Single Cell Protein Production and its Advantages and Disadvantages
Authors: Ajit Kumar Dubedi Anal, Manwendra Singh

The rapidly increasing world population generates the challenge of providing necessary food sources. The increasing world deficiency of protein is becoming a major problem for human kind. India, although a developed nation, its major population is facing nutrition deficiency and food scarcity problems. In the face of such worldwide issues, single cell proteins derived from the waste organic products had been proved a very useful technology. Dried cells of bacteria, algae, yeast, and fungi, which are rich in proteins and could be used as dietary supplements, are called Single Cell Proteins (SCP). The various substrates which have been used as the common material for the production of various types of Single Cell Protein includes orange peel residue, sugarcane residue, paper mill waste rice husk, wheat straw residue, cassava waste, sugar beet pulp, etc.

Production of Single Cell Protein

The production of Single Cell Protein can be done by using waste materials as the substrate.

Following basic steps:

Provision of a carbon source; it may need physical and/or chemical pretreatments.
Addition, to the carbon source, of sources of nitrogen, phosphorus and other nutrients needed to support optimal growth of the selected microorganism.
Prevention of contamination by maintaining sterile or hygienic conditions. The medium components may be heated or sterilized by filtration and fermentation equipments may be sterilized.
SCP processes are highly aerobic (except those using algae). Therefore, adequate aeration must be provided. In addition, cooling is necessary as considerable heat is generated.
The microbial biomass is recovered from the medium.
Processing of the biomass for enhancing its usefulness and/or storability.

Criteria for selection of Microbial strains:-
Performance (growth rate, productivity, yield) on the specific, preferably low-cost substrates to be used.
Temperature and pH tolerance.
Oxygen requirement, heat generation during fermentation and foaming characteristics.
Growth morphology and genetic stability in the fermentation.
Ease of recovery, and requirement for further downstream processing.

Advantages of Single cell protein:

Microbial protein or SCP has various benefits over animal and plant proteins.it can be produced all round the year.
It does not require a large expanse of land.
Their growth are neither seasonal or climate dependent.
It has high protein content with wide amino acid spectrum, low fat content and higher protein carbohydrate ratio than forages.
It can be grown on waste and it is environmental friendly as it helps in recycling waste.

Disadvantages of single cell protein production:
High nucleic acid content and slower in digestibility.
Considered as foreign material by body, which may subsequently results in allergic reactions.

References:
1. Anupama, Ravindra, P. 2000. Value-added food: Single cell protein. Biotechnology advances, 18, 459-479.

About Author / Additional Info:
I am working as a Young Professional-II in ICAR-NRC on Litchi.