海带藻际微生物抗菌活性及其多样性的初步研究

从浙江台州海域健康海带、病烂海带(Laminaria japonica)及其周围海水中分离纯化海带藻际微生物, 利用双层琼脂扩散法对获得的菌株进行抗菌活性筛选, 比较活性菌株与来源的相关性, 并对具有抗菌活性的菌株进行16S rRNA系统发生学分析。结果显示, 在分离的143株海带藻际微生物中, 有42株细菌具有抗菌活性, 其中来源于健康海带和海水的活性菌株比例(35%和29%)大于来源于病烂海带的细菌(23%)。对其中16株具有广谱抗菌活性的菌株进行的16S rRNA系统发生学分析显示, 分别属于Pseudoalteromonas、Rahnella、Donghaeana、Bacillus和Exiguobacterium 5个属。为从藻际微环境的微生物多样性入手了解海带病烂机制以及寻找新的抗菌药物提供研究材料。       

微小卡罗藻(Karlodinium micrum)共附生微生物抗菌与细胞毒活性

【目的】本文对微小卡罗藻共附生微生物进行分离并对其抗菌和细胞毒活性进行初步研究,以期望获得既具有抗菌又具有细胞毒的高活性菌株,为从共附生微生物的角度去研究微小卡罗藻毒素的合成途径以及真正来源提供研究材料。【方法】利用琼脂扩散法和MTT法对细菌培养液的乙酸乙酯提取物进行抗菌和细胞毒活性筛选,并对具有细胞毒活性的细菌菌株进行了16S rRNA系统发生学分析。【结果】在分离到的38株海洋细菌中,25株细菌具有抗菌活性,5株细菌(W-14-2、W-2-2、W-12、E-8-2和W-4)具有细胞毒活性。对这5株具有细胞毒活性的细菌菌株进行16S rRNA系统发生学分析显示它们分别与Alteromonas alvinellae、Stappia aggregata、Pelagibaca bermudensis、Marinobacter kribbensis和Maribacter dokdonensis的16S rRNA基因序列具有较高的相似性。【结论】在分离到的微小卡罗藻共附生微生物中含有较为丰富的活性菌株,且获得5株具有抗菌活性又具有细胞毒的高活性菌株。     

北极海泥菌群的分离鉴定及生物学特性的初步研究

对从北极冰川海面下1500-4000m处的海泥样品中分离的8株冷适应细菌进行了生理特征和分子生物学研究。其中5株嗜冷菌、3株耐冷菌,利用16SrDNA通用引物对5株嗜冷菌基因组DNA进行扩增,测序得到其部分16SrDNA序列。经Blast调出与菌株16SrDNA同源的序列,按照Neighbor-Joining方法构建16SrDNA系统发育树。对8株细菌进行酶检测试验,结果表明其中有部分细菌产低温酶:N014产淀粉酶,R151产明胶酶,P371产纤维素酶。研究结果为进一步开发利用冷适应微生物产物提供参考依据。     

2株耐低温微生物处理污水模拟试验初报

从下水管道的污泥中分离筛选到耐冷细菌H6和耐冷酵母菌J1,采用此2菌株进行模拟污水低温(8℃)处理试验。H6和J1菌株对模拟污水COD的去除率分别为66.6%和72.2%;H6、J1菌株对有机氮去除率分别为76.9%和64.5%;H6、J1菌株对总磷去除率分别为53.9%和14.0%。说明低温微生物在低温环境的污水处理具有广阔的应用前景。     

耐冷细菌的筛选及对畜禽废水处理研究

从若尔盖高原湿地采集沼泽土, 驯化后分离获得了14株对畜禽废水具有降解能力的耐冷细菌, 对供试菌株6°C的生长代时、对畜禽废水CODcr去除能力进行了测定。结果表明, 供试菌株的代时介于4.9 h~11.6 h之间, 据此选取了生长代时在4.9 h~6.5 h的9株耐冷细菌(NLJ1、NLJ6、NLJ7、NLJ9、NLJ10、NLJ11、NLJ12、NLJ13和 NLJ14)用于畜禽废水处理。在6°C~9°C条件下, 单个菌株对畜禽废水CODcr去除率存在差异, 其中, 6株耐冷细菌NLJ6、NLJ7、NLJ9、NLJ10、NLJ11和NLJ13的 CODcr去除率约为60%~70%, 其余菌株的 CODcr去除率小于50%。因此, 用这6个菌株混合接种处理灭菌畜禽废水6 h, 其CODcr去除率达85.42%。进而, 将采自雅安、都江堰和成都等地污水处理厂的活性污泥混合接种上述6株耐冷细菌后处理畜禽废水6 h, 其CODcr平均去除率分别为81.67%、76.32%和70.56%; 方差分析表明, 不同处理间CODcr去除率无显著差异, 说明这6株耐冷细菌对活性污泥的适应性较好。     

