Isolation and description ofHaloanaerobium praevalens gen. nov. and sp. nov., an obligately anaerobic halophile common to Great Salt Lake sediments

A new halophilic species is described that was isolated from the hypersaline (>20%) surface sediments of Great Salt Lake, Utah, via transfer from MPN end-dilution tubes that contained a complex organic medium. The organism was an obligate anaerobe that proliferated optimally at approximately 13% salt, but did not grow significantly at <2% or ≥30% salt. It stained Gram-negative, was nonmotile, nonsporing, and contained an outer-wall membranous layer. The complex lipids of the organism were fatty acid esters that did not change dramatically during growth at 5% or 25% NaCl. The DNA base composition was 27.0±1 mol% guanosine plus cytosine. The temperature range for growth was >5°C and <60°C, the pH range was between 6.0 and 9.0. The doubling time for growth in complex medium with 25% NaCl was 7 h. The organism utilized carbohydrates, peptides, and amino acids. Butyrate, acetate, propionate. H₂, and CO₂ were the major fermentation end products formed. Glucose, mannose, fructose,n-acetyl glucosamine, and pectin were used as energy sources for growth. Methylmercaptan was produced from methionine degradation. The nameHaloanaerobium praevalens gen. nov. sp. nov. is proposed for the type strain GSL which has been deposited as DSM 2228. The taxonomic relationships ofH. praevalens to other obligate halophiles and anaerobes, as well as its biological role in the Great Salt Lake microbial ecosystem, are discussed.     

Production of beta-xylanase and beta-xylosidase by the extremely halophilic archaeon Halorhabdus utahensis

The extremely halophilic archaeon, Halorhabdus utahensis, isolated from the Great Salt Lake, Utah, produced beta-xylanase and beta-xylosidase activities. Both enzymes were active over a broad NaCl range from near zero to 30% NaCl when tested with culture broth. A broad NaCl optimum was observed for beta-xylanase activity between 5% and 15% NaCl, while beta-xylosidase activity was highest at 5% NaCl. Almost half of the maximum activities remained at 27%-30% NaCl for both enzyme activities. When dialyzed culture supernatant and culture broth were employed for determination of beta-xylanase and beta-xylosidase stabilities, approximately 55% and 83% of the initial beta-xylanase and beta-xylosidase activities, respectively, remained after 24 h incubation at 20% NaCl. The enzymes were also shown to be slightly thermophilic; beta-xylanase activity exhibiting two optima at 55 degrees and 70 degrees C, while beta-xylosidase activity was optimal at 65 degrees C. SDS-PAGE and zymogram techniques revealed the presence of two xylan-degrading proteins of approximately 45 and 67 kDa in culture supernatants. To our knowledge, this paper is the first report on hemicellulose-degrading enzymes produced by an extremely halophilic archaeon.     

Isolation and characterisation of Thiobacillus halophilus sp. nov., a sulphur-oxidising autotrophic eubacterium from a Western Australian hypersaline lake

The isolation of a novel obligately chemolithotrophic, halophilic and extremely halotolerant Thiobacillus from a hypersaline lake is described. Attempts to demonstrate sulphur- and ferrous iron-oxidizing chemolithotrophs in neighbouring hypersaline lakes were unsuccessful. The organism isolated differs from any other Thiobacillus species previously described and is formally named as Thiobacillus halophilus. It possesses ribulose bisphosphate carboxylase and grows chemolithoautotrophically on thiosulphate, tetrathionate and sulphur, oxidising them to sulphate. Kinetic constants for oxidation of sulphide, thiosulphate, trithionate and tetrathionate are presented. The organism is obligately halophilic, growing best with 0.8–1.0 M NaCl, and tolerating up to 4 M NaCl. Optimum growth was obtained at about 30° C and pH 7.0–7.3. It contains ubiquinone Q-8 and its DNA contains 45 mol % G+C. Organisms of this type might contribute significantly to the autotrophic fixation of carbon dioxide in some hypersaline extreme environments of the kind described.     

