456 resultados para 237
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本文主要研究了从造纸厂碱性土壤中筛选得到的,能够产生耐碱木聚糖酶的两株放线菌X24-14和X15-17。通过16 S rRNA基因序列分析并结合菌株的形态特征以及生理生化特性,初步认为菌株X15-17为拟诺卡氏菌属(Nocardiopsis)的一个潜在新种;菌株X24-14为纤维化纤维菌(Cellulosimicrobium cellulans)。 在此基础上探索了菌株X24-14和菌株X15-17所产木聚糖酶的基本酶学性质。研究发现,两株菌所产的木聚糖酶的耐碱性均较强: 1)菌株X24-14所产的木聚糖酶,在pH 4.2~9.4的范围内能维持较高的活力,pH 9.4条件下,仍能保持80%的酶活力;2)菌株X15-17所产的木聚糖酶在pH 4.0~9.0的范围内能维持较高的活力,pH 9.0条件下,仍能保持80%的酶活力;3)两株菌所产的木聚糖酶均具有较好的pH稳定性,在pH 2.0~11.0范围内稳定,pH 11.0、4 ℃条件下处理24 h仍具有75%的活力。 本文还重点研究了菌株X24-14在不同培养基成分及不同培养条件下的产酶情况,确定了其适宜的产酶条件。结果显示,菌株X24-14的最适碳源为麸皮;最适氮源为蛋白胨;最适产酶pH为pH 8.5。菌株X24-14适宜的产酶条件为:麸皮60 g/L,蛋白胨10 g/L,K2HPO4 7.0 g/L,pH 8.5,接种量为5%,37 ℃,200 r/min发酵培养108 h。 Two strains of actinomycetes, X24-14 and X15-17, which produced alkali-tolerant xylanase were screened from the soil samples collected from a pulp mill in china. Based on the morphological, physiochemical characteristics and 16S rRNA sequence, X24-14 was priminarily identified as cellulosimicrobium cellulans ; X15-17 was priminarily identified as a new species of Nocardiopsis. The investigation examined the enzyme activities which produced by X24-14 and X15-17 under different pH and different temperatures. The results showed that : 1)The xylanase from X24-14 had characteristic of alkali-tolerance: It remains 80% relative activity at pH ranges between pH 4.2 and pH 9.4 under 50℃. 2)The xylanase from X15-17 also showed characteristic of alkali-tolerance, it remains 80% relative activity at pH ranges between pH 4.0and pH 9.0 under 50℃. 3)The xylanase from the two strains showed alkali-stable characteristics. They were stable at pH ranges between pH 2.0 and pH 11.0, showing 75% of its maximal activity remaining under 24 hours of treatment at 4℃. We also studied the effect of different growth conditions: carbon source, nitrogen sources, inoculum size, and initial pH on the production of xylanase of strain X24-14. The results showed that :The optimal carbon source was wheat bran; The optima nitrogen source was peptone; The maximum xylanase activity was achieved in the medium containing 60 g/L wheat bran, 10 g/L peptone, 7 g/L K2HPO4, inoculum size 5% and pH 8.5, under 37℃ in 108 h.
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捷安肽素是一种由枯草芽孢杆菌(Bacillus subtilis)ZK 产生的抗真菌多肽。本文以柑桔青霉菌(Penicillium italicum)和绿霉菌(Penicillium digitaum)为供试真菌,研究了捷安肽素的抑菌性能及作用机理,为捷安肽素开发为有效的生物杀菌剂提供理论依据。全文共分两部分:第一部分:捷安肽素对柑桔青霉菌和绿霉菌抑制效果研究。采用琼脂扩散法测定捷安肽素对柑桔青霉菌和绿霉菌的抑菌活性。53.9 µg/mL 捷安肽素对绿霉菌和青霉菌的抑菌圈直径分别为26.7mm 和24.1mm。结果表明捷安肽素能够抑制柑桔青绿霉菌的生长,柑桔绿霉菌比青霉菌对捷安肽素敏感。在柑桔果实上,研究了不同浓度、不同接入时间的捷安肽素对柑桔青霉病和绿霉病的防治效果,并与常用化学杀菌剂抑霉唑、咪鲜胺、甲基硫菌灵和多菌灵作比较。53.9 µg/mL捷安肽素处理柑桔果实,柑桔青霉病和绿霉病发病率分别为5.0 %和5.3 %,比对照低95.0 %和94.7 %;柑桔青霉病和绿霉病的病情指数分别为1.87 和2.18,比对照低73.73 和97.82。结果表明,捷安肽素能够有效地防治柑桔青绿霉病。与对照相比,捷安肽素先于或后于柑桔青绿霉菌接入时,对柑桔青绿霉菌均有抑制作用,但抑制效果随接入间隔时间的增长而降低。第二部分:捷安肽素对绿霉菌作用机理研究。首先在光学显微镜和透射电镜下观察捷安肽素处理后绿霉菌菌丝表面形态结构与菌丝体内超微结构的变化。形态观察发现,捷安肽素处理24h以内,绿霉菌菌丝结构无变化。捷安肽素作用36h后,绿霉菌菌丝不规则缢缩和膨大。48h后,在绿霉菌菌丝顶端、中部、末端的多处细胞均可发生畸形的球状结构,这种畸变结构随处理的延长而增加,致使细胞成为捻珠状。处理72 h后,畸变球形细胞开始断裂离解。处理96h后,镜下几乎无完整菌丝,成单个的球状细胞,部分细胞出现破裂。而对照菌丝表面光滑,结构完整。通过透射电镜观察发现,与对照相比,捷安肽素处理后,绿霉菌细胞壁、细胞膜轮廓模糊不清,细胞质外泄。推测捷安肽素能够使绿霉菌细胞膜通透性发生改变。进一步实验利用紫外-可见分光光度计检测捷安肽素作用后绿霉菌胞外液紫外吸光度的变化,表明捷安肽素作用于绿霉菌菌丝后,细胞内蛋白质、核酸缓慢泄漏。通过Atomscan Advantage单道扫描等离子体发射光谱仪(ICP)测定捷安肽素作用后菌丝体内K+浓度的改变,结果表明捷安肽素作用于柑桔绿霉菌1h内,菌丝体内K+含量迅速下降,为对照绿霉菌K+含量的37.53 %,1 h后菌丝体内K+含量变化趋于平缓。K+的迅速泄漏,以及蛋白质、核酸的泄漏表明捷安肽素通过迅速改变绿霉菌细胞膜通透性,使绿霉菌菌丝生长受到抑制。