Dark fermentative bioconversion of glycerol to hydrogen by Bacillus thuringiensis

Biodiesel manufacturing units discharge effluents rich in glycerol. The need is to convert crude glycerol (CG) into useful products such as hydrogen (H-2). Under batch culture, Bacillus thuringiensis EGU45 adapted on pure glycerol (PG, 2% v/v) resulted in an H-2 yield of 0.646 mol/mol glycerol consumed on minimal media (250 mL) supplemented with 1% ammonium nitrate at 37 degrees C over 4 days. Here, H-2 constituted 67% of the total biogas. Under continuous culture, at 2 days of hydraulic retention time, B. thuringiensis immobilized on ligno-cellulosic materials (banana leaves - BL, 10% v/v) resulted in a H-2 yield of 0.386 mol/mol PG consumed. On CG, the maximal H-2 yield of 0.393 mol/mol feed consumed was recorded. In brief, B. thuringiensis could transform CG, on limited resources - minimal medium with sodium nitrate, by immobilizing them on cheap and easily available biowaste, which makes it a suitable candidate for H-2 production on a large scale. (C) 2015 Elsevier Ltd. All rights reserved.