北极苔原土壤中可培养细菌的分离及其抗菌活性测定

【目的】北极地区具有高纬度、低温、高辐射等独特的环境条件。北冰洋及周围大面积的陆地区域鲜有人类踪迹,其中微生物数量不可低估。本研究旨在了解北极土壤中的可培养微生物的多样性及其抗菌活性。【方法】对来源于北极黄河站附近的7份不同植物根下苔原土壤进行直接涂布和富集培养后涂布。【结果】共获得细菌菌株721株,对其中608株进行细菌16S rRNA基因序列测定,归属于86个属,229个种,主要分布于变形菌门(Proteobacteria,54.3%)、放线菌门(Actinobacteria,21.2%)、拟杆菌门(Bacteroidetes,12.8%)、厚壁菌门(Firmicutes,10.0%)和奇异球菌门(Deinococcus-Thermus,1.6%)。其中从16S rRNA基因序列同源性推测有22株细菌菌株为潜在新种/属。从分离菌株中筛选出16株可抑制金黄色葡萄球菌(Staphylococcusaureus)或鲍氏不动杆菌(Acinetobacterbaumannii)生长的拮抗菌。【结论】获得了北极土壤地区特有的微生物菌株资源,为进一步筛选拮抗菌的活性物质提供了菌株基础。     

老鼠簕(Acanthus illicifolius L.)根际内生菌分离与活性评价

从老鼠簕(Acanthus illicifolius L.)根际土壤和植物根、叶、茎中共分离得到97株微生物,其中包括27株放线菌,44株细菌以及26株真菌,并且土壤中的分离得到的微生物最多。对获得的菌株进行细胞毒活性、抗金黄色葡萄球菌和抗白色念珠菌的测定,结果发现细菌的活性百分比最高,而放线菌和真菌活性百分比相对较小。     

从海蜇中筛选抗真菌活性的海洋细菌菌株

从中国北部湾海域采集的海蜇样品中分离到577株海洋细菌,以条件致病真菌白色念珠菌(Candida albicans)作为敏感测试菌株,采用琼脂块法测定了577株海洋细菌的抗真菌活性,结果表明有119株具有抗白色念珠菌活性,占总数的20.6%。对其中的40株高活性菌株进行抗真菌和抗细菌活性研究,结果表明,有21株海洋细菌对3种或3种以上的真菌有抑制活性,23株对细菌有不同程度的抑制作用,其中1株海洋细菌I0s4-18具有广谱的抗菌作用,对革兰氏阴性细菌、革兰氏阳性细菌、酵母菌及丝状真菌均具有抑制作用。海蜇共附生的微生物中能产生抗真菌活性的微生物的比例是很高的,I0s4-18菌株具有良好的开发前景。     

