一株氨化细菌的分离、鉴定及氨氮降解能力的初步分析

养殖水体中高浓度的氨态氮及硝态氮是导致鱼虾发病的直接或间接因素1, 特别是近几年来,不断发生养殖生物氨氮中毒的事件, 给水产养殖业带来了严重的经济损失2, 因此对养殖水体中氨氮浓度的控制以及如何解决养殖水体中的氨氮污染问题, 已成为净化养殖水质的研究热点。       

嗜热厌氧纤维素降解细菌的分离、鉴定及其系统发育分析

利用纤维素降解细菌和纤维素粘附的方法分别从新鲜牛粪、高温堆肥和本实验室保存的纤维素降解富集物中分离得到4株嗜热厌氧纤维素降解细菌。分离菌株为革兰氏染色阴性,直的或稍弯曲杆菌,菌体大小为0.4μm～0.6μm×3μm～15μm,严格厌氧,不还原硫酸盐,形成芽孢。多数芽孢着生于菌体顶端。分离菌株能利用纤维素滤纸、纤维素粉Whatman CFII、微晶纤维素、纤维素粉MN300和未经处理的玉米秆芯、甘蔗渣、水稻秸杆。分离菌株在pH6.2～8.9、温度45℃～65℃范围内利用纤维素,最适pH为7.0～7.5,最适温度为55℃～60℃,发酵纤维素产生乙醇、乙酸、H2和CO2。分离菌株还可利用纤维二糖、葡萄糖、果糖、麦芽糖、山梨醇作为碳源。部分长度的16S rDNA序列分析表明,分离菌株EVAI与Clostridium thermocellum具有99.8%相似性。     

1株聚乙烯醇降解菌的分离鉴定及其降解性能

筛选聚乙烯醇（PVA）降解性能优良且适合驯化的菌种是PVA生物降解的关键环节。为了获取PVA高效降解菌种,采用选择性培养基从某化工厂回流池污泥中筛选菌株,并对菌株的生长及PVA降解过程、培养液pH值、温度、摇床转速、装液量进行测定。结果表明：筛选的1株聚乙烯醇高效降解菌MH 007,基于16S rRNA基因序列的系统发育多样性分析鉴定该菌为Sphingopyxis terrae的一个菌株。该菌PVA降解率可达97.2%,摇床动态培养过程中降解PVA的最佳条件为pH 7.2、温度30 ℃、摇床转速120 r/min和30%的装样量。     

一株硅酸盐细菌的鉴定及其系统发育学分析

从南京地区黄棕壤中分离的一株好氧、革兰氏阴性、产芽孢的硅酸盐细菌NBT菌株,能产生丰厚的荚膜,具有鞭毛,能水解淀粉、产生吲哚、液化明胶,全细胞脂肪酸为硬脂酸C16∶0、软脂酸C18∶1(Δ9)和anteisoC15,DNA的G+C mol%为537%。16S rRNA基因测序和系统发育学分析的结果表明,该菌株与胶质芽孢杆菌B7519（Bacillus mucilaginosus）、土壤芽孢杆菌B7517（B. edaphicus）亲缘关系最近。该菌株与B. edaphicus B7517的总DNA杂交率为69%,在形态、生理生化特征上有差异,故可把NBT菌株定为Bacillus edaphicus的一个亚种。     

一株高效去除亚硝酸氮细菌的分离鉴定及其脱氮特性研究

【目的】从南美白对虾养殖塘中分离到高效去除亚硝酸氮的细菌, 对其分类和脱氮特性进行了研究。【方法】 以除亚硝酸氮为主要指标, 取养殖塘底层水样分离筛选菌株; 依据16S rRNA基因序列和生理生化特征初步鉴定菌株; 研究不同碳源、碳氮比、起始pH、温度、摇床转速和氯化钠浓度对反硝化除亚硝酸氮的影响, 并考查了菌株对硝酸氮和氨氮的利用情况。【结果】得到的菌株中菌株FP6活性最高, 初步鉴定菌株FP6属于地衣芽孢杆菌。菌株FP6的生长最适脱氮碳源为蔗糖, 菌株FP6去除亚硝酸氮有高活性的条件范围为: C/N值15?25、起始pH 7.0?10.0、温度20 °C?37 °C、摇床转速0?200 r/min和氯化钠浓度0?40 g/L。菌株FP6对硝酸氮和氨氮都有一定的去除能力, 利用硝酸氮时不积累亚硝酸氮。【结论】地衣芽孢杆菌FP6具有优良的除亚硝氮特性, 适宜的温度、pH和盐度范围较宽。     

