陕西定边盐湖嗜盐菌A393的分离及其种属鉴定

采用高盐选择性培养基和稀释平板法,从陕西定边盐湖土壤样本中,分离筛选获得嗜盐菌株A393,通过形态学观察、生理生化特征和系统发育学16S rDNA序列分析鉴定嗜盐菌株A393分类学地位。获得的A393最适生产盐浓度在8%～20%。表型特征和16S rDNA序列分析结果初步鉴定其为中度嗜盐菌,属于海球菌属(Marinococcus sp.)菌株。     

一株耐盐菌Halomonas sp. A20的分离及降解糖精钠废水的特性

【背景】糖精钠废水是一种难处理的高盐有机工业废水。【目的】为了提高糖精钠废水的生物降解效果,需要研究糖精钠废水降解菌的特性。【方法】采用纯培养技术从处理糖精钠废水的多级生物接触氧化系统内的活性污泥中分离筛选糖精钠废水降解菌,对分离菌株的形态特征、生理生化特性和16S rRNA基因序列进行分析,利用单因素实验和响应面法考察分离菌株降解糖精钠废水的最佳条件。【结果】筛选获得一株糖精钠废水降解菌A20,归属于盐单胞菌属(Halomonas),当糖精钠废水的盐分为5%,菌接种量为15%,pH值为8.0,温度为30°C时,菌株A20对糖精钠废水中的化学需氧量(chemical oxygen demand,CODcr)去除率在60%以上;通过响应面法优化,菌株A20降解糖精钠废水的最佳条件为：pH 8.0,温度为30.3°C,接种量为14.1%,其CODcr去除率为65.4%。【结论】分离到一株能高效降解糖精钠废水中有机物的耐盐菌Halomonas sp. A20,可为高盐、高浓度糖精钠废水的处理提供优良的微生物菌种资源。     

一株轻度嗜盐反硝化细菌的分离鉴定和反硝化特性初探

从处理高盐度废水的成熟活性污泥中分离筛选得到1株轻度嗜盐反硝化细菌GYL, 通过对该菌株的形态观察、生理生化实验以及16S rDNA序列分析, 确定该菌株为盐单胞菌(Halomonas sp.)。该菌株能在盐度为10%的培养液中生长, 最适盐度为2%~7%, 最适pH为7.5~8.5, 最佳碳源为蔗糖, 在25°C~30°C的温度范围内脱氮效率达到80%以上。对该菌株的异养硝化能力进行了测定, 其对氨氮的去除率可达98.3%, 说明该菌株可实现同步硝化反硝化, 即该菌可以独立完成生物脱氮的全部过程。     

嗜盐菌HBCC-2的16S rRNA基因测序分析及其培养特性

从连云港台南盐场海盐生产区中分离纯化到一株嗜盐古菌HBCC-2,该菌株经PCR扩增后,测定其16S rRNA基因序列,采用BLAST软件对基因库中基因序列进行同源性比较,选取其相似性序列,采用Clustalx1.8和MEGA3.1软件对其16S rDNA序列进行了系统发育分析研究,结果表明HBCC-2菌株与菌株Halorubrum sp.GSL5.48的相似性达99%,结合其形态观察及生理生化反应特性,初步确定该菌株属于嗜盐红菌属(Halorubrum),菌株HBCC-2的16S rDNA序列已登陆到GenBank,其序列号为EF687739.通过比较不同NaCl浓度、pH和培养温度对该菌株生长的影响情况,研究了该菌株的生长特性,结果表明NaCl浓度为4mol/L、温度为35℃和pH为7.0的培养条件下其生长最佳.     

