漳江口红树林沉积物可培养真菌多样性

红树林真菌由于其独特的生态特征、多样性特点和丰富的新型生物活性代谢产物而引起了广泛的关注。本文以漳江口红树林保护区4个采样点的沉积物为研究对象,采用8种筛选培养基（RBM、PDA、CDA、Martin、YM、SDA、ISP2和R2A）分离可培养真菌,根据ITS序列分析对其进行物种鉴定,并利用多样性指数分析评价不同采样点真菌群落的差异。结果共分离到274株真菌,隶属于2门12纲23目39科52属,其中优势属为枝顶孢属（Acremonium）（20.8%）和青霉属（Penicillium）（11.3%）,其次是枝孢属（Cladosporium）（7.3%）和帚枝霉属（Sarocladium）（7.3%）。8种筛选培养基中,分离出真菌种属类型最丰富的培养基是RBM,其次是PDA。根据Shannon-Wiener多样性指数（H′）、Simpson优势度指数（D）、Magalef丰富度指数（R）和Pielou均匀度指数（J）的分析结果,在属的水平上,距海洋的位置越近,真菌的群落多样性越高,真菌分布越均匀。     

Phylogenetic analysis of culturable marine bacteria in sediments from South Korean Yellow Sea

Biogeochemical and microbiological characterization of marine sediments taken from the Yellow Sea of South Korea was carried out. One hundred and thirty six bacterial strains were isolated, characterized and phylogenetic relationship was evaluated. The gene sequences of 16S rDNA regions were examined to study the phylogenetic analysis of bacterial community in the marine sediments. Among 136 isolates, 5 bacterial isolates were identified as novel members, remaining 131 isolates were fall into 5 major linkages of bacterial phyla represented as follows: Firmicutes,, -@Proteobacteria, High G + C and Bacteroidetes. Bacterial community in sediments mainly dominated by Firmicute (58.77%) and followed by @-Proteobacteria (38.16%). @-Proteobacteria domain highly diverged and mainly consists of the genera Vibrio, Marinobacterium, Photobacterium, Pseudoalteromonas, Oceanisphaera, Halomonas, Alteromonas, Stenotrophomas and Pseudomonas. Total N and Organic matter content in Yellow Sea of South Korea were relatively high. The Total-N content in the sediments was varied from 177.31 to 1974.96 (mg/kg) and organic matter ranged from 0.82 to 4.23 (g/100 g⁻¹). The current research work provides clear explanation obtained for the phylogenetic affiliation of the culturable bacterial community in sediments of South Korean Yellow Sea and revealed the relationship with biogeochemical characteristics of the sediments.     

Phylogenetic analysis of culturable marine bacteria in sediments from the South Korean Yellow Sea

Biogeochemical and microbiological characterization of marine sediments taken from the Yellow Sea of South Korea was carried out. One hundred and thirty six bacterial strains were isolated, characterized and phylogenetic relationship was evaluated. The gene sequences of 16S rDNA regions were examined to study the phylogenetic analysis of bacterial community in the marine sediments. Among 136 isolates, 5 bacterial isolates were identified as novel members, remaining 131 isolates were fall into 5 major linkages of bacterial phyla represented as follows: Firmicutes, alpha, gamma-Proteobacteria, High G + C and Bacteroidetes. Bacterial community in sediments mainly dominated by Firmicutes (58.77%) and followed by gamma-Pateobacteria (38.16%). Gamma-Proteobacteria domain highly diverged and mainly consists of the genera Vibrio, Marinobacterium, Photobacterium, Pseudoalteromonas, Oceanisphaera, Halomonas, Alteromonas, Stenotrophomonas and Pseudomonas. Total N and Organic matter content in Yellow Sea of South Korea were relatively high. The Total-N content in the sediments was varied from 177.31 to 1974.96 (mg/kg) and organic matter ranged from 0.82 to 4.23 (g/100 g). The current research work provides clear explanation obtained for the phylogenetic affiliation of the culturable bacterial community in sediments of South Korean Yellow Sea and revealed the relationship with biogeochemical characteristics of the sediments.     

