Question

Which of the following statements regarding single cell protein (SCP) is/are incorrect?

• A. Methylophilus methylotrophus is an alga from which SCP can be derived
• B. Blue-green algae like Spirulina can be grown easily on materials like waste water from potato processing plants (containing starch), straw, molasses, etc.
• C. 250 g of Methylophilus methylotrophus can produce 25 tonnes of protein in the same amount of time when a 250 kg cow produces 200 g of protein
• D. SCP can be used as an alternate source of protein for both humans and animals

Answer 1

The correct option is A Methylophilus methylotrophus is an alga from which SCP can be derived

Single Cell Protein or SCP refers to the edible protein extracted from pure microbial cultures, dead, or dried cell biomass. It can be used as an alternative protein source or supplement for both humans and animals. Microorganisms such algae, fungi, yeast, and bacteria can be used as SCP.
Examples include:
i) Algae: Spirulina, Chlorella
ii) Fungi: Candida, Saccharomyces
iii) Bacteria: Methylophilus methylotrophus (and not alga as given in the statement)

Blue-green algae or cyanobacteria like Spirulina can easily be grown using inexpensive substrates like agricultural wastes, waste water from the potato processing industry, straw, molasses, manure, sewage, human and animal wastes, etc. This makes growing SCP an environment friendly process as it helps in effective waste management.
Thus, large quantities of proteins can be generated by these microbial cultures in less time and with less cost on an industrial scale. This is generally not possible with traditional methods of cattle farming, where 250 kg of cow produces only around 200 gm of protein per day. 250 gm of Methylophilus methylotrophus produce 25 tonnes of protein in the same period due to its rapid growth rate and high rate of biomass production.
Thus, option (b) is the correct answer.