盐地碱蓬内生中度嗜盐菌的分离与系统发育多样性分析

为了了解东营滨海盐地碱蓬植株内生中度嗜盐菌的多样性,采用传统分离鉴定技术和基于16S rRNA序列分析对样品中可培养细菌的多样性进行研究。根据其生理生化特征、16S rRNA序列测定和系统发育分析,分离获得的15株内生菌可分为4个类群,涉及Halomonadaceae科的Chromohalobacter属、Kushneria属、Halomonas属以及Bacillaceae科的Bacillus属。类群I中4菌株的16S rRNA序列与Chromohalobacter israelensis的最高相似性为95%。类群II共7株菌,归属于Kushneria属,是碱蓬内生中度嗜盐菌中的优势类群。类群III菌株的16S rRNA序列与一株尚无明确分类地位的Gammaproteobacteria亚门耐盐固氮细菌Haererehalobacter sp.JG11的相似性为99%。类群IV中的芽孢杆菌的16S rRNA序列与已知细菌的相似性为96%,很可能代表了Bacillus属的新种。各种水解酶类的分析表明,在分离的15株菌中有3株菌产蛋白酶,14株产酯酶,8株产DNA酶,11株产半乳糖苷酶,14株产脲酶。研究结果揭示,盐地碱蓬中存在较为丰富的中度嗜盐菌多样性和系统发育多样性,并且潜藏着较多的新的微生物类群。     

内蒙古锡林浩特地区嗜盐古菌多样性的研究

从内蒙古锡林浩特地区3个不同的盐湖中共分离到165株古菌,通过ARDRA分析后得到不同的类群,从各个类群中随机选取1~2个代表菌株进行16S rDNA序列测定和系统发育的分析。结果表明分离的菌株分布在Halorubrum,Natronococcus,Natronorubrum,Haloterrigena,Halorhabdus,Halobiforma,Haloarcula,Haloferax8个属和另外两个分支中,表现了锡林浩特地区嗜盐古菌的多样性。部分菌株的16S rDNA序列同源性低于97%,可能是潜在的新属或新种,代表了该地区嗜盐古菌的独特类型。     

连云港台北和盐城三圩盐田土壤嗜盐菌多样性研究

盐田土壤嗜盐微生物对盐田生态系统的良性循环和盐的生产至关重要.本文对江苏连云港台北盐田土壤和盐城三圩盐田土壤的嗜盐细菌和古菌的多样性进行了研究,结果表明两地盐土嗜盐细菌和古菌的分布具有相似性和独特性.采用培养法从两地盐土中共分离到17株嗜盐细菌,其中Halomonas为两地盐土共有的嗜盐细菌,而Halobacillus和Pontibacillus仅在三圩盐土中发现.通过非培养的16S rDNA基因文库法从两地盐土中发现了13种嗜盐古菌,台北盐土有Halobacterium和Haloplanus,三圩盐土有Halobacterium, Natronobacterium, Halogeometricum和Haloarcula. 10个嗜盐古菌的16S rDNA和GenBank已知序列的同源性为92%～97%.可能为这些属中的新该研究为盐田环境嗜盐微生物资源的开发和利用奠定了基础.     

青藏高原察尔汗盐湖地区可培养中度嗜盐菌的群落结构与多样性

【目的】研究青海察尔汗盐湖地区的可培养中度嗜盐菌的群落结构及多样性。【方法】采用多种选择性培养基进行中度嗜盐菌的分离、培养;通过16S r RNA基因序列扩增、测定,根据序列信息,进行系统进化树构建、群落结构组成分析及多样性指数计算。【结果】从察尔汗盐湖卤水及湖泥中分离到中度嗜盐菌421株,合并重复菌株后共83株中度嗜盐菌。菌株16S rRNA基因序列信息显示,4株中度嗜盐菌为潜在的新分类单元。83株嗜盐细菌分布于3个门的6个科16个属。其中,Bacillus属、Oceanobacillus属和Halomonas属为优势属。多样性结果显示,水样中的菌株多样性高于泥样,而泥样中的菌株优势度高于水样。【结论】察尔汗盐湖中度嗜盐菌具有丰富的遗传多样性,种群种类丰富,优势菌群集中,该盐湖地区存在可分离培养的中度嗜盐菌的疑似新物种。     