Phylogenetic diversity of culturable bacteria from Antarctic sandy intertidal sediments

The diversity of culturable bacteria associated with sandy intertidal sediments from the coastal regions of the Chinese Antarctic Zhongshan Station on the Larsemann Hills (Princess Elizabeth Land, East Antarctica) was investigated. A total of 65 aerobic heterotrophic bacterial strains were isolated at 4°C. Microscopy and 16S rRNA gene sequence analysis indicated that the isolates were dominated by Gram-negative bacteria, while only 16 Gram-positive strains were isolated. The bacterial isolates fell in five phylogenetic groups: Alpha- and Gammaproteobacteria, Bacteroidetes, Actinobacteria and Firmicutes. Based on phylogenetic trees, all the 65 isolates were sorted into 29 main clusters, corresponding to at least 29 different genera. Based on sequence analysis (<98% sequence similarity), the Antarctic isolates belonged to at least 37 different bacterial species, and 14 of the 37 bacterial species (37.8%) represented potentially novel taxa. These results indicated a high culturable diversity within the bacterial community of the Antarctic sandy intertidal sediments.     

红树林生态系统中不同生境不同深度土壤的可培养真菌的多样性

【目的】了解八门湾红树林生态系统中不同生境(潮间带、海洋到红树区的过渡带、海桑红树区)和不同深度土壤的可培养真菌的多样性。【方法】采用稀释涂布平板法分离土壤中的真菌,利用形态学观察和ITS rDNA序列分析技术研究可培养真菌的表观和遗传多样性。【结果】从八门湾红树林生态系统的3个不同生境中分离到257株真菌,分别属于21属28种,其中青霉属(Penicillium)、曲霉属(Aspergillus)和木霉属(Trichoderma)为优势类群。来自不同生境或者同一生境不同采样深度的土壤真菌种类组成不同,并且有些真菌类群只出现在特定的样品中。从空间角度看,红树区土壤样品的真菌多样性高于其他两个生境的土壤样品;从垂直角度看,潮间带和过渡带的表层土壤样品的真菌多样性高于深层土壤样品,而红树区的深层土壤样品真菌多样性高于表层土壤样品。【结论】八门湾红树林生态系统中的可培养真菌资源丰富,种类多样性较高,但不同生境或不同深度的可培养真菌分布存在较大的差异。这些结果揭示了红树林土壤中可培养真菌的生态分布特点,也为红树林真菌资源的开发利用提供了基础的背景资料。     

云南高黎贡山土壤可培养降解纤维素真菌的多样性

云南高黎贡山是中国生物多样性保护具有全球意义的关键区域,研究该地区土壤中降解纤维素真菌(cellulose-decomposing fungi,CDF)多样性及分布状况对筛选高效CDF和相关功能基因研究具有重要意义.利用羧甲基纤维素(CMC)刚果红平板和PDA平板,分离培养了高黎贡山海拔960～2900m之间0～20cm深度的土壤样品的好氧CDF,通过液体发酵鉴定其纤维素酶活力,并对其rDNA内转录间隔区(ITS)序列进行分析,用Neighbor-Joining法构建系统进化树.结果发现中低海拔地区土壤CDF数量高于高海拔地区,且数量与样地海拔、土壤含水量、温度、有机质和全氮含量呈显著相关(P<0.05);CDF在样地内多样性与土壤有机质、全氮、含水量显著相关(P<0.05);植被类型和人为干扰对CDF的数量和分布都有一定影响.在10个样地中共筛选到35株具有较高降解纤维素类物质能力的真菌,其96h 液体发酵测量CMC酶活力范围在79.6(菌株6)～228.9IU(菌株3).这些株菌分属15个属,其中曲霉属(Aspergillus)、青霉属(Penicillium)、葡萄状穗霉属(Stachybotrys)、毛壳霉属(Chaetomium)的真菌共计20株,占总分离菌株数的57.1%,是高黎贡山土壤中CDF的优势菌群.     