新疆木碱蓬(Suaeda dendroides)根际耐盐促生细菌的筛选及鉴定

【背景】新疆是全国最大的盐渍化土壤分布区,土壤盐渍化严重影响作物生长,耐盐促生菌可以有效改善土壤肥力,提高作物抗逆性,促进植物生长,提高土壤利用率。【目的】分离筛选获得木碱蓬(Suaeda dendroides)根际土壤中耐盐促生菌菌株,对优良促生作用的菌株进行分子鉴定,挖掘微生物资源,为微生物菌剂的研制奠定基础。【方法】采用传统的分离方法筛选获得木碱蓬根际耐盐微生物,采用"三级筛选体系"筛选获得耐盐促生菌菌株,用CTAB法提取菌株DNA,对菌株16S rRNA基因测序进行系统发育分析,确定耐盐促生菌菌株的分类地位。【结果】从木碱蓬根际共分离获得耐盐微生物58株,8株具有固氮活性,解磷活性菌株12株,具有解钾活性菌株15株,产IAA活性的菌株3株,具有较强产氨活性的菌株2株。经过促生平板筛选,菌株GTZW50-5和MH-F促进了拟南芥生长,表现出较好的促生效果,通过小麦盆栽试验,菌株GTZW50-5对小麦的根长以及株高具有显著的促生作用,在一定程度上提高了植物体内的叶绿素含量。MH-F菌株对小麦的根系具有较显著的促生作用,且对小麦的叶绿素及脯氨酸含量在不同盐浓度下都有所提高。经过系统发育分析,GTZW50-5与Bacillus vallismortis (AY603658)序列相似度达到99.43%,鉴定属于Bacillus vallismortis,MH-F与Enterobacterludwigii(JTLO01000001)序列相似度为98.34%,鉴定属于Enterobacter属。【结论】菌株GTZW50-5与MH-F均具有较好的促生效果,这为耐盐微生物资源的开发和利用提供了理论依据。     

新疆乌尔禾地区盐渍土壤耐盐细菌多样性与群落结构研究

研究新疆北部乌尔禾地区盐渍土壤中微生物群落结构及多样性,以期发现新的高盐环境耐盐性微生物资源菌株。采用传统分离培养法获得可培养耐盐菌株并对菌株形态学、16S rRNA基因测序、耐盐特性进行研究,同时结合高通量测序技术分析新疆乌尔禾地区盐渍土壤耐盐细菌的多样性与群落结构。共分离得到耐盐细菌11株,分属6个属,均为中度耐盐菌,以芽胞杆菌属(Bacillus)为优势菌。对盐渍土壤微生物16S rRNA(V3～V4)基因测序,共获得细菌序列290 952条,分属24个门410个属,变形菌门(Proteobacteria, 60.31%)、厚壁菌门(Firmicutes, 21.52%)、拟杆菌门(Bacteroidetes, 6.9%)和放线菌门(Actinobacteria, 6%)相对丰度较高。优势属为克吕沃尔菌属(Kluyvera,21%)、Hafnia-Obesumbacterium(19.6%)和假单胞菌属(Pseudomonas,7.5%)。结果表明,新疆乌尔禾地区盐渍土壤耐盐细菌优势菌群以芽胞杆菌属(Bacillus)居多,细菌群落结构较复杂,潜在可利用微生物资源较为丰富,对高盐极端环境耐盐微生物新资源有进一步研究的意义。     

The composition and persistence of faecal coliforms and enterococcal populations in sewage treatment plants

AIMS: The changes in structure and composition of faecal coliforms and enterococcal populations in sewage from different treatment plants, and the elimination of vancomycin- and erythromycin-resistant enterococci (VRE and ERE, respectively) in these treatment plants was analysed to determine any selective reduction. METHODS AND RESULTS: Faecal coliforms, enterococci, VRE, ERE and spores of sulphite-reducing bacteria were enumerated using standard methods. Samples were enriched where necessary in order to isolate antibiotic resistant strains. The structure and composition of these bacterial populations were determined by biochemical fingerprinting and clustering analysis. High diversity and similarity indexes were detected among all the bacterial populations in raw and treated sewage, independently of their origin and the treatment processes employed. Antibiotic resistant strains were detected in all sewage tested and no selective reduction was observed. CONCLUSIONS: The faecal coliforms and enterococci populations did not differ in the sewage samples studied. The vancomycin and erythromycin resistances of the enterococcal populations were similar in the sewage samples. Resistance to both antibiotics persisted after the treatment process independently of raw sewage flow, faecal origin or size of the human population contributing to sewage. However, sewage of mixed origin (human and animal) presented a lower similarity index for the two bacterial populations compared with that of the other human sewage analysed. SIGNIFICANCE AND IMPACT OF THE STUDY: Although a significant reduction in bacterial populations was observed, the persistence of VRE and ERE strains in the same proportions in sewage suggests that there is no selective elimination of bacterial populations during the treatment processes. The ability of antibiotic resistance strains to survive sewage treatment systems should be considered in certain water reuse programmes.     

