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。     

紫外线诱变提高细菌产纤维素酶活力的研究

从南京红山动物园土样及食草动物的粪便中分离出14种产纤维素酶菌株,其中F1表现出较高的酶活力.以F1为出发菌株,通过紫外线诱变处理,采用透明圈法初筛和摇瓶培养复筛,获得了10株高产纤维素酶的突变株Q1～Q10.经紫外线诱变处理的Q3突变株产酶活力最高,与出发菌株相比酶活力提高了15.8倍.     

厌氧发酵产氢反应器研究进展3

随着生物制氢技术的迅速发展,各种新型厌氧反应器不断出现。为了更好更快实现生物产氢的产业化,许多学者及工程技术员对生物制氢反应器进行研究和设计。本文综述了产氢反应器的发展及生物制氢反应器连续流稳定运行的工程控制参数,比较了这些系统的启动特点及存在的问题,最后展望了生物产氢研究领域反应器发展及这些系统的应用前景。     

新型产氢细菌Biohybactium R3利用乳糖进行发酵产氢的实验研究

以高效产氢新菌Biohybactium R3为研究对象,探讨了以乳糖作为底物时,不同的乳糖浓度和不同的pH对R3的产氢效能和生长的影响.实验发现,R3能很好地运用乳糖为自身的营养物质进行生长和产氧.当乳糖质量浓度为15 g/L、初始pH为6.0时,R3的气体总产量和细胞干重达到最大值,分别为450 mL和1.36 g/L.     

有机垃圾厌氧发酵产氢技术研究进展

利用有机垃圾产氢的研究逐渐兴起,人们利用有机垃圾产氢既可以最大程度地使有机垃圾资源化,减少环境的污染,又可以通过无污染氢气的获得改善能源市场,缓解能源的压力。分析了国内外厌氧发酵产氢的技术现状;以厌氧发酵产氢的原理和机理入手,讨论微生物、发酵过程、过程参数等对产氢效率和速率的影响;最后还对厌氧发酵产氢的可行性进行研究。     

有机垃圾厌氧发酵产氢技术研究进展

利用有机垃圾产氢的研究逐渐兴起,人们利用有机垃圾产氢既可以最大程度地使有机垃圾资源化,减少环境的污染,又可以通过无污染氢气的获得改善能源市场,缓解能源的压力．本文分析了国内外厌氧发酵产氢的技术现状：以厌氧发酵产氢的原理和机理入手,讨论微生物、发酵过程、过程参数等对产氢效率和速率的影响：最后还对厌氧发酵产氢的可行性进行研究．     

有机垃圾厌氧发酵产氢技术研究进展

分析了国内外厌氧发酵产氢的技术现状;从厌氧发酵产氢的原理和机理入手,讨论微生物、发酵过程、过程参数等对产氢效率和速率的影响;还对厌氧发酵产氢的可行性进行研究.     

有机垃圾厌氧发酵产氢技术研究进展

利用有机垃圾产氢的研究逐渐兴起,人们利用有机垃圾产氢既可以最大程度地使有机垃圾资源化,减少环境的污染,又可以通过无污染氢气的获得改善能源市场,缓解能源的压力。本文分析了国内外厌氧发酵产氢的技术现状;以厌氧发酵产氢的原理和机理入手,讨论微生物、发酵过程、过程参数等对产氢效率和速率的影响：最后还对厌氧发酵产氢的可行性进行研究。     

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。     

2-硝基酚厌氧毒性和厌氧降解性研究

在中温(35±1)℃厌氧条件下,采用间歇试验方法,研究了2-硝基酚的厌氧毒性和厌氧降解性。厌氧毒性试验结果表明,2-硝基酚的质量浓度小于96mg/L时,对产甲烷菌几乎没有抑制作用,质量浓度界于131mg/L和163mg/L之间时产生轻度抑制,质量浓度大于或等于553mg/L时产生重度抑制。反应时间为24h时2-硝基酚的80%、50%、20%相对抑制质量浓度分别为155、270和690mg/L。厌氧降解性试验结果表明,污水处理厂一级厌氧消化池污泥对2-硝基酚的处理效果好于ABR反应器和UASB反应器的污泥。用污水处理厂一级厌氧消化池污泥作为接种污泥,以葡萄糖为共基质,处理2-硝基酚的效果比用乙酸钠为共基质更好。     

A simple rate model for the dynamics of immobilization of anaerobic bacteria on a plastic support

