Optimization and kinetics analyses of exopolysaccharide production by Simplicillium lanosoniveum

The optimum synthesis conditions and fermentation kinetic parameters of Simplicillium lanosoniveum DT06 which was a Deuteromycetes fungus being capable of producing unique exopolysaccharide( EPS) was researched. Based on single factor experiment,the optimum culture conditions for EPS yield coefficient were determined applying Box- Behnken design( BBD). Under the optimized conditions( 40.65 g / L glucose,10.38 g / L peptone,p H4.87,temperature 30 ℃ and rotation speed 140 r / min),the highest EPS yield coefficient 0.139 g / g was obtained,which increased 32% compared with that before optimization. Kinetics analyses indicate that the maximum specific growth rate( μmax) of DT06 was 0.156 h- 1,while its EPS synthesis was semi-growth-associated with a maximum specific production rate 0.066 h- 1,which was relative higher than those of other EPS-producing Fungi. Nevertheless its average EPS yield coefficient was relative low.Carbon- balance analysis revealed that apart from EPS DT06 also produced a unknown products with a carbon yield coefficient of 0.129 g / g. These results provided essential parameters for controlling DT06's fermentation process and improving its metabolic network.