石油降解细菌降解条件优化研究

采用富集培养法从工业油污土壤中分离到1株能以石油为惟一碳源而生长的细菌菌株,采用正交设计实验对该菌株的降解条件进行了初步研究。结果表明,最佳降解条件为NH_4Cl 4.0 g/LL,K_2HPO_4 1.5 g/L,pH 8.0,NaCl 15.0 g/L。在最佳条件下,浓度为1 mL/L的原油可在4 d内降解50%以上。     

一株吡虫啉杀虫剂降解菌BB-1的分离鉴定

目的:从福建安溪茶园土壤分离能降解吡虫啉杀虫剂的细菌菌株,对其进行分类鉴定.方法:采用室内培养试验方法,通过富集驯化、平板划线分离得到1株优势细菌BB-1,采用形态、生理生化特征和16S rDNA序列分析对菌株BB-1进行鉴定.结果:菌株BB-1 与多株苍白杆菌(Ochrobactrum)的亲缘关系最近,该菌株鉴定为苍白杆菌属(Ochrobactrum sp.).BB-1在吡虫啉浓度为400mg/L的LB培养基中培养0h～5h为生长延迟期,4h～20h为对数生长期,20h～42h为稳定期,42h以后为衰亡期.菌株BB-1对多种抗生素敏感,可耐受的NaCl浓度超过10%.结论:BB-1能降解吡虫啉杀虫剂,分类上应属于Ochrobactrum sp..     

甲胺磷降解细菌的分离鉴定及其降解效能的研究

从土壤中分离筛选获得两株对甲胺磷农药有较强降解效能的细菌,经鉴定分别为头状葡萄球菌(Staphylococcus capitis)(称为D菌)和粪产碱菌(Alcaligenes faecalis)(称为J菌)。D菌和J菌在甲胺磷浓度为500mg.L-1,30℃,180r.min-1摇床上用基础培养基中培养72h,对甲胺磷的降解率分别达到58.49%和65.80%。D菌和J菌混合培养可提高对甲胺磷的降解效能,对甲胺磷72h的降解率达到72.93%。     

一株农药降解生防细菌的分离与鉴定

从花生根际土壤中分离到一株对多种土传植物病原真菌具有拮抗作用的生防细菌B3, 该菌能够以100 mg/L高效氯氰菊酯、毒死蜱和吡虫啉为唯一碳源生长, 7 d的降解率分别为54.42%、57.44%和49.24%, 显示了该菌在植物病害生物防治和土壤生物修复方面具有潜在的开发价值。通过形态特征、生理生化及16S rRNA同源性序列分析, 鉴定该菌为多粘类芽孢杆菌(Paenibacillus polymyxa)。     

一株苯酚降解菌的分离与鉴定

目的：筛选能高效降解苯酚的微生物,并进行初步鉴定。方法：从某焦化厂排水沟采集污泥,通过逐步驯化筛选苯酚降解菌株;利用形态观察、生理生化检测、16SrDNA序列分析进行初步鉴定。结果：筛选获得1株苯酚降解菌JDM-2—1,该菌能够以苯酚为惟一碳源,耐酚能力高达2200mg／L,在30℃和pH7．0条件下,42h内能将800mg／L的苯酚彻底降解;初步鉴定其为球形芽孢杆菌（Bacillus sphaericus）。结论：菌株JDM-2-1是一株高效降解苯酚的球形芽孢杆菌。     

一株碱性淀粉酶产生菌Bacillus flexus XJU-3的分离鉴定及酶学特性分析

[目的]从新疆石河子市一处碱性工业污水(pH11.0)分离﹑鉴定高产碱性淀粉酶菌株,并对其所产酶酶学特性进行研究.[方法]在碱性淀粉酶分离培养基上对所分离菌株进行筛选,分离到一株高产碱性淀粉酶菌株,并将其编号XJU-3.应用生理生化试验,脂肪酸含量,16S rDNA序列以及(G C) mol%含量等方法对菌株进行鉴定,同时对XJU-3所产碱性淀粉酶的生物学特性进行研究.[结果] XJU-3可在pH4.0～12.5的LB培养基上生长,最适生长温度37℃.16S rDNA序列构建的系统进化树表明XJU-3与Bacillus flexus类聚在一起,且序列同源性为99%.该菌产生的淀粉酶最适pH10.0,最适温度40℃,且在pH9.0～13.0内有较高活性和稳定性.Co2 和Mg2 能明显提高酶的活性.[结论] XJU-3被鉴定为Bacillus flexus,由于XJU-3与B. flexus DSM 1320T在尿素水解和优势脂肪酸含量上有差异,且具有宽范围pH耐受性,因此XJU-3被认为是B.flexus的一个新菌株.XJU-3所产的碱性淀粉酶酶学特性良好,具有极大的工业应用潜力.     