Jiean-peptide produced by Bacillus subtilis ZK has broad-spectrumresistance to plant pathogens. In this study, we investigated the antifungal propertyand the possible antifungal mechanism of jiean-peptide against two commonphytopathogenic fungi of citrus fruits: blue molds (P. italicum) and green molds (P.digitatum).The paper involved two parts:Part 1 is the study of the antifungal property of jiean-peptide against blue moldsand green molds of citrus fruits. The in vitro inhibition effect of jiean-peptide againstblue molds and green molds was detected by agar diffusion method. The diameters ofinhibition zones of green molds and blue molds are 26.7mm and 24.1mm respectivelyby treating with 53.9 µg/mL jiean-peptide. It shows that jiean-peptide effectivelyinhibits the both phytopathogenic fungi, and it is more effective for inhibiting greenmolds than blue molds. The effectiveness of jiean-peptde to inhibit green molds andblue molds in vivo was investigated compared with four conventional fungicides thatare imazalil, prochloraz, carbendazin and methylthiophanate. The result is that the incidences of the blue mold disease and green mold disease are 5.0 % and 5.3 %, thedisease severities are 1.87 and 2.18 respectively when citrus are inoculated with 53.9µg/ml jiean-peptide. The decay incidences and disease severities were significantlyreduced by treating with jiean-peptide compared with the control. The results indicateJiean-peptide is effective for controlling blue molds and green molds on citrus. Theoptimized inoculation time was also investigated. When inoculated with jiean-peptideat 0 h, 6 h, 12 h, 24 h and 48 h before or after pathogens’ inoculation, Jiean-peptidecan suppress the occurrence of blue molds and green molds compared with the control, but the effect of later inoculation decreases compared with the inoculation at the sametime.In Part 2, we investigated the possible antifungal mechanism against greenmolds of citrus. At first, we observed the exterior morphological changes andultrastructural changes of blue molds under light microscopy (LM) and transmissionelectron microscopy (TEM). Compared with untreated control cells which aregenerally uniform in shape, the appearances of treated hyphae change obviously. Itshows that some cells of hyphae irregularly shrink or enlarge when cultured for 36h.When the treating time of jiean-peptide increases, the aberrance of the hyphaebecomes more obvious, and hyphae exhibit the moniliform appearances. Finally, thereis no intact hypha leaved except only single cells, and some of which appear fractured.By transmission electron microscopy (TEM) observation, we find that the outline ofthe cell wall and the cell membrane of hyphae are blurry, and the cytoplasma oozesout. The observation result under LM and TEM suggests that jiean-peptide mightchange the permeability of the cell membrane. So we conducted further experiment todetect the change of permeability when the cells of blue molds were treated withjiean-peptide. And the effect of jiean-peptide on non-growing cells of blue molds wastested. By the spectrophotometer measurement, we found that compounds with lightabsorption at 260 nm and 280 nm were released and amounts increased within 12 hcompared with the control. Moreover, by the ICP measurement, the leakage of K+occurred immediately in the presence of jiean-peptide within 1 h, but with nearly nofurther change after 1 h. All these results indicate that jiean-peptide could change themembrane permeability of blue molds immediately and result in leaking nucleotides,proteins and K+ from cells.