Characterization of brine shrimp Artemia from Cam Ranh Bay in Central Vietnam

Artemia cysts collected from inoculation experiments in Cam Ranh salterns are evaluated for their potential use in aquaculture. Cyst biometrics, hatching quality, naupliar fatty acid profile and naupliar growth were measured and compared to reference Artemia strains. Cyst characteristics reveal that the parthenogenetic strain (PR China) used in inoculations, was eliminated from the environment and that the remaining brine shrimp are likely to be composed of Macau and Great Salt Lake Artemia strains, and of their cross-breds. Differences in cyst diapause deactivation characteristics between Macau and Great Salt Lake Artemia may have resulted in the disappearance of Macau Artemia during the rainy season and the persistence of Great Salt Lake Artemia during the following dry season.     

Sulfate Reduction Dynamics and Enumeration of Sulfate-Reducing Bacteria in Hypersaline Sediments of the Great Salt Lake (Utah, USA)

Bacterial sulfate reduction activity (SRA) was measured in surface sediments and slurries from three sites in the Great Salt Lake (Utah, USA) using radiolabeled 35S-sulfate. High rates of sulfate reduction (363 ± 103 and 6,131 ± 835 nmol cm-3 d-1) were measured at two sites in the moderately hypersaline southern arm of the lake, whereas significantly lower rates (32 ± 9 nmol cm-3 d-1) were measured in the extremely hypersaline northern arm. Bacterial sulfate reduction was strongly affected by salinity and showed an optimum around 5-6% NaCl in the southern arm and an optimum of around 12% NaCl in the more hypersaline northern arm of the lake. High densities of sulfate-reducing bacteria (SRB) ranging from 2.2 × 107 to 6.7 × 108 cells cm-3 were determined by a newly developed tracer MPN-technique (T-MPN) employing sediment media and 35S-sulfate. Calculation of specific sulfate reduction rates yielded values comparable to those obtained in pure cultures of SRB. However, when using a conventional MPN technique with synthetic media containing high amounts of Fe(II), the numbers of SRB were underestimated by 1-4 orders of magnitude as compared to the T-MPN method. Our results suggest that high densities of slightly to moderately halophilic and extremely halotolerant SRB are responsible for the high rates of sulfate reduction measured in Great Salt Lake sediments.     

Competitive exclusion of Cyanobacterial species in the Great Salt Lake

The Great Salt Lake is separated into different salinity regimes by rail and vehicular causeways. Cyanobacterial distributions map salinity, with Aphanothece halophytica proliferating in the highly saline northern arm (27% saline), while Nodularia spumigena occurs in the less saline south (6–10%). We sought to test if cyanobacterial species abundant in the north are competitively excluded from the south, and if southern species are excluded by the high salinity of the north. Autoclaved samples from the north and south sides of each causeway were inoculated with water from each area. Aphanothece, Oscillatoria, Phormidium, and Nodularia were identified in the culture flasks using comparative differential interference contrast, fluorescence, and scanning electron microscopy. Aphanothece halophytica occurred in all inocula, but is suppressed in the presence of Nodularia spumigena. N. spumigena was found only in inocula from the less saline waters in the south, and apparently cannot survive the extremely hypersaline waters of the northern arm. These data suggest that both biotic and abiotic factors influence cyanobacterial distributions in the Great Salt Lake.     

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。     

Ecology and molecular adaptations of the halophilic black yeast Hortaea werneckii

