignant tumors of the skin or mucous membrane
Carcinoma is a type of cancer that develops in the epithelial cells, which are the cells that line the inner and outer surfaces of the body. These cells include the skin, the lining of the respiratory and digestive tracts, and the lining of the genitourinary tract. Carcinomas are the most common type of cancer, accounting for about 80% of all cancer cases.
The other options are incorrect:
- Malignant tumors of the connective tissue are called sarcomas. Sarcomas are less common than carcinomas and account for about 1% of all cancer cases.
- Malignant tumors of the colon are adenocarcinomas, which is a type of carcinoma that develops in glandular tissue. Adenocarcinomas are the most common type of colorectal cancer.
- Malignant tumors of the connective tissue are called sarcomas. Sarcomas are less common than carcinomas and account for about 1% of all cancer cases.
- Transgenic animals are for improvement of the quality of?
- Milk
- Meat
- Eggs
- All of the above
Answer and Explanation
Answer: All of the above
- Milk: Transgenic cows could be produced that produce milk with higher levels of protein, calcium, or other nutrients. They could also be produced that produce milk with lower levels of lactose, which is a sugar that can cause digestive problems in some people.
- Meat: Transgenic pigs could be produced that produce meat with lower levels of fat or cholesterol. They could also be produced that produce meat with higher levels of omega-3 fatty acids, which are beneficial for heart health.
- Eggs: Transgenic chickens could be produced that lay eggs with lower levels of cholesterol. They could also be produced that lay eggs with higher levels of vitamins or minerals.
- Thermo resistant bacteria are important in the preservation of foods by?
- Freezing
- Canning
- Chemicals
- Irradiation
Answer and Explanation
Answer: Canning
Thermophilic bacteria are heat-resistant microorganisms that can survive and thrive at elevated temperatures. In the canning process, foods are typically heated to high temperatures to destroy pathogenic bacteria and enzymes that could spoil the food. Thermophilic bacteria play a role in this process by being resistant to the heat treatment, ensuring that the canned food remains safe and free from spoilage during storage.
The other options are incorrect:
- Freezing: While freezing is a preservation method, it is not specifically associated with the action of thermo-resistant bacteria. Freezing primarily involves lowering the temperature to inhibit microbial growth and enzymatic activity.
- Chemicals: Chemical preservatives can be used in food preservation, but the question is specifically about thermo-resistant bacteria, and chemicals are not directly related to their resistance to heat.
- Irradiation: Food irradiation involves exposing food to ionizing radiation to kill bacteria and parasites. It is effective in food preservation, but the question specifically asks about thermo-resistant bacteria, and irradiation is not directly related to their resistance to heat.
- The fungus used in the industrial production of citric acid?
- Rhizopus Oryzac
- Fusarium moniliformae
- Rhizopus nigricans
- Aspergillus nigricans
Answer and Explanation
Answer: Aspergillus nigricans
Aspergillus niger is a filamentous fungus that is widely used in the industrial production of citric acid. It is a highly productive organism that can produce up to 80 grams of citric acid per liter of fermentation broth. Aspergillus niger is also relatively easy to grow and maintain, making it a good choice for industrial production.
The other options are incorrect:
- Rhizopus oryzae is a fungus that is commonly used in the production of tempeh, a fermented soy product. It is not as efficient at producing citric acid as Aspergillus niger.
- Fusarium moniliformae is a fungus that can produce citric acid, but it is also a plant pathogen that can cause damage to crops. This makes it less desirable for industrial production.
- Rhizopus nigricans is a fungus that is commonly found on bread and other moldy foods. It can produce citric acid, but it is not as efficient as Aspergillus niger.
- Penicilin is commercially produced by?
- P.notatum
- P.chrysogenum
- P.citrinum
- P.roquefortii
Answer and Explanation
Answer: P.chrysogenum
While Penicillium notatum was the original source of penicillin discovered by Alexander Fleming, Penicillium chrysogenum is the species that is widely used for the commercial production of penicillin. This species has characteristics that make it more suitable for large-scale fermentation and penicillin production.
The other options are incorrect:
- P. notatum: Penicillium notatum was the original source of penicillin discovered by Alexander Fleming. However, it is not the primary species used for commercial production.
- P. citrinum: Penicillium citrinum is a different species of Penicillium and is not the main species used for commercial penicillin production.
- P. roquefortii: Penicillium roquefortii is used in the production of blue cheese, but it is not the primary species used for the commercial production of penicillin.
- The most commonly used microorganism in alchohol fermentation is?
