Hydrogen Production with High Evolution Rate and High Yield by Immobilized Cells of Hydrogen-producing Bacteria Strain B49 in a Column Reactor

To improve the hydrogen evolution rate in continuous hydrogen production of a fermentative hydrogen-producing bacteria strain B49 (AF481148 in EMBL), 4% immobilized cells by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate in a column reactor obtain hydrogen yield of 2.31 mol H2/mol glucose and hydrogen evolution rate of 1435.4 ml/L culture&middoth respectively at medium retention time of 2 h with a medium containing l0 g glucose/L. As the cell density in gel beads is increased to 8%, hydrogen yield and hydrogen evolution rate for l0 g glucose/L are 2.34 mol H2/mol glucose and 2912.4 ml/L culture &middot h respectively at medium retention time of 1 h, and for molasses wastewater COD of 7505.9 mg/L hydrogen production potential of 205.6 ml/g COD and hydrogen evolution rate of 2057.7 ml/L culture&middoth at hydraulic retention time of 0.75 h are observed. In the continuous culture pH value keeps around 3.9 by self regulation.

Comparative analysis of hydrogen-producing bacteria and its immobilized cells for characteristics of hydrogen production

A strain of hydrogen producing bacteria was immobilized by polyvinyl alcohol-boric acid method, with the addition of a small amount of calcium alginate. The immobilized cells were insensitive to the presence of traces of O2. Moreover, the immobilized cells increased both the evolution rate and the yield of hydrogen production. Batch experiments with a medium containing 10 g/L glucose demonstrated the yields of hydrogen production by the immobilized and free cells were 2.14 mol/mol glucose and 1.69 mol/mol glucose, respectively. In continuous cultures at medium retention time of 2.0 h, the yield and the evolution rate of hydrogen production by the immobilized cells were 2.31 mol/mol glucose and 1 435.4 ml/（L·h） respectively. However, at medium retention time of 6.0 h, the yield and the evolution rate of hydrogen production by free cells were only 1.75 mol/mol glucose and 362.9 ml/（L·h）, respectively.

Improvement of Taihu water quality by the technology of immobilized nitrogen cycle bacteria

Experimental studies were carried out on the purification of eutrophicTaihu Lake water by dynamic experiment using immobilized nitrogen cycle bacteria(INCB). The results showed that the eutrophic water of Taihu Lake can be purifiedeffectively as it passes through the experimental reactor into which some immobilizednitrogen cycle bacteria were put. The removal efficiencies for Total N (TN), NH4+-Nwith immobilized nitrogen cycle bacteria were 72.4% and 85.6%, respectively. It wasfound that the immobilized nitrogen cycle bacteria also have purificatory effect oneutrophic water of Taihu Lake at winter temperature (7°C), and that the removalmefficiencies for Total N (TN), NH4+-N were 55.6%, and 58.9%, respectively. Theremoval efficiencies for TN and NH4+-N depend on the time the water stays in theexperimental reactor.

Restaurant emissions removal by a biofilter with immobilized bacteria

Pseudomonas sp. ZD8 isolated from contaminated soil was immobilized with platane wood chips to produce packing materials for a novel biofilter system utilized to control restaurant emissions. The effects of operational parameters including retention time, temperature, and inlet gas concentration on the removal efficiency and elimination capacity were evaluated. Cri- teria necessary for a scale-up design of the biofilter was established. High and satisfactory level of rapeseed oil smoke removal efficiency was maintained during operation and the optimal retention time was found to be 18 s corresponding to smoke removal efficiency greater than 97%. The optimal inlet rapeseed oil smoke loading was 120 mg/(m3?h) at the upper end of the linear cor- relation between inlet loading and elimination capacity.

Preservation Property and Decay Kinetic of Polyurethane Immobilized Nitrifying Bacteria Pellets

The preservation methods of polyurethane immobilized nitrifying bacteria pellets which had been enriched in laboratory were provided. Factors such as temperature, pH and light, which affect the nitrification activity of polyurethane immobilized pellets, were investigated. The result showed that dark, deionized water and low temperature is suitable for polyurethane immobilized nitrifying bacteria pellets’ long term preservation.

