Fermentative Hydrogen Production Research Articles

Improving fermentative hydrogen production from water hyacinth with genetically modified bacteria

Water hyacinth pretreated with microwave‐assisted dilute acid was used for fermentation to produce hydrogen using four kinds of genetically modified bacteria for the first time in this study. The genes of several hydrogenase were over‐expressed in Enterobacter cloacae CICC10017 and Enterobacter aerogenes ATCC13408. Four recombinant strains including E. cloacae/HPP, E. aerogenes/HycE, E. aerogenes/HycG, and E. aerogenes/HoxEFUYH were obtained. Hydrogen yields from water hyacinth were investigated, which were enhanced using the recombinant strains. When water hyacinth was pretreated by microwave at 140°C for 15 min with 1% H2SO4 and then hydrolyzed by cellulase, the reducing sugar yield of 49.4 g/100 g hyacinth was 91.4% of the theoretical reducing sugar yield. Among the four genetically modified bacteria, E. cloacae/HPP gave the highest hydrogen yield of 74.9 mL/g‐ total volatile solids, which was 50% higher than that given by the wild strain from pretreated water hyacinth. © 2017 American Institute of Chemical Engineers Environ Prog, 36: 1296–1300, 2017

Landfill leachate enhances fermentative hydrogen production from glucose and sugarcane processing derivatives

Fermentation can use renewable raw materials as substrate, which makes it a sustainable method to obtain H2. This study evaluates H2 production by a mixed culture from substrates such as glucose and derivatives from sugarcane processing (sucrose, molasses, and vinasse) combined with landfill leachate. The leachate alone was not a suitable substrate for biohydrogen production. However, leachate blended with glucose, sucrose, molasses, or vinasse increased the H2 production rate by 2.0-, 2.8-, 4.6-, and 0.5-fold, respectively, as compared with the substrates without the leachate. Determination of metals (Cu, Cd, Pb, Hg, Ni, and Fe) at the beginning and at the end of the fermentative assays showed how they were consumed during the fermentation and demonstrated improved H2 production. During fermentation, Cu, Fe, and Cd were the most consumed leachate metals. The best substrate combination to produce H2 was molasses and leachate, which gave high volumetric productivity—469 ml H2/l h. However, addition of the leachate to the substrates stimulated lactic acid formation pathways, which lowered the H2 yield. The use of leachate combined with sugarcane processing derivatives as substrates could add value to the leachate and reduce its polluting power, generating a clean energy source from renewable raw materials.

Improving phosphorus removal efficiency and Chlorella vulgaris growth in high-phosphate MFC wastewater by frequent addition of small amounts of nitrate

Microalgae coupled with the wastewater treatment and CO2 biofixation becoming a promising biomass feedstock for fermentative hydrogen production. Microbial fuel cells wastewater (MFCW) contained high phosphorus but low nitrogen (N/P is 1:73) due to phosphate buffer. To keep a high microalgae growth rate in MFCW and P removal efficiency, some extra NaNO3 was added into MFCW to balance N/P. With 0.5 g L−1 NaNO3 adding, Chlorella vulgaris showed the highest biomass yield of 4.7 g L−1 and highest lipid productivity of 61.29 mg L−1 d−1. In order to avoid the inhibition of excess nitrate that added one-time on microalgae growth, NaNO3 was added frequently with small amounts during cultivation. The biomass yield of microalgae by adding NaNO3 twice increased by 13.4% compared to that cultivated by adding the same amount of NaNO3 one-time. Moreover, with a NaNO3 adding frequency of 0.5 g L−1 3 d−1, the maximum R=(S0−St)/(t0−tt) removal rate was up to 45.16 mg L−1 d−1.

