Feed Stuff Production from Methanol by Methylotrophic Microorganisms

Methanol has been great interest as a substrate for production as a novel feed grade protein in Iran. Up to 160 methylotrophic strains isolated at the Jahad-e Agriculture Research Engineering Center for Scientific Research. Various batch experiments were carried out at different pH, temperature, agitation, aeration rate and methanol concentrations. By these experiments, optimum production conditions were determined for one of the strain by taguchi method. The results showed optimum pH around 8, at temperatures of 26 to 30°C, aeration equal to 3 vvm, agitation about 800 rpm and methanol was found to be optimum at concentration equal to 18 g.l–1. In this conditions biomass yield coefficient was 0.52 g/g methanol, biomass dry weight was 20-25 g/l and crude protein content was about 70-78%. A deep jet fermentor of 1 m3 capacity with working volume of 600 liter was used for SCP production by isolated strains. In this continuous system, dilution rates ranging from 0.15 to 0.2 lit.h-1 was used to establish optimal condition for biomass production. By this condition 30 kg cell dry weight per day was obtained. These experiments showed that the selected methylotrophic strain has good potential for SCP production from methanol as a substrate.

کلیدواژه ها:

Single Cell Protein ، SCP ، Methylotrophic microorganisms ، Methylobacterium ، Optimization ، Taguchi method