Microbes in Household Products Questions in English

(C) The conversion of milk into curd is carried out by Lactic Acid Bacteria $(LAB)$ such as Lactobacillus.
These bacteria grow in milk and convert it into curd.
During this process,$LAB$ significantly increases the nutritional quality of curd by increasing the amount of Vitamin $B_{12}$.
Therefore,the correct option is $C$.

(C) The Assertion is correct because $Saccharomyces \text{ } cerevisiae$ (brewer's yeast) is widely used in the baking industry to ferment sugars in the dough.
The Reason is incorrect because the rising of the bread dough is caused by the entrapment of $CO_2$ gas bubbles produced during fermentation, not by thermal expansion. Thermal expansion would only occur during the actual baking process in the oven, whereas the 'rising' of the dough occurs primarily due to the accumulation of gas.

(N/A) Curd can be used as a sample for the study of microbes. Curd contains numerous lactic acid bacteria $(LAB)$ or $Lactobacillus$. These bacteria produce acids that coagulate and digest milk proteins. $A$ small drop of curd contains millions of bacteria,which can be easily observed under a microscope.

(N/A) Microbes release gases during metabolism,which can be demonstrated through the following examples:
$1$. Fermentation in Dough: The dough used for making foods like $Idli$ and $Dosa$ is fermented by bacteria. During this metabolic process,bacteria release $CO_2$ gas. This gas gets trapped in the dough,causing it to puff up or rise.
$2$. Fermentation by Yeast: Yeast ($Saccharomyces$ $cerevisiae$) performs fermentation on sugars to produce alcohol and $CO_2$. The chemical reaction is:
$Glucose \xrightarrow{\text{Without oxygen}} Alcohol + Energy + CO_2$
These examples confirm that metabolic activities of microbes,such as fermentation,result in the production and release of gases like $CO_2$.

(N/A) Lactic acid bacteria $(LAB)$ are commonly found in curd.
These bacteria grow in milk and convert it into curd by producing acids that coagulate and partially digest the milk proteins.
During this process,they significantly increase the nutritional quality of curd by increasing the content of vitamin $B_{12}$.
In our stomach,$LAB$ play a beneficial role by checking disease-causing micro-organisms and maintaining gut health.

(N/A) Microbes play a significant role in the preparation of various traditional Indian foods through the process of fermentation.
$1$. Wheat: Products like $Bread$ and $Cake$ are prepared using $Saccharomyces$ $cerevisiae$ (Baker's yeast).
$2$. Rice: Foods like $Idli$ and $Dosa$ are prepared from a fermented batter of rice and black gram,involving the action of various bacteria like $Leuconostoc$ and $Streptococcus$ species.
$3$. Bengal gram (Chickpea): Foods like $Dhokla$ and $Khandvi$ are prepared using fermented batter of Bengal gram flour (besan),which involves microbial fermentation to improve texture and flavor.

(N/A) Microbes and their derivatives are used in our daily lives. $A$ common example is the production of curd from milk.
- Microorganisms such as $Lactobacillus$ and others,commonly called Lactic Acid Bacteria $(LAB)$,grow in milk and convert it into curd. During this process,$LAB$ produce acids that coagulate and partially digest milk proteins.
- $A$ small amount of curd added to fresh milk as an inoculum or starter contains millions of $LAB$,which multiply at suitable temperatures,converting milk into curd and improving its nutritional quality by increasing vitamin $B_{12}$.
- In our stomach,$LAB$ play a beneficial role in checking disease-causing microbes.
- The dough used for making foods like Dosa and Idli is fermented by bacteria. The puffed-up appearance of the dough is due to the production of $CO_2$ gas.
- Similarly,the dough used for making bread is fermented using baker's yeast ($Saccharomyces$ $cerevisiae$).
- Many traditional drinks and foods are made by microbial fermentation. 'Toddy',a traditional drink in parts of southern India,is made by fermenting sap from palms.
- Microbes are also used to ferment fish,soybean,and bamboo shoots.
- Cheese is one of the oldest food items involving microbes. Different varieties of cheese are known for their characteristic texture,flavor,and taste,which depend on the specific microbes used. For example,the large holes in 'Swiss cheese' are due to the production of a large amount of $CO_2$ by the bacterium $Propionibacterium$ $sharmanii$. 'Roquefort cheese' is ripened by growing specific fungi on it,giving it a particular flavor.

(A) $Propionibacterium \text{ } sharmanii$ is the bacterium used to produce Swiss cheese.
This cheese is characterized by large holes, which are formed due to the production of a large amount of $CO_{2}$ gas during the fermentation process.

