SIMULTANEOUS SACCHARIFICATION AND FERMENTATION OF THE OLEAGINOUS ACTINOBACTERIUM STREPTOMYCES FRADIAE FOR LIPID PRODUCTION

Abstract

Producing lipids for biofuel conversion requires saccharification of simple sugars by oleaginous microorganisms during fermentation. This work investigates the biomass of oleaginous actinobacteria required for lipid production. Waste Rice Water (WRW) was used as a substrate for microbial biomass production. Substituting WRW during fermentation influenced biomass growth in the oleaginous actinobacterium Streptomyces fradiae. The efficiency of biomass production in delivering the highest lipid content during the exponential growth phase was evaluated. The total lipid content was evaluated using the calorimetric sulfo-phosphovannilin assay. WRW at 25% dilution proved to be an alternative substrate for the ISP2 (International Streptomyces Project 2) growth medium, which showed a maximum yield of 60.3g/L of biomass and total lipid content of 38.6% (w/w). Enzymatic degradation of starch has resulted in simple sugar formation, and fermentation of simple sugars further initiated biomass and lipid accumulation. The relatively higher carbon and nitrogen content of WRW increases lipid accumulation in the oleaginous actinobacteria Streptomyces fradiae. This indicates that starch from WRW was completely degraded by the oleaginous actinobacteria Streptomyces fradiae and shows a notable impact on lipid production.