金属纳米颗粒在暗发酵生物制氢中的应用研究进展

介绍了金属纳米颗粒的种类及其影响暗发酵产氢的作用机理,进一步对Fe、Ni及其氧化物纳米颗粒和其它金属纳米颗粒应用于微生物暗发酵产氢的影响作用进行了综述,并对其应用于暗发酵产氢的研究方向进行了总结和展望。     

“双碳”下金属纳米颗粒优化暗发酵制氢策略及前景

氢能是“双碳”下推动化石能源低碳转型的重要方向,微生物暗发酵制氢是实现生物质绿氢转化的有效途径。其中,利用具有量子尺寸效应、比表面积大和电导率高的金属纳米颗粒（MNPs）优化暗发酵制氢技术是近年研究热点。综述和评论了国内外添加MNPs用于优化暗发酵制氢性能的作用机制、技术难点和制氢效果等,重点阐述并比较了铁、镍和锌基三类热门MNPs优化策略在提高产氢酶系活性、增强代谢产氢途径和优化微生物群落结构等方面的作用,展望了暗发酵制氢可深入MNPs优化氢化酶活性、拓宽生物质发酵底物以及产氢菌筛选和反应器设计、生物质发酵技术开发等研究方向和应用前景。     

生物质厌氧发酵制氢技术研究进展

聚焦生物质厌氧发酵制氢技术进展,分别从发酵菌源、生物质制氢原料、生物质制氢反应器、发酵制氢影响因素和优化工艺等方面进行综述。研究结果显示,不同种类的生物质原料能有效拓展生物质发酵制氢的应用范围,反应器结构和发酵工艺因素的优化有利于提高生物质发酵制氢的产率和效率。近年来,通过固定化技术、添加纳米颗粒等方法能够促进生物质发酵产氢,通过将暗发酵与光发酵偶联,有利于提升生物质发酵制氢工艺的经济性。在此基础上,对生物质发酵制氢技术进行了展望。     

高浓度有机废水发酵法制取氢气技术

利用两相厌氧高浓度有机废水处理的产酸相制取氢气技术引起世界的普遍关注。介绍了厌氧发酵生物制氢系统的产氢机理、工艺流程与设计、工程控制参数等许多技术问题。认为发酵产氢微生物有丁酸型发酵、乙醇型发酵和甲酸裂解等3种产氢代谢途径。工艺设计以活性污泥的混合培养为主要形式,也发展了细菌的纯培养或辅之细胞固定化工艺。目前已经分离出肠杆菌属(Enterobacter)、梭状芽孢杆菌属(Clostridium)、柠檬酸菌属(Citrobacter)和新型乙醇型发酵产氢细菌等菌属的发酵产氢细菌,这些菌种除了可以纯培养制氢外,还可以进行投入反应系统进行生物强化和细胞固定化技术应用。乙醇型发酵生物制氢理论(双碳发酵产氢学说或理论)指导下发酵法混合培养生物制氢工艺已分别进行了小试和中试,并将进入生产示范工程阶段。     

活性污泥降解有机物制氢技术

生物制氢技术在世界范围受到了极大重视，产氢机理的研究对于制氢技术的发展有着重要的作用。本文在前人研究的基础上，对活性污泥厌氧发酵产氢的多种途径和机理进行了全面探讨，认为活性污泥利用甲酸、丙酮酸、各种脂肪酸等有机物，淀粉纤维素等糖类产氢途径主要是丙酮酸脱氢和NADH/NAD平衡调节产氢气，发酵类型有丙酸型发酵、以及乙醇型发酵，同时对国内外研究现状进行评述，提出今后的研究方向。     

生物制氢研究进展(Ⅰ)产氢机理与研究动态

阐述了7类生物制氢系统的产氢机理、影响因素以及提高产氢率和产氢量的方法,介绍了国外最新的研究进展。光发酵生物制氢技术和厌氧发酵生物制氢技术是研究的热点,而厌氧发酵由于产氢效率较高而成为最具潜力的生物制氢技术之一。光合-发酵杂交技术不仅减少了所需光能,而且增加了氢气产量,同时也彻底降解了有机物,使该技术成为生物制氢技术的发展方向。     

纯培养生物制氢的分批培养工艺的建立与调控

氢气是一种理想的能源,具有转化率高、可再生和无污染等优点。试验利用厌氧发酵技术分离培养产氢细菌,并对产氢细菌进行理化分析。在乙醇型发酵的产氢原理上,以蔗糖作为产氢微生物的培养基,通过间歇培养的方式研究产氢微生物的产氢特性,采取分批培养的方式来研究纯培养生物制氢工艺。纯培养生物制氢工艺的主要工程控制对策为:按反应溶液体积的2%接种新鲜产氢细菌种子培养液,底物浓度采用20%,反应启动时间63 h,温度35℃。     