- A spergilus niger
- Bacillus subtilis
- Sacharomyces cerevisiae
- Escherichia coli
Answer and Explanation
Answer: Sacharomyces cerevisiae
Saccharomyces cerevisiae is a type of yeast that is commonly used in the production of alcohol. It is responsible for converting sugars into ethanol and carbon dioxide, which are the main components of alcoholic beverages. Saccharomyces cerevisiae is a very versatile organism that can be used to ferment a variety of sugars, including those found in grapes, grains, and fruits. It is also tolerant of a wide range of temperatures and pH levels, which makes it well-suited for industrial fermentation processes.
The other options are incorrect:
- Aspergillus niger is a type of fungus that is commonly used in the production of citric acid.
- Bacillus subtilis is a type of bacterium that is commonly used as a probiotic.
- Escherichia coli is a type of bacterium that is commonly found in the intestines of humans and animals.
- Vitam in B12 can be estimated and determined by using organism?
- Lactobacillus sps
- Lactobacillus Leichmanni
- Bacillus subtilis
- E.Coli
Answer and Explanation
Answer: Lactobacillus Leichmanni
Lactobacillus Leichmanni is commonly used in microbiological assays for the estimation and determination of Vitamin B12. This organism has specific requirements and responses that make it suitable for this purpose.
The other options are incorrect:
- Lactobacillus sps: Lactobacillus sps is not specified, and different species within the Lactobacillus genus may have varied abilities in Vitamin B12 determination. L. Leichmanni is a more specific and commonly used organism for this purpose.
- Bacillus subtilis: Bacillus subtilis is not commonly used for Vitamin B12 determination. It is more associated with other types of microbial assays and processes.
- Escherichia coli (E. coli): is not typically used for Vitamin B12 estimation. Its primary applications are in molecular biology and biotechnology rather than vitamin assays.
- Batch fermentation is also called?
- Closed system
- Open system
- Fed-Batch system
- Sub-merger system
Answer and Explanation
Answer: Closed system
Batch fermentation is also known as a closed system, where a fixed quantity of substrate is added at the beginning, and the fermentation process occurs without the addition of nutrients or withdrawal of products during the fermentation.
The other options are incorrect:
- Open system: An open system involves continuous addition of fresh nutrients and removal of spent media during fermentation, which is not characteristic of batch fermentation.
- Fed-Batch system: Fed-Batch is a different type of fermentation where nutrients are added at different stages to enhance product yield. It is not synonymous with batch fermentation.
- Sub-merger system: “Sub-merger system” is not a recognized term in the context of fermentation. It may be a typographical error. The correct term is likely “submerged system” or “submerged fermentation,” but it doesn’t specifically refer to batch fermentation.
- To differentiate lactose and non-lactose fermentors the medium used is?
- Mac Conkey’s medium
- Stuart’s medium
- Sugar medium
- Citrate medium
Answer and Explanation
Answer: Mac Conkey’s medium
Mac Conkey’s medium is used to differentiate between lactose fermenting and non-lactose fermenting bacteria. It contains lactose, neutral red dye, and crystal violet. Lactose fermenters produce acid, causing a color change in the medium.
The other options are incorrect:
- Stuart’s medium: Stuart’s medium is typically used for the transportation and preservation of clinical specimens, particularly for swabs, and is not designed for differentiating lactose fermenters.
- Sugar medium: “Sugar medium” is a general term and doesn’t specify the components necessary for distinguishing lactose fermenters. Mac Conkey’s medium is more specific for this purpose.
- Citrate medium: Citrate medium is used to test the ability of bacteria to utilize citrate as a sole carbon source. It is not designed for differentiating lactose fermenters.
- Industrial microbiology, mainly depends on the phenomenon?
- Pasteurisation
- Fermentation
- Vaccination
- Both Pasteurisation and Vaccination
Answer and Explanation
Answer: Fermentation
Industrial microbiology mainly depends on fermentation. This process involves the controlled growth of microorganisms to produce commercially valuable products, such as antibiotics, enzymes, organic acids, and biofuels.
The other options are incorrect:
- Pasteurisation: Pasteurization is a heat treatment process used to kill or inactivate harmful microorganisms in food and beverages. While it is important for food safety, it is not the primary focus of industrial microbiology.
- Vaccination: Vaccination is a medical intervention aimed at preventing infectious diseases by stimulating the immune system. It is not a central aspect of industrial microbiology, which is more concerned with the large-scale production of microbial products.
- Streptokinase is also termed as?
