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41.
42.
A novel actinomycete, strain HMC10T, was isolated from a soil sample taken from the banks of the Gamka River in the Swartberg Nature Reserve, Western Cape Province,
South Africa. Strain HMC10T was identified as a member of the genus Nonomuraea by a polyphasic approach. Strain HMC10T could be differentiated from other members of the genus Nonomuraea on the basis of physiology and 16S rRNA gene sequence analysis. DNA-DNA hybridization further differentiated strain HMC10T from its nearest phylogenetic neighbour, Nonomuraea turkmeniaca NRRL B-16246T (4.5 ± 3.8% DNA relatedness). Strain HMC10T exhibited weak antibiosis against Mycobacterium aurum A+, but none against Mycobacterium tuberculosis H37RvT. The name Nonomuraea candida is proposed, with the type strain HMC10T (= DSM 45086T = NRRL B-24552T).
The GenBank accession number for the 16S rRNA gene sequence of Nonomuraea candida HMC10T is DQ285421. 相似文献
43.
放线菌对干旱胁迫下黑麦草生长及抗氧化特性的影响 总被引:1,自引:0,他引:1
采用菌剂接种及盆栽生物实验,研究了干旱缺水条件下放线菌对黑麦草生长和抗氧化特性的影响。结果显示:(1)干旱胁迫下,土壤中接种放线菌显著促进黑麦草的生长,其中根分蘖及根部生物量分别显著增加35.00%和37.47%;(2)接种放线菌后,黑麦草叶片的叶绿素总量和类胡萝卜素含量分别显著增加了12.02%和10.38%;(3)加菌后3种主要的抗氧化酶超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)较不加菌对照均增加,其增率分别为12.72%、2.38%和24.83%,其中SOD和CAT的活性增加显著。研究表明,干旱胁迫下放线菌接种土壤后,提高了黑麦草叶绿素含量和类胡萝卜素含量,增强了黑麦草抗干旱胁迫的抗氧化酶活性,可显著促进黑麦草的生长,增加其生物量。 相似文献
44.
以根状茎克隆植物紫竹为对象,研究克隆整合对遭受异质性光照胁迫分株根际土壤有机碳(SOC)、总氮(TN)、溶解性有机碳(DOC)、溶解性有机氮(DON)、氨氮(NH_4~+-N)、硝态氮(NO_3~--N)以及微生物群落组成的影响。所取紫竹克隆片段由一个母本分株和一个子代分株组成,母本分株置于全光照下,而子代分株置于80%遮阴环境中,同时母本分株与子代分株间的根茎保持连接或割断处理。结果表明:与切断处理相比,紫竹遮荫子代分株根际土壤的SOC、TN、DOC、NH_4~+-N在保持根状茎连接时显著更高,这表明异质性光照环境下克隆整合可能改善紫竹连接遮荫子代分株根际土壤的氮素有效性。克隆整合提高了连接遮阴状态下紫竹子代分株根际土壤中的放线菌、真菌和革阴细菌的PLFAs浓度。通过对遮阴子代分株根际土壤微生物群落PLFAs主成分分析得出克隆整合导致遮阴子代分株根际土壤微生物群落结构发生显著变化。该研究结果暗示了紫竹可能通过克隆整合作用降低土壤中某些对氮利用有效性影响较低的细菌数量,而增加对土壤氮利用起重要作用的放线菌和真菌的数量,进而改善紫竹对土壤中氮利用的有效性,这有利于增强克隆植物对时空异质性生境的适应能力。 相似文献
45.
Actinomycetes‐mediated biogenic synthesis of metal and metal oxide nanoparticles: progress and challenges 下载免费PDF全文
Actinomycetes‐mediated biogenic synthesis of metal nanoparticles and their antimicrobial activities are well documented. Actinomycetes facilitate both intracellular and extracellular metal nanoparticles synthesis and are efficient candidates for the production of polydispersed, stable and ultra‐small size metal nanoparticles. Secondary metabolites and new chemical entities derived from Actinomycetes have not been extensively studied for the synthesis of metal/metal oxide nanoparticles. The present review focuses on biogenic synthesis of metal nanoparticles from Actinomycetes and the scope for exploring Actinomycetes‐derived compounds (enzymes, organics acids and bioactive compounds) as metal and metal oxide reducing agents for the synthesis of desired nanoparticles. This review also focuses on challenges faced in the applications of nanoparticles and the methods to synthesize biogenic metal nanoparticles with desired physiochemical properties such as ultra‐small size, large surface to mass ratio, high reactivity etc. Methods to evade their toxicity and unique interactions with biological systems to improve their chance as an alternative therapeutic agent in medical and pharmaceutical industry are also discussed. 相似文献
46.