(N/A) Micro-organisms such as $Lactobacillus$ and others,commonly called Lactic Acid Bacteria $(LAB)$,grow in milk and convert it into curd.
During growth,the $LAB$ produce acids that coagulate and partially digest the milk proteins.
$A$ small amount of curd added to fresh milk as an inoculum or starter contains millions of $LAB$,which multiply at suitable temperatures,thus converting milk into curd.
This process also improves the nutritional quality of curd by increasing the content of Vitamin $B_{12}$.
In our stomach,$LAB$ play a very beneficial role in checking disease-causing microbes.

(C) The conversion of milk into curd is carried out by microorganisms known as Lactic Acid Bacteria $(LAB)$.
These bacteria,such as $Lactobacillus$,grow in milk and convert it into curd.
During this process,they produce acids that coagulate and partially digest the milk proteins $(casein)$.
Therefore,the correct option is $C$.

(A) Lactic Acid Bacteria $(LAB)$,such as Lactobacillus,grow in milk and convert it into curd.
During this process,they produce acids that coagulate and partially digest the milk proteins.
Additionally,$LAB$ play a significant role in improving the nutritional quality of curd by increasing the content of vitamin $B_{12}$.

(C) Microorganisms such as $Lactobacillus$ and others commonly called Lactic Acid Bacteria $(LAB)$ grow in milk and convert it into curd.
During growth, these bacteria produce acids that coagulate and partially digest the milk proteins.
Specifically, they produce $Lactic$ $acid$ which lowers the $pH$ of the milk, leading to the coagulation of milk proteins (casein) to form curd.

(A) The traditional drink of Southern India is known as 'Toddy'.
It is a form of fermented beverage made from the sap of palm trees.
The sap is collected and allowed to ferment naturally by the action of yeast and bacteria present in the environment.
Therefore,the correct option is $A$.

(B) Toddy is a traditional drink of South India. It is prepared by fermenting sap from palms,such as the Palmyra palm ($Borassus$ $flabellifer$) or the Date palm ($Phoenix$ $sylvestris$). The fermentation is carried out by naturally occurring yeasts present in the sap.

(D) Curd is formed by the fermentation of milk by microorganisms known as Lactic Acid Bacteria $(LAB)$.
These bacteria,such as Lactobacillus,grow in milk and convert it into curd.
During this process,they produce acids that coagulate and partially digest the milk proteins.
$LAB$ also improves the nutritional quality of curd by increasing the content of Vitamin $B_{12}$.

(A) $LAB$ stands for Lactic Acid Bacteria. These bacteria grow in milk and convert it into curd. During growth,they produce acids that coagulate and partially digest the milk proteins.

(A) $LAB$ (Lactic Acid Bacteria) are beneficial bacteria that grow in milk and convert it into curd.
They improve the nutritional quality of curd by increasing vitamin $B_{12}$ content.
In our stomach,$LAB$ play a very beneficial role in checking disease-causing microbes and maintaining a healthy gut flora.

(A) The dough used for making foods like dosa and idli is fermented by bacteria.
During the process of fermentation,these bacteria perform anaerobic respiration.
As a result of this metabolic activity,$CO_2$ gas is released.
The entrapment of this $CO_2$ gas within the dough causes it to appear puffed up or swollen.

(B) Toddy is a traditional drink made in some parts of southern India. It is prepared by the fermentation of sap extracted from palms. The process of fermentation is carried out by naturally occurring yeasts and other microbes present in the sap.

(C) The production of bread involves the process of fermentation.
$Saccharomyces cerevisiae$, commonly known as baker's yeast, is used for this purpose.
During fermentation, the yeast releases $CO_2$ gas, which causes the dough to rise and gives the bread its porous and soft texture.

(A) Roquefort cheese is ripened by growing a specific fungus called $Penicillium$ $\text{roqueforti}$ on it. This fungus gives the cheese its characteristic flavor and blue-veined appearance.

(D) 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 in the cheese.

(D) Microbes,especially bacteria and yeast,play a crucial role in fermentation processes used in food production.
$1$. $Toddy$: $A$ traditional drink made by fermenting sap from palms.
$2$. $Dosa$ and $Idli$ batter: The dough is fermented by bacteria (e.g.,$Leuconostoc$ and $Streptococcus$ species),which produces $CO_2$ gas,making the dough puffy.
$3$. $Alcoholic$ $beverages$: Yeast ($Saccharomyces$ $cerevisiae$) ferments fruit juices or malted cereals to produce ethanol.
Since all these products are results of microbial fermentation,the correct answer is $D$.

