Bioethanol production from woody stem Prosopis juliflora using thermo tolerant yeast Kluyveromyces marxianus and its kinetics studies

Abstract

In the present study, Kluyveromyces marxianus was utilized to study the batch fermentation kinetics of biomass production, substrate utilization and bioethanol production from woody stem Prosopis juliflora. The pre-treated substrate was subjected to Simultaneous Saccharification and Fermentation (SSF) under optimised conditions of pH (4.9), temperature (41 °C), substrate concentration 5% (w/v), inoculum concentration 3% (v/v) and the maximum concentration of bioethanol was found to be 21.45 g/l. The experimental data thus obtained from cell growth, substrate utilization and product formation are employed in the determination of kinetic parameters. Biological models such as Logistic model, Hinshelwood model were used for microbial growth and substrate utilization kinetics respectively. In case of product kinetics, Leudking-Piret plot, Gompertz model and Modified Gompertz model were utilised. Based on these models, kinetic parameters like maximum specific growth rate (µm), saturation constant (Ks), growth associated (α), non-growth associated (β) and yield coefficients (YX/S, YP/S) were estimated.