- Fibrionolysin
- Catalase
- Coagulase
- Hyaluronidase
Answer and Explanation
Answer: Fibrionolysin
Streptokinase is also termed as fibrinolysin because it is an enzyme that plays a role in breaking down blood clots by converting plasminogen to plasmin, which is involved in fibrinolysis.
The other options are incorrect::
- Catalase: Catalase is an enzyme that catalyzes the breakdown of hydrogen peroxide into water and oxygen. It is not another term for streptokinase.
- Coagulase: Coagulase is an enzyme that promotes blood clotting. It is not synonymous with streptokinase, which has fibrinolytic properties.
- Hyaluronidase: Hyaluronidase is an enzyme that breaks down hyaluronic acid, a component of connective tissues. It is not an alternate term for streptokinase, which is primarily associated with fibrinolysis.
- Streptokinase is produced by?
- Staphylococcus aureus
- Streptococcus pneumoniae
- Str. faecalis
- Str. pyogenes
Answer and Explanation
Answer: Str. pyogenes
Streptokinase is produced by Streptococcus pyogenes. It is an enzyme produced by this bacterium that plays a role in breaking down blood clots, making it useful in medical applications for thrombolytic therapy.
The other options are incorrect::
- Staphylococcus aureus: Staphylococcus aureus does not produce streptokinase. It is more associated with producing enzymes like coagulase.
- Streptococcus pneumoniae: Streptococcus pneumoniae is not a significant producer of streptokinase. It is more associated with causing respiratory infections.
- Str. faecalis: While Streptococcus faecalis is a bacterium within the Streptococcus genus, it is not a primary producer of streptokinase. Str. pyogenes is more commonly associated with streptokinase production.
- Large vessel containing all the parts and condition necessary for the growth of desired microorganisms is called?
- Bio reactor
- Auto reactor
- Impeller
- None of these
Answer and Explanation
Answer: Bio reactor
A bioreactor is a large vessel designed to provide optimal conditions for the growth of desired microorganisms. It includes components such as temperature control, pH regulation, and nutrient supply, facilitating the cultivation of microorganisms for various purposes, such as fermentation and the production of bioproducts.
The other options are incorrect::
- Auto reactor: “Auto reactor” is not a standard term in the context of microbiology or bioprocessing. The correct term is “bioreactor” for a vessel supporting microbial growth.
- Impeller: An impeller is a component inside a bioreactor that helps in mixing and aerating the culture, but it does not refer to the entire vessel. The correct term for the vessel is “bioreactor.”
- Basic principle in industrial microbiology is?
- Suitable growth conditions
- Fermentation
- Providing aseptic conditions
- All of these
Answer and Explanation
Answer: All of these
Suitable growth conditions, fermentation, and providing aseptic conditions are all basic principles in industrial microbiology.
- Suitable growth conditions are essential for the growth and production of microorganisms. This includes factors such as temperature, pH, nutrient availability, and oxygen levels.
- Fermentation is a metabolic process in which microorganisms convert sugars into acids, gases, or alcohol. Fermentation is used to produce a variety of products, including food, beverages, and pharmaceuticals.
- Providing aseptic conditions is important to prevent contamination of microorganisms. This is done by using sterile equipment and techniques.
- For thorough mixing of medium of medium and inoculum the part of fermentor useful is?
- Shaft
- Headspace
- Impeller
- Sparger
Answer and Explanation
Answer: Impeller
The impeller is the part of a fermentor that is crucial for thorough mixing of the medium and inoculum. It helps in creating turbulence and ensures uniform distribution of nutrients and microorganisms throughout the fermentation broth.
The other options are incorrect::
- Shaft: The shaft is a structural component that supports the impeller, but the impeller itself is responsible for mixing. The shaft does not perform the mixing function directly.
- Headspace: Headspace refers to the empty space above the liquid in the fermentor. While important for gas exchange, it is not directly involved in mixing the medium and inoculum.
- Sparger: The sparger is responsible for introducing gases into the liquid, promoting aeration. It is not primarily designed for mixing the medium and inoculum but rather for facilitating gas-liquid interactions.
- Infermentor the top portion left without broth is called?
- Shaft
- Head space
- Impeller
- Sparger
Answer and Explanation
Answer: Head space
In a fermentor, the top portion left without broth is called the headspace. It is the empty space above the liquid level in the fermentor.
The other options are incorrect:::
- Shaft: The shaft is a structural component that supports the impeller but is not specifically related to the top portion without broth (headspace).
- Impeller: The impeller is responsible for mixing the broth and is not related to the top portion without broth (headspace).
- Sparger: The sparger is responsible for introducing gases into the liquid but is not related to the top portion without broth (headspace).
