Application of Taguchi Method in Optimization of Single Cell Protein (SCP) Production in Lab Fermenter

Single Cell Protein (SCP) is a term coined in the 1960´s to define microbial biomass products which were produced by fermentation. SCP production technologies are applied to solve the problem of worldwide protein shortage. They evolved as bioconversion processes which turned low value substrate, often wastes, into products with added nutritional value. In this research, Taguchi experimental design was applied to optimize the conditions for Single Cell Protein (SCP) production by Methylobacteriumsp. NO. 69. The objective of this research was to determine the significant parameters in the production of SCP in submerged fermentation with methanol as sole Carbone source. Four factors viz., Methanol concentration, Aeration rate, Agitation speed and pH, each at three levels, were selected and an orthogonal array layout of L9 performed. The experiment result indicated that Methanol (18 g/L), Aeration (3 vvm), agitation (800 rpm) and pH (8) were the important factors for SCP production by selected methylotrophic strain in submerged fermentation at the optimum levels.Under the optimal culture condition, the maximum biomass concentration was 16 g/L, which is about two times higher than that at the batch culture in erlenmeyer flask. The total and true protein content of the product was up to 74 and 62% respectively. The protein content, biomass concentration and amino acid profileof the microbial biomass showed that it was enriched with all essential amino acids and could be employed in protein enrichment of animal feed supplements. But Additional laboratory and field experiments are necessary to evaluate the nutritional value of this product.