Microbes in Industrial Products Questions in English

(A) $Saccharomyces$ $cerevisiae$,commonly known as Brewer's yeast,is a fungus used in the industrial production of ethanol.
It performs fermentation of sugars present in cereal grains and fruit juices to produce ethanol and $CO_2$.
This process is fundamental in the brewing and distilling industries.

(A) Yeast, specifically $Saccharomyces$ $cerevisiae$ (also known as brewer's yeast), is used in the fermentation process.
It is widely used in the baking industry for the production of bread, where it releases $CO_2$ that makes the dough rise.
It is also used in the brewing industry for the production of ethanol (alcohol) in beverages like beer and wine.

(C) The bacterium $Acetobacter$ $aceti$ is used for the production of acetic acid (vinegar). However,in the context of food flavorings derived from molasses,$Saccharomyces$ $cerevisiae$ (yeast) is commonly used for fermentation,but it is a fungus. Among the given options,$Acetobacter$ is a bacterium involved in the production of vinegar,which is used as a food flavor and preservative. Note: While $Saccharomyces$ is often associated with molasses,it is a yeast,not a bacterium. Given the options provided and the context of industrial microbiology,$Acetobacter$ is the correct bacterial choice.

(B) In a fed-batch culture,the substrate (such as sugar) is added periodically to the bioreactor. This is done to maintain the growth of microorganisms at a specific rate and to prolong the production phase of secondary metabolites,such as antibiotics. By controlling the nutrient supply,the culture can be kept in a state of high productivity for a longer duration.

(B) The first organic acid produced on a commercial scale by microbial fermentation is $Lactic$ $acid$. It is produced by the bacterium $Lactobacillus$ $delbrueckii$ or $Lactobacillus$ $bulgaricus$ through the fermentation of sugars. Therefore, the correct option is $B$.

(C) Rennet is a complex of enzymes produced in the stomachs of ruminant mammals. The key enzyme in rennet is chymosin (or rennin),which is a protease. It is primarily used in the process of cheese making to coagulate milk,which separates the milk into solid curds and liquid whey.

(C) The industrial production of citric acid is primarily carried out using the fungus $Aspergillus$ $niger$.
$Aspergillus$ $niger$ is a filamentous fungus that is highly efficient at converting sugars (such as glucose or sucrose) into citric acid through aerobic fermentation.
$Lactobacillus$ $bulgaricus$ is used for the production of lactic acid.
$Penicillium$ $citrinum$ is known for producing citrinin,a mycotoxin.
$Rhizopus$ $nigricans$ is often used in the production of fumaric acid.

(D) Myocardial infarction,commonly known as a heart attack,is caused by the formation of a blood clot in the coronary arteries.
Streptokinase is an enzyme produced by the bacterium $Streptococcus$ and is genetically engineered to be used as a 'clot buster'.
It is administered to patients who have suffered myocardial infarction to dissolve the blood clots in the blood vessels,thereby restoring blood flow to the heart muscle.
Therefore,the correct option is $D$.

(B) The yeast $Monascus$ $purpureus$ is commercially used for the production of statins.
Statins are competitive inhibitors of the enzyme responsible for cholesterol synthesis in the body.
They act by lowering blood cholesterol levels,thereby helping in the management of cardiovascular diseases.

(C) The medicine Cyclosporin $A$ is used as an immunosuppressive agent in patients undergoing organ-transplant.
It is produced by the fungus $Trichoderma$ $polysporum$.
Therefore, the correct pair for the blanks is $(a)$ Organ-transplant and $(b)$ $Trichoderma$.

(C) The production of vinegar (acetic acid) from alcohol (ethanol) is a process of aerobic fermentation.
This process is carried out by the bacterium $Acetobacter$ $aceti$.
These bacteria oxidize ethanol to acetic acid in the presence of oxygen.
Therefore,the correct option is $C$.

(B) Beer is an alcoholic beverage produced by the fermentation of starch-based materials,primarily malted barley. The process involves the conversion of starch into sugars by enzymes,followed by fermentation by yeast ($Saccharomyces$ $cerevisiae$). While other grains like wheat or corn can be used,barley is the most common source.