- Over heating of fermentator during fermentation is controlled by?
- Cooling jacket
- Steam
- Cool air
- None of these
Answer and Explanation
Answer: Cooling jacket
Overheating of the fermentator during fermentation is controlled by a cooling jacket. A cooling jacket is a part of the fermentor that allows for temperature control by circulating a cooling medium (such as water or glycol) around the vessel to absorb excess heat generated during the fermentation process.
The other options are incorrect:
- Steam: Steam is used for heating, not cooling. It would not be used to control overheating during fermentation.
- Cool air: While cool air can be used in some systems, the most common method for controlling overheating in a fermentor is through a cooling jacket.
- Antifoam agent is?
- Silicon compounds
- Corn oil
- Soyabean oil
- All of these
Answer and Explanation
Answer: All of these
Antifoam agents are substances added to fermentation processes to control foaming. They can include various compounds, and commonly used antifoam agents include silicon compounds, corn oil, and soybean oil.
- The capacity of laboratory fermentors is?
- 12–15 liters
- 2000 gallons
- 500 liters
- 10000 gallons
Answer and Explanation
Answer: 12–15 liters
The capacity of laboratory fermentors is typically 12–15 liters. They are designed for small-scale experiments and research studies. However, there are also some laboratory fermentors that have a capacity of up to 500 liters. These are typically used for pilot-scale studies.
The other options are incorrect:
- 2000 gallons: 2000 gallons is equivalent to about 7571 liters. This is too large for a laboratory fermentor.
- 500 liters: 500 liters is a common capacity for laboratory fermentors.
- 10000 gallons: 10000 gallons is equivalent to about 37854 liters. This is too large for a laboratory fermentor.
- For the production of ethanol the raw material used is?
- Molasses
- Cellulose
- Sulphite waste liquor
- None of these
Answer and Explanation
Answer: Molasses
Molasses is a common raw material used for the production of ethanol. It is a byproduct of the sugar refining process and contains fermentable sugars that can be converted into ethanol through fermentation.
The other options are incorrect:
- Cellulose: While cellulose can be a potential raw material for ethanol production through advanced processes like cellulosic ethanol production, molasses is a more traditional and commonly used source.
- Sulphite waste liquor: Sulphite waste liquor is not a typical raw material for ethanol production. Molasses, with its high sugar content, is a more suitable choice.
- Different methods of strain improvement are?
- Protoplast fusion
- Recombinant DNA technique
- Genetic recombination
- All of these
Answer and Explanation
Answer: All of these
Strain improvement, also known as microbial mutagenesis, is the process of modifying a microorganism’s genetic material to improve its desired characteristics. This can be done through a variety of methods, including:
- Protoplast fusion: Protoplast fusion is a technique that fuses the protoplasts of two different microorganisms to create a hybrid organism with the desired characteristics of both parents.
- Recombinant DNA technique: Recombinant DNA technique is a technique that inserts DNA from one organism into the DNA of another organism. This can be done to add or remove genes, or to modify existing genes.
- Genetic recombination: Genetic recombination is the natural process of exchanging genetic material between two organisms. This can occur through sexual reproduction or through other mechanisms, such as plasmid conjugation.
- Protoplasts can be prepared from?
- Gram positive bacteria
- Gram negative bacteria
- Both Gram positive bacteria & Gram negative bacteria
- None of these
Answer and Explanation
Answer: Both Gram positive bacteria & Gram negative bacteria
Protoplasts can be prepared from both Gram-positive and Gram-negative bacteria. Protoplast formation involves the removal of the cell wall, and this can be achieved in bacteria of both Gram types.
The other options are incorrect:
- Gram-positive bacteria: Protoplasts can indeed be prepared from Gram-positive bacteria, so “Both Gram-positive bacteria & Gram-negative bacteria” is the correct answer.
- Gram-negative bacteria: Protoplasts can also be prepared from Gram-negative bacteria, making “Both Gram-positive bacteria & Gram-negative bacteria” the correct option.
- Upto the product ion of desirable production in the fermentor is called?
- Upstream process
- Downstream process
- Surface fermentation
- None of these
Answer and Explanation
Answer: Upstream process
Up to the production of the desired product in the fermentor is referred to as the upstream process. This phase includes all the steps from selecting the microorganism, preparing the culture, and the fermentation process itself.
The other options are incorrect:
- Downstream process: Downstream process refers to the steps involved after the fermentation process, such as product recovery, purification, and packaging. It is not the correct term for the initial stages in the fermentor.