Fermentative hydrogen production from indigenous mesophilic strain Bacillus anthracis PUNAJAN 1 newly isolated from palm oil mill effluent

In the present study, a new mesophilic bacterial strain, identified as Bacillus anthracis strain PUNAJAN 1 was isolated from palm oil mill effluent (POME) sludge, and tested for its hydrogen production ability. Effect of physico-chemical factors such as temperature, initial pH, nitrogen source and carbon sources were investigated in order to determine the optimal conditions for hydrogen production. The maximum hydrogen yield of 2.42 mol H2/mol mannose was obtained at 35 °C and initial pH of 6.5. Yeast and mannose were used as the main carbon and nitrogen sources respectively in the course of the hydrogen production. Apart from synthetic substrate, specific hydrogen production potentials of the strain using POME was calculated and found to be 236 ml H2/g chemical oxygen demand (COD). The findings of this study demonstrate that the indigenous strain PUNAJAN 1 could be a potential candidate for hydrogen using POME as substrate.

In-depth observations of fermentative hydrogen production from liquid swine manure using an anaerobic sequencing batch reactor

In this study, experiments were designed to reveal in-depth information of the effect of pH and hydraulic retention time (HRT) on biohydrogen fermentation from liquid swine manure supplemented with glucose using an Anaerobic Sequencing Batch Reactor (ASBR) System. Five values of HRT (8, 12, 16, 20, and 24 h) were first tested and the best HRT determined was further studied at five pH levels (4.4, 4.7, 5.0, 5.3, and 5.6). The results showed that for HRT 24 h, there was a dividing H2 content (around 37%) related to the total biogas production rate for the ASBR System running at pH 5.0. When the H2 content went beyond 37%, an appreciable decline in biogas production rate was observed, implying that there might exist an H2 content limit in the biogas. For other HRTs (8 through 20 h), an average H2 content of 42% could be achieved. In the second experiment (HRT 12 h), the highest H2 content (35%) in the biogas was found to be associated with pH 5.0. The upswing of pH from 5.0 to 5.6 had a significantly more impact on biogas H2 content than the downswing of pH from 5.0 to 4.3. The results also indicated good linear relationships of biogas and H2 production rates with HRT (r=0.9971 and 0.9967, respectively). Since the optimal ASBR operating conditions were different for the biogas/H2 production rates and the H2 yield, a compromised combination of the running parameters was determined to be HRT 12 h and pH 5.0 in order to achieve good biogas/H2 productions.

Pre-treatment technologies for dark fermentative hydrogen production: Current advances and future directions

Hydrogen is regarded as a clean and non-carbon fuel and it has a higher energy content compared to carbon fuels. Dark fermentative hydrogen production from organic wastes is the most promising technology for commercialization among chemical and biological methods. Using mixed microflora is favored in terms of easier process control and substrate conversion efficiencies instead of pure cultures. However, mixed cultures should be first pre-treated in order to select sporulating hydrogen producing bacteria and suppress non-spore forming hydrogen consumers. Various inoculum pre-treatments have been used to enhance hydrogen production by dark fermentation including heat shock, acid or alkaline treatment, chemical inhibition, aeration, irradiation and inhibition by long chain fatty acids. Regarding substrate pre-treatment, that is performed with the aim of enhanced substrate biodegradability, thermal pre-treatment, pH adjustment using acid or base, microwave irradiation, sonication and biological treatment are the most commonly studied technologies. This article reviews the most investigated pre-treatment technologies applied for either inoculum or substrate prior to dark fermentation, the long-term effects of varying pre-treatment methods and the subsequently feasibility of each method for commercialization.

Industrialization roadmap model for fermentative hydrogen production from biomass in Taiwan

The study aimed to construct a technology industrialization roadmap model and apply it to illustrate the fermentative hydrogen production from biomass in Taiwan. The paper distinguishes and defines the emerging industrialization process technology and collects and analyzes secondary data. Subsequently, it identifies the current phase of technology development and investigates the future activities of the industrial phase and the relationship between technology, product, applications, and markets by further formulating the industrialization roadmap. The results are as follows. The industrialization of hydrogen production by fermentation from biomass in Taiwan is currently in the “technology-application transition phase,” in which key technologies such as selection and cultivation of dominant hydrogen-producing bacteria, processing of biomass feedstock, and control of operation parameters have been mastered. The industrialization roadmap has designated the years 2016–2020 as the “nurture phase,” 2021–2025 as the “application-market transition phase,” and 2026–2035 as the “growth phase.”

