Microorganisms in Food Production

For improved industrial production of citric acid, mutant strains of Aspergillus niger have been developed. These mutant strains can tolerate high sugar concentration and low pH with reduced synthesis of undesirable byproducts.

Blakeslea trispora is the most preferred strain for production of beta-carotene due to its high yield. It produces 3 g/l beta-carotene.

Ashbya gossypii is the most preferred organism for the industrial production of riboflavin as it is more stable with a high producing capacity of riboflavin.

Dodecane, i.e. kerosene increases the solubility of hydrophobic substrates and doubles the production of beta carotene in fermentation by + and - mix strains of trispora.

Yoghurt is obtained by the action of Streptococcus thermophilus, using milk as raw material.

Microorganisms can be grown in a physiological steady state under constant environmental conditions in a continuous culture. In the steady state, growth occurs at a constant specific growth rate and all culture parameters remain constant.

Ochratoxin is a mycotoxin that comes in three secondary metabolite forms, A, B, and C. All are produced by Penicillium and Aspergillus species. The three forms differ in that Ochratoxin B (OTB) is a nonchlorinated form of Ochratoxin A (OTA) and that Ochratoxin C (OTC) is an ethyl ester form Ochratoxin A. Aspergillus ochraceus is found as a contaminant of a wide range of commodities including beverages such as beer and wine.

Enzymes of Penicillium camemberti play a role in the manufacture of the cheeses Camembert and Brie, while those of Penicillium roqueforti do the same for Gorgonzola, Roquefort and Stilton.

Yeasts, like all fungi, may have asexual and sexual reproductive cycles. The most common mode of vegetative growth in yeast is asexual reproduction by budding. Here, a small bud (also known as a bleb), or daughter cell, is formed on the parent cell.

Heating of milk for boiling to kill microbes is known as pasteurization. Milk is prevented from spoilage for several days by pasteurization.

Changes that cannot be reversed are called irreversible changes. Milk changes into curd

Glucoamylase: Aspergillus niger, Rhizopus spp. Pectinase: Aspergillus niger β-glucanase: Aspergillus niger, Bacillus subtilis All the three enzymes are obtained from Aspergillus niger. So, this option is correct.

Yoghurt is prepared by fermenting artificially concentrated milk with a mixture of Lactobacillus bulgaricus and Streptococcus thermophilus at a temperature of 24-5^oC for 4 hours followed by fermentation with a yeast.

Alcohol fermentation by yeast converts pyruvate to ethanol and releases CO2 as a byproduct. This process creates carbonation in bread and beverages. Glycolysis produces pyruvate without releasing CO2, lactic acid fermentation converts pyruvate to lactate without CO2, and glycogen hydrolysis only breaks glycogen into glucose units.

When milk turns sour, bacteria (mainly Lactobacillus) ferment lactose (milk sugar) into lactic acid through the process of fermentation. This is what gives sour milk its characteristic tangy taste and is the principle behind yogurt production.