- Surface fermentation: “Surface fermentation” is not a recognized term in this context. The correct term for the initial stages in the fermentor is the upstream process.
- The purification and recovery of the production after fermentation is called?
- Upstream process
- Downstream process
- Surface fermentation
- None of these
Answer and Explanation
Answer: Downstream process
The purification and recovery of the desired product after fermentation are referred to as the downstream process. It includes steps such as separation, purification, and formulation of the final product.
The other options are incorrect:
- Upstream process: The upstream process involves all the steps leading up to the fermentation, such as selecting the microorganism, preparing the culture, and the fermentation process itself. It does not include purification and recovery.
- Surface fermentation: “Surface fermentation” is not a recognized term for the phase involving purification and recovery after fermentation. The correct term is downstream process.
- If the microorganisms are allowed to nutrient medium is called?
- Submerged fermentation
- Surface fermentation
- Dual fermentation
- All of these
Answer and Explanation
Answer: Submerged fermentation
When microorganisms are allowed to grow in a nutrient medium where they are submerged or completely immersed, it is referred to as submerged fermentation. This method is commonly used in industrial processes for the production of various products.
The other options are incorrect:
- Surface fermentation: Surface fermentation involves microbial growth on the surface of a medium rather than complete submersion. It is not synonymous with the term used for microorganisms growing in a nutrient medium.
- Dual fermentation: “Dual fermentation” is not a standard term and may not accurately describe the condition where microorganisms are allowed to grow in a nutrient medium. The correct term is submerged fermentation.
- Submerged fermentations are?
- Batch fermentation
- Continuous fermentation
- Both Batch fermentation and Continuous fermentation
- None of these
Answer and Explanation
Answer: Both Batch fermentation and Continuous fermentation
Submerged fermentations can be both batch fermentations and continuous fermentations. In a batch fermentation, all the necessary nutrients are added at the beginning, and the fermentation is allowed to proceed until completion. In continuous fermentation, fresh nutrients are continuously added, and product is continuously removed, allowing for a more sustained process.
The other options are incorrect:
- Batch fermentation: Batch fermentation is one type of submerged fermentation, but the correct answer includes both batch and continuous fermentation.
- Continuous fermentation: Continuous fermentation is another type of submerged fermentation, but the correct answer includes both batch and continuous fermentation.
- Batch fermentation is also called?
- Closed system
- Open system
- Fed-batch system
- None of these
Answer and Explanation
Answer: Closed system
Batch fermentation is also referred to as a closed system. In batch fermentation, a fixed quantity of substrate is added at the beginning of the process, and the fermentation occurs without the addition of nutrients or withdrawal of products during the fermentation period.
The other options are incorrect:
- Open system: Open systems involve continuous addition of fresh nutrients and removal of spent media during fermentation. Batch fermentation is not considered an open system.
- Fed-batch system: Fed-batch systems involve the addition of nutrients at different stages to enhance product yield. Batch fermentation is a distinct process and is not synonymous with fed-batch systems.
- If more than one microorganism is used to obtain the required product, that type of fermentation is called?
- Batch
- Continuous
- Dual
- Fed-batch
Answer and Explanation
Answer: Dual
If more than one microorganism is used to obtain the required product, it is called dual fermentation. In dual fermentation, two or more microorganisms work together to achieve a specific outcome in the fermentation process.
The other options are incorrect:
- Batch: Batch fermentation involves a single culture of microorganisms, not more than one. It is a simpler form of fermentation where all the necessary nutrients are added at the beginning.
- Continuous: Continuous fermentation involves a continuous supply of nutrients and removal of products. It does not inherently involve the use of more than one microorganism.
- Fed-batch: Fed-batch fermentation typically involves the addition of nutrients at different stages to enhance product yield but does not necessarily involve the use of multiple microorganisms. Dual fermentation specifically refers to the use of more than one microorganism.
- L. lysine is produced from?
- Coryne bacterium glutamicum
- Corynebacterium sps.
- Mycobacterium sps.
- None of these
Answer and Explanation
Answer: Coryne bacterium glutamicum
L. lysine is commonly produced from Corynebacterium glutamicum. This bacterium is well-known for its ability to produce amino acids, including lysine, through fermentation processes.
The other options are incorrect:
- Corynebacterium sps.:Corynebacterium glutamicum is a species within the Corynebacterium genus that is commonly used for lysine production. The specific strain involved may vary.
- Mycobacterium sps.: Mycobacterium species are not typically associated with the industrial production of L. lysine. Corynebacterium glutamicum is the more relevant microorganism for this purpose.
- Methods used to get immobilized enzymes?