Research perspectives on constraints, prospects and opportunities in biohydrogen production

Hydrogen gas can be formed from sewage sludge treatment via anaerobic digestion (AD) as this sludge contains large amount of organic matters. In this review, a comprehensive attempt has been made to revisit the main updates, advantages and disadvantages surveyed in recent research (2012–2017) on fermentative hydrogen production from a variety of biomass. The main findings of this review are now stated. The biological hydrogen production processes consist of indirect and direct biophotolysis, dark fermentation, two-stage fermentation and photo-fermentation. To maximize hydrogen gas yield via such technique, the activity of hydrogen-consuming bacteria should be inhibited at the acetate and hydrogen formation stage to stop or reduce hydrogen consumption. The major constraints in biological hydrogen production processes are raw material cost, low hydrogen evolution rate and yield at large scale. Lignocellulosic materials generate low yield of hydrogen gas due to the presence of refractory lignin while food waste containing carbohydrates and starch yields more hydrogen gas. Effective pretreatment of substrates and inoculum can enhance hydrogen yield. In dark fermentation process, better performance can be obtained with pretreatment. Nitrogen sources such as yeast result in higher biohydrogen generation rate and cell growth from the presence of amino acids and proteins. In photo-fermentation, better results can be obtained by using a combination of photosynthetic bacteria and green microalgae, as it enhanced solar energy utilization. Future development such as genetic manipulation could be employed, which mainly focuses on the disruptive characteristics of endogenous genes. The efficiency of biohydrogen production can also be increased by lowering the costs of delivery, production, conversion, storage and practical applications. Apart from using biodegradable wastes, green wastes will be the mostly preferable targeted feedstock for hydrogen fermentation because of their large quantity and having simultaneous waste treatment benefit.

Efficient dark fermentative hydrogen production from enzyme hydrolyzed rice straw by Clostridium pasteurianum (MTCC116)

In the present work, production of hydrogen via dark fermentation has been carried out using the hydrolyzed rice straw and Clostridium pasteurianum (MTCC116). The hydrolysis reaction of 1.0% alkali pretreated rice straw was performed at 70°C and 10% substrate loading via Fe3O4/Alginate nanocomposite (Fe3O4/Alginate NCs) treated thermostable crude cellulase enzyme following the previously established method. It is noticed that under the optimized conditions, at 70°C the Fe3O4/Alginate NCs treated cellulase has produced around 54.18g/L sugars as the rice straw hydrolyzate. Moreover, the efficiency of the process illustrates that using this hydrolyzate, Clostridium pasteurianum (MTCC116) could produce cumulative hydrogen of 2580ml/L in 144h with the maximum production rate of 23.96ml/L/h in 96h. In addition, maximum dry bacterial biomass of 1.02g/L and 1.51g/L was recorded after 96h and 144h, respectively with corresponding initial pH of 6.6 and 3.8, suggesting higher hydrogen production.

Dark fermentative hydrogen production from sucrose and molasses

Summary There are many factors affecting the dark fermentative hydrogen production. The interaction of these factors, that is, their combined effects, should be investigated for better design of the systems with stable and higher hydrogen yields. This study aimed to investigate the combined effects of initial substrate, pH, and biomass (or initial substrate to biomass) values on hydrogen production from sucrose and sugar-beet molasses. Therefore, optimum initial chemical oxygen demand (COD), pH, and volatile suspended solids (VSS) or initial substrate to biomass (VSS) ratio (S/Xo) values leading to the highest dark fermentative hydrogen production were investigated in batch reactors. An experimental design approach (response surface methodology) was used. Results revealed that when sucrose was the substrate, maximum hydrogen production yield (HY) of 2.3 mol H2/mol sucroseadded was obtained at initial pH of 7 and COD of 10 g/L. Initial S/Xo values studied (4–20 g COD/g VSS) had no effect on HY, while the initial pH was found as the parameter mostly affecting both HY and hydrogen production rate (HPR). When substrate was molasses, initial COD concentration was the only variable affecting HY and HPR. Maximum of both was achieved at 10 g/L initial COD. Initial VSS values studied (2.5–7.5 g/L) had no effect on HPR and HY. This study also indicated that molasses leads to homoacetogenesis for potentially containing intrinsic microorganism and/or natural constituents; thus, sucrose is more advantageous for hydrogen production via fermentation. Homoacetogenesis should be prevented for effective optimization via response surface methodology, if substrate is a natural carbon source potential to have intrinsic microorganisms. Copyright © 2017 John Wiley & Sons, Ltd.

