Biology

Microorganisms in Food Production

1,120 Questions

Microorganisms play a vital role in food production through processes like fermentation and bioprocessing. Questions on this topic cover the use of yeast, bacteria, and industrial microbiology. These concepts are important for science sections in various competitive exams.

Alcoholic fermentationDairy beverage productionIndustrial ethanol preparationCitric acid productionBiodigester temperature

Microorganisms in Food Production Questions

Multiple choice

Antioxidants are either man-made or natural substances which inhibit various types of cell damages occurring in the body. Which of the following fungi is a source of antioxidants?

  1. Pleurotus citrinopileatus

  2. Pleurotus dryinus

  3. Pleurotus nebrodensis

  4. Pleurotus ostreatus

  5. Pleurotus eryngii
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The golden oyster mushroom, like other species of oyster mushroom, is a wood-decay fungus. In the wild, P. citrinopileatus most commonly decays hardwoods such as elm.P. citrinopileatus mushrooms are a source of antioxidants. Extracts from P. citrinopileatus have been studied for their antihyperglycemic properties, decreasing blood sugar levels.

Multiple choice

The mycotoxin found as a major contaminant of beer and wine is

  1. patulin

  2. ergot alkaloid

  3. citrinin

  4. ochratoxin

  5. fusarium
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

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.

Multiple choice

A gill is a respiratory organ found in many aquatic organisms which helps in breathing. Which among the following is the only fungus having true gills?

  1. Aspergillus lentulus

  2. Aspergillus clavatus

  3. Batrachochytrium dendrobatidis

  4. Phruensis

  5. Psathyrella aquatica
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

Psathyrella aquatica with true gills has been observed fruiting underwater in the clear, cold, flowing water. Fruiting bodies develop and mature in the main channel, where they are constantly submerged, and were observed fruiting over 11 wk. These mushrooms develop underwater, not on wood recently washed into the river.

Multiple choice

Traditional French Brie and Camembert cheeses are made with raw milk. The enzymes of which among the following fungi are used to make these cheeses?

  1. Tolypocladium inflatum

  2. Aspergillus oryzae

  3. Penicillium camemberti

  4. Schizosaccharomyces pombe

  5. Saccharomyces cerevisiae
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Multiple choice

Yeast is a microscopic unicellular fungus that is used to make bread, wine and beer. Which among the following statements regarding yeasts is incorrect?

  1. Nutritional yeast is an excellent source of B-complex vitamins.

  2. Yeasts can also tolerate high concentrations of salt and heavy metals.

  3. The most common mode of vegetative growth in yeast is asexual reproduction by regeneration.

  4. Yeasts are chemoorganotrophs.

  5. Yeasts can generate electricity in microbial fuel cells.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Multiple choice

Which of the following enzymes are obtained from the fungus Aspergillus niger?

  1. Penicillin amidase, Pectinase, β-glucanase

  2. Lactase, Rennin, Penicillin amidase

  3. Glucoamylase, β-glucanase, Penicillin amidase

  4. Lactase, Rennin, Pectinase

  5. Glucoamylase, Pectinase, β-glucanase
Reveal answer Fill a bubble to check yourself
E Correct answer
Explanation

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.

Multiple choice

Which of the following microbes are used in preparation of yoghurt?

  1. Lactobacillus bulgaricus and Streptococcus thermophilus

  2. Leuconostoc mesenteroids and Enterobacter aerogenes

  3. Enterobactor aerogens and Fusarium moniliforme

  4. Streptococcus lactis and Leuconostoc citrovorus

  5. Fusarium moniliforme and Streptococcus thermophilus
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

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

Multiple choice

Which of the following processes releases a carbon dioxide molecule?

  1. Glycolyis

  2. Lactic acid fermentation

  3. Alcohol fermentation

  4. Hydrolysis of glycogen
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

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.

Multiple choice

When milk turns sour, one of the products formed is

  1. tartaric acid

  2. lactic acid

  3. citric acid

  4. ascorbic acid
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

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.

Multiple choice

Which of the following statements is incorrect?

  1. Bacteriophage genomes are especially mosaic.

  2. Bacteriophages are used in hydrological tracing and modelling in river systems.

  3. Bacteriophages may have a lytic cycle or a lysogenic cycle.

  4. Bacteriophages are composed of glycolipids that encapsulate their genome.

  5. Phages replicate within the bacterium.
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Bacteriophages are composed of proteins that encapsulate a DNA or RNA genome and may have relatively simple or elaborate structures. Their genomes may encode as few as four genes and as many as hundreds of genes.