Molecular studies on halophilic adaptations have focused on prokaryotic microorganisms due to a lack of known appropriate eukaryotic halophilic microorganisms. However, the black yeast Hortaea werneckii has been identified as the dominant fungal species in hypersaline waters on three continents. It represents a new model organism for studying the mechanisms of salt tolerance in eukaryotes. Ultrastructural studies of the H. werneckii cell wall have shown that it synthesizes dihydroxynaphthalene (DHN) melanin under both saline and non-saline growth conditions. However, melanin granules in the cell walls are organized in a salt-dependent way, implying the potential osmoprotectant role of melanin. At the level of membrane structure, H. werneckii maintains a sterol-to-phospholipid ratio significantly lower than the salt-sensitive Saccharomyces cerevisiae. Accordingly, membranes of H. werneckii are more fluid over a wide range of NaCl concentrations, indicating high intrinsic salt stress tolerance. Even H. werneckii grown in high NaCl concentrations maintains very low intracellular amounts of potassium and sodium, demonstrating the sodium-excluder character of this organism. The salt-dependent expressions of two HwENA genes suggest roles for them in the adaptation to changing salt concentrations. The high similarity of these ENA ATPases to other fungal ENA ATPases involved in Na⁺/K⁺ transport indicates their potential importance in H. werneckii ion homeostasis. Glycerol is the main compatible solute which accumulates in the cytoplasm of H. werneckii at high salinity, although it seems that mycosporines may also act as supplementary compatible solutes. Salt dependent increase in glycerol synthesis is supported by the identification of two copies of a gene putatively coding for glycerol-3-phosphate-dehydrogenase. Expression of only one of these genes is salt dependent.     

Isolation and Characterization of a Halophilic Methanogen from Great Salt Lake

A halophilic methanogenic microorganism isolated from sediments collected from the southern arm of Great Salt Lake, Utah, is described. Cells were irregular, nonmotile cocci approximately 1.0 μm in diameter and stained gram negative. Colonies from anaerobic plates and roll tubes were foamy, circular, and cream-yellow. Methanol, methylamine, dimethylamine, and trimethylamine supported growth and methanogenesis. Hydrogen-carbon dioxide, formate, and acetate were not utilized. Sodium and magnesium were required for growth; the optimum NaCl concentration ranged between 1.0 and 2.0 M, with the minimum doubling time occurring at 2.0 M. The optimum growth temperature was 35°C, with maximum growth rate occurring at pH 7.5. The DNA base composition was 48.5 mol% guanine + cytosine. SLP is the type strain designation (= ATCC 35705).     

Isolation and characterization of Actinopolyspora halophila, gen. et sp. nov., an extremely halophilic actinomycete.

An actinomycete, isolated as a contaminant of a culture medium containing 25% NaCl, has been classified as Actinopolyspora halophila gen. et sp. nov. in the family Nocardiaceae. The morphology and biochemical characteristics of this organism distinguish it from other members of the family Nocardiaceae and other genera possessing a type IV cell wall. It requires high NaCl concentrations for growth and can grow in saturated NaCl. The lowest concentration permitting growth in liquid medium is 12%, and on solid medium, 10%. Colonies developing at lower salt concentrations contain holes resembling viral plaques. No growth occurred in a medium containing 30% KCl instead of NaCl. This organism can grow in simple media with NH4+ salts as nitrogen source and different sugars and other compounds as carbon source. Though it has a salt requirement almost as great as the extremely halophilic rods and cocci, it differs from these in containing diaminopimelic acid and in sensitivity to lysozyme; both properties suggest that it has a mucopeptide cell wall. It also contains some phospholipids common to other actinomycetes, but does not contain any phytanyl ether linked lipids characteristic of other extremely halophilic bacteria.     

Rhodospirillum sodomense,sp. nov., a Dead Sea rhodospirillum species

A new species of halophilic anoxygenic purple bacteria of the genus Rhodospirillum is described. The new organism, isolated from water/sediment of the Dead Sea, was vibrio-shaped and an obligate halophile. Growth was best at 12% NaCl, with only weak growth occurring at 6% or 21% NaCl. Growth occurred at Mg²⁺ concentrations up to 1 M but optimal growth was obtained at 0.05–0.1 M Mg²⁺. Bromide was well tolerated as an alternative anion to chloride. The new organism is an obligate phototroph, growing photoheterotrophically in media containing yeast extract and acetate or a few other organic compounds. Growth of the Dead Sea Rhodospirillum species under optimal culture conditions was slow (minimum t_d 20 h). Cells contained bacteriochlorophyll a and carotenoids of the spirilloxanthin series and mass cultures were pink in color. Absorption spectra revealed the presence of a B875 (light-harvesting I) but no B800/B850 (light-harvesting II) photopigment complex. The new organism shares a number of properties with the previously described halophilic phototrophic bacterium Rhodospirillum salinarum and was shown to be related to this phototroph by 16S rRNA sequencing. However, because of its salinity requirements, photosynthetic properties, and isolation from the Dead Sea, the new phototroph is proposed as a new species of the genus Rhodospirillum, R. sodomense.     