(B) In $1928$,Alexander Fleming discovered the first antibiotic,Penicillin,while working on the bacterium $Staphylococcus$.
He observed that the mold $Penicillium$ $notatum$ inhibited the growth of the bacteria.
This discovery marked a significant milestone in the field of medicine.

(B) Malt is primarily produced from germinated cereal grains, most commonly barley $(Hordeum \text{ } vulgare)$.
During the malting process, the grains are soaked in water and allowed to germinate, which activates enzymes that break down starches into simpler sugars like maltose.
This malted barley is widely used in the brewing and distilling industries, as well as in the production of food products like malted milk.

(C) Roquefort cheese is ripened by growing a specific fungus called $Penicillium$ $roqueforti$ on it. This fungus gives the cheese its characteristic flavor and texture. Therefore,the correct option is $C$.

(B) $Saccharomyces$ $cerevisiae$,also known as Brewer's yeast,is used in the fermentation process for the production of ethanol and carbon dioxide.
It is widely used in the baking industry for making bread and in the brewing industry for producing alcoholic beverages like beer and brandy.
Cheese production,however,primarily involves the use of bacteria such as $Lactobacillus$ or $Propionibacterium$ $sharmanii$ and $Penicillium$ species for ripening,not $Saccharomyces$ $cerevisiae$.
Therefore,cheese cannot be obtained with the help of this yeast.

(A) Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. Microorganisms,such as bacteria and yeast,primarily utilize carbohydrates (sugars) as their main energy source to perform fermentation. For example,$Lactobacillus$ converts lactose (a carbohydrate) in milk into lactic acid,and yeast performs alcoholic fermentation on sugars. While some microbes can break down proteins or lipids,the primary and most common substrate for fermentation in biological and industrial contexts is carbohydrates.

(B) Swiss cheese is produced by the bacterium $Propionibacterium \text{ } shermanii$.
This bacterium produces a large amount of $CO_2$ during the fermentation process, which creates the characteristic large holes found in Swiss cheese.

(C) Silage is a type of fodder made from green foliage crops which have been preserved by acidification,a process achieved through the fermentation of carbohydrates present in the plant tissues by lactic acid bacteria. This process is commonly used in agriculture to store feed for livestock.

(B) Assertion $A$ is true: Roquefort cheese is ripened by growing a specific fungus,$Penicillium$ $roqueforti$,on it,which gives it a particular flavor.
Reason $R$ is true: Swiss cheese is produced by the bacterium $Propionibacterium$ $sharmanii$,which produces large amounts of $CO_2$ resulting in the characteristic large holes.
Conclusion: Both statements are scientifically correct,but the reason does not explain why fungi are used for Roquefort cheese. Therefore,$R$ is not the correct explanation of $A$.

(B) $Propionibacterium$ $sharmanii$ is a bacterium used in the production of Swiss cheese.
It performs fermentation,which releases a large amount of $CO_2$ gas.
This $CO_2$ gas creates the characteristic large holes found in Swiss cheese.

(A) Swiss cheese is produced by the large-scale fermentation of milk using the bacterium $Propionibacterium$ $shermanii$. This bacterium produces a large amount of $CO_2$ during the fermentation process, which creates the characteristic large holes found in Swiss cheese.

(D) Statins are produced by the yeast $Monascus$ $purpureus$.
Statins act as blood-cholesterol lowering agents by competitively inhibiting the enzyme responsible for the synthesis of cholesterol.
They do not prevent blood clotting; blood clotting is prevented by clot busters like streptokinase.
Therefore,Statement $A$ is false because statins do not prevent blood clotting,and Reason $R$ is true because statins lower cholesterol levels.

(D) Alexander Fleming discovered penicillin from the mold $Penicillium$ $notatum$. However,its full potential as an effective antibiotic was established much later by Ernest Chain and Howard Florey. They were awarded the Nobel Prize in $1945$ along with Fleming for this discovery and its development.

(D) Microbes are extensively used in the industrial sector for the production of various valuable products.
$1$. Enzymes: Microbes like $Aspergillus$ $niger$ are used for the production of citric acid,and various lipases,proteases,and pectinases are produced industrially.
$2$. Steroids: Certain microbes are used in the biotransformation of steroids,which are essential for pharmaceutical applications.
$3$. Biofuels: Microbes are used to produce biofuels like ethanol and biogas through fermentation processes.
Since all these products are synthesized by microbes in industrial settings,the correct option is $D$.