对叶榕榕果内生细菌分离鉴定及抑菌活性的研究

【目的】为植物-内生细菌的生态关系研究, 以及植物内生细菌资源的利用提供一定的依据。【方法】采用微生物学传统分离培养的方法从对叶榕果实中分离到内生细菌54株, 通过限制性酶切分析(ARDRA)共有16个操作分类单元(Operational taxonomic units, OTUs), 对16株代表菌株16S rDNA序列系统发育分析。【结果】16个菌株都找到了与其相似性最高的菌株, 相似性达到95%?100%。其中6株为芽孢杆菌Bacillus属, 为对叶榕果实内生细菌优势菌属; 3株为Staphylococcus属, 2株为Pseudomonas属, 1株为Serrata属, 1株为非培养细菌的同源菌, 1株为Kocuria属, 1株为Delftia属, 还有1株为Acinetobacter属。【结论】这16株内生菌在系统发育树中明显聚为两大支; 在参与抑菌试验的14株内生菌中, 有13株对受试菌有不同程度的拮抗作用。尤其是其中的芽孢菌属的Swx15和不动杆菌属的Swx25菌株, 抑菌作用较强, 且有较广的抑菌谱性。     

中国主要矿区油页岩可培养细菌的分离与鉴定

【目的】研究油页岩本源环境中可培养细菌多样性,对于发掘利用尚未开发的油页岩细菌资源具有重要意义。【方法】以野外采集的吉林桦甸、广东茂名和辽宁抚顺3个中国主要矿区的油页岩作为研究对象,采用稀释平板培养法,以营养琼脂培养基对油页岩中的细菌进行分离纯化,并对分离菌株进行基于16S rRNA基因的序列测定和系统发育分析。【结果】3个矿区共鉴定出10属,其中抚顺矿的9个操作分类单元(Operational taxonomic units,OTUs)属于Pantoea、Brevibacillus、Paenibacillus、Microbacterium、Arthrobacter、Pseudomonas和Bacillus菌属;茂名矿的5个OTUs属于Bacillus和Sinomona菌属,桦甸矿的5个OTUs属于Staphylococcus、Acinetobacter、Bacillus和Arthrobacter菌属。【结论】3个矿区可培养细菌群落组成均较简单,且在门的分类层次上相似,即均具有厚壁菌门和放线菌门,抚顺矿和桦甸矿还存在部分变形菌门细菌。在属的分类层次上,各矿区差异较大。     

一株海藻多糖降解菌的分离与鉴定

【目的】从腐烂的褐藻中筛选一株海藻多糖降解菌,编号L206,分析其对不同多糖的降解能力。【方法】通过形态观察、生化单因子试验及16S r RNA基因鉴定细菌,DNS法测定海藻多糖降解酶活性等。【结果】海洋细菌L206,革兰氏阴性短杆菌,生长对数期为3-21 h,适宜生长的Na Cl质量浓度为0-3%(质量体积比);通过16S r RNA基因鉴定为白色噬琼胶菌(Agarivorans albus);L206被海带粉诱导至72 h时,综合复合酶活力达到最大,其中淀粉酶活力最高(28.17 U/m L),木聚糖酶次之(23.83 U/m L)。【结论】白色噬琼胶菌L206是一株多能型多糖降解菌,对褐藻多糖有特殊的降解能力,具有潜在开发价值。     

A new method for liquid nitrogen storage of phototrophic bacteria under anaerobic conditions

A simple, effective and economical method for the long-term preservation of bacteria in liquid nitrogen under anaerobic conditions is described. As a case example anaerobic photosynthetic bacteria were successfully preserved. Gas tight small screw-cap glass ampoules with butyl rubber septa were used for freezing the specimen anaerobically. During experimental manipulations no anaerobic chamber or glove boxes were required. All teste cultures yielded high recoveries after repeated thawing and during storage. After freezing, survival recoveries of Rhodospirillaceae range from 70–100%, whereas with strict anaerobic strains of Chlorobiaceae and Chromatiaceae a maximum loss of 1–2 log₁₀ counts was observed. No further loss in viability occurred after 1–2 years of storage.The small size of the ampoules and the use of single ampoule for 15–20 repeated retrievals proved economical with respect to storage space and costs.The system is compact and suitable for the preservation of anaerobic phototropic bacteria and other fragile anaerobic microorganisms.     