新疆地区盐湖的中度嗜盐菌16S rDNA全序列及DNA同源性分析

通过数值分类和16S rDNA PCR-RFLP分析,对分离自新疆地区的中度嗜盐革兰氏阴性菌进行研究,发现了一个新类群。在此基础上,进行了中心株AI－3的16S rDNA全序列分析,并与中度嗜盐菌已知种和相关种进行比较,得到系统发育树状图。在此树状图中,大多数参比菌株聚在一起,其16S rDNA全序列的同源性在96％以上,而AI－3与参比菌株的16S rDNA全序列相比,其相似性低于75％。但是,AI－3与Alcanivorax borkumensis^[1]的16S rDNA全序列的相似性为96％,与Halobacillus litoralis的16S rDNA全序列的相似性为99％,三者构成一个独立的发育分支。这说明在系统发育上,AI－3与参比菌株属于不同的分支,是一个新的类群。在新类群内,菌株之间的DNA同源性大于70％,而中心株AI－3与标准菌株伸长盐单胞菌（Halomonas elongata)的DNA同源性为44％,表明新分离的菌株可能构成一个新种群。     

新疆罗布泊周边地区极端环境嗜盐菌的研究

为了研究分析新疆罗布泊周边地区pH值5-6的盐湖嗜盐古菌资源。从湖中分离筛选出一批嗜盐古菌,对其进行了生理生化特性研究,发现其中6株菌的生理特性和产酶特性比较特殊,并采用PCR方法扩增出其16SrRNA基因（16S rDNA）,并测定了基因的核苷酸序列。基于16S rDNA序列的同源性比较以及16S rDNA序列的系统发育学研究表明,菌株B20-RDX是盐盒菌属Haloarchaeon属中新种成员,GenBank登录号为FJ561285,该菌株为革兰氏阴性菌,最适盐浓度25%,最适pH 8.0,能产过氧化氢酶、淀粉酶,对四环素有抗性,能利用精氨酸和丁二酸盐。迄今为止,国内极少有关罗布泊周边地区极端环境微生物研究的报道,该研究可为今后研究同类极端环境中新的物种资源开发应用以及微生物多样性研究提供素材和参考。     

Microbial diversity in hypersaline wastewater: the example of tanneries

In contrast to conventional wastewater treatment plants and saline environments, little is known regarding the microbial diversity of hypersaline wastewater. In this study, the microbial communities of a hypersaline tannery effluent, and those of three treatment systems operating with the tannery effluent, were investigated using 16S rDNA phylogenetic markers. The comparative analysis of 377 bacterial sequences revealed the high diversity of this type of hypersaline environment, clustering within 193 phylotypes (≥ 97% similarity) and covering 14 of the 52 divisions of the bacterial domain, i.e. Proteobacteria, Bacteroidetes, Firmicutes, Actinobacteria, Chlorobi, Planctomycetes, Spirochaetes, Synergistes, Chloroflexi, Thermotogae, Verrucomicrobia, OP3, OP11 and TM7. Most of the phylotypes were related to halophilic and pollutant-degrading bacteria. Using statistical analysis, the diversity of this type of environment was compared to that of other environmental samples selected on the basis of their salinity, oxygen content and organic load.     

Diversity of halophilic archaea from six hypersaline environments in Turkey

The diversity of archaeal strains from six hypersaline environments in Turkey was analyzed by comparing their phenotypic characteristics and 16S rDNA sequences. Thirty-three isolates were characterized in terms of their phenotypic properties including morphological and biochemical characteristics, susceptibility to different antibiotics, and total lipid and plasmid contents, and finally compared by 16S rDNA gene sequences. The results showed that all isolates belong to the family Halobacteriaceae. Phylogenetic analyses using approximately 1,388 bp comparisions of 16S rDNA sequences demonstrated that all isolates clustered closely to species belonging to 9 genera, namely Halorubrum (8 isolates), Natrinema (5 isolates), Haloarcula (4 isolates), Natronococcus (4 isolates), Natrialba (4 isolates), Haloferax (3 isolates), Haloterrigena (3 isolates), Halalkalicoccus (1 isolate), and Halomicrobium (1 isolate). The results revealed a high diversity among the isolated halophilic strains and indicated that some of these strains constitute new taxa of extremely halophilic archaea.     