一株发酵产氢细菌对戊糖的氢气转换及产氢机理

引言制约发酵法生物制氢进一步发展的关键问题是,如何找到来源广泛价格低廉的底物。纤维素、半纤维素和木质素是农作物秸秆的主要组成成分,其酶解液主要由五碳糖、六碳糖和简单多聚糖组成。因此研究和筛选能够利用五碳糖产氢发酵的微生物及其产氢规律,对于扩展底物范围具有重要意义。目前,国内外学者大都集中研究利用已糖(葡萄糖)的发酵产氢上,尚未发现有关利用五碳糖发酵产氢的报道。本文试图通过产氢细菌发酵几种五碳糖来探讨产氢的可能性和产氢机理,为发     

光合细菌与暗发酵细菌生物制氢的应用基础分析

传统能源的开发利用引起的环境污染、资源利用率低、资源严重短缺等一系列问题,在一定程度上严重地阻碍了社会经济的发展。氢气是一种可再生新能源,具有环保、成本低、产量大的特点,利用微生物之间的相互作用来制备氢气是一种绿色环保的制氢技术。本文以微生物联合制氢为核心,并联合暗发酵细菌生物进行制氢的研究以及对联合制氢的应用基础进行了详细地分析。     

发酵产氢细菌的紫外线诱变筛选高产菌株

引言厌氧发酵生物制氢主要依靠细菌的发酵产氢,而如何高效地利用细菌发酵产氢是一个非常重要的问题,高效厌氧产氢细菌的诱变选育研究就是为了找到高效产氢细菌并投入生产。环境微生物的育种仍是以使用物理诱变、化学诱变或两者复合诱变的诱变育种作为最主要的方法。通过诱变育种能达到以下几个目的:(1)提高氢气的产率;(2)改善菌种特性,提高产品质量;(3)简化工艺条件;(4)开发新品种,通过选择几种具有代表性     

厌氧与光合微生物联合制氢工艺实验研究

利用厌氧细菌暗发酵产氢和光合细菌光发酵产氢的优势和互补协同作用而联合起来的两步法制氢,探讨不同底物浓度对厌氧发酵阶段产氢的影响、厌氧发酵时间对产氢发酵过程的影响;光合微生物发酵随发酵时间的产氢情况。结果表明,葡萄糖浓度对厌氧生物产氢有很大的影响, 15 g/L 的葡萄糖浓度有较好的产氢量。葡萄糖利用率和挥发性脂肪酸的总量随厌氧发酵时间的变化情况表明,在厌氧发酵阶段,以葡萄糖为底物,最佳的葡萄糖浓度为 15 g/L。在 37 h 的葡萄糖利用率达到 72.08%,挥发性脂肪酸总量达到 9 326.3 mg/L,每克葡萄糖累计产氢量为 182 mL。在厌氧发酵时间 37 h 时把厌氧发酵的产物移到光合发酵反应器,接种位于生长对数期的光合细菌群,调节培养液的pH值和加入光源进行光合产氢,88 h 时每克葡萄糖累计产氢达到 352 mL,两步联合制氢每克葡萄糖累计产氢量共可达到 534 mL。     

Designed Surface Residue Substitutions in [NiFe] Hydrogenase that Improve Electron Transfer Characteristics

Photobiological hydrogen production is an attractive, carbon-neutral means to convert solar energy to hydrogen. We build on previous research improving the Alteromonas macleodii “Deep Ecotype” [NiFe] hydrogenase, and report progress towards creating an artificial electron transfer pathway to supply the hydrogenase with electrons necessary for hydrogen production. Ferredoxin is the first soluble electron transfer mediator to receive high-energy electrons from photosystem I, and bears an electron with sufficient potential to efficiently reduce protons. Thus, we engineered a hydrogenase-ferredoxin fusion that also contained several other modifications. In addition to the C-terminal ferredoxin fusion, we truncated the C-terminus of the hydrogenase small subunit, identified as the available terminus closer to the electron transfer region. We also neutralized an anionic patch surrounding the interface Fe-S cluster to improve transfer kinetics with the negatively charged ferredoxin. Initial screening showed the enzyme tolerated both truncation and charge neutralization on the small subunit ferredoxin-binding face. While the enzyme activity was relatively unchanged using the substrate methyl viologen, we observed a marked improvement from both the ferredoxin fusion and surface modification using only dithionite as an electron donor. Combining ferredoxin fusion and surface charge modification showed progressively improved activity in an in vitro assay with purified enzyme.     

Bio-hydrogen production from a marine brown algae and its bacterial diversity

The aim of this study was to determine how bio-hydrogen production was related to the composition of the bacterial community in a dark fermentation fed with marine brown algae (Laminaria japonica). The bacterial diversity was ascertained by 16S rDNA PCR-sequencing. A total of 444 mL of bio-hydrogen was produced from 10 g/L of dry algae in a 100 mL of culture fluid for 62 h. The pH varied from 8.74 to 7.05. Active bio-hydrogen production was observed from 24 to 48 h, and maximum bio-hydrogen production was 106 mL over 1 L gas. The bacterial community of the activated sludge consisted of 6 phyla, where H₂ producing and consuming bacteria coexisted. The only detectable bacterial phylum after bio-hydrogen generation with heat-treated (65 °C, 20 min) seeding was Firmicutes. Clostridium and Bacillus species constituted 54% and 46%, respectively, of the bacterial mixture and the most abundant species was Clostridium beijierinckii (34%). These results may provide a better understanding of how different biohydrogen communities affect hydrogen production and aid in the optimization of bio-hydrogen production.     