(C) Cyclosporin $-A$ is a bioactive molecule produced by the fungus $Trichoderma$ $polysporum$.
It is widely used as an immunosuppressive agent in patients undergoing organ transplants.
It functions by suppressing the immune system, thereby preventing the body from rejecting the transplanted organ.

(C) Statins are bioactive molecules produced by the yeast $Monascus \text{ } purpureus$.
They act as blood-cholesterol lowering agents.
They function by competitively inhibiting the enzyme responsible for the synthesis of cholesterol in the liver.

(A) Penicillin was the first antibiotic discovered by Alexander Fleming. It is extracted from the fungus $Penicillium \text{ } notatum$. While other species like $Penicillium \text{ } chrysogenum$ are used for large-scale industrial production today, $Penicillium \text{ } notatum$ is the historically recognized source for the discovery of penicillin.

(D) The fungus $Aspergillus$ $niger$ is industrially used for the production of citric acid.
$Acetic$ $acid$ is produced by the bacterium $Acetobacter$ $aceti$.
$Butyric$ $acid$ is produced by the bacterium $Clostridium$ $butylicum$.
$Lactic$ $acid$ is produced by the bacterium $Lactobacillus$.
Therefore,the correct option is $D$.

(B) The fungus $Monascus$ $purpureus$ is used in the commercial production of statins.
Statins are blood-cholesterol lowering agents.
They act by competitively inhibiting the enzyme responsible for the synthesis of cholesterol in the body.

(C) Streptokinase is an enzyme produced by certain strains of the bacterium $Streptococcus$.
It is used as a 'clot buster' for removing clots from the blood vessels of patients who have undergone myocardial infarction leading to heart attack.
Therefore,the correct source of streptokinase is bacteria.

(B) Streptokinase is an enzyme produced by the bacterium $Streptococcus$.
It is genetically engineered and used as a 'clot buster' for removing clots from the blood vessels of patients who have undergone myocardial infarction (heart attack).

(D) $Saccharomyces$ $cerevisiae$,commonly known as brewer's yeast,is used for the commercial production of ethanol (industrial alcohol).
It ferments sugars present in cereals and fruit juices into ethanol and $CO_2$ through the process of fermentation.

(A) Cyclosporin-$A$ is a bioactive molecule produced by the fungus $Trichoderma polysporum$.
It is widely used as an immunosuppressive agent in patients undergoing organ transplantation to prevent the rejection of the transplanted organ by the body's immune system.

(D) The correct answer is $D$.
$1$. $Acetobacter$ $aceti$ is used for the production of acetic acid.
$2$. $Clostridium$ $butylicum$ is used for the production of butyric acid.
$3$. $Aspergillus$ $niger$ is used for the production of citric acid.
$4$. $Lactobacillus$ is used for the production of lactic acid,but in the context of industrial products mentioned in the $NCERT$ chapter 'Microbes in Human Welfare',the primary industrial examples for organic acids are $Acetobacter$ $aceti$ (acetic acid),$Aspergillus$ $niger$ (citric acid),$Clostridium$ $butylicum$ (butyric acid),and $Lactobacillus$ (lactic acid). However,if we look for the mismatch in a standard multiple-choice question context where one is often considered the odd one out based on specific industrial applications,$Lactobacillus$ is primarily associated with the conversion of milk to curd,whereas the others are explicitly listed for large-scale industrial acid production.

(C) Acetic acid is commercially produced by the fermentation of alcohol using the bacterium $Acetobacter$ $aceti$.
$Acetobacter$ is an aerobic bacterium that oxidizes ethanol to acetic acid.
Therefore,the correct option is $C$.

(C) Citric acid is a commercially important organic acid produced on a large scale using the fungus $Aspergillus$ $niger$.
This fungus is widely used in the fermentation industry for the production of citric acid due to its high yield and efficiency in metabolizing sugar substrates.

