Isolation and characterisation of an environmental Clostridium beijerinckii strain for biohydrogen production from dairy wastes

Biological dihydrogen (H-2) production is a promising alternative to the conventional nonrenewable energies. H-2 production by dark fermentation is particularly studied regarding its independence from fossil fuel and electricity, its cultivation into bioreactors and the broad range of substrate that can be used. A major goal application of dark fermentation is the valuation of wastes. In this context, cheese whey wastes are particularly adapted, since rich in organic matter, abundant and low cost. A novel H-2-producing strain was isolated from a sample of mixed bovine manure and cheese whey, collected in a cheese-producing dairy farm. The strain was identified as a Clostridium beijerinckii strain based on morphological and physiological characteristics, and 16S rDNA sequencing. The optimum temperature and pH for H-2 production was 40 degrees C and pH 7, respectively. Substrate and stress tolerance tests showed that C. beijerinckii C.sp.1.3 could produce H-2 from glucose, lactose, maltose, cellobiose, galacturonic acid, xylose, and sucrose, and to a lesser extent from starch, cellulose and glycerol. The H-2 production potential from a mix of dairy industrial wastes of this strain has been evaluated. The highest productivity in batch for 5 g L-1 of Total Organic Carbon (TOC) was 833.1 mL H-2 L-1 d(-1), with a yield of 2.03 mM(H2) mM(lactose)(-1), demonstrating the potential of this strain for H-2 production from industrial wastes. (c) 2023 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.