人工湿地中降解有机污染物细菌的分离筛选

采用平板划线法从人工湿地污水处理系统底泥和污水中分离出 2 3株细菌 ,在实验室条件下检测了这些细菌对灭菌污水和自然污水CODcr的去除效果 ,结果表明其中 8株细菌 (DN -4、DN -5、DN- 6、DN -10、DN -11、DN -12、DN- 13、WS- 5 )对灭菌污水和自然污水的CODcr均有较高的去除率 ,胞外酶检测表明该 8株细菌均能产生淀粉酶和接触酶 ,这些细菌具有潜在的应用价值。     

高效降解生活污水中COD的根际微生物的分离筛选

采用平板划线法从人工湿地的芦苇、美人蕉的根际土壤中分离出若干细菌、真菌、放线菌菌株,在实验室条件下检测了这些菌株对灭菌生活污水和自然生活污水COD的去除效果,结果表明4株细菌、1株放线菌、1株真菌对灭菌生活污水和自然生活污水COD均具有较高的去除率。4株细菌在降解灭菌生活污水COD的去除率在48 h后依次为75.4%、78.7%、83.5%、69.8%;其在降解未灭菌生活污水COD的去除率在48 h后依次为43.4%、47.8%、50.7%、36.8%;真菌对灭菌和未灭菌生活污水COD的去除率在48 h后分别为60.2%、41.3%;放线菌对灭菌和自然生活污水COD 48 h后的去除率分别为57.8%、46.4%。这几株高效降解COD的湿地根际微生物具有潜在的应用价值。     

海口市污水处理厂活性污泥中细菌的分离鉴定及耐药性分析

为了解海口市白沙门污水处理厂活性污泥中细菌抗生素耐性情况,采用平板分离技术分离、纯化细菌,并通过BIOLOG微生物鉴定系统对筛选到的细菌进行鉴定,同时采用Kirby-Bauer纸片琼脂扩散法进行药敏试验并进行抗生素耐性分析。本研究共分离到18株细菌,分属8个属,14个种,其中G+和G-均为9株。抗生素药敏性试验结果表明,所有菌株均耐药,菌株单重耐药率、双重耐药性及多重耐药性分别为50%、38.9%、和11.1%。菌株对9种常用抗生素:头孢他啶、环丙沙星、庆大霉素、链霉素、氨苄西林、红霉素、氯霉素、四环素、卡那霉素的耐药率分别为61.1%、0%、5.6%、16.7%、50%、16.7%、11.1%、0%、5.6%。综上所述,白沙门污水处理厂活性污泥中的细菌耐药性比较严重,存在潜在的环境生态和人畜健康风险。本研究揭示了当前白沙门污水处理厂活性污泥中细菌对常见抗生素耐药的严重现状,为建议污水处理厂加强出水及污泥中抗生素耐药性及耐药基因的检测并评估其生态影响提供基础,避免出水及污泥中的抗性菌和耐药基因可能带来的风险问题。     

Microbial Ecology of Activated Sludge: I. Dominant Bacteria

Over 300 bacterial strains were isolated from seven samples of activated sludge by plating on sewage agar. Gram-negative bacteria of the genera Zoogloea and Comamonas predominated. Many isolates (51%) showed sudanophilic inclusions of poly-β-hydroxybutyric acid, whereas 34% accumulated iodophilic material on media containing starch. A large number required either vitamins or amino acids, or both, for growth. None of the isolates tested for their ability to bring about changes in autoclaved sewage produced an effluent comparable in quality to the activated sludge control, although the Zoogloea did produce activated sludgelike flocs. A study of 150 bacterial strains isolated from raw sewage revealed that they differed from the sludge isolates in several respects. Coliforms, which constitute nearly a quarter of the sewage isolates, were rarely encountered in sludge.     