The dynamics of biofilm formation on polyethylene bioparticles in mesophilic anaerobic conditions, using an inverse fluidized bed as immobilization system, have been studied. The immobilization process was carried out using acetate and glucose as carbon sources. Scanning electron microscopy (SEM) showed cocci cells and Methanosaeta rods embedded into an exopolimeric substances (ESP) matrix. The acetoclastic activity was found to increase as soon as the lag biomass accumulation phase ended. The rate of immobilization was found to conform to a pseudo first order kinetics with good correlation. This kinetic model was used to estimate rate and equilibrium constants for the immobilization process. Rate properties have been explained in terms of attachment and detachment processes. © 2000 Society of Chemical Industry     

3株厌氧产电菌的分离与特性

采用Hungate厌氧菌培养技术从微生物电解池（MEC）中分离得到3株厌氧产电菌Z1、Z2和Z3。16S rDNA基因测序和系统发育树构建结果表明,Z1属于柠檬酸杆菌属（Citrobacter）,Z2和Z3属于梭菌属（Clostridium）。生理生化特性研究表明,Z1为兼性厌氧菌,Z2和Z3为严格厌氧菌;3种菌株能够耐受较酸的pH值条件,在pH值为5～7.5的环境中增殖良好;Z1的最适生长温度为35 ℃,Z2和Z3的最适生长温度为30 ℃;3种菌株的最适NaCl浓度为0.1%～2.0%;均能以蔗糖、淀粉、丙酸钠、乙酸钠等为碳源生长。产电活性测试试验表明,3种菌株在?0.29 V时具有较大还原峰,氧化峰不明显,适用于微生物燃料电池（MFC）的阴极。在MFC的启动试验中,加入3种菌株的混合物后,可显著缩短其启动周期,同时产电效能提高了18.1%。     

污泥厌氧消化系统的启动与调试

上海市白龙港污水处理厂污泥厌氧消化工程包括八座单体容积为12400m^3的卵形污泥厌氧消化池。结合厌氧消化工艺的原始培养、接种和加大接种量等实践,稳步实现八座卵形消化池启动;通过调节,实现厌氧消化系统的稳定运行。该文结合厌氧消化装置特性和自身实际情况,对厌氧消化系统各阶段的操作调节与控制进行了技术分析。     

A systematic approach for preferential crystallization of 4-hydroxy-2-pyrrolidone: Thermodynamics, kinetics, optimal operation and in-situ monitoring aspects

A systematic approach has been developed and applied to the preferential crystallization of 4-hydroxy-2-pyrrolidone in isopropanol. The concept of critical supersaturation control was introduced for preferential crystallization process. System thermodynamics, crystallization kinetics, optimal operation and in-situ monitoring were combined and integrated to establish the strategy for the critical supersaturation control. Subsequently, the solubility and metastable zone widths of 4-hydroxy-2-pyrrolidone with different compositions in isopropanol under different cooling rates were determined using an automatic lab reactor (Mettler Toledo LabMax) system equipped with Lasentec Focused Beam Reflectance (FBRM) probe. The crystal nucleation and growth kinetics were measured with s-plane analysis. A modified technique was proposed for size-dependent crystal growth. Based on the thermodynamics properties and crystallization kinetics, a simplified cooling profile was proposed and applied to the critical supersaturation control. The final product's high optical purity, good crystal size distribution, SEM imagines and the in-situ observations, all suggested that the critical supersaturation control was essential and the systematic approach was successful and applicable for preferential crystallization.     

Analysis of disuiphide bridge function in recombinant bovine prolactin using site-specific mutagenesis and renaturation under mild alkaline conditions: a crucial role for the central disuiphide bridge in the mitogenic activity of the hormone

We have previously described a method for isolating Escherichiacoli-produced methionyl bovine prolactin (Met-bPRL) and itsrenaturation using thioredoxin. This report describes an alternativerenaturation procedure in which extracted Met-bPRL is incubatedin air at pH 10 and 20°C. Within 1 h of such treatment essentiallyall of the reduced Met-bPRL was converted to the oxidized form;this was accompanied by an increase to full mitogenic activityin the Nb2 cell bioassay. It was also found that, to minimizecontamination by high mol. wt Met-bPRL derivatives, it is essentialto have a reducing agent (dithiothreitol) present during disruptionof the bacteria and to extract the protein at neutral pH. Thecontribution of each of the three disuiphide bridges in bPRLto its bioactivity was studied with Met-bPRL variants, preparedvia site-specific mutagenesis, in which cysteines were replacedby serines to prevent disulphide bond formation. Variants lackingthe C4–C11 bridge, the C191–C199 bridge or boththese terminal bridges were as mitogenic as authentic bPRL.(Variants lacking the C191–C199 bridge had markedly increasedsolubility in the presence of deoxycholate.) In contrast, variantslacking the C58–C174 bridge had greatly reduced bioactivity,indicating that integrity of the large disulphide loop is crucialto the hormone's mitogenic activity.