- Adsorption
- Encapsulation
- Covalent bonding
- All of these
Answer and Explanation
Answer: All of these
There are several methods that can be used to immobilize enzymes. The most common methods are:
- Adsorption: This method involves attaching the enzyme to the surface of a support material through non-covalent interactions, such as hydrogen bonding or hydrophobic interactions.
- Encapsulation: This method involves trapping the enzyme within a porous support material, such as a gel or a membrane.
- Covalent bonding: This method involves forming a covalent bond between the enzyme and the support material. This is the most stable type of immobilization, but it can also be the most difficult to achieve.
- Raw-material used for the production of alcohol is?
- Molasses
- Starch
- Sulphite waste water
- All of these
Answer and Explanation
Answer: All of these
A variety of raw materials can be used for the production of alcohol, depending on the type of alcohol being produced.
- Molasses: Molasses, a byproduct of sugar processing, is a common raw material for alcohol production, especially in the fermentation of sugarcane or sugar beet.
- Starch: Starch, derived from sources like grains or tubers, can be used for alcohol production through processes such as enzymatic hydrolysis and fermentation.
- Sulphite waste water: Sulphite waste water is not a typical raw material for alcohol production. The correct options are molasses and starch, making “All of these” the accurate answer.
- Microorganisms used for alcohol production?
- Saccharomyces cerevisiae.
- Bacillus subtilis
- Penicillium chrysogenum
- None of these
Answer and Explanation
Answer: Saccharomyces cerevisiae.
Saccharomyces cerevisiae is a yeast commonly used for alcohol production. It efficiently ferments sugars to produce ethanol and carbon dioxide, making it a key microorganism in the brewing and distilling industries.
The other options are incorrect:
- Bacillus subtilis: Bacillus subtilis is not commonly used for alcohol production. It is a bacterium known for its role in various industrial processes, but not for ethanol fermentation.
- Penicillium chrysogenum: Penicillium chrysogenum is a fungus used in the production of the antibiotic penicillin, but it is not a primary microorganism for alcohol production.
- For streptomycin production the microorganisms required are?
- Streptomyces griseus
- Streptomyces niger
- Saccharomyces cereviceae
- All of these
Answer and Explanation
Answer: Streptomyces griseus
Streptomycin is primarily produced by the bacterium Streptomyces griseus. This species of Streptomyces is known for its ability to produce antibiotics, including streptomycin.
The other options are incorrect:
- Streptomyces niger: Streptomyces niger is not the correct microorganism for streptomycin production. Streptomycin is predominantly associated with Streptomyces griseus.
- Saccharomyces cerevisiae: Saccharomyces cerevisiae is a yeast commonly used in various fermentation processes, but it is not the microorganism involved in streptomycin production.
- For acetic acid production the methods followed are?
- Orleans process
- Rapid process
- Submerged process
- All of these
Answer and Explanation
Answer: All of these
Acetic acid can be produced through several different methods, including:
- The Orleans process: This is the oldest method of acetic acid production and is still used today. It is a slow and labor-intensive process that involves the fermentation of ethanol in a series of wooden casks. The casks are lined with Acetobacter bacteria, which convert the ethanol to acetic acid.
- The rapid process: This is a more modern method of acetic acid production that is based on the fermentation of ethanol in stainless steel tanks. The tanks are sparged with air to provide the Acetobacter bacteria with oxygen, which allows them to produce acetic acid more quickly than in the Orleans process.
- The submerged process: This is the most modern method of acetic acid production and is also the most efficient. It is based on the fermentation of ethanol in a submerged culture of Acetobacter bacteria. The culture is constantly agitated and aerated to provide the bacteria with the optimal conditions for growth and acetic acid production.
- For amylase production the microorganism required is?
- B. subtilis
- S. cereviceae
- A. nigar
- None of these
Answer and Explanation
Answer: B. subtilis
Bacillus subtilis is a microorganism commonly used for amylase production. It is a bacterium known for its ability to produce various enzymes, including amylases.
The other options are incorrect:
- S. cereviceae: Saccharomyces cerevisiae is a yeast and is not the primary microorganism used for amylase production. It is more commonly associated with fermentation processes in the brewing and baking industries.
- A. nigar: Aspergillus niger is a fungus known for producing various enzymes, but it is not the primary microorganism used for amylase production. Bacillus subtilis is more commonly associated with this process.
- Pectinase is industrially produced from?
- S.cereviceae
- Trichoderma Koningi
- A. nigar
- None of these
Answer and Explanation
Answer: A. nigar
Pectinase is a group of enzymes that break down pectin, a complex polysaccharide found in plant cell walls. Pectinase is used in a variety of industrial applications, including fruit juice production, winemaking, textile processing, and papermaking.
