Effect of temperature and temperature shock on the stability of continuous cellulosic-hydrogen fermentation

Improved cellulose conversion to bio-hydrogen with thermophilic bacteria and characterization of microbial community in continuous bioreactor

“…Compared to its pure/co-culture counterparts, a mixed culture has two clear advantages: i) the diversity of microflora guarantees a high hydrogen yield and cellulose degradation efficiency [7], and ii) the fermentation process is more tolerant to environmental and operational variations, such as temperature shock and pH change [8]. Although extensive studies have been conducted on mixed microbial consortia in batch modes [9], few have focused on continuous modes [6,10,11]. Therefore, the objectives of this study were to enhance hydrogen production, process stability and cellulose degradation efficiency in a thermophilic continuous bioreactor using mixed microflora.…”

Significance of acclimatization for biohydrogen production from synthetic lignocellulose hydrolysate in continuous-flow systems

“…Although the results obtained from R1 and R2 in phases 2 and 3 were within the optimum range reported in the literature [17,18], the hydrogen yields were significantly lower than in phase 1 at a higher F/M ratio. This could be attributed to the change in feed composition [4,11,16] and soluble by-products [11].…”

“…The aforementioned authors attributed the marked deterioration in substrate conversion to the sensitivity of the selected population to the substrate concentration and/or increased product concentration [4]. One possible explanation is that the unexpected changes in the operating parameters such as an alteration of substrate and substrate concentration variation [11,16] may have resulted in an imbalance in the fermentation process. Another explanation is that the other hydrogen producers may have been washed out during enrichment of the culture using xylose in the first phase.…”

454-Pyrosequencing Reveals Microbial Community Structure and Composition in a Mesophilic UAFB System Treating PTA Wastewater

“…The microbial composition and spatial distribution in anaerobic system treating terephthalate have also been characterized using molecular techniques [27]. Nevertheless, these researches are mostly in related with steady-state operation at particular temperature, like 33°C [18], 37°C [9,11], 55°C [5], or focused on comparison between psychrophilic, mesophilic, and thermophilic systems [1,6,7,17,25].The discrepancy of reactor performance at a certain mesophilic range was rarely investigated according to previous references. Therefore, in this research, we compared the performances of an up-flow anaerobic fixed bed (UAFB) system [22] treating with high-strength PTA wastewater at 33 and 37°C.…”