2-4.微生物を利用した発酵水素製造(未来を担う水素エネルギー,Session(2)水素エネルギー)

2-4.微生物を利用した発酵水素製造(未来を担う水素エネルギー,Session(2)水素エネルギー)

Mesophilic continuous fermentative hydrogen production from acid pretreated de-oiled jatropha waste hydrolysate using immobilized microorganisms

Mesophilic hydrogen production from acid pretreated hydrolysate (biomass concentration of 100g/L and 2% hydrochloric acid) of de-oiled jatropha waste was carried out in continuous system using immobilized microorganisms at various hydraulic retention times (HRTs) ranging from 48 to 12h. The experimental results of the reusability of immobilized microorganisms showed their stability up to 10 cycles with an average cumulative hydrogen production of 770mL/L. The peak hydrogen production rate and hydrogen yield were 0.9L/L*d and 86mL/greducing sugars added, respectively at 16h HRT, with butyrate as the predominant volatile fatty acid. The microbial community analysis revealed that majority of the PCR-DGGE bands were assigned to genus Clostridium and were perhaps the key drivers of the higher hydrogen production.

Increased energy production from sucrose by controlled hydrogen-producing fermentation followed by methanogenic fermentation

ABSTRACTTo improve the low energy production efficiency of fermentative hydrogen production (FHP) and fermentative methane production (FMP), the two types of fermentation were effectively combined in this study. Using sucrose as feedstock, both successive fermentative production of hydrogen followed by methane (SFPHM) and successive fermentative production of methane followed by hydrogen (SFPMH) were performed to improve the energy production efficiency of the overall anaerobic process. The results showed that the energy conversion efficiency of SFPHM was 79.85% whereas that of SFPMH was only 43.12%. Therefore, SFPHM can significantly improve the energy production efficiency of traditional anaerobic biological treatment.

Isolation and characterization of a novel strain Clostridium butyricum INET1 for fermentative hydrogen production

A novel hydrogen-producing strain was isolated from gamma irradiated digested sludge and identified as Clostridium butyricum INET1. The fermentative hydrogen production performance of the newly isolated C. butyricum INET1 was characterized. Various carbon sources, including glucose, xylose, sucrose, lactose, starch and glycerol were used as substrate for hydrogen production. The operational conditions, including temperature, initial pH, substrate concentration and inoculation proportion were evaluated for their effects on hydrogen production, and the optimal condition was determined to be 35 °C, initial pH 7.0, 10 g/L glucose and 10% inoculation ratio. Cumulative hydrogen production of 218 mL/100 mL and hydrogen yield of 2.07 mol H2/mol hexose was obtained. The results showed that C. butyricum INET1 is capable of utilizing different substrates (glucose, xylose, sucrose, lactose, starch and glycerol) for efficient hydrogen production, which is a potential candidate for fermentative hydrogen production.

Biohydrogen production from sugarcane bagasse hydrolysate: effects of pH, S/X, Fe2+, and magnetite nanoparticles