薇甘菊根际可培养固氮菌和氨化细菌的分离鉴定与促生作用

【目的】固氮菌和氨化细菌是氮循环产生生物有效氮的关键起始环节,直接影响了外来入侵植物的生长速度和扩散进程。然而,关于典型入侵植物薇甘菊根际可培养固氮菌和氨化细菌的研究尚未见报道,这在很大程度上制约了我们对薇甘菊根际高效的氮素转化机制的深刻理解。【方法】采用传统平板涂布培养法对野外采集的薇甘菊根际土壤中的可培养固氮菌和氨化细菌进行了分离鉴定,并进行了接种验证实验。【结果】结果表明,入侵植物薇甘菊根际土壤中的固氮菌和氨化细菌的菌群密度显著高于两个本地伴生植物(火炭母和鸡屎藤),其固氮效率及有机氮矿化效率也优于2个本地种;系统发育分析表明：薇甘菊根际的固氮菌菌株归类于5个属,分别为伯克霍尔德氏菌属(Burkholderia)、肠杆菌属(Enterobacter)、植物杆菌属(Phytobacter)、新肠杆菌属(Kosakonia)和根瘤菌属(Rhizobium);氨化细菌归类于7个属,分别为沙雷氏菌属(Serratia)、不动杆菌属(Acinetobacter)、假单胞菌属(Pseudomonas)、博德特氏菌属(Bordetella)、寡养单胞菌属(Stenotrophomonas)、苍...     

Isolation,identification and growth conditions of photosynthetic bacteria found in seafood processing wastewater

Four photosynthetic bacteria, isolated from 14 samples taken from seafood processing plants, were identified as species of Rhodocyclus gelatinosus, belonging to the purple, non-sulphur bacteria of the family Rhodospirillaceae. Cultivation in synthetic medium under four different conditions indicated that all four strains gave maximum carotenoid and bacteriochlorophyll synthesis under anaerobic conditions in the light, with values of 11 to 12.6 and 102 to 108 mg/g dry cell wt, respectively. These values are 87% higher than the pigment content obtained from aerobic cultivation, although the cell biomass of all strains (1.7 to 2.3 g/l) was 22 to 38% higher under aerobic conditions. Protein content was always between 32 and 43%. The specific growth rates of all isolates in aerobic cultivation (0.04 to 0.06 h^-1) were twice those in anaerobic conditions in the light. No growth occurred in anaerobic conditions in the dark.     

两株四环素降解菌的分离鉴定及降解条件优化

为发掘四环素高效降解菌株,本研究从以四环素为唯一生长碳源的养鸡场粪便堆肥样品中分离筛选到2株四环素降解菌TC-04和TC-09,并通过形态特征、生理生化特征和16SrRNA基因序列分析,对其进行鉴定.采用单因素试验分别探究不同碳源、氮源、微量元素这3个培养基成分和培养时间、接种量和装液量这3个培养条件对两株菌降解四环素...     

Isolation,genetic identification and degradation characteristics of COD-degrading bacterial strain in slaughter wastewater

Contamination of water by meat production is an important and extensive environmental problem and even threat to human health. Biodegradation is a major mechanism which removes the pollutants from the environment. Therefore, the present study aimed to isolate and characterize a COD degrading bacteria which can effectively degrade slaughter wastewater. Six COD degrading bacteria were isolated from slaughtering waste water and sludge in Hunan a meat product Co., Ltd. And the COD degradation rate of each strain was determined by potassium permanganate method. Through observing morphologically and analyzing sequence to 16S rDNA, the highest COD degradation strain was Bacillus velezensis by preliminarily identified and classified, reaching 11.80%. The suitable conditions of the growth of Bacillus velezensis strain were 37 °C, pH 7.0, the peptone concentration 1.5%, and the yeast extract concentration 0.8%.     

Isolation,gene detection and solvent tolerance of benzene,toluene and xylene degrading bacteria from nearshore surface water and Pacific Ocean sediment

BTX (benzene, toluene and xylene) degrading bacteria were isolated from Pacific Ocean sediment and nearshore surface water. In the seawater near a ferry dock, degrading bacteria of a relatively wide diversity were detected, including species of Pseudomonas, Rhodococcus, Exiguobacterium and Bacillus; while species of Bacillus only have been detected from the deep-sea sediment. Most of the isolates showed degradation to more than one compound. Generally better growth was obtained with p-xylene and ethylbenzene than with the other two. All the bacteria could tolerate and grow with the compounds at 5–20% (v/v). Both benzene and toluene degradation related genes had been successfully PCR cloned from the isolates of nearshore water, the detected benzene dioxygenase gene was identical among all the species and close to its soil counterpart. However, they were not detected in all the isolates from deep sea. Results in this report suggested that BTX degrading bacteria widely spread in marine environments and they might be of potentials in biotreatment of BTEX in saline environments.