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通过单因子和多因子摇瓶正交试验,确定了米曲霉液态发酵产氨基酰化酶的最佳发酵条件。优化发酵培养基组成(ρ/g L-1): 葡萄糖40,蔗糖10,可溶性淀粉20,蛋白胨2.5,马铃薯液1 000mL, pH自然。培养基装量50mL/250mL三角瓶,接种量4%。培养温度30℃,转速100 rmin-1,发酵时间42h。每50mL培养物的总酶活由优化前的2627U提高到7338U,是优化前的2.79倍。 研究了米曲霉氨基酰化酶的部分酶学性质,该酶催化反应的最适pH为7.0,最适温度为40℃,低浓度的Co2+(5×10-4mol/L)对酶活激活作用显著,催化反应过程中,底物浓度大于0.2 mol/L时,存在高浓度底物抑制酶活力现象。 初步探索了包埋法固定化米曲霉氨基酰化酶的载体,在实验的五种载体中,以海藻酸钠为载体包埋固定化米曲霉氨基酰化酶酶活保留率高,且操作简单,成本低廉。对包埋法固定化米曲霉氨基酰化酶酶学性质进行了研究,较游离米曲霉氨基酰化酶,最适温度未发生改变,最适pH向碱性范围偏移至8.0,对酸碱和热的稳定性增强,最适底物浓度增大到0.4 mol/L。 根据氨基酰化酶能立体专一水解L-氨基酰化物的特点,利用米曲霉氨基酰化酶对消旋苯丙氨酸进行了拆分。在米曲霉氨基酰化酶选择性的作用于底物N-乙酰-L-苯丙氨酸,得到L-苯丙氨酸后,通过732阳离子树脂和结晶法分别将L-苯丙氨酸和N-乙酰-D-苯丙氨酸分离,N-乙酰-D-苯丙氨酸通过酸水解脱去乙酰基得到D-苯丙氨酸,拆分得到光学纯度为98%的L-苯丙氨酸(收率84.8%)和光学纯度为92.3%的D-苯丙氨酸(收率89.5%)。 separate factors tests and orthogonal experiments,the optimum fermentation conditions of aminoacylase –producing Aspergillus oryzae were determined, as follows(ρ/g L-1),glucose 40,sucrose 10,soluble starch 20,peptone 2.5,potato juice 1000ml, inoculation volume 4%and fermentation temperature 30℃,rotation speed 100rmin-1.The highest total enzyme activity ,7338μ,was obtained after fermentation for 42 h, increased by 279% compared with the original value of 2627μbefore optimization. We dicussed partial characteristics of aminoacylase. The optimal pH and temperature of aminoacylase were 7.0 and 40℃ respectively. Low- concentration Co2+ (5×10-4mol/L)activated the aminoacylase remarkably while high-concentration substrate lowered the aminoacylase . Five vectors has been used for immobolizing the enzyme and calcium alginate showed to be the best one for it had the slightest influence on the enzyme activity, easy to operate ,and low in price, comparing with other fours. The enzymatic charateristic study showed that its optimum temperature didn’t change, but the optimum pH and substrat concentration were higher after immobilization. The stability of immobolized enzyme to acid, alkaline and heat rised as well. The aminoacylse from Aspergillus oryzae was used to resolute racemic phenylalanine to obtain D-phenylalanine. After catalyzing process, we took two methods to separate D-phenylalanine .In end,L-phenylalanine was obtained with 98% optical purity in 84.8% yield, D-phenylalanine was obtained with 92.3% optical purity in 89.5% yield.
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恶臭假单胞菌;异养硝化-好氧反硝化;自养硝化;生活污水脱氮;Pseudomonas putida;heterotrophic nitrification-aerobic denitrification;autotrophic nitrification;nitrogen removal for domestic wastewater treatment
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钻井废水是油气井开采钻探过程中产生的废水,钻井废水成分复杂,有机物浓度高、色度高、悬浮物浓度高,水质变化大,排放点分散,不经处理排放会污染环境,破坏生态。随着石油工业的不断发展和国家环保法律法规的日益严格,钻井废水的治理也越来越受到重视。如何采用经济有效的方法处理废弃钻井液,对油气井开采业的可持续发展具有重要意义。本论文以遂宁磨153 井的钻井废水为主要研究对象,在对废水进行絮凝沉降预处理和生物法处理探索的基础上,针对钻井废水可生化性差的特点,采用水解酸化和Fenton 试剂改善钻井废水的可生化性,对反应过程进行了比较详细的考察,对可生化性改善的机理进行了探索。主要研究结论如下:1 用PFS 和PAC 配制的混合混凝剂对钻井废水COD 的去除效果比较显著,在最佳条件下COD 的去除率可达75%,且絮体沉降速度较快,出水pH 保持中性;2 水解酸化法处理钻井废水可显著改善废水的可生化性。经48 小时水解酸化处理,钻井废水的理论BOD5可提高约22 倍,表观BOD5/COD值由0.004 提高到0.034。用接触氧化反应器处理经水解酸化处理后的废水,处理效果比较稳定,COD平均去除率达35.5%;3 研究了Fenton反应中各影响因子对废水COD去除率、BOD5/COD的影响并分析其作用机制,确定了最佳条件:初始pH为4.0,H2O2/Fe2+(摩尔浓度比)为20,H2O2/COD(质量浓度比)为1,反应时间为2 个小时。此条件下,废水的COD去除率约为40%,BOD5/COD值从0.002~0.003 提高至0.15~0.2,可生化性得到很大提高。本论文的主要创新点在于:1 以成分复杂、水质变化大的气井钻井废水为研究对象,从理论BOD 和表观BOD 两方面对水解酸化过程中废水可生化性的变化进行了分析;2 对Fenton 试剂改善钻井废水可生化性的过程、主要影响因素进行了比较详细的考察。本论文的研究成果,可为生物法处理钻井废水的深入研究提供理论依据。Drilling wastewater is produced in the process of oil-gas well drilling,because of its complicated composition, high concentrate of organic compound andsuspended solid, high chroma, levity of water quality and decentralization ofdischarge point, it pollutes environment seriously if discharged without treatment.With the development of petroleum industry and the issuing of more strict laws forenvironmental protection, it has been paid more and more attention on drillingwastewater treatment. It is of great importance for the sustainable development ofoil-gas well drilling to treat drilling wastewater by economical and effective methods.In this paper, drilling wastewater of Mo No.153 well in Suining was studied asthe main object. On the basis of research on pre-treatment with flocculant andbiological treatment, and according to the character of poor biodegradability, thedrilling wastewater was treated by hydrolytic acidification and Fenton’s reagent toimprove its biodegradability. The process and mechanism of biodegradabilitychanging were investigated. The primary conclusions are:1 It is effective to treat drilling wastewater with mixing PFS and PAC asflocculant. The removal rates of COD came up to 75% under optimal conditions, thesedimentation rate of flocculation is rapid, and the pH value of treated water remainedneutral;2 The biodegradability of drilling wastewater was highly improved afterhydrolytic acidification process. The theoretic BOD5 of drilling wastewater increasedby 22 times and its detected BOD5/COD ratio increased from 0.004 to 0.034 afterhydrolytic acidification for 48 hours. The wastewater after hydrolytic acidificationwas treated by biological contact oxidation reactor. Stable treatment performance was achieved, and the average removal rates of COD came up to 35.5%;3 The effects of various affection factors on the removal efficiency of COD andBOD5/COD radio in treating drilling wastewater by Fenton’s reagent wereinvestigated and the mechanism was analyzed. The optimal conditions were: initialpH of solution was 4.0, the molar ratio of H2O2 and Fe2+ was 20, the concentrationratio of H2O2 and COD was 1 and the reaction time was 120 min. Under the aboveconditions, the removal efficiency was about 40% and the ratio of BOD5 and CODincreased from 0.002 ¡« 0.003 to 0.15 ¡« 0.2. The biodegradability of drillingwastewater was greatly improved.The innovations of this thesis are:1 The drilling wastewater was taken as the research object which hascomplicated composition and variational water quality, and the changes ofbiodegradability were analyzed from theoretic BOD and detected BOD aspects duringhydrolytic acidification process;2 The biodegradability changing process and primary affection factors of drillingwastewater treating by Fenton’s reagent were investigated.The results of this study could provide theoretic foundation for further researchon biological treatment of drilling wastewater.