<Emphasis Type="Italic">Marinimicrobium haloxylanilyticum</Emphasis> sp. nov., a new moderately halophilic,polysaccharide-degrading bacterium isolated from Great Salt Lake,Utah

A new moderately halophilic, strictly aerobic, Gram-negative bacterium, strain SX15^T, was isolated from hypersaline surface sediment of the southern arm of Great Salt Lake (Utah, USA). The strain grew on a number of carbohydrates and carbohydrate polymers such as xylan, starch, carboxymethyl cellulose and galactomannan. The strain grew at salinities ranging from 2 to 22% NaCl (w/v). Optimal growth occurred in the presence of 7–11% NaCl (w/v) at a temperature of 35°C and a pH of 6.7–8.2. Major whole-cell fatty acids were C16:0 (30.5%), C18:0 (14.8%), C18:1ω7c (13.1%) and C12:0 (7.8%). The G+C content of the DNA was 60 ± 0.5 mol%. By 16S rRNA gene sequence analysis, strain SX15^T was shown to be affiliated to members of the gammaproteobacterial genus Marinimicrobium with pair wise identity values of 92.9–94.6%. The pheno- and genotypic properties suggest that strain SX15^T represents a novel species of the genus Marinimicrobium for which the name Marinimicrobium haloxylanilyticum is proposed. The type strain is SX15^T (= DSM 23100^T = CCUG 59572^T).     

Identification of several intracellular carbohydrate-degrading activities from the halophilic archaeon Haloferax mediterranei

Three different amylolytic activities, designated AMY1, AMY2, and AMY3 were detected in the cytoplasm of the extreme halophilic archaeon Haloferax mediterranei grown in a starch containing medium. This organism had also been reported to excrete an α-amylase into the external medium in such conditions. The presence of these different enzymes which are also able to degrade starch may be related to the use of the available carbohydrates and maltodextrins, including the products obtained by the action of the extracellular amylase on starch that may be transported to the cytoplasm of the organism. The behavior of these intracellular hydrolytic enzymes on starch is reported here and compared with their extracellular counterpart. Two of these glycosidic activities (AMY1, AMY3) have also been purified and further characterized. As with other halophilic enzymes, they were salt dependent and displayed maximal activity at 3 M NaCl, and 50°C. The purification steps and molecular masses have also been reported. The other activity (AMY2) was also detected in extracts from cells grown in media with glycerol instead of starch and in a yeast extract medium. This enzyme was able to degrade starch yielding small oligosaccharides and displayed similar halophilic behavior with salt requirement in the range 1.5–3 M NaCl. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

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。     

Salt-induced changes in lipid composition and membrane fluidity of halophilic yeast-like melanized fungi

The halophilic melanized yeast-like fungi Hortaea werneckii, Phaeotheca triangularis, and the halotolerant Aureobasidium pullulans, isolated from salterns as their natural environment, were grown at different NaCl concentrations and their membrane lipid composition and fluidity were examined. Among sterols, besides ergosterol, which was the predominant one, 23 additional sterols were identified. Their total content did not change consistently or significantly in response to raised NaCl concentrations in studied melanized fungi. The major phospholipid classes were phosphatidylcholine and phosphatidylethanolamine, followed by anionic phospholipids. The most abundant fatty acids in phospholipids contained C₁₆ and C₁₈ chain lengths with a high percentage of C18:2^9,12. Salt stress caused an increase in the fatty acid unsaturation in the halophilic H. werneckii and halotolerant A. pullulans but a slight decrease in halophilic P. triangularis. All the halophilic fungi maintained their sterol-to-phospholipid ratio at a significantly lower level than did the salt-sensitive Saccharomyces cerevisiae and halotolerant A. pullulans. Electron paramagnetic resonance (EPR) spectroscopy measurements showed that the membranes of all halophilic fungi were more fluid than those of the halotolerant A. pullulans and salt-sensitive S. cerevisiae, which is in good agreement with the lipid composition observed in this study.Communicated by W.D. Grant     