The other options are incorrect:
- S. cerevisiae: Saccharomyces cerevisiae is a yeast commonly used in fermentation processes, but it is not a primary source for industrial production of pectinase.
- Trichoderma Koningi: Pectinase is industrially produced from the fungus Trichoderma koningi. This fungus is known for its ability to produce enzymes, including pectinases, which are used in various industrial processes, particularly in the food and beverage industry.
- Industrial Production of Vitamin-B12 is from?
- Propionibacterium sps.
- Pseudomonas sps.
- Both Propionibacterium sps. and Pseudomonas sps.
- None of these
Answer and Explanation
Answer: Both Propionibacterium sps. and Pseudomonas sps.
Industrial production of vitamin B12 is primarily from both Propionibacterium sps. and Pseudomonas sps. These microorganisms are capable of synthesizing vitamin B12 during fermentation processes. Propionibacterium sps. are commonly used for the production of cheese and certain dairy products, while Pseudomonas sps. are found in various environments, including soil, water, and plants.
The selection of specific strains of Propionibacterium sps. and Pseudomonas sps. is crucial for maximizing vitamin B12 production. These strains are optimized for their ability to efficiently convert the fermentation broth into vitamin B12 under controlled conditions.
- Clostridium acetobutylicum is used for the production of?
- Acetone – Butanol
- Ethanol
- Vitamin-B12
- None of these
Answer and Explanation
Answer: Acetone – Butanol
Clostridium acetobutylicum is used for the production of acetone and butanol through a fermentation process known as acetone-butanol-ethanol (ABE) fermentation. This bacterium can convert sugars into these valuable solvents.
The other options are incorrect:
- Ethanol: While Clostridium acetobutylicum is involved in fermentation, its primary product is acetone and butanol, not ethanol.
- Vitamin-B12: Clostridium acetobutylicum is not typically used for the production of Vitamin B12. Its primary application is in the ABE fermentation for acetone and butanol.
- In the production of ethanol industrially the yeast used is?
- K.pneumoniae
- Kluyreromyces fragilis
- S. cerevisiae
- Both Kluyreromyces fragilis and S. cerevisiae
Answer and Explanation
Answer: S. cerevisiae
In the industrial production of ethanol, the yeast commonly used is Saccharomyces cerevisiae. This yeast is well-known for its ability to ferment sugars and produce ethanol.
The other options are incorrect:
- K. pneumoniae: Klebsiella pneumoniae is a bacterium and is not typically used for the industrial production of ethanol. Yeasts, particularly Saccharomyces cerevisiae, are more commonly employed for this purpose.
- Kluyveromyces fragilis: Kluyveromyces fragilis is a yeast, but Saccharomyces cerevisiae is the more widely used yeast for ethanol production.
- Both Kluyveromyces fragilis and S. cerevisiae: While Kluyveromyces fragilis is a yeast, the most common yeast used in the industrial production of ethanol is Saccharomyces cerevisiae. “Both Kluyveromyces fragilis and S. cerevisiae” is not the most accurate option in this context.
- Citric acid is used as?
- Flavouring agent in food
- As an antioxident
- As preservative
- All of the above
Answer and Explanation
Answer: All of the above
Citric acid is a versatile organic acid that is widely used in the food industry for its various properties. It is commonly used as a flavoring agent, an antioxidant, and a preservative.
- Flavouring agent: Citric acid contributes a sour taste to food and beverages, enhancing their overall flavor profile. It is often added to soft drinks, candies, jams, and other food products to provide a tart and refreshing taste.
- Antioxidant: Citric acid acts as an antioxidant, protecting food and beverages from oxidation and spoilage. It neutralizes free radicals, preventing them from causing damage to cells and tissues. This property extends the shelf life of food products and preserves their nutritional value.
- Preservative: Citric acid can also act as a preservative in food and beverages. It lowers the pH level of the food, making it less hospitable for the growth of microorganisms that cause spoilage. This helps to extend the shelf life of food products and prevent foodborne illnesses.
- C itr ic ac id is produced in aerob ic conditions by the fungi?
- Aspergillus
- Penicillin
- Mucor
- All of these
Answer and Explanation
Answer: All of these
Citric acid can be produced under aerobic conditions by several fungi, including Aspergillus, Penicillium, and Mucor. These fungi are capable of efficiently converting sugars into citric acid through a process called the Krebs cycle. The specific strain of fungi used will depend on the desired yield and production conditions.