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本文叙述了影响甲烷氧化细菌沼气甲基产孢弧菌81Z菌株生长和甲烷单加氧酶(MMO)活性的若干因素。沼气甲基产孢弧菌81Z菌株细胞生长被高浓度PO43-(>8mM),NH4+([NH4cl]>500mg/l)抑制;[CuSO4·5H2O]在0~4mg/l范围内。生长随[Cu2+]升高而加强,低[Cu2+](0.1mg/l CuSO4·5H2O)培养基中,添加Cocl2·6H2O(0.238mg/l);促进菌体细胞生长。发酵罐分批培养过程中,生长延迟期过后,沼气甲基产孢弧菌81Z菌株细胞MMO比活很快达到最高,并稳定至对数生长中后期,随即急剧下降至初始水平。发现沼气甲基产孢弧菌81Z细胞中存在一种MMO活性,它不同于已报道过的两种MMO,MMOL最适PH6.2~6.4,4℃相对稳定,其产生不受培养基中[Cu2+]调控能与甲醇-甲醇脱氢酶系统相偶联,在无细胞抽提液中其活性被400μM[Cu2+]抑制。在低[Cu2+]发酵罐培养条件下,沼气甲基产孢弧菌81Z菌株产生可溶性MMC,其最适PH7.0,4℃不稳定,可被DE-52分离为三组分:A、B、C。为了获得沼气甲基产孢弧菌81Z细胞MMO的最佳催化活性,①采用高[Cu2+]培养基进行发酵罐培养,收集对数生长中期的细胞;②选择反应缓冲液PH6.3;③反应体系中添加5mM甲醇或甲酸是有效的方法。在本研究所采取过的最佳条件下,测得MMO活性为15.9nmol/min·mg干细胞,是以前报道的该菌株活性0.97nmol/min·mg干细胞的十六倍。Some factors which influence growth and MMO activity of Methylosporovibrio methanica 81Z were described. The growth of Methylosporovibrio methanica 81Z is inhibited by high concentration of PO43-(8mM)or NH4+(500mg/lNH4cl). The growth of Methylosporovibrio methanica 81Z increased with rising of copper concentration up to 4mg/l CuSO4·5H2O. At low copper concentration(0.1mg/lCuSO4·5H2O),adding Cocl2·6H2O(0.238mg/l)could enhance the growth of Methylosporovibrio methanica 81Z.With batch culture of Methylosporovibrio methanica 81Z in a fermentor, after lag phase, the activity of MMO reached the highest level rapidly and steady until later log phase, then falled to initial level.MMOL activity differenct from that of two types of MMO reported before was found from Methylosporovibrio methanica 81Z with optimum PH value from 6.2 to 6.4 and relative stabilty at 4℃. Synthsis of the MMOL was not regulated by copper concentaration in medium. Its activity could couple with methane-l-methanoldehydrogenase system, and in cell-free extract, were inhibited by 400μm copper ion. At low copper concentration(0.1mg/lCuSO4·5H2O) and in a fermentor, Methylosporovibrio methanica 81Z could syntheis soluble MMO similar to solble MMO reported before by Palton and Patel. Its optimum PH value was 7.0. It was unstable at 4℃. It could be resoluted into three components: A, B, and C. It was effentive for obtaining the maxtmum MMO with Methylosporovibrio methanica 81Z that (1) to keep high copper concentration(4mg/lCuSO4·5H2O) in a fermentor and harvest cell at middlel lag phase;(2) to choose 6.3 as the PH value of reaction buffer;(3)and to add 5mM methanol or formate into reaction system. In this dy, the MMO activity of cells of Methylosporovibrio methanica 81Z was reached 15.9 nmol/min.mg, dry weight, sixteen times as high as the value(0.97nmol/min.mg, dry weight) reported with the same strain.
