Feasibility of ethanol production with enhanced sugar concentration in bagasse hydrolysate at high temperature using Kluyveromyces sp. IIPE453

Abstract

Background: Ethanol from lignocellulosic biomass and nonfood sources has caught worldwide attention because of its potential use as an alternative automotive fuel. Results: In batch fermentation using Kluyveromyces sp. IIPE453 at 50°C on bagasse hydrolysate containing total fermenting sugar concentration 35 ±1.9 g l^-1, the strain could produce ethanol concentration 14.5 ± 0.2 g l^-1 with ethanol productivity 0.71 ± 0.001 g l^-1 h^-1 as compared with sugarcane juice 2 ± 0.04 g l^-1 h^-1, molasses 2.6 ± 0.05 g l^-1 h^-1 and mahua flower extract 3.4 ± 0.06 g l^-1 h^-1. In addition, the fermentation was carried out with enhanced sugar concentration in bagasse hydrolysate by mixing sugarcane juice, molasses and extract of mahua flowers. The ethanol productivities upon mixture of bagasse hydrolysate with sugarcane juice, molasses and extract of mahua flowers were 1.7 ± 0.06 g l^-1 h^-1, 1.75 ± 0.03 g l^-1 h^-1 and 2.57 ± 0.1 g l^-1 h^-1, respectively. Conclusion: The ethanol productivity could be increased by enhancing sugar concentration in bagasse hydrolysate. The product inhibition could be minimized by in situ ethanol recovery at high temperature.

Ethical conduct of research

The authors state that they have obtained appropriate institutional review board approval or have followed the principles outlined in the Declaration of Helsinki for all human or animal experimental investigations. In addition, for investigations involving human subjects, informed consent has been obtained from the participants involved.

Acknowledgements

We thank MO Garg, Director, Indian Institute of Petroleum, Dehradun, India, for his valuable suggestion and encouragement to carry out this research work. We would like to thank Doiwala Sugar Mills, Doiwala, Dehradun, India, for providing bagasse, sugarcane juice and molasses. We would also like to thank Praveen Tiwari, Indian Institute of Petroleum, for arranging fresh mahua flowers.

Financial & competing interests disclosure

Sachin Kumar gratefully acknowledges Senior Research Fellowship awarded by the Council of Scientific and Industrial Research (CSIR), India. The authors have no other relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript apart from those disclosed. No writing assistance was utilized in the production of this manuscript.