Efficient hydrogen gas production from cassava and food waste by a two-step process of dark fermentation and photo-fermentation

Integrative Biological Hydrogen Production: An Overview

“…In these cases, starchy wastes have been employed, which had originated from wheat, rice and cassava (Table 1). In other studies, cattle dung, dairy manure and mixed cultures in combinations with Rhodobacter capsulatus, R. palustris, and R. sphaeroides, and their combinations have been shown to yield 3.40-7.15 mol H 2 /mol hexose [33,38,43,47,55,56]. In these cases, starchy wastes, cheese whey and water hyacinth have been fermented for quite long periods 2-10 days of the dark phase followed by 11-21 days of the light period and exceptionally it was 90/100 days under repeated batch culture [47].…”

“…Instead of dwelling on optimization efforts being made on individual parameters of BHP process, an emerging proposal is to combine the dark-and photofermentative H 2 producing organisms [7,10,35,36]. The efforts in this direction have been targeted on the following combinations: (i) using defined dark-and photo-fermentative H 2 producing organisms in a sequential manner in two independent stages (ii) using undefined dark-fermentative H 2 -producers along with defined photosynthetic organisms in two stages (iii) using the two types of BHP processes into a single stage, and (iv) using effluent from a dark-fermentative process (not necessarily a H 2 production reactor) and exploiting photo-fermentative bacteria for their H 2 producing abilities [33,[37][38][39][40][41][42][43][44][45][46][47][48]. In our recent efforts, we have emphasized only on using defined bacterial cultures in a sequential manner and evaluate it with respect to their individual H 2 producing abilities from pure substrates and biowastes [7].…”

Succession of the Bacterial Community and Dynamics of Hydrogen Producers in a Hydrogen-Producing Bioreactor

“…The fermentation reaction mixture was kept at pH 5.8, with stirring at 100 rpm. Other fermentation conditions for batch hydrogen production from 18 g liter Ϫ1 sucrose were the same as in a previous study (27). The evolved biogas was collected by the water displacement method.…”

Characterization by length heterogeneity (LH)-PCR of a hydrogen-producing community obtained in dark fermentation using coastal lake sediment as an inoculum

“…Thus, the freezing and the strict control of anaerobiosis may have selected the Clostridium species. Although the data presented cannot distinguish the H 2 producers from the other community members, the literature reported H 2 production for strains of C. butyricum, C. bifermentans, and C. acetobutylicum in pure cultures [23][24][25] and C. perfringens in complex communities in bioreactors [11].…”