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用羟胺体外诱变质粒RP4,我们选择到一株温度敏感的菌落形成抑制突变体(temperature-sensitive colony-formation inhibition mutant,简称CFIts突变体)。其表型为在非允许温度时,在固体平板上不能由单个菌体繁殖为集落,类似于在非允许温度时,在固体平板上不能由单个菌体繁殖为集落,类似于文献报道的RP4的KiV基因表型。这种突变体初步认为是kor(KiV控制基因)的温度敏感性突变体,即由于kor蛋白产物的热变性导致KiV产物的过量或异常表达。生化分析研究表明:在非允许条件下,突变体的生长逐步受到抑制(其表现时倍增时间延长),大约繁殖两代后即全面抑制(菌数不再增加);此时宿主菌的DNA、RNA、蛋白质等大分子合成几乎全部下降,噬菌体产率也明显降低。此时状态是完全可逆的,即在全面抑制后的20小时内,仍可因放回允许温度培养而形成集落。据此抑制现象(KiV表型)的逐步发生性,大分子合成的全面抑制性和完全可逆性判断,很象是宿主菌株在紧急状态下的整体调节机制——严紧型反应。
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本文介绍了从厌氧间歇膨胀光合反应器内的活性污泥中分离并鉴定的泥生绿菌(Chlorobium limicola Nadson)S1,它属严格厌氧光能自养型细菌,在有硫化物和少量碳酸氢盐存在下,有广泛利用有机物的能力,它的最适生长温度为28-30℃,最适生长PH为6.5-7.0,且含有氢化酶。因此,它能与甲烷发酵菌共存而共同作用,达到废水净化之目的。通过光照(2#反应器)和黑暗(1#反应器)对比实验,表明了在光照条件下即有泥生绿菌S1存在下,反应系统能更好地降低CODcr、BOD5 和提高CH4 含量,在四个负荷段的运行中,2#反应器在后三个负荷段的甲烷含量能稳定在91.6%而1#反应器为87%,2#反应器的二氧化碳含量为4.5%而1#反应器为8.8%,于28.35g/l.d的负荷下,2#反应器CODcr去除率达83.4%,BOD去除率达74.53%,分别较1#反应器高10.8%,6.4%。COD去除率提高了14%,BOD去除率提高了9.3%。本试验的试验条件为:白天自然光照,晚上电源光照,光照强度为1000-2500lux,通过连续动态运转,并以恒定的流速将废液注入反应器中,进水PH控制在6.5-7.2,反应器厌氧,恒温室温度控制在30±1℃。为使整个试验中同一水质条件下进行,进水采用化学合成培养基。This paper reports a Chlorobium Liwicola S1's isolation and identification. It is a strictly anaerobic and photosynthetic autotrophic bacterium. Along with sulfidedepondent CO2 assiwilaton,a few simple organic compounds can be photoassimilated. Acetate is most effectively used. Its best conditons of growth are 28-30℃,PH 6.5-7.0, and it contains hydrogenase. So it can live with methanefermentative bacteria in order to treat wastewater. At the same time, the treatment of wastwater using Chlorobium Limicola S1 with methane-fermontative bacteria under dark anaerobic and light anaerobic conditions is studied. In contrast with 1# reactor-darken, 2# reactor-illuminated can lossen wastewater's CODcr, BOD5 and on hance CH4 content better. In the test, 2# reactor's CH4 content is stable at 91.6%, but 1# reactor's is 87%. The CO2 content of 2# reactor is 4.5%, but 1# reactor's is 8.8%. When the load of teatment is 28.35g/l.d, the COD removal effficiency is 83.4% and the BOD removal efficiency is 74.53% in 2# reactor. They are separately 10.8%, 6.4% higher than 1# reactor's.
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造纸行业是造成我国水环境有机污染物的重要污染源之一,其水污染的特点是小厂多、草浆多、工艺落后、污染扩散面广、造成废 水排放量大,每年排放的废水量约39亿立方米,占全国工业废水排放量的1/6,其中有机污染物(以BOD5计)160万吨左右,约占全 国工业废水中有机污染物总量的1/4。尤以占全国制浆造纸行业90%以上的碱法草浆造纸厂的蒸煮黑液量大面广,除含有机物外,还 含有木质素、残碱、硫化物、氯化物等污染物,属于PH值高、色度深、难于治理的高浓度有机废水,对水体污染特别严重,各地要 求治理呼声很高,急待研究并尽快找出各种有效的治理途径。对于碱法草浆蒸煮,黑液高浓度废水的治理,有各种方法,根据国内 的研究进展和我们已有试验工作表明,最经济有效,具有实用价值,在生产上可获得成功是厌氧处理法。近10多年来,国外关于高 效厌氧处理技术研究进展迅速,并出现了多种多样的工艺设备,如高效厌氧生物反应器,并在实用化方面取得了很大成绩,建立了 生产性装置,达到了高负荷运行,效果良好。本试验是根据我们已有研究基础,针对我国国情,对小型制浆造纸厂水污染防治除了 开发碱回收及各种综合利用技术外,要特别加强废水(废液)实用技术研究的指导思想,本试验采用改进型的上流式厌氧污泥床反应 器,设计了两种试验方案,通过试验结果如下。1. 试验方案I—碱法草浆黑液酸化和厌氧发酵I号UASB反应器动态模型试验结果表 明:(1). 采用中温35℃±1℃高效厌氧反应器USAB内装有填料(陶粒)和三相分离器,具有保持高浓度生物量和防止污泥流失的特点 ,污泥浓度Vs 可达30%以上,因而具有高效、节能、产能、滞留期短的优点,当进水CODcr在7500-10000mg/l,HRT由7天缩短到3天 ,有机容积负荷在1.22gCODcr/l·d-3.43gCODcr/l·d时,CODcr平均去除率可达55%-45.5%,最高CODcr去除率可达60.2-63.5%, BOD5去除率可达75.9-83.2%,沼气容积产气率可达0.29-0.67l/l·d,每克CODcr转化为沼气产率达0.39-0.48l/gCODcr·d,CH4含量 65.8-75.5%。厌氧发酵出水再用化学法进行后处理脱除难降解的木质素,CODcr总去除率达80%以上。(2). 动态试验结果表明:采 用酸化—厌氧发酵处理黑液工艺合理,技术路线可行。2. 试验方案II—黑液用化学法(Hcl)去除木质素进行厌氧发酵,II号UASB反 应器动态模型试验结果表明:(1). 采用中温35℃±1℃高效厌氧反应器UASB(内有软填料),当进水CODcr7000-13000mg/l左右,HRT 由6天缩短到1天,有机负荷由0.98gCODcr/l·d增加到11gCODcr/l·d时,COD平均去除率均可稳定在70-77%,BOD5去除率为87.3- 93.1%,沼气容积产气率0.21-2.6l/l·d,每克CODcr转化为沼气产率为0.39-0.48l/gCODcr·d,高的可达0.53l/gCODcr·d,转化 率较高,CH4含量63-70%。(2). 试验证明碱法草浆黑液物化预处理—厌氧发酵处理的技术路线也是可行的,工艺合理、效果较好。 在有条件的工厂可采用。3.厌氧发酵阶段几大类群微生物计数表明:(1). 当发酵工艺和运行处于相对稳定状态时,微生物群体的 组成也达到相对的稳定,各类微生物之间保持动态平衡关系。当产乙酸菌的数量为107-108个/ml时,产甲烷菌的数量为105-106 个/ml,当产乙酸菌数量为106-107个/ml时,产甲烷菌的数量为103-105个/ml。(2).稳态运行条件下,黑液预处理为甲烷发酵创造 了有利的生态环境,获得了较好的处理效果和较高的COD转化为沼气的产率0.39-0.48l/g·CODcr·d,反应器中形成较为稳定而数 量较下水污泥中高1-2个数量级的厌氧发酵微生物区系组成。这一结果为黑液厌氧发酵提供了微生物理论依据。