好氧反硝化微生物多样性及其反硝化功能初步研究

为研究污水厂/养殖池中好氧反硝化微生物的多样性及菌株反硝化能力,本研究采集了位于福建省厦门市和漳州市的污水处理厂、排污口、污水池、对虾养殖池的污水和污泥样品进行好氧反硝化微生物的富集、分离、鉴定和功能筛选。分别以NaNO3、NaNO2作为唯一氮源共分离纯化获得128株单菌。其中以NaNO3为唯一氮源分离得到63株,以NaNO2为唯一氮源分离得到65株。16SrRNA基因序列分析表明,128株单菌分属于γ-变形菌纲(Gammaproteobacteria,58.6%)、芽胞杆菌纲(Bacilli,6.4%)、放线菌纲(Actinobacteria,11.7%)、α-变形菌纲(Alphaproteobacteria,8.6%)、纤维菌纲(Cytophagia,2.3%)、鞘脂杆菌纲(Sphingobacteria,0.8%)和黄杆菌纲(Flavobacteria,1.6%)7个纲中的38个属。其中盐单胞菌属(Halomonas,29.7%)和芽胞杆菌属(Bacillus,12.5%)为优势菌属,并且广泛存在于各个样品中。反硝化功能初筛结果表明,35株菌能在72h内将20mg·L-1 NO-3-N/NO-2-N完全去除;复筛结果表明,21株菌能在72h内将100 mg·L-1 NO-3-N/NO-2-N完全去除,并且盐单胞菌属、卓贝尔氏菌属(Zobellella)、斯塔普氏菌属(Stappia)及节杆菌属(Arthrobactor)反硝化效果较好,其中斯塔普氏属是首次报道具有好氧反硝化功能。本研究结果表明,污水场/养殖池等环境中可培养反硝化细菌多样性丰富,同时高效反硝化菌的获得也为含氮废水的生物处理提供了良好的菌种资源。     

Isolation and characterization of Rhodococcus sp. strains TMP2 and T12 that degrade 2,6,10,14-tetramethylpentadecane (pristane) at moderately low temperatures

Branched alkanes including 2,6,10,14-tetramethylpentadecane (pristane) are more resistant to biological degradation than straight-chain alkanes especially under low-temperature conditions, such as 10 degrees C. Two bacterial strains, TMP2 and T12, that are capable of degrading pristane at 10 degrees C were isolated and characterized. Both strains grew optimally at 30 degrees C and were identified as Rhodococcus sp. based on the 16S rRNA gene sequences. Strain T12 degraded comparable amounts of pristane in a range of temperatures from 10 to 30 degrees C and strain TMP2 degraded pristane similarly at 10 and 20 degrees C but did not degrade it at 30 degrees C. These data suggest that the strains have adapted their pristane degradation system to moderately low-temperature conditions.     

Some properties of methylotrophic bacteria isolated from sewage sludges derived from mechanical and biological sewage treatment plants.

The presented studies were carried out to get more information about physiological properties of methylotrophic bacteria selected from sewage sludges derived from mechanical and biological sewage treatment plants. All the isolated bacterial strains belonged to facultative methylotrophs. The majority of them utilized glucose, starch and lipids. Moreover, most of them were also found to possess proteolytic properties and were able to hydrolyze urea but they were incapable of asparagine ammonification.     

Microbial degradation of components of waste water from phenol-producing industry

Processes of aerobic biodegradation of components of phenol production sewage (phenol, acetophenone, dimethylphenylcarbinol, cumene hydroperoxide, alpha-methylstyrene, benzoate, and p-hydroxybenzoate) by bacterial strains obtained from the collection of Saratov Institute of Biocatalysis were studied. The metabolic reactions were shown to be oxidative and have a common catabolic sequence (cumene hydroperoxide-dimethylphenyl-carbinol alpha-methylstyrene-acetophenone-phenyl acetate-phenol-pyrocatechol-aromatic ring breakage). Benzoate and p-hydroxybenzoate were degraded through the formation of pyrocatechol and protocatechuate, respectively. Metabolic pathways were similar in model mixtures of components and sewage samples.     

医院污水中硝化细菌的筛选及高通量鉴定

为了减轻医院污水中氮元素对环境的污染,经富集驯化从医院污水样品中筛选出了呈硝化阳性的硝化菌菌群HH-C、HH-E、HH-I、HH-J,采用高通量方法对硝化菌群进行鉴定,用氨氮、亚硝酸盐和硝酸盐快速测定试剂盒对其进行定性测定,再经单菌筛选纯化出10株呈硝化阳性的硝化细菌HH-3、HH-6、HH-8、HH-12、HH-13、HH-16、HH-18、HH-19、HH-21、HH-22,经复筛对这10株菌进行功能验证,选出了3株COD和氨氮降解率高的菌HH-12、HH-13和HH-22并应用到医院污水的处理中。