(A) Strains of $Saccharomyces$ $cerevisiae$ (yeast) are extensively used for the leavening of bread.
During the process of fermentation,the yeast cells metabolize sugars to produce alcohol and carbon dioxide $(CO_2)$.
The release of $CO_2$ gas creates bubbles within the dough,which causes the bread to rise and become porous.

(B) Dough kept overnight in warm weather becomes soft and spongy due to the process of fermentation.
During fermentation,microorganisms like yeast present in the dough break down sugars into ethanol and carbon dioxide $(CO_2)$.
The release of $CO_2$ gas bubbles causes the dough to rise,making it soft and spongy.

(C) Toddy is a traditional drink of some parts of South India.
It is produced by the fermentation of sap extracted from palm trees by microbes.
Therefore,both statements $I$ and $II$ are correct.

(A) During the process of fermentation,microorganisms like yeast ($Saccharomyces$ $cerevisiae$) break down sugars into ethanol and carbon dioxide $(CO_{2})$. The release of $CO_{2}$ gas causes the dough to rise and gives it a puffy appearance,which is essential for making bread.

(C) The correct answer is $C$. The starter or inoculum used in the preparation of curd from milk contains millions of Lactic Acid Bacteria $(LAB)$.
These bacteria grow in milk and convert it into curd by producing acids that coagulate and partially digest the milk proteins.

(C) The small amount of curd added to milk is known as a starter or inoculum. It contains millions of Lactic Acid Bacteria $(LAB)$,which grow in milk and convert it into curd by producing acids that coagulate and partially digest the milk proteins.

(C) $Lactobacillus$ is a type of lactic acid bacteria $(LAB)$ that is widely known for its role in converting milk into curd.
In the human digestive system,$Lactobacillus$ acts as a beneficial probiotic.
It helps in maintaining a healthy balance of gut microbiota by inhibiting the growth of disease-causing pathogens.
Furthermore,it contributes to the synthesis of certain vitamins and improves overall digestion and immunity.

(B) Microorganisms like $LAB$ (Lactic Acid Bacteria) are added to milk as a starter or inoculum to form curd.
These bacteria grow in the milk and produce acids,specifically lactic acid $(A)$,which coagulates and partially digests the milk proteins (casein).
This process not only converts milk into curd but also improves the nutritional quality of the curd by increasing the content of vitamin-$B_{12}$ $(B)$.

(C) small amount of curd added to fresh milk as an inoculum or starter contains millions of $LAB$ (Lactic Acid Bacteria).
At suitable temperatures,these bacteria multiply and convert milk into curd.
This process improves the nutritional quality of milk by increasing the content of vitamin-$B_{12}$.
Furthermore,in our stomach,$LAB$ play a very beneficial role in checking the growth of disease-causing microbes.

(A) $A-$Acid; $B-$Milk protein.
Lactic Acid Bacteria $(LAB)$ such as $Lactobacillus$ are added to milk.
These bacteria grow in milk and produce acids that coagulate and partially digest the milk protein,$Casein$.
This process converts milk into curd,which improves its nutritional quality by increasing vitamin $B_{12}$ content.

(C) $LAB$ (Lactic Acid Bacteria) plays a beneficial role in our stomach by checking the growth of disease-causing microbes. They create an acidic environment that inhibits the survival of harmful pathogens,thereby promoting gut health.

(A) The microbe used for making bread is $Saccharomyces \ cerevisiae$, commonly known as Baker's yeast. It ferments the sugars present in the dough to produce $CO_2$ and ethanol, which makes the bread soft and porous.

$Saccharomyces \ cerevisiae$	Baker's yeast
$Saccharomyces \ ellipsoidens$	Wine yeast
$Saccharomyces \ pireformis$	Ale yeast
$Saccharomyces \ sake$	Sake yeast

(B) Toddy is a traditional drink of some parts of southern India. It is produced by fermenting the sap secreted from palms, such as $Caryota \text{ urens}$.

(C) The ripening of Swiss cheese is carried out by the bacterium $Propionibacterium \text{ } sharmanii$. This bacterium produces a large amount of $CO_2$ during fermentation, which creates the characteristic large holes in Swiss cheese.

$Penicillium \text{ } roquefortii$	Roquefort cheese
$P. \text{ } camembertii$	Camembert cheese
$Propionibacterium \text{ } sharmanii$	Swiss cheese
$Streptomyces \text{ } griseus$	Streptomycin antibiotic

(D) Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes.
Many traditional food products are prepared from soybeans using microbial fermentation.
$1$. Tempeh is a traditional Indonesian soy product made by fermenting soybeans with the fungus $Rhizopus oligosporus$.
$2$. Tofu is a popular soy-based food, often prepared by coagulating soy milk and then pressing the resulting curds into soft white blocks. While sometimes considered a non-fermented product, many traditional varieties involve fermentation.
$3$. Sufu is a type of Chinese fermented bean curd made from soybeans.
Since all three options ($Tempeh$, $Tofu$, and $Sufu$) are well-known soy-based food products often associated with fermentation processes, the correct answer is $All of these$.