Paper industry is one of the important pollution source of water environment in our country. Its character of water pollution is many small factories, much grass pulp, disadvantageous technique, large preading area of pullution. Its effluent makes up 1/6 of whole country's industry wastwater. Its organic pollutant accounts 1/4 of whole country's. Alkaline grass paper pulp effluent with pollutants such as ligoin, remaining alkali sulfide, chloride besides organic material, is a kind of high concentrate organic wastewater which has high PH walug, dark colour and is difficult in treatment. There is urgent require to find ways to treat the wastewater. There are different ways to treat alkaline paper grass pulp effluent. According to the research advances and our experiment work, the most economical and useful way is anaerobic degradation which was advanced quick in last ten years. In the control of waste water of small pulp paper mill, the study of wastewater utilization technology should be emphasized, besides alkaline retrieving and different kinds of comprehensive utilization technology. Our experiment used modified UASB(Upflow Anaerobic Sludge Blanket Reactor). Two kinds of plan were disgned. The results are lined below. 1. The first experiment plant-aciding black pulp effluent and methanogenic digestion. The dynamic model experiment results of I-UASB reactor showed: (1)The mesophilic(35℃±1℃)high effect UASB reactor having haydite and threee state seperation in it had the character of keeping high bioimass concentration and preventing losss of sludge. It had advantages of high effect, energe saving, energe prodcing and short HRT(Hydroulic retention time). When the influent COD was 7500-10000mg, HRT was shortened from 7 days to 3days, organic loading rate was 1.22g-3.43COD/l· d, the average COD removal efficiency was 55%-45%. The highest COD efficiency was 60.2-63.5%, BOD removal of 75.9 -83.4% was achieved. Biogass production rate were up to 0.29-0.67l/l·d. Biogass converted efficiency from every gram of COD could reach 0.39-0.48l/gCOD·d. Methane content was 65.0-75.5%. Chemical method was used to deplate lignin in anaerobic digestion effluent. Total COD removal efficiency could be more than 80%. (2)Using aciding annaerobic digestion to treat the black effluent was reseanable in technique and technology. 2. The second experiment plan-anaerobic digestion was used after the chemical method was used to deplate lignin in the black effluent. The result of dynamic experiment of II-UASB reactor showed: (1)High effect mesophilic (35℃±1℃)UASB reactor having soft slaffing in was used. When influent COD was about 7000-13000mg/l, HRT was shortened from 6 days to 1 day and organic loading rate was increased from 0.90 to 11g COD /l·d, average COD removal efficiency remained stable on 70-77%. BOD, removal efficiency was between 87.3-93.1%. Biogass production rate was 0.2-2.6l/l ·d .Biogass converted efficiency from a gram of COD was 0.39-0.481/gCOD·d with the high value of 0.53l/gCOD·d. Methane content was 63-70%. (2)The way that using physical, chemical Pre-treatment-anaerobic digestion to treat alkaline black effluent is feasible and can be used in some factories when the condition exists. 3. Counting of several class of microoganisms in anaerobic digestion stage showed: (1)As the disgestion was in stable motion, the compositon of microorganic colony could get relative stable. Dynamic balance was remaining among different kinds of microorganism such as methanogenic bacteria, Acidogenic bacteria, sulfate reducing bacteria, and heterotrophic bacteria. (2)Under stable motion, the pre-treatment of black effluent produced favourable eco-enviroment for methanegenic digestion. Good treatment effect and high biogass convertent efficiency from COD(0.39-0.48l/g·COD· d)were gotten. Some stable and high quantity(10-100times more than sewage sludge)microorganism colony were formed in the reactor. This result provided theoretical basis for anaerobic digestion of black effluent.