中国稻谷可培养真菌群落组成及多样性

真菌生长导致粮食品质下降及真菌毒素污染,是造成粮食损失的主要原因。我们采用形态学与分子系统发育分析相结合的方法,对中国13个省78份稻谷样品的真菌群落组成及多样性进行研究。结果表明,本次共分离622株真菌,经初步鉴定分属于17属73个物种。南北方因气候条件差异较大,稻谷真菌数量和物种组成都存在很大差异。南方稻谷表面真菌数量（10 ⁴cfu/g）明显高于北方（10 ³cfu/g）。北方收获期的优势种主要属于枝孢属Cladosporium,南方收获期的优势种为黄曲霉Aspergillus flavus、黑曲霉Aspergillus niger和阿姆斯特丹曲霉Aspergillus amstelodami等。进入储藏期后,由于中国仓储管理要求较高,储藏环境相对稳定（aw≤0.75）,耐旱真菌阿姆斯特丹曲霉和多育曲霉Aspergillus proliferans（占比40%以上）成为优势种,这类真菌可作为储藏期粮堆异常的早期预警指示菌。南方收获期感染的黄曲霉和黑曲霉进入储藏期后仍保持优势比例,导致储藏期间毒素污染风险必然增加,因此南方稻谷收储环节均应加强监管。本研究通过分析南北方收获和储藏环节稻谷真菌群落组成差异及产毒真菌的分布规律,以期为中国粮库在稻谷收储环节的真菌毒素防控提供依据。     

中国青岛沿岸潮间带海藻中的可培养真菌多样性（英文）

从中国青岛沿岸潮间带采集9种海藻,包括3种褐藻、4种绿藻和2种红藻,通过传统培养方法共分离获得92株真菌。根据形态学特征和真菌转录间隔区(ITS)r DNA序列分析对所得菌株进行鉴定,结果显示:92株真菌隶属子囊菌门56种,担子菌门1种及接合菌门1种;优势属为枝顶孢属、曲霉属、枝孢属、青霉属和帚霉属;无性型真菌40种,占总菌株数量的75%;绿藻门刺松藻的真菌多样性最高,其次为褐藻门鼠尾藻,红藻门珊瑚藻的真菌多样性最低。本研究首次对中国沿岸潮间带海藻中的真菌多样性进行报道,为进一步研究藻生真菌生态功能提供参考。     

Diversity of culturable ericoid mycorrhizal fungi of Rhododendron decorum in Yunnan, China

The diversity of ericoid mycorrhizal fungi isolated from Rhododendron decorum Franch. in Yunnan, southwestern China, was examined for the first time. In total 300 hair-root samples were collected from 13 R. decorum individuals in two adjacent wild population sites and one cultivated population site. Two hundred eighteen slow-growing isolates were obtained; the ability of some to form ericoid mycorrhiza was tested in vitro. One hundred twenty-five isolates formed hyphal structures morphologically corresponding to ericoid mycorrhiza, and these were determined by morphological and molecular means to belong to 12 fungal species. There were hardly any differences in species among the three sampled populations. The sequences of several isolates were similar to those of Oidiodendron maius and ericoid mycorrhizal fungi from Helotiales, accounting respectively for 18.4% and 24.8% of the total culturable ericoid mycorrhizal fungi assemblage. Dark septate endophytes were detected in the sampled hair roots by microscopy.     

Phylogenetic analysis of lichen-forming fungi Rhizoplaca zopf from China based on ITS data and morphology

A molecular phylogenetic analysis of Rhizoplaca melanophthalma, Rhizoplaca chrysoleuca, Rhizoplaca peltata and Rhizoplaca haydenii is presented based on the nuclear ribosomal internal transcribed spacer (ITS) regions and morphology. Rhizoplaca species were collected at 3400-3900 m in Tianshan Mountains, Xinjiang province, China. Rhizoplaca haydenii is reported for the first time in China. Maximum parsimony (MP) analysis of ITS sequences obtained from Tianshan Mountains samples and GenBank reveals that the evolution relationship of Rhizoplaca melanophthalma and Rhizoplaca chrysoleuca is closer to each other than to Rhizoplaca peltata, and Rhizoplaca haydenii showed closer relatedness to Rhizoplaca melanophthalma. When the four species groups from Tianshan Mountains were analyzed alone through the neighbour-joining (NJ) and minimum evolution method, we obtained the same result. The morphology analysis of Rhizoplaca Zopf which reveals the pruinose discs and apothecial discs of species did not show convincing evidences to prove phylogenetic relationship among Rhizoplaca species In our study, the result further proved that Rhizoplaca should be rejected as a genus separate from Lecanora.     