Treatment of Agate Dyeing Wastewater Using an Immobilized Gel Mixture with Nano-Fe_(3)O_(4) Sulfate-Reducing Bacteria

To solve the problems of high Cr^(6+),Cr^(3+),SO_(4)^(2-)and H+concentrations,pollution and processing costs associated with agate dyeing industrial drainage,we prepared an immobilized gel mixture for the treatment of such drainage on the basis of microbial immobilization technology.The immobilized gel mixture was composed of sulfate-reducing bacteria(SRB),corn cob,and nano-Fe_(3)O_(4)(nFe_(3)O_(4)).We used a single-factor experiment to determine the optimal dose of each matrix component.We analyzed the mechanism underlying the treatment of agate dyeing wastewater with an immobilized gel mixture by X-ray diffraction and scanning electron microscopy detection.The results of the single-factor test showed that the best treatment was obtained under the following conditions for each matrix component:SRB mass percentage of 30%,nFe_(3)O_(4) dose of 3%,and corn cob mesh size of 100 and dose of 3%.On this basis,we conducted an L9(34)orthogonal experiment to determine the optimal proportion of each matrix component.The results showed that the best treatment was obtained when the gel mixture met the following conditions:SRB mass percentage of 40%,nFe_(3)O_(4) dose of 4%,and corn cob dose of 1%and mesh size of 100.Accordingly,the SO_(4)^(2-),Cr^(6+)and Cr^(3+)removal rates from the agate dyeing drainage were 70.54%,84.75%,and 73.80%,respectively;the total Fe and chemical oxygen demand releases were 1.086 mg·L^(-1)and 1104 mg·L^(-1),respectively;and the pH was 6.27.The gel mixture had the best treatment effect on agate dyeing wastewater under this composition ratio.

Composite Mesh Electrodes with Immobilized Bacteria for Bio-Batteries

An anode was constructed using a novel technique and subsequently tested in a bio-battery. The anode comprised of a composite electrode coated with immobilized bacteria. The immobilized bacteria used in this study were Escherichia coli K-12. The composite electrode contained three layers: a 304 L stainless steel mesh base, an electro-polymerized layer of pyrrole, and an electro-polymerized layer of methylene blue. The bacteria were immobilized utilizing a technique incorporating a carbon nanoparticle and TeflonTM emulsion. The composite electrode combined with immobilized bacteria was examined whilst incorporated into the anodic chamber of a bio-battery. Different tests were conducted, including Electrochemical Impedance Spectroscopy. Results from these tests were compared with data obtained from alternate configurations and values from the open literature. The maximum power density generated by the composite electrode with immobilized bacteria whilst incorporated into the anodic chamber of a bio-battery was 378 mW/m2. Results demonstrate this composite anode configuration with immobilized bacteria produced approximately 69% more power density and 53% more current density than alternate electrode configurations with bacteria suspended in solution. Also, it was found that a significant portion of the bio-battery’s resistance to charge transfer occurred at the surface of the anode and this resistance was lowered by 51% through bacteria immobilization.

Removal of Nitrogen, Phosphorus, and Organic Pollutants From Water Using Seeding Type Immobilized Microorganisms

Objective To study the possibility of removing nitrogen, phosphorus, and organic pollutants using seeding type immobilized microorganisms. Methods Lakes P and M in Wuhan were chosen as the objects to study the removal of nitrogen, phosphorus, and organic pollutants with the seeding type immobilized microorganisms. Correlations between the quantity of heterotrophic bacteria and the total nitrogen （TN）, total phosphorus （TP）, and total organic carbon （TOC） in the two lakes were studied. The dominant bacteria were detected, inoculated to the sludge and acclimated by increasing nitrogen, phosphorus and decreasing carbon source in an intermittent, time-controlled and fixed-quantity way. The bacteria were then used to prepare the seeding type immobilized microorganisms, selecting diatomite as the adsorbent cartier. The ability and influence factors of removing nitrogen, phosphorus, and organic pollutant from water samples by the seeding type immobilized microorganisms were studied. Results The coefficients of the heterotrophic bacterial quantity correlated with TOC, TP, and TN were 0.9143, 0.8229, 0.7954 in Lake P and 0.9168, 0.7187, 0.6022 in Lake M. Ten strains of dominant heterotrophic bacteria belonging to Pseudomonas, Coccus, Aeromonas, Bacillus, and Enterobateriaceae, separately, were isolated. The appropriate conditions for the seeding type immobilized microorgansims in purifying the water sample were exposure time=24 h, pH=7.0-8.0, and quantity of the immobilized microorganisms=0.75-1g/50 mL. The removal rates of TOC, TP, and TN under the above conditions were 80.2%, 81.6%, and 86.8%, respectively. Conclusion The amount of heterotrophic bacteria in the two lakes was correlated with TOC, TP, and TN. These bacteria could be acclimatized and prepared for the immobilized microorganisms which could effectively remove nitrogen, phosphorus, and mixed organic pollutants in the water sample.