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经过细心的条件选择实现了无甲烷条件下甲烷氧化菌沼气甲基弯菌81Z(methylosinus methanica 81Z)利用C2化合物的生长,同时 发现二碳代谢中间产物甘氨酸的胞外积累及对生长的抑制作用。又在此基础上从81Z原种中富集得到一株菌81Z-A,兼性生长能力大 幅度提高,而且除乙酸外又能利用丙酮酸、苹果酸、柠檬酸、葡萄糖而生长。对细胞氧化各种有机底物时氧吸收的测定及酶分析结 果发现了在其它甲烷氧化细菌中未曾发现的异柠檬酸裂解酶和苹果酸酶的存在,表明81Z除了具有通常II型菌的碳代谢途径外,具 有特殊的补偿代谢途径——乙醛酸支路以及从乙酸生糖的回补途径。因此推证其兼性生长的能力是固有的,从而说明了甲烷氧化菌 的专一性概念没有普遍意义。说明了81Z还能在含有二碳的培养基中厌氧生长,包括细胞的分裂和增值行为。虽然这种厌氧生长还 很弱,但至少可以说明它不是严格好氧的,这对于传统的关于甲烷氧化菌的严格好氧的概念是一个冲击。81Z正常条件下是利用甲 烷而生长的,当供给它乙酸、乙醛酸和丝氨酸时能促进含C-C键有机物氧化的活性,而对甲烷单加氧酶和其它C2化合物的氧化有抑 制或阻遏作用,对碳同化的丝氨酸途径的关键酶羟基丙酮酸还原酶有阻抑作用。同时也证明了81Z的甲烷单加氧酶和甲醇氧化活性 可被甲烷、甲醇所诱导,而因甲酸而降低。The growth of Methylosinus methanica 81Z on C2-compounds without methane was realized by selecting suitable conditions. The intermediate product Gly from its C2 metabolism was found to accumulate out cells and inhibit its growth. 81Z-A, which was obtained from 81Z by richening, could grow on C2- compounds rapidly. It can even grow on pyruvate, malate, citrate and glucose. The results of measurements of oxygen consumption by cell suspensions in the presence of various organic compounds and the results of enzyme assays of detected activities of isocitrate lyaze and malic enzyme in cell extracts which were not found in other methantrophs showed that 81Z possesses not only the regular carbon metabalic pathways but also some peculiar anaplerotic pathways--the glyoxylate cycle and the gluconeogenic pathway from acetate. As a consequence of these studies, its ability of facultative growth is inherent. Therefore, the concept of obligate dependence on C2- compounds of methanotrophs is not of universal significance. The ability of 81Z's growth(including desintegration and proliferation behaviour) on C2-compounds anaerobically was also demonstrated. Despite of the weakness of this growth, at least it could be said that 81Z is not strictly aerobic. This is a strike to the traditonal concept about the strictly aerobic action of methanotrophs. Regularly, 81Z grows on methane. The presence of acetate, glyoxylate and serine could increaze its ability of oxidizing the organic coumpounds containing C-C ponds. In contrast, they could inhibit the activities of MMO and other C2-compounds oxidation, they also repressed the key enzyme hydroxypyruvate reductase of the serine-pathway for carbon assimilation. At the some time, it was testified that the activities of MMO and methanol oxidation were inducible by methane or methanol and were lower in the presence of formate.
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In this paper, bioconversion of trans-cinnamic acid(t-Ca)to L-phenylalanine (L-phe) has been investigated by using immobilized yeast cells with induced L-phe Ammonia-lyase(PAL, EC.4.3.1.5) as biocatalysts. The contents are the following. (1) Thirty strains of yeasts, including two genera (Rhodotorula, Sporobolomyces), six species (R. glutinis R. minuta,R.rubra,R.sineses,R.roseus and S.salmonicolor)were screened for their ability to converse the substrates, t-Ca and ammonia, to the product, L-phe, by using yeast cells as biocatalyst, and primary evaluation for PAL activity of the selected strains was investigated. From the results of the screening experiments, it was found that 22 strains were able to produce L-phe from t-Ca with the range of conversion yield from 2% to 67%. Studies on PAL formation time course during cultivation show that the maximum PAL activity of several different strains ranges from 2.3 to 14.4×10-3U/mg cell dry weight. The biomass of tested strains at their maximum enzyme activity is also greatly varied. (2)One of the selected strains, R. rubra as 2.166, was used for immobilized cells as biocatalysts to produce L-phe. The