Direct Bioconversion of Cellulose into Ethanol by Mixed Culture ?Batch Kineticand Modeling
The present work attempts to investigate the ability of fusariumoxysporum and neurosporacrassa to ferment cellulose to ethanol directly. Batch experiments were performed for both the strain at 30.c in 250ml conical flasks.1000ml of production medium was distributed equally in 7 sterile,250 ml conical flasks, each containing various initial concentrations of cellulose 20,30,40,50,60,70 and 80g/l respectively.20ml of inoculum medium was transferred to each 100ml production medium in sterile conditions. Initial values of ethanol concentration, cellulose concentration and cell mass were determined. The inoculated flasks were maintained at 300 C in a rotary shaker operating at 200 rev min-1.Analyses were carried out for every 24 hours using the contents of the various conical flasks.Experiments were conducted for mixed cultures of different compositions 80:20, 60:40, 40:60, and 20:80by volume respectively.The cultures fusariumoxysporum and neurosporacrassa were mixed in proportion 80:20,60:40,40:60,and 20:80 respectively mixed cultures were used for inoculation.Based on the kinetic models, equations have been developed for the determination cell mass, product and substrate concentration as a function of time. Using the experimental data, constants of these equations have been evaluated. These mathematical relationships can be used with reasonable accuracy.
P.Nagarajan, T.Karunanithi, Yulin Deng