大兴安岭地区可培养毛霉门真菌多样性与分布

为查明大兴安岭地区可培养毛霉门真菌的资源、多样性及其分布, 本研究选取9个代表市县, 采集了279份枯枝落叶、腐殖质、土壤和粪便样品, 采用稀释平板挑取法、稀释平板切块法和样品直接培养挑取法进行分离培养。通过形态初步观察鉴定, 共得到毛霉门真菌1,153株。选取代表性的菌株706株, 基于真菌分子条形码ITS rDNA进行分子系统发育多样性分析, 明确了毛霉门真菌总计3目8科10属38种。优势属为被孢霉属(Mortierella)、伞形霉属(Umbelopsis)和毛霉属(Mucor), 优势种为类变形被孢霉(Mortierella amoeboidea)、冻土毛霉(Mucor hiemalis)和深黄伞形霉(Umbelopsis isabellina)。本文同时汇总了全国已报道毛霉亚门和被孢霉亚门共计26属的分布, 分析了大兴安岭优势属和优势种在全国的分布。按三大主要生态区(东部湿润、半湿润生态区, 西北干旱、半干旱生态区和青藏高原高寒生态区)对所有属进行区域分析, 结果表明: 有9个属在3个大区都有分布; 对特有属而言, 东部湿润、半湿润生态区发现9个, 西北干旱、半干旱生态区仅有1个, 青藏高原高寒生态区未发现。     

Phylogenetic diversity of culturable fungi associated with the Hawaiian Sponges Suberites zeteki and Gelliodes fibrosa

Sponges are well documented to harbor large amounts of microbes. Both culture-dependent and molecular approaches have revealed remarkable bacterial diversity in marine sponges. Fungi are commonly isolated from marine sponges, yet no reports on phylogenetic diversity of sponge-inhabiting fungi exist. In this report, we investigated the phylogenetic diversity of culturable fungi from the Hawaiian alien marine sponges Suberites zeteki and Gelliodes fibrosa. A total of 44 independent isolates were recovered from these two sponge species, representing 7 orders and 22 genera of Ascomycota. The majority (58%) of fungal isolates from S. zeteki resided in the Pleosporales group, while the predominant isolates (52%) from G. fibrosa were members of the Hypocreales group. Though differing in fungal species composition and structure, culturable communities of these two sponges displayed similar phylogenetic diversity. At the genus level, only two genera Penicillium and Trichoderma in the Eurotiales and Hypocreales orders, respectively, were present in both sponge species. The other genera of the fungal isolates were associated with either S. zeteki or G. fibrosa. Some of these fungal genera had been isolated from sponges collected in other marine habitats, but more than half of these genera were identified for the first time in these two marine sponges. Overall, the diversity of culturable fungal communities from these two sponge species is much higher than that observed in studies of marine sponges from other areas. This is the first report of phylogenetic diversity of marine sponge-associated fungi and adds one more dimension to our current understanding of the phylogenetic diversity of sponge-symbiotic microbes.     

Diversity and biotechnological potential of culturable bacteria from Brazilian mangrove sediment

Mangrove ecosystems are environments subject to substantial degradation by anthropogenic activities. Its location, in coastal area, interfacing the continents and the oceans makes it substantially important in the prospection for biotechnological applications. In this study, we assessed the diversity of culturable bacteria present over the seasons at two depths (0–10 and 30–40 cm) in a mangrove sediment and in a transect area from the land to the sea. In total, 238 bacteria were isolated, characterized by Amplified Ribosomal DNA Restriction Analysis (ARDRA) and further identified, by Fatty Acid Methyl Esther (FAME-MIDI), into the orders of Vibrionales, Actinomycetales and Bacillales. Also the ability of the isolates in producing economically important enzymes (amylases, proteases, esterases and lipases) was evaluated and the order Vibrionales was the main enzymatic source.     