optimum conversion conditions and effective stablization agents were investigated. The results shown that polyacrylamide gel was chosen as a suitable matrix for immobilization of the yeast cells, and it can retain 88% of the PAL activity in the reverse direction at the following reactive conditions: [t-Ca]: 34mM. [NH4OH]: 6.OM.PH10.00, temperature: 30℃. (3) The effects of various kinds of effectors on the production of L-phe were also examined. Membrane permeabilizing agents can stimulate L-phe synthesis, but make the stability of PAL decline greatly. Polyalchoholic agents and glutamic acid were very effective for the stabilization of PAL. At the presence of glutamic acid (5%), the half life of L-phe productivity with the immobilized cells was extended to 192 hours, which was much higher than most of that having been reproted, while the half life of resting cells was only about 15 hours. (4) Use of initial velocity studies on the kinetics of enzyme-catalized reaction indicated that the apparent Km value was 13.0mM for the immobilized cells, and 4.8mM for the resting cells. Thermostability of the immobilized cells was better than the resting cells. Fluid bed bioreactor is more effective than batch bioreator in prolonging the thermostability of the biocatalysts. (5) CGA- 688 resin column chromatographic procedure was employed in the isolation and purification of L-phe, t-Ca and other substances from the reactire mixture. (6) Preparative-scale production of L-phe on a level of gram amount by immobilized cells from the culture broth of R. rubra AS2.166 allowed for the conversion yield with 30%. The characteristic physico-chemical criteria (including melting point, optical activity, elements analysis, IR, NMR) are the same with the standard L-phe. 本文报告了利用诱导的苯丙氨酸解氨酶 (PAL.EC.4.3.1.5)催化反式肉桂酸(t-Ca)氨加 成制备L-苯丙氨酸(L-phe)的研究,主要内容为:(1) 我们搜集了三十株酵母菌株,利用全细胞转化t-Ca生成L-phe的能力进行了直 接筛选,并对其PAL活性水平进行了初步评估研究。研究结果表明,其中22株酵母具有转化t-Ca生产L-phe的能力,它们包括 Rhodotorula glutinis,R.rubra, R.sineses 和Sporobolomyces roseus 的菌株,转化率在2-67%。细胞生长和PAL形成过程的研究 表明,不同菌株PAL最大活力在2.3-14.4×10-3U/mg 细胞干重,达到最大PAL活性时各株酵母的生长情况也极不一致。(2) 利用筛 选出的一株深红酵母R.rubra AS2.166 作为供试菌株,研究了细胞固定化条件下生物转化的最适条件及PAL在固定化条件下的稳定 性。结果表明以聚丙烯酰胺凝胶包埋法较为理想,能使细胞合成L-phe活力保持88%,最适t-Ca浓度为34mM,最适NH4OH浓度为6M,最 适PH10.0,最适温度45℃。(3) 多种效应物对L-phe 合成的影响研究表明:表面活性剂能刺激L-phe的合成,但使PAL稳定性下降。 多羟基化合物及Glu对PAL的稳定十分有效在有Glu存在下,能使固定化细胞合成L-phe的半寿期达192小时左右,高于大部分现已报 导的固定化结果。(4) 用初速度法研究了深红酵母AS2.166中PAL的酶促反应特征,测得固定化细胞对t-Ca的表观米氏常数Km为 13.0mM,全细胞为4.8mM,细胞固定后热稳定性提高。(5) 建立了适合低浓度分离纯化产物与底物的聚苯乙烯大孔树脂柱层析技术 ,能使L-phe与t-Ca及产物混合物中其它成分有效分开。(6) 利用固定化的R.rubra AS2.166细胞所做的制备实验能够使L-phe的产 率达到30%左右,其主要的理化指标(包括熔点、比旋光度、元素分析、IR、NMR等)与标准L-phe一致。
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我们从成都东郊垃圾堆里分离到一株产生水不溶性葡聚糖降解酶的菌株CIB871,经鉴定为假单孢菌。CIB871在30℃生长良好。适宜的产酶培养条件是在含有一定金属离子的盐溶液中加入氮源多胨(终浓度0.3%)和碳源IG(终浓度0.03%)或甘露醇(终浓度1%)。上清液酶浓度在培养60-65小时达到最高。利用饱和度50%-70%的硫酸铵沉淀该酶。酶作用的最佳PH为7.0,最佳温度37℃,热稳定性不良。5mM的Ag+,Co2+,Hg2+, Mg2+, Zn2+ 对酶有抑制作用。Fe2+,Fe3+对酶有激活作用。
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从四川化工总厂热交换器中分离到一株嗜热硫酸盐还原菌,该菌对金属有腐蚀作用。菌体形状呈微弯或直杆状,大小为0.5-0.8μm宽,2.8-4.3μm长,革兰氏阴性,周生鞭毛,运动,形成次端生的椭圆形芽孢,细胞内部构造丰富,菌落在不含Fe++盐的培养基上生长时,呈灰白色,直径为0.5mm,边缘不整齐,在含Fe++盐的培养基上生长时则为黑色,直径为2-3mm,菌落中央有0.5mm左右的小突起,该菌最适生长温度为50℃,最适PH6.5,不耐盐,可于沸水(99℃)中处理6小时而不失活,能利用H2+CO2,乙醇,卜葡糖 ,可溶性淀粉,甲酸盐,乳酸盐,丙酮酸盐为唯一碳源,生长需要酵母膏,无脱硫弧菌素和细胞色素C3。
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为结合一般白酒存在的杂醇油含量偏高或超标问题,作者试图寻找能嗜高醇类(含杂醇油)的有效菌株加以开发利用。本文研究了一株从富集分离、定向诱导得到的嗜异戊醇的W-2菌,该菌能以异戊醇或其它某些多碳醇作为唯一的碳源和能源进行生长。该菌在PH8.5的环境条件下,异戊醇的利用率可高达84.4%。此外,该菌还能广泛利用糖类、醇、有机酸、酯、盐等有机物作为唯一的碳源和能源。一般不利用—碳化合物。该菌具单极生鞭毛,呈杆状,适宜生长温度范围4℃—43℃。最适生长温度36℃,在PH4.0—11.0均能生长,最适生长PH为8.5—9.0,在培养基产生蓝绿色色素。W-2菌经形态,生理生化鉴定为假单胞菌属中的铜绿假单胞菌的一个变种。初步定名为Pseudomonas aeruginosa W-2。本文最后讨论了该菌的开发应用前景。