Batch dark fermentation experiments were conducted to investigate the effects of initial pH, substrate-to-biomass (S/X) ratio, and concentrations of Fe2+ and magnetite nanoparticles on biohydrogen production from sugarcane bagasse (SCB) hydrolysate. By applying the response surface methodology, the optimum condition of steam-acid hydrolysis was 0.64% (v/v) H2SO4 for 55.7min, which obtained a sugar yield of 274mgg-1. The maximum hydrogen yield (HY) of 0.874mol (mol glucose-1) was detected at the optimum pH of 5.0 and S/X ratio of 0.5g chemical oxygen demand (COD, gVSS-1). The addition of Fe2+ 200mgL-1 and magnetite nanoparticles 200mgL-1 to the inoculum enhanced the HY by 62.1% and 69.6%, respectively. The kinetics of hydrogen production was estimated by fitting the experimental data to the modified Gompertz model. The inhibitory effects of adding Fe2+ and magnetite nanoparticles to the fermentative hydrogen production were examined by applying Andrew's inhibition model. COD mass balance and full stoichiometric reactions, including soluble metabolic products, cell synthesis, and H2 production, indicated the reliability of the experimental results. A qPCR-based analysis was conducted to assess the microbial community structure using Enterobacteriaceae, Clostridium spp., and hydrogenase-specific gene activity. Results from the microbial analysis revealed the dominance of hydrogen producers in the inoculum immobilized on magnetite nanoparticles, followed by the inoculum supplemented with Fe2+ concentration. Graphical abstract ᅟ.

Optimisation and Comparative Evaluation of Fermentative Hydrogen Production using Pure and Co-culture of Clostridium beijerinckii and Enterobacter aerogenes

Hydrogen, the only fuel to produce water as a by-product is seen as an ideal fuel for the future that can be produced from waste feedstock. The use of optimum bioreactor conditions and co-cultures with well-defined strains offer great potential to enhance hydrogen production due to diverse metabolic pathways. This study was aimed at determining the optimum pH and temperature on hydrogen production rate by Clostridium beijerinckii 6444 using glucose as substrate as well as investigating the influence of co-culture comprising of C. beijerinckii 6444 and Enterobacter aerogenes NCIMB 10102 on rate of hydrogen production and yield from glucose, molasses, crude glycerol and seed cake via dark fermentation. Batch fermentation in serum bottles was carried out in order to determine the total accumulative hydrogen gas, biomass concentration, and feedstock consumption in four days of fermentation. The co-culture was further scaled up to a 5 L fermenter. The optimum pH and temperature corresponding to 6.2 and 30 oC respectively were determined. The co-culture recorded the highest cumulative hydrogen volume (66.5 ± 4.2 ml) from crude glycerol though it did not significantly increase the yields. The decrease in hydrogen production was observed as a result of formation of volatile fatty acids (acetic acid 1.5-3.1 g/l, butyric acid 3.2-5.6 g/l) among others which have inhibitory effects. The highest dead cell count of 3.4 x 108 cells/ml indicated that pH was inhibitory. The scale-up showed an increase in the hydrogen production rate from 13.38 ml/l/hr to 24.13 ml/l/hr and yield of 1.37 mol H2/mol glycerol after 24 hrs. The study showed that the co-culture of C. beijerinckii and E. aerogenes can be used to enhance hydrogen production from crude glycerol as a cheap carbon source.

A critical review on factors influencing fermentative hydrogen production.

Biohydrogen production by dark fermentation of different waste materials is a promising approach to produce bio-energy in terms of renewable energy exploration. This communication has reviewed various influencing factors of dark fermentation process with detailed account of determinants in biohydrogen production. It has also focused on different factors such as improved bacterial strain, reactor design, metabolic engineering and two stage processes to enhance the bioenergy productivity from substrate. The study also suggest that complete utilization of substrates for biological hydrogen production requires the concentrated research and development for efficient functioning of microorganism with integrated application for energy production and bioremediation. Various studies have been taken into account here, to show the comparative efficiency of different substrates and operating conditions with inhibitory factors and pretreatment option for biohydrogen production. The study reveals that an extensive research is needed to observe field efficiency of process using low cost substrates and integration of dark and photo fermentation process. Integrated approach of fermentation process will surely compete with conventional hydrogen process and replace it completely in future.