构树可培养内生真菌的多样性初探

构树Broussonetia papyrifera为桑科重要的资源植物。为调查逆境构树内生真菌的多样性,我们对铅锌矿区构树根、茎、叶和果实各部位进行内生真菌分离鉴定,从中分离得到187株内生真菌,根据形态学与分子生物学方法鉴定为20属,其中链格孢属Alternaria（50.27%）、镰孢属Fusarium（11.76%）为优势属。不同培养基的内生真菌分离率结果表明,马铃薯葡萄糖琼脂培养基（PDA）分离出的菌株数最多,占总数的73.96%;构树不同部位的菌株分离数目显示,叶中分离出的菌株较多,占38.02%。在属的分类水平上,根、茎、叶、果实不同部位的真菌数量也存在明显差异。Shannon-Wiener多样性指数和Simpson多样性指数分析结果提示不同样地的构树内生真菌的多样性也存在差异。Chao1指数和ACE指数也提示构树内生真菌丰富度与样地和组织有关。     

Phylogenetic analysis of culturable dimethyl sulfide-producing bacteria from a spartina-dominated salt marsh and estuarine water

Dimethylsulfoniopropionate (DMSP), an abundant osmoprotectant found in marine algae and salt marsh cordgrass, can be metabolized to dimethyl sulfide (DMS) and acrylate by microbes having the enzyme DMSP lyase. A suite of DMS-producing bacteria isolated from a salt marsh and adjacent estuarine water on DMSP agar plates differed markedly from the pelagic strains currently in culture. While many of the salt marsh and estuarine isolates produced DMS and methanethiol from methionine and dimethyl sulfoxide, none appeared to be capable of producing both methanethiol and DMS from DMSP. DMSP, and its degradation products acrylate and beta-hydroxypropionate but not methyl-3-mecaptopropionate or 3-mercaptopropionate, served as a carbon source for the growth of all the alpha- and beta- but only some of the gamma-proteobacterium isolates. Phylogenetic analysis of 16S rRNA gene sequences showed that all of the isolates were in the group Proteobacteria, with most of them belonging to the alpha and gamma subclasses. Only one isolate was identified as a beta-proteobacterium, and it had >98% 16S rRNA sequence homology with a terrestrial species of Alcaligenes faecalis. Although bacterial population analysis based on culturability has its limitations, bacteria from the alpha and gamma subclasses of the Proteobacteria were the dominant DMS producers isolated from salt marsh sediments and estuaries, with the gamma subclass representing 80% of the isolates. The alpha-proteobacterium isolates were all in the Roseobacter subgroup, while many of the gamma-proteobacteria were closely related to the pseudomonads; others were phylogenetically related to Marinomonas, Psychrobacter, or Vibrio species. These data suggest that DMSP cleavage to DMS and acrylate is a characteristic widely distributed among different phylotypes in the salt marsh-estuarine ecosystem.     

Phylogenetic analysis of manganese-oxidizing fungi isolated from manganese-rich aquatic environments in Hokkaido, Japan

Three strains of Mn-oxidizing fungi were isolated from manganese-rich aquatic environments: sediment in a stream (Komanoyu) in Mori-machi and inflow to an artificial wetland in Kaminokuni-cho, Hokkaido, Japan. The characteristics of each strain were then established. Genetic analysis based on the ribosomal RNA (rRNA) gene was performed to clarify their classification. The sequences of the 18S rRNA and internal transcribed spacer (ITS1)-5.8S rRNA-ITS2 genes showed that all three strains are Ascomycetes. Based on its morphology, it seems probable that the KY-1 strain from Mori-machi belongs to the genus Phoma or Ampelomyces. The phylogenetic analysis indicates that this strain belongs to Phoma rather than Ampelomyces. Morphological identification of WL-1 and WL-2 strains from Kaminokuni-cho was impossible because of the lack of a sexual stage and specific organs. Phylogenetic analysis of the sequence in the ITS1-5.8S rRNA-ITS2 gene suggests that the WL-1 strain corresponds to Paraconyothyrium sporulosum and that WL-2 also belongs to the genus Paraconiothyrium. Because the ability to oxidize Mn has not been evaluated for most species of Phoma or Paraconiothyrium (Coniothyrium), further study is needed to confirm the status of these three strains.     

湛江特呈岛红树植物群落结构特征

2008年6月,采用样方调查法对湛江特呈岛红树植物群落结构及白骨壤(Avicennia marina)的种群特征进行了全面调查.结果表明:该地区红树林是白骨壤纯林以及白骨壤为主,有红海榄(Rhizophora stylosa)、木榄(Bruguieragymnorrhiza)和桐花树(Aegiceras corniculatum)的混交林.白骨壤在潮滩上连续分布,红海榄、木榄和桐花树生长于近陆林缘及潮滩的中部,物种多样性指数由陆缘向海缘呈降低趋势.通过分析白骨壤种群的株高、地径在潮滩上的变化规律得出年幼的个体聚集于近陆林缘,近海林缘较少.白骨壤种群的年龄结构为增长型,但是根据生境条件及白骨壤种群在海滩上的分布格局,分析得出该红树林资源处于退化的状态.     

