Anaerobic Biohydrogen Production Bacteria Selection and Its Optimization of Biohydrogen Fermentation Process

Abstract:

This research adopted silt as the sample, and the five highest hydrogen production performing strains contained in the sample were isolated. The strain whose hydrogen production was the highest was identified as Enterobacter cloacae by the analysis of 16S rDNA sequencing and comparison. It is showed by Plackett-Burman Experimental Design that only glucose, citric buffer and reducing agent had significant effects on hydrogen production by Enterobacter cloacae FML-C1. The path of steepest ascent was undertaken to approach the optimal response region of those three factors. Central Composite Design (CCD) and Response Surface Methodology (RSM) were employed to investigate the interaction of the variables and to ascertain the optimal values of the factors, which finally led to the maximum hydrogen production (VH2). The theoretical optimal medium conditions were: glucose 21.5 g/L, citric buffer 13.6 mL/L, reducing agent 10.0 mL/L. The five tentative tests matched this model well. The final VH2 was up to 2347.4 mL/L, which was 127.42% enhanced in comparison to the original. The result shows that PB experiment design and RSM analytical method work well in selecting factors which have significant influences on the hydrogen production and, moreover, achieve the ideal optimal result.

Key words:Biological hydrogen, Screening, Anaerobic fermentation, Culture optimization, Response surface