CONSOLIDATED BIOPROCESS BY CLOSTRIDIUM THERMOCELLUM DSM 1313 IN IN SITU STERILISABLE STIRRED TANK FERMENTER FOR ENHANCED DIGESTIBILITY AND INCREASED BIOETHANOL PRODUCTION FROM SUGARCANE BAGASSE

Abstract

Consolidated bioprocess by Clostridium thermocellum DSM1313 is studied here for the hydrolysis of pre-treated sugarcane bagasse and banana pseudostem for ethanol production. Ethanol titre of 26.27 and 9.12mM and release of 4.770±0.107and 3.281±0.109g/L of reducing sugars from sugarcane bagasse and banana pseudostem respectively were observed in flask level studies. Sugarcane bagasse was taken further for scale-up studies in a 3L in situ sterilisable industrial fermenter. An increased growth rate with two fold increase in release of reducing sugars and a final ethanol titre of 54.35mM highlights the efficient hydrolysis of the substrate not only by the organism but also due to the direct steam-substrate contact during sterilisation. Due to the thermophilic conditions of the broth, ethanol recovery was found to be 3.43% efficient than the control. This paper emphasizes the importance of a controlled environment for efficient lignocellulosic hydrolysis, and an energy efficient ethanol recovery.