The Feasibility of Immobilization of Bioflocculant-producing Bacteria Using Mycelial Pellets as Biomass Carriers

Bioflocculant-producing bacteria Agrobacterium tumefaciens F2 and Bacillus sphaeicus F6 were immobilized onto mycelial pellets to investigate the bioflocculant-producing potential of this combined organism and the corresponding flocculating efficiency. The atomic force microscope ( AFM) images of mycelial surface indicate that the mycelia pellet can immobilize bioflocculant-producing bacteria F2 and F6 as a biomass carrier. The flocculating efficiency of bioflocculant produced by this combined organism was studied under the optimum flocculating conditions obtained by Response Surface Methodology ( RSM ) . The fermentation yield of the combined mycelial pellet is about 2. 6 g / L,which is higher than that of the free bacteria ( only 2. 2 g / L) . Flocculating efficiency of the combined mycelial pellet was comparable with that of bioflocculant generated by the free bacteria. The bioflocculant yield is enhanced and the flocculating efficiency of the co-culture is uninfluenced after immobilized with mycelial pellet as a carrier. In conclusion,the mycelial pellet is feasible as a biomass carrier for the immobilization of bioflocculant-producing bacteria.

Simultaneous removal of cesium and strontium using a photosynthetic bacterium, <i>Rhodobacter sphaeroides</i>SSI immobilized on porous ceramic made from waste glass

This study investigated practical and simultaneous removal of cesium (Cs, initial concentration of 5 mg/L) and strontium (Sr, initial concentration of 5 mg/L) using a photosynthetic bacterium, Rhodobacter sphaeroides SSI, immobilized on recovery-type porous ceramic made from glass waste. When 4 - 8 pieces /L of SSI immobilized ceramic were added to synthetic sewage wastewater containing glucose, almost 100% of Cs and 57% - 61% removal of Sr was observed after 3 day’s aeration treatment. The high potassium (K) concentration in wastewater suppressed Cs removal, but did not affect Sr removal. Other substrates such as lactic, acetic, and propionic acids were useful for Cs and Sr removal. But, removal efficiencies were lower than about 50%. When the practical outdoor removal experiment carried out using1 m3 vessel, almost 100% of Cs and 51% of Sr were removed like a laboratory experiment after 3 day’s aerobic treatment. After treatment, the SSI immobilized ceramic was recovered easily from water using an electromagnet. This SSI immobilized ceramic seem to remove radioactive Cs and Sr from water environments of Fukushima,Japan.

Removal of Radioactivity from Sediment Mud and Soil and Use for Cultivation of Safe Vegetables in Fukushima, and Removal of Toxic Metals Using Photosynthetic Bacteria

The immobilized photosynthetic bacterium, Rhodobacter shpaeroides SSI (SSI), cultured on porous 2 cm ceramic beads, effectively removed and recovered 20 mg/L of non-radioactive Cs (almost 100%) and Sr (≌50%), after 3 - 5 days of aerobic treatment. Toxic and heavy metals such as Hg, Cr, Pb and As were also removed, almost 100%, after 6days of aerobic treatment. A practical method of removal of radioactivity of 10 - 30 μSv/h, caused mainly by radioactive Cs released from the accident at the Daiichi Nuclear Power Plant on 11th March 2011, from sediment mud and soil in Fukushima, Japan, was also carried out. Using immobilized SSI beads, more than 90% and 42% - 73% of radioactive Cs was removed and recovered from sediment mud and soil, respectively, after 3 - 14 days of aerobic treatment in an outdoor 60 L vessel. The weight and mass of the harvested beads could be reduced by more than 97% after desiccation. This technology of removal and recovery had therefore, considerable advantages over other technologies that demanded very large storage facilities in Fukushima. After removal of radioactivity from polluted soil, vegetables like Komatsuna (Turrip leaves) and Chingensai (Green pakchoi) were cultivated on remediated soil. Safe vegetables grown on these treated soils showed a radioactivity content lower than the recommended limit for edible foods in Japan, i.e. less than <100 Bq/kg. Treatment by SSI beads, therefore, appeared to be a compact and suitable technology that could make significant contributions towards agricultural recovery in radioactively polluted areas of Fukushima.

