Marine-derived filamentous fungi and their potential application for polycyclic aromatic hydrocarbon bioremediation

Eight marine-derived fungi that were previously selected for their abilities to decolorize RBBR dye were subjected to pyrene and benzo[a]pyrene degradation. The fungus Aspergillus sclerotiorum CBMAI 849 showed the best performance with regard to pyrene (99.7%) and benzo[a]pyrene (76.6%) depletion after 8 and 16 days, respectively. Substantial amounts of benzo[a]pyrene (>50.0%) depletion were also achieved by Mucor racemosus CBMAI 847. Therefore, these two fungal strains were subjected to metabolism evaluation using the HPLC-DAD-MS technique. The results showed that A. sclerotiorum CBMAI 849 and M. racemosus CBMAI 847 were able to metabolize pyrene to the corresponding pyrenylsulfate and were able to metabolize benzo[a]pyrene to benzo[a]pyrenylsulfate, suggesting that the mechanism of hydroxylation is mediated by a cytochrome P-450 monooxygenase, followed by conjugation with sulfate ions. Because these fungi were adapted to the marine environment, the strains that were used in the present study are considered to be attractive targets for the bioremediation of saline environments, such as ocean and marine sediments that are contaminated by PAHs.     

南麂岛海洋沉积物抑菌真菌的筛选及其代谢产物特性的初步研究

以7种水产病原菌为指示菌,采用菌饼法对分离自南麂岛海域的15个沉积物样品中的78株海洋真菌进行抑菌活性初筛,获得了对至少一种病原指示菌有抑菌活性的菌株19株.采用打孔扩散法对这19株真菌的发酵液进行抑菌活性复筛,共有9个菌株的次级代谢产物对一种或者几种病原指示菌有抑制作用,其中菌株NJ0104的次级代谢产物对除灿烂弧菌...     

老鼠簕植物内生真菌Aspergillus terreus (W-8)抗肿瘤活性成分的研究

对红树林植物的枝干、枝叶样品进行微生物分离,以P388细胞为模型进行活性评价得到14株具有抗肿瘤活性的真菌。采用溶剂萃取、柱色谱及半制备HPLC等分离手段对来源于红树林植物老鼠簕Acanthus ilicifolius Linn.的菌株Aspergillus terreus(W-8)发酵产物进行了活性追踪分离,共得到5个化合物。通过理化性质及波谱技术,结合文献,鉴定其结构分别为aspulvinone H1(1)、aspulvinone H(2)b、utyrolactone I(3)t、errein(4)和3-propylbenzene-1,2-diol(5),其中化合物1的核磁数据为首次报道。采用MTT法初步评价了单体化合物的抗肿瘤活性,结果表明化合物4、5对A549、K562和Hela细胞均具有中等强度的细胞毒活性。     

Arbuscular mycorrhizal fungi improve reestablishment of Leymus chinensis in bare saline-alkaline soil: Implication on vegetation restoration of extremely degraded land

Salinization and alkalinization are increasing problems in the world. Some land has been degraded to bare saline-alkaline soil where vegetation restoration is difficult because high toxic ionic content and pH are harmful to the survival of introduced plants. We grew Leymus chinensis with and without arbuscular mycorrhizal fungi (Glomus mosseae and G. geosporum) in either pots filled with soil from bare saline-alkaline land, or transplanted seedlings into field plots, to determine the influence of AM fungi on the reestablishment of this dominant grass species in bare degraded land. Association with AM fungi increased the absorption of N, P, K⁺, Ca²⁺, but decreased Mg²⁺, Na⁺ and Cl⁻ uptake under saline-alkaline stress. Therefore, higher K/Na, Ca/Na, P/Na, and P/Cl ratios were found in the inoculated plants. Plants inoculated with AM fungi accumulated significantly higher biomass, root/shoot ratio and tiller number than non-inoculated plants. AM fungi also significantly increased the survival of seedlings when they were transplanted into a bare saline-alkaline land in the field. The improvement of survival, growth and asexual reproduction of inoculated plants indicated that the plant-AM fungi mutualism could improve the reestablishment of vegetation in bare saline-alkaline soil, drive the vegetation restoration to a community dominated by original species.     

普里兹湾沉积物样品产油真菌筛选及胞内脂肪酸成分分析

对中国第29次南极科学考察获得的南极普里兹湾海域23个站位的深海沉积物样品进行了真菌分离培养,共获得了11个属的21株真菌,分别是:青霉属(Penicillium,9株)、枝孢属(Cladosporium,3株)、支顶孢属(Acremonium,1株)、短梗霉属(Aureobasidium,1株)、孢盘菌属(Botryotinia,1株)、散囊菌属(Eurotiales,1株)、外瓶霉属(Exophiala,1株)、镰孢菌属(Fusarium,1株)、丛赤壳属(Nectria,1株)、茎点霉属(Phoma,1株)、帚枝霉属(Sarocladium,1株).南极普里兹湾海域的真菌多样性较高,其中青霉属菌株最多,占总菌株比例为42.85%,是普里兹湾真菌中的优势属,其次为枝孢属菌株,占总菌株比例为14.29%.分别用尼罗红和氯化三苯基四氮唑(TTC)对这21株菌进行产油筛选,得到8株产油菌,分属于Penicillium(2株)、Aureobasidium(1株)、Cladosporium(1株)、Eurotiales(1株)、Exophiala(1株)、Fusarium(1株)、Sarocladium(1株)等7个属,这些产油菌产油量大致在20.1%到52.0%之间.对这8株菌的产油量和胞内脂肪酸成分进行分析,结果表明:这些产油菌所含的基本为短链脂肪酸,且不饱和脂肪酸含量较高,适合作为生物柴油的生产菌株.     