微生物厌氧发酵制氢技术现状和展望

介绍了利用有机物厌氧发酵生物制氢工艺的基本原理和影响因素,并对国内外在厌氧生物制氢领域内的研究现状进行了综述,对厌氧生物制氢在未来的进一步发展进行了分析和展望。     

有机废水资源化技术——厌氧发酵产氢

氢气作为一种清洁高效的可再生能源日益受到重视。利用有机废水发酵产氢,既保护环境又可获得氢能,是一条符合可持续发展战略的废水资源化途径,极具发展前景。作者介绍了厌氧发酵产氢原理以及影响因素等,并就以有机废水为对象发酵产氢的研究进行了探讨,建议了有机废水厌氧产氢的研究方向。     

Electrically conducting particle networks in polymer electrolyte as three-dimensional electrodes for hydrogenase electrocatalysis

Efficient H₂ oxidation and production by hydrogenase enzymes has attracted much interest because of the possibilities it raises for clean energy cycling without the need for precious metal catalysts. Although hydrogenases are extremely active electrocatalysts, high surface-area electrode structures will be necessary if the enzymes are to find application in energy technologies. Taking inspiration from fuel cell electrode assemblies, in which metal nanoparticles are commonly mounted on particulate carbon supports encased in polymer electrolyte, we show that high surface-area hydrogenase electrodes can be constructed from enzyme-loaded pyrolytic graphite particles in pH-neutralised Nafion. Pyrolytic graphite is the favoured surface for direct electrochemistry of many redox proteins, and on sanding, yields micron-dimension platelike particles. By modifying graphite platelets with hydrogenase before assembling the particles into a network, we ensure a high, uniform enzyme coverage. Incorporation of hydrogenases into high surface-area conducting network electrodes enhanced electrocatalytic H₂ oxidation currents by 30-times compared to values obtained for a planar hydrogenase electrode, while retaining efficient conductivity and H₂ mass transport through the network. This approach should make it possible to directly compare enzyme and precious metal electrocatalysis and to benchmark what opportunities are possible with selective enzyme catalysts.     

玉米秸秆生物产氢菌的分离培养及鉴定研究

以牛粪为菌种来源,利用玉米秸秆进行厌氧发酵产氢实验,在产氢效果达160 mL/h,秸秆产氢能力225 mL/g的最佳状态下,从实验中提取发酵菌液进行细菌的分离培养,并对产氢效果最好的R-3菌种进行生理生化试验研究和初步鉴定,确定产氢细菌为Clostridium sp.Fanp2.     

碳化金属-有机骨架强化种间电子传递产甲烷

为了解决厌氧发酵系统中氢分压限制种间氢扩散速率问题,利用金属-有机骨架ZIF-8衍生多孔碳材料促进乙醇厌氧发酵生产甲烷,探究其对微生物种间电子传递的增强机理。扫描电镜SEM表明ZIF-8衍生多孔碳起到菌群固定化作用,并且能促进纳米导线产生。实验结果表明,随着ZIF-8衍生多孔碳添加量的增加,甲烷产量和最大产甲烷速率逐渐提高。添加200 mg/L ZIF-8衍生多孔碳时,系统导电性提高了3.58倍,三维荧光光谱分析表明ZIF-8衍生多孔碳能够促进微生物胞外聚合物（EPS）中类富里酸的相对含量由18.0%提高到23.6%,对应的甲烷产量和最大产甲烷速率分别增加了18.81%和19.04%。     

Metal-organic framework carbide enhances interspecies electron transfer to produce methane

To solve the problem that the hydrogen partial pressure in the anaerobic fermentation system limits the hydrogen diffusion rate among species, porous metal materials derived from the metal-organic framework ZIF-8 are used to promote the anaerobic fermentation of ethanol to produce methane, and the mechanism for enhancing the electron transfer between microorganism species is explored. Scanning electron microscopy (SEM) shows that ZIF-8 derived porous carbon plays immobilized role of microbial communities and promotes nanowires generation. The results show that the methane yield and the maximum methane production rate increase with an increase of ZIF-8 derived porous carbon addition. When 200 mg/L ZIF-8 derived porous carbon is added, the system conductivity increases by 3.58-fold. Moreover, three-dimensional fluorescence spectroscopy analysis (3D-EEM) showed that ZIF-8 derived porous carbon promotes the relative content of fulvic acid in extracellular polymeric substance (EPS) from 18.0% to 23.6%, corresponding to methane yield and maximum methane production rate increasing by 18.81% and 19.04% respectively.