Diversity of Archaea in hypersaline environments characterized by molecular-phylogenetic and cultivation studies

The diversity of Archaea from three different hypersaline environments was analyzed and compared by polymerase chain reaction (PCR)-based molecular phylogenetic techniques and cultivation approaches. The samples originated from a crystallization pond of a solar saltern in Spain (FC); an alkaline lake in Nevada, USA, (EMF); and a small pond from a slag heap of a potassium mine in Germany (DIE). Except for two 16S rDNA sequences that were related to crenarchaeota from soil and did not apparently belong to the indigenous halophilic community, all sequences recovered from environmental DNA or cultivated strains grouped within the Halobacteriaceae. Mostly 16S rDNA sequences related to the genera Halorubrum and Haloarcula were detected in sample FC, and organisms belonging to these genera were also recovered by cultivation. In contrast, sequences related to five different groups of halophilic archaea were amplified from sample DIE (including novel lineages with only uncultivated phylotypes), but the organisms that were cultivated from this sample fell into different groups (i.e., Natronococcus, Halorubrum, or unaffiliated) and did not overlap with those predicted using the culture-independent approach. With respect to the highly alkaline sample, EMF, four groups were predicted from the environmental 16S rDNA sequences, two of which ( Natronomonas and Haloarcula) were also recovered through cultivation together with Natronococcus isolates. In summary, we found that halophilic archaea dominate the archaeal populations in these three hypersaline environments and show that culturability of the organisms predicted by molecular surveys might strongly depend on the habitat chosen. While a number of novel halophilic archaea have been isolated, we have not been able to cultivate representatives of the new lineages that were detected in this and several other environmental studies.     

PCR and blot hybridization for rapid identification of Haloferax species

Based on the amplification of a 16S rDNA, a PCR assay for the identification of species of Haloferax to genus level was performed. Two variable regions of the 16S rDNA in Haloferax spp. were selected as genus-specific primers for the PCR assay and hybridization probe. Five genera of halophilic Archaea and Escherichia coli were examined as outside groups. Using this approach, all strains of Haloferax spp. were positive. In contrast, all species belonging to the most closely related genera, including Natrinema, Halorubrum, Halobacterium, and Haloarcula, were negative. In addition, the mass bloom of halophilic Archaea that develops in the El-Mallahet saltern of Alexandria City was positive using the same approach. This assay, which does not require pure cultures of microorganisms, is a specific and rapid method for identifying Haloferax spp. in hypersaline environments.     

Biodegradation of Phenanthrene by a Halophilic Bacterial Consortium Under Aerobic Conditions

A halophilic bacterial consortium that degraded phenanthrene was developed from oil-contaminated saline soil containing 10% salinity. The biodegradation of phenanthrene occurred at 5%, 10%, and 15% salinity, whereas no biodegradation took place at 0.1% and 20% salinity. A 16S rRNA gene analysis showed that all sequences from the denaturing gradient gel electrophoresis profile were similar to those of halophilic bacteria. This is the first report of a halophilic bacterial consortium capable of degrading phenanthrene under hypersaline conditions.     

新疆塔里木盆地可培养嗜盐放线菌系统发育多样性

应用纯培养手段和基于16S rRNA基因序列的系统发育分析,对从塔里木盆地高盐环境土壤样品中分离的18株可培养嗜盐放线菌多样性进行了研究.实验结果表明,18株嗜盐放线菌可3个(GlycomycetaceaePseudonocardineae和Nocardiopsaceae),在有效发表的5个属的嗜盐放线菌中有4个属的嗜盐放线菌被分离到.多数菌株属于Actinopolyspora属(38.9%),Nocardiopsis属(27.8%)和Streptomonospora属(22.2%),是塔里木盆地高盐环境中嗜盐放线菌的优势类群.这些分离菌株中,菌株YIM 92370与最近种的相似性为92%,在Glycomycetaceae科内形成一个独立的分支,极有可能代表Glycomycetaceae科的一个新属.研究结果表明塔里木盆地高盐环境中存在有较为丰富的嗜盐放线菌系统发育多样性,并且潜藏着新类型的放线菌资源.     

嗜盐菌耐盐机制相关基因的研究进展

嗜盐微生物能够在高盐环境中生存,其耐盐机制一直是微生物学家研究的热点。目前嗜盐微生物耐盐机制的研究主要集中在细胞吸K+排Na+作用、胞内积累小分子相容性溶质及嗜盐酶的氨基酸组成特性三个方面。文章从基因水平综述了嗜盐菌的耐盐机制,并对其在高盐废水处理上的应用进行讨论与展望。