Pt20RuxSny nanoparticles dispersed on mesoporous carbon CMK-3 and their application in the oxidation of 2-carbon alcohols and fermentation effluent

We report the synthesis of Pt-Sn binary and Pt-Ru-Sn ternary alloy nanoparticles (NPs) dispersed on mesoporous carbon CMK-3 for bioalcohol fuel cell applications where ethanol, ethylene glycol, and fermentative hydrogen production effluent were used as the fuels. The proposed alloy electrocatalysts, denoted as Pt20RuxSny@C (where 20, x, and y represent the weight fractions of Pt, Ru, and Sn, respectively), were examined using scanning electron microscopy, energy-dispersive X-ray spectroscopy mapping, transmission electron microscopy, Brunauer-Emmett-Teller measurements, X-ray diffraction analysis, and electrochemical measurements, in order to determine their morphologies, microstructures, compositions, phase structures, and electrochemical characteristics. The effects of the Sn content on the following factors were examined: 1) average particle size of the alloy NPs, 2) mesoporosity, 3) electrochemically active surfaces of Pt20RuxSny@C, and 4) ethanol oxidation reaction and ethylene glycol oxidation reaction activities. Higher Sn contents improved the catalytic efficiency of Pt20RuxSny when x=0 or x=10, with the optimized compositions being Pt20Sn30 and Pt20Ru10Sn15 for the binary and ternary alloys, respectively. Based on the ethanol and ethylene glycol oxidation reactions, we explain the role of Sn in promoting CC bond cleavage and in improving catalyst tolerance against poisoning. Overall, for both the ethanol system and the ethylene glycol system, the catalytic activities could be arranged as follows: Pt20Ru10Sn15@C>Pt20Sn30@C>Pt20Ru10@C>Pt20@C. The chronoamperometric measurement shows that Pt20Ru10Sn15@C is more stable than commercial E-TEK Pt/C catalyst under ethanol environment. Finally, the catalyst Pt20Ru10Sn15 was used successfully to demonstrate the feasibility of using the bioalcohol from a fermentation effluent as a fuel.

Statistical optimization of simultaneous saccharification fermentative hydrogen production from Platanus orientalis leaves by photosynthetic bacteria HAU-M1

Hydrogen is a promising alternative energy, and can be produced from various materials. Platanus orientalis leaves (POL) was utilized to produce hydrogen through simultaneous saccharification fermentative (SSF) method with photosynthetic bacteria HAU-M1. The method was investigated using response surface methodology (RSM) with central composite design (CCD). The Plackett–Burman design was first used to screen the factors (initial pH, light intensity, temperature, substrate concentration and initial inoculum) that influence SSF hydrogen production. Results indicated that initial pH, temperature and inoculation amount had a statistically significant effect on SSF hydrogen production. Central composite design was further carried out to evaluate interaction between the selected variables. The optimal conditions were determined to be initial pH of 6.18, temperature of 35.59 °C, and inoculation amount of 26.29% (v/v). The predicted maximum hydrogen yield was 65.03 mL H2/g TS, which was very close to the experimental result of 64.10 mL H2/g TS obtained under the optimal conditions. The R2 value was 0.9396, indicating a good model fit for SSF hydrogen production.

Effects of pH and substrate concentrations on dark fermentative biohydrogen production from xylose by extreme thermophilic mixed culture.

Biohydrogen is considered as one of the most promising energy alternatives considering the climate and energy crisis. The dark fermentative hydrogen production from xylose at extreme thermophilic condition (70°C) using mixed culture was conducted in this study. The effects of initial pH values (ranged from 5.0 to 10.0) and substrate concentrations (ranged from 2.5 to 15.0g/L) on the hydrogen production, substrate degradation and metabolite distributions were investigated using batch-mode operations. Results showed that initial substrate pH values in the neutral region (6.0-7.0) were beneficial for hydrogen production. The fermentation at initial pH 7.0 and 7.5g/L xylose reached an optimal hydrogen yield of 1.29mol-H2/mol-xyloseconsumed. Ethanol, butyrate, and propionate were the major liquid metabolites. The xylose biodegradation efficiency of the mixed culture decreased sharply at high initial culture pH values. The increase of xylose concentration resulted in the accumulation of propionate and an obvious decrease in the final pH value, as well as a low hydrogen yield. Polymerase chain reaction-denaturing gradient gel electrophoresis analysis indicated that hydrogen producing bacteria were enriched by repeated culture under extreme thermophilic conditions. Also, the mixed culture was dominated with bacterial species related to Clostridium and Thermoanaerobacterium.