Microorganisms in Food Production

The microorganisms in the making of cheese are Leuconostoc mesenteroides and Lactobacillus plantarum, for sauerkraut the microorganisms are Lactobacillus delbrueckii and Streptococcus thermophillus, for Kefir making Lactobacillus casei and Streptococcus thermophillus and the microorganisms in the making of yoghurt are Lactobacillus acidophilus and Lactobacillus delbrueckii. Hence, the correct answer  is P - 1, Q - 3, R - 4, S - 2.

Dekkera bruxellensis is used in the manufacturing of beer by fermentation.

Yes, the yeast will turn the sugar in the juice into alcohol and carbon dioxide.

Aerobic bacteria require oxygen and consume organic matter during wastewater treatment. Human excreta is rich in organic material that serves as a food source for these bacteria, which break it down as part of the biological treatment process. Inorganic materials like cans, paints, and oils are not consumed by aerobic bacteria.

This option corrects the error of subject-verb mismatch. It uses singular verb for singular subject (the great deficiency; 'is' the excess of acid).

Pseudomonas selectively grows on cetrimide agar. Cetyltrimethylammonium bromide, a quaternary ammonium and cationic detergent, is the component of cetrimide agar and allows for the selective isolation of Pseudomonas aeruginosa. Cetyltrimethylammonium bromide, when in contact with bacteria, causes the release of nitrogen and phosphorus from the bacterial cell. Organisms other than P. aeruginosa are unable to withstand this germicidal activity. Pseudomonas aeruginosa produces a characteristic fruity or grape juice-like aroma due to the production of an aromatic compound called aminoacetophenone.

Yellow slant and pink butt (acid slant and alkaline butt) indicate that only glucose is fermented. So, only a glucose fermentor is in the bacterial culture.

Claviceps purpurea produces LSD.

Monascus purpureus is used to produce statins, which are now being commercialised as blood cholesterol lowering agents.

Statins produced by the yeast Monascus purpureus have been commercialised as blood-cholesterol lowering agents. It acts by competitively inhibiting the enzyme responsible for synthesis of cholesterol.

In koji process, for the fermentation to produce citric acid, Aspergillus niger is used with solid substrate as Ipomoea batatas.

Yes, it is the correct answer. This is the only incorrect statement. Lacto bacillus (bacteria) promotes the conversion of milk into curd, not yeast.

Yeast reproduces asexually through the process of budding, where a small outgrowth (bud) forms on the parent cell, enlarges, and eventually separates to become a new individual. This is different from binary fission (equal division), multiple fission (division into many), or regeneration (regrowing lost parts). The observation of dough rising is due to CO2 production during fermentation, not just reproduction.

Ria demonstrates keen observation by noticing her mother adding yeast to idli paste, observing the dough rising, and connecting this to her textbook knowledge about yeast in brewing. This shows scientific curiosity and the ability to connect observations with theoretical knowledge. Ignance would mean not noticing, sympathetic would mean feeling pity for the dough, and dominating doesn't fit this context.

Yeast multiplies rapidly under favorable conditions (warmth, moisture, and food in the idli batter), producing carbon dioxide gas through fermentation. This CO2 gets trapped in the dough, causing it to rise and become soft and fluffy. Yeast doesn't just absorb water, get dissolved, or need to be separated - its fermentation and growth are what make the idli batter rise and become spongy.