(A) The production of ethanol from cereals and fruit juices is carried out through the process of fermentation.
This process is mediated by the yeast $Saccharomyces$ $cerevisiae$,which is commonly known as Brewer's yeast.
$Saccharomyces$ $cerevisiae$ ferments the sugars present in cereals and fruit juices into ethanol and $CO_2$ under anaerobic conditions.
Therefore,Brewer's yeast is the correct answer.

(B) The fungus $Ashbya$ $gossypii$ is an industrial microorganism used for the commercial production of Vitamin $B_2$ (Riboflavin). It is highly efficient in synthesizing this vitamin through fermentation processes.

(C) Lipases are enzymes that catalyze the hydrolysis of fats (lipids).
In laundry detergents,lipases are used to effectively remove oily and greasy stains from clothes.
These enzymes break down the lipid molecules into fatty acids and glycerol,which are then easily washed away by water and surfactants.
Therefore,the correct option is $C$.

(C) Assertion $A$ is true because Cyclosporin-$A$ is an immunosuppressive agent used as an organ-transplant rejection inhibitor.
Reason $R$ is false because the agent that lowers blood cholesterol is a statin (e.g.,Monascus purpureus),not Cyclosporin-$A$.
Therefore,$A$ is true and $R$ is false.

(D) The correct answer is $D$.
$Glucoamylase$, $Renin$, and $Cellulase$ are all examples of enzymes (biocatalysts) produced by microbes for industrial applications.
$Riboflavin$ (Vitamin $B_2$) is a vitamin, not an enzyme.
Therefore, $Riboflavin$ is the odd one out.

(B) Assertion $A$ is true because $Alexander \text{ Fleming}$ discovered penicillin, but it was $Ernest \text{ Chain}$ and $Howard \text{ Florey}$ who established its full potential as an effective antibiotic and improved its mass production.
Reason $R$ is also true because penicillin was indeed first isolated from the fungus $Penicillium \text{ notatum}$.
However, the reason $R$ explains the source of the antibiotic, not why $Chain$ and $Florey$ were able to improve its production. Therefore, $R$ is not the correct explanation of $A$.

(B) Progesterone is a steroid hormone. In industrial microbiology, the fungus $Rhizopus$ $nigricans$ is widely used for the biotransformation of steroids. Specifically, it is employed in the production of progesterone from precursors like progesterone-like compounds or through the modification of other steroidal substances. Therefore, the correct option is $B$.

(B) Cyclosporin $A$ is an immunosuppressive agent used in organ transplant patients to prevent rejection.
It is commercially produced by the fungus $Trichoderma$ $polysporum$.

(B) Hydroxyprogesterone is a steroid hormone.
In the pharmaceutical industry,microbial transformation is used to produce various steroid derivatives.
The fungus $Rhizopus$ $nigricans$ is specifically employed for the $11\alpha$-hydroxylation of progesterone to produce hydroxyprogesterone.
Therefore,the correct option is $B$.

(A) Streptokinase is an enzyme produced by the bacterium $Streptococcus$. It is used as a 'clot buster' to dissolve blood clots in the blood vessels of patients who have undergone myocardial infarction (heart attack).

(B) The production of various organic acids is carried out by specific microbes.
$1$. $Clostridium$ $butyricum$ is a bacterium used for the commercial production of butyric acid.
$2$. $Lactobacillus$ is used for the production of lactic acid.
$3$. $Acetobacter$ $aceti$ is used for the production of acetic acid.
$4$. $Aspergillus$ $niger$ (a fungus) is used for the production of citric acid.
Therefore,the correct option is $B$.

(B) The fungus $Ashbya$ $gossypii$ is industrially used for the commercial production of riboflavin (Vitamin $B_2$). It is highly efficient in synthesizing this vitamin,making it a primary source in biotechnology.

(C) The incorrect statement is that Streptokinase is useful for blood clotting at the injured site.
In reality,Streptokinase,produced by the bacterium $Streptococcus$ and modified by genetic engineering,is used as a 'clot buster' to remove clots from the blood vessels of patients who have undergone myocardial infarction (heart attack).
It dissolves existing blood clots rather than promoting clotting.
Statins are correctly identified as cholesterol-lowering agents.
$Rhizopus$ $nigricans$ is indeed used in the biotransformation of progesterone.
Immunosuppressive agents (like Cyclosporin $A$) are essential after organ transplantation to prevent rejection.