Abstract

Ethanol production using jaggery was enhanced in submerged fermentation when the effect of metal inducers was studied using the Plackett-Burman and Box-Behnken designs. Saccharomyces cerevisiae (NCIM 3288) was used as the fermenting organism. The Plackett-Burman design was used to initially screen seven of which the four elements were found to have significant effect on ethanol production. In the next stage, Box-Behnken design was used obtain concentrations of metal ion’s that may be supplemented to get maximum ethanol in during production process. It was observed that ethanol yield has increased to 94.8 from 75.4g/l when supplemented with the critical concentrations of salts provided by the model. These were as follows (g/l): FeSO₄. 7H₂O 0.0036, MgSO₄.7H₂O 0.0033, MnCl₂. 4H₂O 0.0017 and ZnSO₄.7H₂O 0.0026, in the presence of 220 g/l of jaggery supplemented with (NH₄)₂SO₄ 2.612 g/l and KH₂PO₄  3.407 g/l, while the predicted concentration of ethanol as per the model is 95.35 g/l.

Key words: Jaggery, ethanol, Plackett-Burman design, Box-Behnken design, metal inducers.