Question

How many of the following organisms are associated with single cell protein?
Yeast, Chlorella, Spirulina, Nostoc, Methylophilus methylotrophus, Mushroom, Clostridium

• A. Two
• B. Five
• C. Four
• D. Three

Answer 1

Answer: (B)

Dried biomass of a single species of microbe that can be used as a protein source in the diet is known as single cell protein (SCP). Many types of animal feeds contain single cell proteins. 60-80% dry cell weight; contains nucleic acids, fats, carbohydrates, vitamins and minerals. Such proteins are rich in essential amino acids like lysine, methionine, etc.
The term SCP, however, is misleading because it not only obtained from unicellular microorganisms but also from multicellular microorganism. Microorganisms which can be explored for obtaining SCP are:
i) Fungi : Yeast (Candida utilis), Fusarium graminearum, mushrooms. Mushrooms are eaten by many people and large scale mushroom culture is a growing industry makes it believable that microbes to would become acceptable as food.
ii) Cyanobacteria: Spirulina can be grown easily on medium like waste water obtained from potato processing plants (containing starch), straw, sewage, molasses, and even animal manure, to produce large quantities and can serve as food rich in carbohydrates, vitamins, protein, minerals, and fats. Incidentally such utilization also reduces environmental pollution.
iii) Bacteria : It has been estimated that a 250 kg cow produces 200 g of protein per day. In the same period about 250 g of Methylophilus methylotrophus (a bacteria), can produce about 25 tonnes of protein per day, because of its high rate of biomass production and growth,
iv) Algae: Chlorella, Scendesmus
v) Yeast: Saccharomyces cerevisiae