Richness and bioactivity of culturable soil fungi from the Fildes Peninsula,Antarctica

Since the discovery of penicillin, fungi have been an important source of bioactive natural products. However, as a specific resource, the bioactive potentiality and specificity of fungal metabolites from the Antarctic region have had little attention. In this paper, we investigated the diversity patterns and biological activities of cultivable fungi isolated from soil samples in Fildes Peninsula, King George Island, Antarctica. Fungal communities showed low abundance and diversity; a total of 150 cultivable fungi were isolated from eight soil samples. After being dereplicated by morphological characteristics and chemical fingerprints, 47 fungal isolates were identified by ITS-rDNA sequencing. We confirmed that these isolates belonged to at least 11 different genera and clustered into nine groups corresponding to taxonomic orders in the phylogenetic analysis. Using two different fermentation conditions, 94 crude extracts acquired from the abovementioned different metabolite characteristic isolates were screened by bioactivity assay and 18 isolates produced biologically active compounds. Compared with HPLC–DAD–UV fingerprint analysis of culture extracts and standard compounds, two bioactive components secalonic acid and chetracins were identified. Our research suggests that the abundance and diversity of Antarctic cultivable fungal communities exhibit unique ecological characteristics and potential producers of novel natural bioactive products.     

Phylogenetic diversity of nitrogen-fixing bacteria in mangrove sediments assessed by PCR-denaturing gradient gel electrophoresis

Culture-independent PCR–denaturing gradient gel electrophoresis (DGGE) was employed to assess the composition of diazotroph species from the sediments of three mangrove ecosystem sites in Sanya, Hainan Island, China. A strategy of removing humic acids prior to DNA extraction was conducted, then total community DNA was extracted using the soil DNA kit successfully for nifH PCR amplification, which simplified the current procedure and resulted in good DGGE profiles. The results revealed a novel nitrogen-fixing bacterial profile and fundamental diazotrophic biodiversity in mangrove sediments, as reflected by the numerous bands present DGGE patterns. Canonical correspondence analysis (CCA) revealed that the sediments organic carbon concentration and available soil potassium accounted for a significant amount of the variability in the nitrogen-fixing bacterial community composition. The predominant DGGE bands were sequenced, yielding 31 different nifH sequences, which were used in phylogenetic reconstructions. Most sequences were from Proteobacteria, e.g. α, γ, β, δ-subdivisions, and characterized by sequences of members of genera Azotobacter, Desulfuromonas, Sphingomonas, Geobacter, Pseudomonas, Bradyrhizobium and Derxia. These results significantly expand our knowledge of the nitrogen-fixing bacterial diversity of the mangrove environment.     

印度洋红树林沉积物可培养海洋放线菌多样性及其活性

【目的】本研究旨在了解印度洋红树林沉积物可培养海洋放线菌多样性、抗菌活性及产酶活性。【方法】选用24种碳源为唯一能源培养基,利用稀释平板涂布方法对8个印度洋红树林沉积物样品进行分离,并基于16S rRNA基因系统发育分析的方法研究样品中海洋放线菌多样性;对分离得到的菌株进行抗菌活性和产酶活性检测。【结果】24种唯一碳源分离培养基中,非糖类碳源特别是甘油、丙氨酸分离效果最好,其次是多糖物质,最后是单糖。共分离得到521株海洋放线菌,经并菌后选取其中的139株代表性菌株测序,结果发现它们主要分布在放线菌纲7个亚目10个科的16个属,其中35个为潜在新种。有43.1%、33.3%、26.9%、25.5%、15.7%的实验菌株分别对枯草芽孢杆菌、白色念珠菌、大肠埃希氏菌、金黄色葡萄球菌、黑曲霉具有抑制作用;有36.5%、26.5%、22.4%、15.9%的实验菌株分别具有蛋白酶活性、纤维素酶活、淀粉酶活性、酯酶活性。【结论】印度洋红树林沉积物蕴藏着丰富的海洋放线菌资源,并具有较高生物活性,为后续工作提供良好的实验材料。