Production of ethanol from cellulosic biomass by Clostridium thermocellum SS19 in submerged fermentation: screening of nutrients using Plackett-Burman design.

Plackett-Burman design, a statistical methodology, was used to screen 23 nutrients belonging to three categories--carbon, nitrogen, and salt/mineral sources--for the production of ethanol from cellulosic biomass by Clostridium thermocellum SS19 in anaerobic submerged fermentation. In this design, just n number of experiments is required for screening n-1 variables. The experimental data were subjected to statistical analysis for calculating the regression coefficients and t-values. Filter paper, Solka Floc, corn steep liquor (CSL), cysteine HCl, magnesium chloride, and ferrous sulfate showed relatively higher regression coefficients on ethanol production and growth. Among the 23 nutrients screened, based on their performance in terms of product-promoting ability, availability, and cost, filter paper, CSL, cysteine HCl, magnesium chloride, and ferrous sulfate were identified as the most effective and, therefore, selected for inclusion in further optimization studies.