Enhanced hydrogen production performance of Rubrivivax gelatinosus M002 using mixed carbon sources

Enhanced hydrogen production from cornstalk by dark- and photo-fermentation with diluted alkali-cellulase two-step hydrolysis

“…As proven by Abo-Hashesh et al, a hydrogen yield of 3.3 mol-H 2 /mol-glucose and 4.73 mol-H 2 /mol-glucose could be obtained in batch tests [27,36], and the yield increased dramatically into 9.0 mol-H 2 /mol-glucose when the pH value of the culture was controlled properly in continuous process i n t e r n a t i o n a l j o u r n a l o f h y d r o g e n e n e r g y x x x ( 2 0 1 5 ) 1 e8 [37]. As shown in our previous report [28], when proper amount of acetate and butyrate were co-fed with glucose to Rubrivivax gelatinosus M002, some synergistic effect showed up and the pH value could be tuned automatically. In this study, the cornstalk hydrolysate was also fed to R. sphaeroides HY01, which is a purple non-sulfur bacterium with high performance on photo-fermentative H 2 production [27], for studying its potential on one-step photo-fermentative hydrogen production.…”

“…Rhodobacter sphaeroides HY01 used as inocula was precultured as described in literature [27]. 30 mL syringes were employed as photo-reactor as shown in literature [28]. Each of the experiments in dark-fermentation and photofermentation were conducted in triplicate.…”

Experimental study of the effects of heavy metal ions on the hydrogen production performance of Rhodobacter sphaeroides HY01

“…Each 30-mL syringe was filled with 10 mL inoculated culture and each reaction was carried out in triplicate. Each syringe port was connected with silicone pipe (F5 mm  1 mm) and sealed with pinchcock as shown in our previous work [26]. All of the reactions were carried out in a photo-incubator (Jiangnan Instrument) at light intensity of 5000 ± 300 lux and 30 ± 0.5 C. The light irradiation was offered by 10 W halogen tungsten lamps.…”

“…After assimilation of these organic acids, the alkaline such as sodium hydroxide could remain in the solution and lead to the increase of pH value. Once most part of organic acids were assimilated for hydrogen production, they would be oxidized into carbon dioxide finally, and the carbon dioxide could neutralize the alkaline remained after the assimilation of organic acids, therefore the pH could be maintained at proper value (7e7.5) [26]. If most of the organic acids assimilated flowed to biosynthesis, carbon oxide produced could be much less than those used for hydrogen production, therefore it cannot neutralize the alkaline by carbon dioxide and promoted the pH value consequently [30].…”

Coexpression of Mo- and Fe-nitrogenase in Rhodobacter capsulatus enhanced its photosynthetic hydrogen production

“…The activity of nitrogenase is positively related with the hydrogen production performance of PNSB [6,12]. The disruption of hupSL genes resulted in enhanced nitrogenase expression level and nitrogenase activity [13], which could be the reason of the enhanced hydrogen production performance of hupSL À mutant.…”