高效烃降解菌群的驯化、降解特性及初步应用

微生物技术在石油污染土壤的修复中具有广阔的应用前景,而获得具有高降解效率的菌(菌群)是保证高效修复的关键。该研究从4种不同含油土壤中驯化、培养获得稳定、高效降解石油烃的1号菌群,对其进行高通量测序,确定菌群组成;研究不同环境因素对该菌群石油烃降解能力的影响,确定了最佳降解条件;对菌群降解石油烃的特性和降解动力学进行了分析;探究了该菌群在较高浓度含油土壤中的应用潜力,以及以破碎荞麦壳为载体,将菌群固定化后修复石油烃-镉复合污染土壤的能力。结果表明,该菌群主要由寡养单胞菌属(Stenotrophomonas)、假单胞菌属(Pseudomonas)、苍白杆菌属(Ochrobactrum)、乳杆菌属(Lactobacillus)和无色杆菌属(Achromobacter)等组成;在原油质量浓度为0.5%,p H为8,盐度为1%,温度为35℃,C∶N∶P为100∶2∶1,以硝酸铵为氮源的最佳条件下,培养10 d后,菌群对石油的降解率由52.1%提高至76.6%;GC-MS分析结果显示,培养9 d和24 d后菌群对C13~C26烷烃平均降解率分别为90.3%和97%,说明该菌群能够快速高效降解中长链烷烃。菌群对原油初始浓度为0.5%和4%的降解符合一级反应动力学模型。将菌群接种于石油含量为4 631 mg/kg、8 591 mg/kg的土壤中,40 d后降解率分别为47.7%、26.4%;固定化后的菌群用于修复石油烃-镉复合污染土壤,石油烃降解率、土壤脱氢酶活性和过氧化氢酶活性高于其他组,可交换态镉的浓度低于其他组。以上结果充分显示了该菌群在石油浓度较高的土壤以及石油烃-镉复合污染土壤修复中的应用潜力。

净水污泥固定化硫氧化菌去除河道中AVS污染的试验研究

目的 研究净水污泥固定化硫氧化菌去除河道中的酸可挥发性硫化物污染方法,为净水污泥资源化利用提供一种新的思路。方法 通过高温焙烧的方法制备净水污泥固定化载体,采用XRD、SEM、BET对载体进行表征,使用净水污泥、绿沸石、活性炭3种载体对硫氧化菌进行固定化,分析其对底泥中AVS的去除效果以及固定化效果的影响,并通过高通量测序技术分析其对微生物种群变化的影响。结果 净水污泥固定化载体的最佳焙烧温度为600℃,无论是单一载体,还是固定化硫氧化菌,净水污泥组对于AVS的去除效果均要优于绿沸石和活性炭;同时硫氧化菌在温度为30℃、pH=6、固定化时间为24 h条件下的固定化效果最好;净水污泥固定化硫氧化菌的加入有利于降解硫化物优势菌种的群居,抑制了硫酸盐还原菌的生长繁殖。结论 净水污泥固定化硫氧化菌能有效去除河道中的AVS污染,降低底泥生物种群的多样性,有利于去除AVS优势菌种的群聚,抑制硫酸盐还原菌的繁殖,促进水体黑臭环境的改善。