(A) Curd is considered more nutritious than milk because during the fermentation process,$LAB$ ($Lactic$ $Acid$ $Bacteria$) increases the nutritional quality of milk by increasing the content of Vitamin $B_{12}$.
Additionally,$LAB$ present in curd plays a beneficial role in our stomach by checking the growth of disease-causing microbes.

(A) Toddy is a traditional drink made by fermenting sap from palms.
When toddy is left for a few hours, it undergoes natural fermentation by microbes present in the environment.
This fermentation process continues over time, and after $24 \; \text{hours}$, the excessive fermentation makes the toddy sour and unpalatable.
Therefore, both the Assertion and the Reason are correct, and the Reason provides the correct explanation for the Assertion.

(B) Cheese is one of the oldest food items prepared by the use of various types of micro-organisms.
Different varieties of cheese are known by their characteristic texture,flavour,and taste,which are determined by the specific microbes used during the fermentation process.
$e.g.$,Swiss cheese is produced by the bacterium $Propionibacterium$ $sharmanii$,while Roquefort cheese is ripened by growing a specific fungus on them.
Therefore,both statements are correct,but the Reason does not explain why cheese is one of the oldest food items; it merely describes the properties of cheese varieties.

(D) Lactic Acid Bacteria $(LAB)$,such as Lactobacillus,grow in milk and convert it into curd.
During this process,they produce acids that coagulate and partially digest the milk proteins.
$LAB$ also play a significant role in improving the nutritional quality of curd by increasing the content of Vitamin $B_{12}$.

(B) The process of converting milk into curd involves the following steps:
$1$. $LAB$ (Lactic Acid Bacteria) such as Lactobacillus grow in milk and convert it into curd.
$2$. $LAB$ produces acids that coagulate and partially digest the milk proteins (casein).
$3$. $A$ small amount of curd added to fresh milk as an inoculum contains millions of $LAB$,which at suitable temperatures multiply and convert milk into curd.
$4$. $LAB$ also improves the nutritional quality of curd by increasing the content of Vitamin $B_{12}$.
Since all four statements $(I, II, III, IV)$ are correct,the total number of correct statements is $4$.

(A) The dough used for making foods like dosa and idli is fermented by bacteria (specifically species like Leuconostoc and Streptococcus).
During the process of fermentation,these bacteria perform anaerobic respiration.
As a result of this metabolic activity,carbon dioxide $(CO_2)$ gas is released.
The accumulation of this $CO_2$ gas within the dough causes it to puff up or rise,giving it a soft and spongy texture.

(C) The organism used for making bread is $Saccharomyces \ cerevisiae$,commonly known as Brewer's yeast or Baker's yeast.
$Saccharomyces \ cerevisiae$ belongs to the kingdom $Fungi$.
During the process of bread making,yeast ferments the sugars present in the dough,releasing $CO_2$ and ethanol.
The $CO_2$ gas gets trapped in the dough,causing it to rise and making the bread soft and porous.

(A) Fermentation is a metabolic process that produces chemical changes in organic substrates through the action of enzymes. In many cultures,fish,soybeans,and bamboo are processed using fermentation to enhance their nutritional value,flavor,and shelf life. For example,fermented soybean products include soy sauce and tempeh,while various fermented fish products are common in Southeast Asian cuisine. Microorganisms like bacteria,yeasts,and molds are responsible for these transformations.

(D) During the fermentation process,microbes such as yeast ($Saccharomyces$ $cerevisiae$) and various bacteria break down carbohydrates into simpler compounds.
In the production of dough (e.g.,for idli or dosa),cheese,and beverages like beer or wine,the metabolic activity of these microbes results in the release of carbon dioxide $(CO_2)$ as a byproduct.
This $CO_2$ is responsible for the 'puffy' appearance of dough and the characteristic holes in Swiss cheese.

(D) The large holes in 'Swiss cheese' are caused by the production of a large amount of $CO_2$ by the bacterium $Propionibacterium$ $sharmanii$.
This bacterium ferments the milk sugars to produce lactic acid and carbon dioxide gas.
The accumulation of $CO_2$ gas bubbles within the cheese curd creates the characteristic large holes or 'eyes' seen in Swiss cheese.