旅游干扰对五大连池药泉山土壤真菌群落结构影响

以五大连池药泉山为研究对象,研究旅游干扰对土壤真菌群落结构的影响以及真菌群落结构与土壤化学性质变化之间的响应关系。研究表明：药泉山土壤真菌数量在（0.34~2.47）×10⁶cfu/g之间,整个山体真菌群落结构组成相似性为45.30%。山顶、山腰、山脚总体之间土壤真菌多样性指数、均匀度指数和丰富度指数差异性不显著,除有机质含量外,总氮、总磷、速效磷、pH含量差异不显著。随着旅游干扰程度的增加,真菌数量有下降趋势,多样性指数（H′）呈现先降低再升高的趋势。RDA分析发现,有机质含量对真菌群落结构的分布影响相对较大,其次为总氮、总磷、速效磷、pH。     

Microbial status in seawater and coastal sediments during pre- and post-tsunami periods in the Bay of Bengal, India

Tsunami, the natural disaster, which occurred on December 26, 2004 in the Indian Ocean, caused severe damage to mankind in the coastal areas. Total loss of life and economic loss because of this disaster have been estimated by various agencies but its effect on microbial density has not been probed. With our previous results on microbial populations in four locations of the Chennai coast of the Bay of Bengal, India in the pre‐tsunami period, the change in microbial populations was studied after the tsunami at regular intervals in the same locations. Coastal sediment and seawater samples were collected from four different locations after 5–10 h and thereafter at intervals of every 7 days up to 28 days post‐tsunami. Bacteria, fungi and actinomycetes were isolated from the marine samples by serial dilution on respective media. Before the tsunami, the bacterial population was higher in seawater samples than the sediments, whereas fungi and actinomycetes were recorded only in the sediments. The microbial population remarkably increased 5–10 h post‐tsunami in all the marine samples irrespective of the location. However, it slowly declined in the subsequent days and became similar to that of the population recorded before the tsunami. The population of gram‐positive bacteria increased whereas the gram‐negative bacterial population decreased after the tsunami. Further, populations of pathogenic bacteria such as coliform and vibrios did not increase after the tsunami. It has been observed that the increase in populations of bacteria and actinomycetes even after 28 days of tsunami may be due to the introduction of foreign microorganisms that developed the ability to survive in the extreme environment by exhibiting special characteristics such as pigmentation and production of exopolysaccharides.     

海洋真菌多样性的研究进展

海洋微生物作为海洋生物的一个组成，有其独特的特性，耐盐性不能作为区分海洋型与陆生型微生物的标志。本文对海洋真菌的的界定、数量、附着基质、生态类型以及其产生的生物活性物质做了概述。     

海洋细菌B-9987 胞外代谢产物的纯化及抑菌机理初探

由渤海海泥中分离得到 30 0株菌株 ,从中筛选获得海洋生境芽孢杆菌B 9987菌株 ,其胞外物质经乙醚萃取、硅胶G薄层层析、官能团显色反应及紫外扫描 ,测其组分 ;以不同浓度B 9987菌株的抑菌液测定对植物病原真菌的抑制效果。结果表明 ,B 9987菌株的胞外抑菌物质可能是酚类化合物 ;该物质对植物病原真菌茄交镰孢菌、大丽轮枝菌、黄枝孢菌、立枯丝核菌的抑制作用 ,主要是造成真菌孢子或菌丝末端膨大成球状 ,继而胞壁崩解 ,原生质外泄。对尖刀镰孢菌和莴苣霜霉菌的抑制作用 ,则表现为孢子萌发率降低和菌丝长度明显变短。该抑菌物质可望开发为农用抗生素     

Holocene occurrence of Lophodermium piceae, a black spruce needle endophyte and possible paleoindicator of boreal forest health

Holocene occurrences of conifer needle endophytes have not previously been reported. We report the fossil remains of Lophodermium piceae (Fckl.) Hoehn., a fungal endophyte of black spruce (Picea mariana (Mill.) B.S.P.) needles, in macrofossils dating back to 8000 cal yr BP. Spruce budworm head capsules and L. piceae remains were found preceding charcoal layers delineating the transformation of four spruce−moss forest sites to spruce−lichen woodland. As L. piceae is found solely on senescent needles, its increased presence during these transformation periods likely indicates that the forests were in decline due to the spruce budworm (Choristoneura fumiferana (Clem.)) when they burned. Future paleoecological studies incorporating needle fungi observations could be used to investigate the historical occurrence of tree disease and the role of fungi in forest health and decline.