Inhibitory effect of acetic acid on dark-fermentative hydrogen production

Yin, Yanan; Song, Weize; Wang, Jianlong

doi:10.1016/j.biortech.2022.128074

Cited by 16 publications

(4 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Fed-batch D consumed the highest amount of acetic acid (see previous paragraph), producing, at the same time, the highest concentration of LA (7.0 gL −1 ) as compared to fed-batch C (5.5 gL −1 ). Interestingly, also Yin et al [26] found that when UAA concentrations were in the range of 16-55 mgL −1 , the activation of L-lactate dehydrogenase, the enzyme responsible for LA production, was observed. 1,3 PD production, a metabolite of glycerol degradation [39], occurs through the reductive pathway as a means of ensuring redox-balanced conditions by recycling the NADH generated during the growth of microorganisms [40].…”

Section: Increasing the Cg Concentration: Metabolic Pathways And Prod...mentioning

confidence: 94%

“…Notably, the lower UAA concentration (90.2 mgL −1 ) observed in fed-batch D, compared to C (121.0 mgL −1 ), was related to the effect of N 2 sparging on pH (see next paragraph). The highest UAA concentration (159 mgL −1 ) of fed-batch E suggested the decisive role of UAA in substrate degradation inhibition [26]. During fed-batch C, the highest volume of H2 production (1.84 LL −1 ) was recorded within the starting phase (0-20 h), and the H2 production subsequently decreased until the end, including the feed addition phase (117 h).…”

Section: Role Of Acetic Acid As the Main Impurities Of Cg During The ...mentioning

confidence: 95%

“…A relative standard deviation < 5% was obtained for all data. The corresponding Undissociated Acetic Acid (UAA) was calculated according to Formula (2), as described in Yin et al [26].…”

Section: Gas and Metabolite Analysismentioning

confidence: 99%

“…At a ratio of 1:1, the authors observed the significant inhibition of glycerol consumption and EtOH production, both related to the undissociated form of AA in culture medium. According to Yin et al [26], the undissociated AA (UAA) concentration was the critical factor in AA inhibition. Indeed, during a fermentative process with glucose inoculated with anaerobic sludge, decreases in H 2 production by 50% and 90% were observed when the UAA concentrations were 76.3 mgL −1 and 686.7 mgL −1, respectively.…”

Section: Role Of Acetic Acid As the Main Impurities Of Cg During The ...mentioning

confidence: 99%

See 3 more Smart Citations

Simultaneous Hydrogen and Ethanol Production from Crude Glycerol by a Microbial Consortium Using Fed-Batch Fermentation

et al. 2023

View full text Add to dashboard Cite

Simultaneous bioproduction of hydrogen and ethanol from cheaper waste feedstock has the potential for the development of a more cost-effective biofuel generation process. Crude glycerol (CG), a by-product of the biodiesel industry, is a renewable resource, abundant, sold at low prices and available worldwide. However, the main CG limitations in fermentation processes are mainly related to the presence of impurities and the lack of nitrogen sources, both acting on microbial activity. In this study, a fermentation process with CG was improved using a highly specific microbial consortium called GlyCeroL (GCL). The process was developed in fed-batch fermentation mode using not diluted substrate and carried out under non-sterile conditions and at increasing amounts of the substrate (from 20 to 80 gL−1 of glycerol). The results showed higher H2 (from 6 to 8 LL−1) and EtOH (from 13 to 20 gL−1) production by increasing glycerol concentration from 20 to 40 gL−1. On the other hand, a decrease in glycerol degradation efficiency (from 75 to 56%) was observed. Then, the nitrogen sparging strategy was applied. Using CG of 40 gL−1, process improvement was achieved, leading to the increased production of hydrogen (10 LL−1) but not that of ethanol (20 gL−1). A further increase to 60 gL−1 of glycerol produced a slight increment of EtOH (21 gL−1) and H2 (11 gL−1) but a sharp decrease in glycerol degradation efficiency (41%). Acetate, as the main impurity of CG, was an additional carbon source for GCL microorganisms contributing to EtOH production and increasing that of lactic acid to restore the redox balance. The Denaturing Gradient Gel Electrophoresis (DGGE) fingerprint at the end of all fed-batch fermentations supported the robustness of GCL functional units and their adaptability to fermentation conditions.

show abstract

Section: Increasing the Cg Concentration: Metabolic Pathways And Prod...mentioning

confidence: 94%

Section: Role Of Acetic Acid As the Main Impurities Of Cg During The ...mentioning

confidence: 95%

“…A relative standard deviation < 5% was obtained for all data. The corresponding Undissociated Acetic Acid (UAA) was calculated according to Formula (2), as described in Yin et al [26].…”

Section: Gas and Metabolite Analysismentioning

confidence: 99%

Section: Role Of Acetic Acid As the Main Impurities Of Cg During The ...mentioning

confidence: 99%

See 2 more Smart Citations