固定化菌藻填料强化人工湿地去除营养盐和PFOS效果研究

针对全氟辛烷磺酸(Perfluorooctane Sulfonate, PFOS)污染现状,开展3种人工湿地去除复合污染水体中营养盐和全氟辛烷磺酸的效果研究。选取普通垂直流人工湿地(Constructed Wetlands, CW)、固定化菌人工湿地(Immobilized Bacteria Constructed Wetlands, IB-CW)和固定化菌藻填料人工湿地(Immobilized Bacteria Algal Constructed Wetlands, IBA-CW)为研究对象,通过露天试验研究3种湿地在不同质量浓度PFOS下对水体中污染物的去除效果。结果显示,3种湿地对水体中的营养盐和PFOS均具有较好的去除能力,且PFOS对各营养盐的去除具有一定的影响。高质量浓度(100μg/L)PFOS抑制风车草生长,CW植物PFOS质量比达到试验最高值,为(100.56±3.28)μg/g, IB-CW和IBA-CW风车草的总生物量分别比CW增加了10.73%和18.52%。低质量浓度(1μg/L)PFOS促进风车草的生长,IBA-CW风车草总生物量达到了试验最高值,与未加PFOS的处理组相比,生物量增长了16.05%。在高质量浓度PFOS胁迫下,3种人工湿地化学需氧量(Cemical Oxygen Demand, COD)、NH3-N、总氮(Total Nitrogen, TN)和总磷(Total Phosphorus, TP)的去除效果均有所降低。其中,与对照组(无PFOS)相比,IBA-CW对COD、NH3-N、TN、TP的去除率分别降低了(4.23±0.21)百分点、(10.50±0.45)百分点、(13.33±0.51)百分点和(6.87±0.25)百分点,比其他两种湿地降幅小。3种人工湿地均可以有效去除废水中的PFOS,IBA-CW对PFOS的去除率优于CW和IB-CW。3种人工湿地中填料吸附占比均大于植物占比,IBA-CW中填料贡献率比CW高12.90百分点,比IB-CW高5.51百分点。

Nitrification performance of nitrifying bacteria immobilized in waterborne polyurethane at low ammonia nitrogen concentrations

Suspended and waterborne polyurethane immobilized nitrifying bacteria have been adopted for evaluating the effects of environmental changes, such as temperature, dissolved oxygen （DO） concentration and pH, on nitrification characteristics under conditions of low ammonia concentrations. The results showed that nitrification was prone to complete with increasing pH, DO and temperature. Sensitivity analysis demonstrated the effects of temperature and pH on nitrification feature of suspended bacteria were slightly greater than those of immobilized nitrifying bacteria. Immobilized cells could achieve complete nitrification at low ammonia concentrations when DO was sufficient. Continuous experiments were carried out to discuss the removal of ammonia nitrogen from synthetic micropollute source water with the ammonia concentration of about 1mg/L using immobilized nitrifying bacteria pellets in an up-flow inner circulation reactor under different hydraulic retention times （HRT）. The continuous removal rate remains above 80% even under HRT 30 min. The results verified that the waterborne polyurethane immobilized nitrifying bacteria pellets had great potential applications for micro-pollution source water treatment.

磁性炭基菌球降解土壤阿特拉津性能的研究

本研究通过海藻酸钠包埋磁性生物炭与降解菌DNS32形成磁性炭基菌球(DMBC-P),并将其用于阿特拉津(ATZ)污染土壤的修复,探讨其去除ATZ的效能及促进大豆幼苗生长的能力。研究表明,当海藻酸钠与氯化钙的浓度为2%时,DMBC-P对ATZ的去除能力最强。在DMBC-P投加量为2%、温度为30℃、pH=7.3时,其对水体中ATZ的去除率可达到99.99%;并且在pH为3.3~7.3、温度为10~50℃以及ATZ浓度为30~140 mg·L^(-1)的环境中,DMBC-P对ATZ的去除性能仍然十分优异且其可以被有效回收。盆栽试验结果表明,施用DMBC-P进行修复后,该处理下大豆幼苗的生理指标显著高于空白对照处理,叶绿素a、叶绿素b、类胡萝卜素和总叶绿素含量分别提高79.14%、45.48%、67.87%和110.78%。研究表明,DMBC-P施用于污染土壤中能够实现ATZ的高效去除和材料有效回收,是一种极具潜力的污染土壤修复材料。