Sambhar Salt Lake

The saline and alkaline brines from the Sambhar Salt Lake (SSL), both from the main lake and from the solar evaporation pans at Sambhar Salt Limited, Sambhar, Rajasthan, India, were studied with respect to their chemical composition and presence of red, extremely haloalkaliphilic archaebacteria. The brines had pH values of 9.5±0.2 and a total salt content ranging from 7% (w/v) to more than 30% (w/v). Sodium chloride, sodium carbonate, sodium bicarbonate and sodium sulphate were the principal salts present in these brines which lacked divalent cations (calcium and magnesium). Six strains of red, extremely haloalkaliphilic bacteria, designated SSL 1 to SSL 6, were isolated. All the isolates showed obligate requirements for sodium chloride (>15%, w/v) and high pH (>9.0). Magnesium ions were required in traces for maintaining morphological structure and pigmentation. All these strains possessed the diether core lipids, phosphatidylglycerol (PG), phosphatidylglycerophosphate (PGP), and bacterioruberins characteristic of halophilic archaebacteria. The strains were assigned to the newly proposed genus Natronobacterium.Part of the paper was presented by the authors at XIV International Congress of Microbiology 7–13 September 1986, Manchester, UK     

Phylogenetic diversities and community structure of members of the extremely halophilic Archaea (order Halobacteriales) in multiple saline sediment habitats

We investigated the phylogenetic diversity and community structure of members of the halophilic Archaea (order Halobacteriales) in five distinct sediment habitats that experience various levels of salinity and salinity fluctuations (sediments from Great Salt Plains and Zodletone Spring in Oklahoma, mangrove tree sediments in Puerto Rico, sediment underneath salt heaps in a salt-processing plant, and sediments from the Great Salt Lake northern arm) using Halobacteriales-specific 16S rRNA gene primers. Extremely diverse Halobacteriales communities were encountered in all habitats, with 27 (Zodletone) to 37 (mangrove) different genera identified per sample, out of the currently described 38 Halobacteriales genera. With the exception of Zodletone Spring, where the prevalent geochemical conditions are extremely inhospitable to Halobacteriales survival, habitats with fluctuating salinity levels were more diverse than permanently saline habitats. Sequences affiliated with the recently described genera Halogranum, Halolamina, Haloplanus, Halosarcina, and Halorientalis, in addition to the genera Halorubrum, Haloferax, and Halobacterium, were among the most abundant and ubiquitous genera, suggesting a wide distribution of these poorly studied genera in saline sediments. The Halobacteriales sediment communities analyzed in this study were more diverse than and completely distinct from communities from typical hypersaline water bodies. Finally, sequences unaffiliated with currently described genera represented a small fraction of the total Halobacteriales communities, ranging between 2.5% (Zodletone) to 7.0% (mangrove and Great Salt Lake). However, these novel sequences were characterized by remarkably high levels of alpha and beta diversities, suggesting the presence of an enormous, yet-untapped supply of novel Halobacteriales genera within the rare biosphere of various saline ecosystems.     