- Aspergillus niger is the most commonly used fungus for industrial citric acid production. It is known for its high yield and ability to grow under a wide range of conditions.
- Penicillium chrysogenum is also used for citric acid production, but it is less common than Aspergillus niger. Penicillium chrysogenum is primarily used for the production of penicillin, an antibiotic.
- Mucor spp. are also capable of producing citric acid, but they are not as commonly used as Aspergillus niger or Penicillium chrysogenum. Mucor spp. are typically used for other applications, such as the production of enzymes and organic acids.
- The raw material for citric acid production is?
- Corn
- Molasses
- Starch
- None of these
Answer and Explanation
Answer: Molasses
Molasses is the raw material commonly used for citric acid production. It serves as a source of fermentable sugars that can be metabolized by citric acid-producing microorganisms, such as Aspergillus niger, during the fermentation process.
The other options are incorrect::
- Corn: Corn is not a typical raw material for citric acid production. Molasses, derived from sugar processing, is more commonly used.
- Starch: Starch is not the primary raw material for citric acid production. Molasses, which contains sugars, is a more suitable substrate for the fermentation process.
- Aspergillus niger is used generally for the production of?
- Ethanol
- Penicillin
- Citric acid
- Lactic acid
Answer and Explanation
Answer: Citric acid
Aspergillus niger is commonly used for the industrial production of citric acid. It is a fungus that has the ability to efficiently produce citric acid through fermentation processes.
The other options are incorrect::
- Ethanol: Aspergillus niger is not typically used for the production of ethanol. Yeasts, such as Saccharomyces cerevisiae, are more commonly associated with ethanol production.
- Penicillin: Penicillin is produced by fungi of the genus Penicillium, not Aspergillus niger.
- Lactic acid: Aspergillus niger is not a common microorganism used for the production of lactic acid. Lactic acid bacteria, such as Lactobacillus species, are more commonly associated with lactic acid production.
- In the citric acid production, the pH to be maintained in the fernmenter is?
- 7.0
- 5.0 to 6.0
- 8.0 to 9.0
- 1.0 to 6.0
Answer and Explanation
Answer: 5.0 to 6.0
In citric acid production, the pH to be maintained in the fermenter is typically in the range of 5.0 to 6.0. This pH range is optimal for the growth and activity of the citric acid-producing microorganism, usually Aspergillus niger, during the fermentation process.
The other options are incorrect::
- 7.0: A pH of 7.0 is neutral, but in citric acid production, a slightly acidic pH range is preferred for the activity of the citric acid-producing microorganism.
- 8.0 to 9.0: A pH range of 8.0 to 9.0 is more alkaline, and it is not conducive to the optimal production of citric acid. The preferred range is slightly acidic.
- 1.0 to 6.0: While a pH range of 1.0 to 6.0 is generally acidic, the specific optimal range for citric acid production is typically within 5.0 to 6.0.
- The requ ired temperature for the production of citric acid is?
- 10°C – 80°C
- 30°C – 50°C
- 20°C – 50°C
- 25°C – 30°C
Answer and Explanation
Answer: 25°C – 30°C
The required temperature for the production of citric acid is typically in the range of 25°C to 30°C. This temperature range is optimal for the growth and metabolic activity of the citric acid-producing microorganism, such as Aspergillus niger, during the fermentation process.
The other options are incorrect::
- 10°C – 80°C: This temperature range is too broad, and the upper limit (80°C) is far too high for the production of citric acid, which is typically carried out at moderate temperatures.
- 30°C – 50°C: While this range is within the limits for microbial growth, the optimal temperature for citric acid production is typically slightly lower, around 25°C to 30°C.
- 20°C – 50°C: This range is also broader than the typical requirements for citric acid production, and the lower limit (20°C) may be on the cooler side for optimal fermentation. The preferred range is slightly higher.
The questions are typically designed to assess the technical skills and knowledge required for the laboratory profession, including the ability to analyze laboratory test results, perform laboratory procedures, and maintain laboratory equipment.
To prepare for these MCQs, candidates should have a thorough understanding of the key concepts and principles of laboratory science. They should also be familiar with common laboratory equipment and procedures, as well as laboratory safety protocols.
Candidates may also benefit from studying specific laboratory science textbooks or taking online courses that cover the material tested in the MCQs. Additionally, practicing sample MCQs and reviewing the answers can help candidates identify areas where they may need to improve their knowledge or skills.
Overall, the MCQs for lab technologists are designed to be challenging and comprehensive, requiring candidates to demonstrate a high level of proficiency in the field of laboratory science.
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