Evaluation of biohydrogen production from glucose and protein at neutral initial pH

Abstract

GlucoseNeutral initial pH Protein a b s t r a c t Organic wastes are considered as potential substances for economical biohydrogen production, because the carbohydrate and protein are main components. Previous investigations indicate that an optimum hydrogen production appear in acidic conditions to carbohydrates, or in alkali condition to protein. However, in practice, the treatment of these organic wastes by anaerobic fermentation usually carries out at neutral pH condition, in which biohydrogen production is only a middle process. So, the purpose of this paper is to evaluate the biohydrogen production at neutral pH condition from carbohydrates or protein. Batch tests were conducted to investigate the differences in biohydrogen production by anaerobic fermentation at neutral initial pH using carbohydrate and protein (glucose and peptone) as the sole carbon source. The experimental results showed that the maximal hydrogen yields of two substrates were about 0.14 ml H 2 /mg glucose and 0.077 ml H 2 /mg protein, respectively, at neutral initial pH. Although the hydrogen yields of glucose is far greater than that of protein at neutral pH, they were lower than previous results of hydrogen production in acidic condition to carbohydrate or in alkali condition to protein.This result shows that the neutral pH is not an optimal condition for biohydrogen production. In this experiment of biohydrogen production, a phenomenon has been observed that the hydrogen production and hydrogen consumption occurred simultaneously in the fermentation of protein, whereas the hydrogen production occurred only in the fermentation of glucose. Furthermore, the different evaluation of the main components of the organic liquid by-products produced by fermentation of each substrate implied that the biohydrogen production pathways of these two substrates were different. Molecular analysis indicated that the dominant microorganisms during the anaerobic fermentation of these two substrates are greatly different.

Sequential hydrolysis of oat straw and hydrogen production from hydrolysates: Role of hydrolysates constituents

“…2) was due to the contribution of Celluclast 1.5 L. This is an interesting finding because main components of Celluclast 1.5 L are protein and sorbitol. It has been reported that sorbitol or protein can be fermented to H 2 [31,32]. However, this is the first report that provides experimental evidence of the actual contribution of a commercial enzyme to the H 2 production.…”

Enhanced Bio-hydrogen Production from Protein Wastewater by Altering Protein Structure and Amino Acids Acidification Type

“…The hydrogen production reached 205.2 mL/g-protein, which was much higher than that reported in the literature2. pH 12 pretreatment induced the unfolding of protein, damaged the protein hydrogen bonding networks, destroyed the disulfide bridges and changed their conformations, which increased the susceptibility of protein to protease and enhanced the hydrolysis of protein9.…”

Performance characteristics of single-stage biohythane production by immobilized anaerobic bacteria

“…Figure 4 displays the rapid decline of HY at an initial cultivation pH of 7.5 (32, 25, 1.4 and 0.05 mL H 2 g -1 glucose at cycle 1, 2, 3 and 4, respectively). It was reported that at cultivation pH 7.7, a batch sole biohydrogen production yielded 140 mL H 2 g -1 glucose at glucose concentration 3 g L -1 [37]. Therefore, the low HY obtained in this study should be correlated to the MB activities, which were increasingly enhanced over cycles (MY was 2, 7, 8 and 37 mL CH 4 g -1 glucose at cycle 1, 2, 3 and 4, respectively).…”