Production of surfactant and detergent-stable,halophilic, and alkalitolerant alpha-amylase by a moderately halophilic <Emphasis Type="Italic">Bacillus</Emphasis> sp. Strain <Emphasis Type="Italic">TSCVKK</Emphasis>

A moderately halophilic alkalitolerant Bacillus sp. Strain TSCVKK, with an ability to produce extracellular halophilic, alkalitolerant, surfactant, and detergent-stable alpha-amylase was isolated from soil samples obtained from a salt-manufacturing industry in Chennai. The culture conditions for higher amylase production were optimized with respect to NaCl, substrate, pH, and temperature. Maximum amylase production of 592 mU/ml was achieved in the medium at 48 h with 10% NaCl, 1% dextrin, 0.4% yeast extract, 0.2% tryptone, and 0.2% CaCl₂ at pH 8.0 at 30 °C. The enzyme activity in the culture supernatant was highest with 10% NaCl at pH 7.5 and 55 °C. The amylase that was partially purified by acetone precipitation was highly stable in various surfactants and detergents. Glucose, maltose, and maltooligosaccharides were the main end products of starch hydrolysis indicating that it is an alpha-amylase.     

Characterization and origin of polar dissolved organic matter from the Great Salt Lake

Polar dissolved organic matter (DOM) was isolated from a surface-water sample from the Great Salt Lake by separating it from colloidal organic matter by membrane dialysis, from less-polar DOM fractions by resin sorbents, and from inorganic salts by a combination of sodium cation exchange followed by precipitation of sodium salts by acetic acid during evaporative concentration. Polar DOM was the most abundant DOM fraction, accounting for 56% of the isolated DOM. Colloidal organic matter was ¹⁴C-age dated to be about 100% modern carbon and all of the DOM fractions were ¹⁴C-age dated to be between 94 and 95% modern carbon. Average structural models of each DOM fraction were derived that incorporated quantitative elemental and infrared, ¹³C-NMR, and electrospray/mass spectrometric data. The polar DOM model consisted of open-chain N-acetyl hydroxy carboxylic acids likely derived from N-acetyl heteropolysaccharides that constituted the colloidal organic matter. The less polar DOM fraction models consisted of aliphatic alicyclic ring structures substituted with carboxyl, hydroxyl, ether, ester, and methyl groups. These ring structures had characteristics similar to terpenoid precursors. All DOM fractions in the Great Salt Lake are derived from algae and bacteria that dominate DOM inputs in this lake.     

运城盐湖细菌群落结构及生态多样性分析

运城盐湖作为一个人类活动深入参与的高盐环境,其中的细菌群落结构及生态多样性既有盐湖环境的共性,又有自身的特殊性。【目的】运城盐湖湖水颜色丰富,蕴含着大量嗜盐及耐盐微生物资源。为了深入探究运城盐湖细菌资源分布规律,对不同水域中细菌多样性和群落结构进行研究,探讨运城盐湖不同水域中细菌群落结构的变化规律。【方法】基于16S rRNA基因的扩增子高通量测序,对运城盐湖不同水域的细菌群落结构进行分析,同时对微生物的潜在代谢功能进行预测。【结果】运城盐湖不同水域中的优势细菌类群有所差异,在盐湖中部,假单胞菌门(Pseudomonadota)、放线菌门(Actinobacteriota)和拟杆菌门(Bacteroidota)是优势类群;而在运城盐湖东部,芽孢杆菌门(Bacillota)则是主要类群;在运城盐湖西部,髌骨菌门(Patescibacteria)类群较为丰富。对运城盐湖不同区域的细菌多样性进行分析,数据显示盐湖中部浅黄色湖水中微生物多样性显著高于盐湖东部和西部区域,但盐湖中部红色湖水区域的微生物多样性较低。另外,在盐湖中部,湖水颜色不同的区域细菌物种分布也具有较大的差异。对运城盐湖细菌代谢功能进行预测分析发现,在盐湖不同区域的微生物参与的代谢通路活性各不相同,表现出较强的区域分布性,盐湖东部和西部的微生物代谢比盐湖中部更具有活性。【结论】运城盐湖微生物多样性丰富,不同水域的细菌多样性具有显著差异,盐湖不同水域的环境对细菌群落结构具有一定影响。本研究为运城盐湖细菌资源多样性的保育及开发利用提供了重要的理论基础。