Intensified hydrogen yield using hydrogenase rich sulfate-reducing bacteria in bio-electrochemical system

In this study, the Bio-electrochemical system was used for the suppression of methanogens, the competitors of the sulfate-reducing bacteria, as well as recovery of higher hydrogen yields. The optimized conditions are applied by keeping the variables in range to focus on maximum hydrogen production during both phases. The confirmatory experiments conducted helps in a better understanding of the shift in metabolism towards hydrogen producers by preventing hydrogenotrophic methanogenic consumption under externally applied potential. Model adequacy checking was performed whether the approximate model would give poor or misleading results was also confirmed by the principal components analysis of the angle between vectors. The hydrogen production confirmation (up to 2.523 +/- 0.230 H-2 mole/mole glucose) extends for the individual bi-phasic hydrogen yield as well as overall recovery. The average carbon chain elongation to 3.829 indicates the possible consumption of CO2 for the synthesis of higher chain hydrocarbons (fatty acids). The Anderson-Darling (AD) statistic of the residuals of actual and predicted hydrogen production computed values, less than the critical value of statistic and higher than significance (>0.05), and various kinetic model coefficients test also confirms the suitability prediction by the model. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study used a Bio-electrochemical system to suppress methanogens, competitors of sulfate-reducing bacteria, and recover higher hydrogen yields. By conducting confirmatory experiments and checking model adequacy, the maximum hydrogen production and carbon chain elongation were successfully predicted.