石油降解菌株的生物炭固定化及性能研究

固定化菌剂是一种理想的有机污染物降解材料。以壳基生物炭作为载体,高效石油降解菌为目标微生物,采用吸附法制备固定化石油降解菌剂。探究菌接种量、炭投加量、时间、温度和摇床转速对固定率的影响,通过正交试验和响应面分析法确定菌剂最佳制备条件。以投加量和石油质量分数为变量,考察生物炭、游离菌和固定化菌剂的除油性能。结果显示:0.3 g炭投加量、2.26 mL菌接种量、8.462 h固定、转速为38.331 r/min、30℃,此条件下固定率最佳,可达87.261%。影响固定率的主次因素为:菌接种量>摇床转速>固定化时间>炭投加量。该固定化菌剂对石油整体降解能力在74%—84%,优于游离菌及生物炭对石油的降解效果,表明固定化菌剂对于石油污染土壤的生物修复具有较好的应用前景。

壳聚糖固定化石油烃降解菌的降解性能研究

本研究以筛选获得的一株石油烃降解菌HYHG-06为研究对象,选择壳聚糖为固定化载体材料,戊二醛为交联剂,通过交联反应固定化制备壳聚糖固定化石油烃降解菌;通过改变降解环境的温度、初始pH、盐度及石油烃浓度,探究4个因素对石油烃降解菌降解性能的影响。结果表明,固定化菌的降解性能优于游离菌,在温度30℃、初始pH8.0、盐度3.5%、石油烃浓度1.5%的环境条件下,固定化菌的石油烃降解率高达86.62%,可开发高效消油产品,为海上石油污染提供了一种高效可行的生化处理方法。

Systematic degradation mechanism and pathways analysis of the immobilized bacteria:Permeability and biodegradation,kinetic and molecular simulation

In order to effectively improve the degradation rate of diesel,a systematic analysis of the degradation mechanism used by immobilized bacteria is necessary.In the present study,diesel degradation mechanisms were assessed by analyzing permeability,biodegradation,adsorption kinetics,and molecular simulation.We found that bacteria immobilized on cinnamon shells and peanut shells degraded relatively high amounts of diesel(69.94%and 64.41%,respectively).The primary degradation pathways used by immobilized bacteria included surface adsorption,internal uptake,and biodegradation.Surface adsorption was dominant in the early stage of degradation,whereas biodegradation was dominant in later stages.The diesel adsorption rate of the immobilized bacteria was in agreement with the pseudo second-order kinetic model.The immobilized bacteria and diesel interacted through hydrogen bonds.

铅污染矿区中耐铅解磷菌对玉米的促生及根际铅的固化效应

矿产资源的开采、冶炼活动造成了一定的生态环境问题,土壤中可溶性重金属随着地表径流和地下渗透造成矿区和周边农田重金属污染。而矿区中土壤微生物对重金属具有一定耐性,研究微生物对植物根际微生态环境的改善作用具有重要意义。在矿区废弃地土壤中筛选耐铅(Pb)解磷菌的基础上,将含有菌株分泌物的上清液、菌液、发酵液(上清液+菌株)分别施用到玉米(Zea mays L.)根际土壤中,对比三者对玉米的促生效果及根际土壤铅的形态变化,探究解磷菌对玉米的促生机制及其对土壤铅的固化作用。所筛菌株被鉴定为巴氏克雷伯菌(Klebsiella pasteurii),其通过分泌乙酸、乳酸、酒石酸和草酸对Ca3(PO4)2的溶磷率为26.5%,并能分泌生长素(IAA)。在玉米根际土壤中施用菌株的上清液、菌液和发酵液后,较对照组玉米株高、茎直径、地上与地下生物量均显著增加,其中施用发酵液组增幅最高,较对照组分别增加了128%,216%、266%、147%。同时,3个处理组中玉米地上生物量中铅含量分别降低68.6%、58.1%、70.1%,地下部铅含量分别降低119%、36.7%、39.5%。施用菌株上清液、菌液和发酵液后均使玉米根际土壤中可溶态的铅向稳定态铅转化,这可能是巴氏克雷伯菌在解离土壤磷素的过程中,其解离的磷可能与铅形成稳定态的磷铅化合物,进而降低植物对铅的吸收。由此可以得出,在铅污染土壤中巴氏克雷伯菌能够显著固化重金属铅并抑制玉米对铅的吸收,对玉米具有促生作用,因此,巴氏克雷伯菌在土壤重金属修复和保障农作物食品安全方面具有重要价值。