Kohji Ishihara Hitomi Yamaguchi Nobuyoshi Nakajima 《Journal of Molecular Catalysis .B, Enzymatic》2003,23(2-6):171-189
This review covers the possibility of aerobic thermophilic bacteria (Bacillus strains and thermophilic actinomycetes) and microalgae (Chlorella strains and marine algae) as new biocatalysts for the stereoselective reduction of - and β-keto esters. The mechanistic interpretation of the reduction by a thermophilic actinomycete is also delineated. 相似文献
47.
Chinyere K. Okoro Roselyn Brown Amanda L. Jones Barbara A. Andrews Juan A. Asenjo Michael Goodfellow Alan T. Bull 《Antonie van Leeuwenhoek》2009,95(2):121-133
The Atacama Desert presents one of the most extreme environments on Earth and we report here the first extensive isolations
of actinomycetes from soils at various locations within the Desert. The use of selective isolation procedures enabled actinomycetes
to be recovered from arid, hyper-arid and even extreme hyper-arid environments in significant numbers and diversity. In some
cases actinomycetes were the only culturable bacteria to be isolated under the conditions of this study. Phylogenetic analysis
and some phenotypic characterisation revealed that the majority of isolates belonged to members of the genera Amycolatopsis, Lechevalieria and Streptomyces, a high proportion of which represent novel centres of taxonomic variation. The results of this study support the view that
arid desert soils constitute a largely unexplored repository of novel bacteria, while the high incidence of non-ribosomal
peptide synthase genes in our isolates recommend them as promising material in screening for new bioactive natural products. 相似文献
48.
Subramani Ramesh Mahalingam Rajesh Narayanasamy Mathivanan 《Bioprocess and biosystems engineering》2009,32(6):791-800
Totally 191 different marine actinomycetes were isolated from 256 different marine samples collected from the Bay of Bengal
and its associated Pulicat lake and Pichavaram mangrove, India. Among them, 157 produced caseinase, 113 produced gelatinase
and 108 produced both the protease enzymes. An isolate coded as MML1614 was selected for further study as it exhibited high
proteolytic activity. The MML1614 was identified as Streptomyces fungicidicus based on polyphasic taxonomical approach including 16S rRNA sequence analysis. The culture conditions were standardized for
the growth and protease production in S. fungicidicus MML1614. The protease was isolated from a 6-day-old culture filtrate of S. fungicidicus MML1614 and partially purified up to 4.5-fold. The protease was optimally active at pH 9 and 40 °C and it was stable up to
pH 11 and 60 °C. PMSF and NaCl inhibited the enzyme activity up to 22 and 11%, respectively. The partially purified protease
removed the blood stain more effectively when combined with different detergents than the detergents alone. 相似文献
49.
银沙槐内生放线菌抗菌活性及其与内生细菌的拮抗关系 总被引:2,自引:1,他引:1
从荒漠濒危植物银沙槐根部分离到内生放线菌12株和内生细菌31株.以大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌为指示菌对内生放线菌进行了抗菌活性筛选.结果表明:3株放线菌对3种指示菌均有抑制作用,2株完全无抑菌作用.采用菌块抑制法分析内生放线菌对来自同一植物内生细菌的抑制效果,44.9%的组合出现抑制现象,最大抑菌圈直径为28.5mm,最小者仅8.25 mm,主要抑制对象是革兰氏阴性菌和芽孢菌;55.1%的组合无抑制现象.说明内生菌的相互作用具有多样性. 相似文献
50.
大连渤海老虎滩海域沉积物可培养放线菌的多样性 总被引:1,自引:0,他引:1
【目的】研究大连渤海老虎滩海域可培养放线菌的多样性。【方法】利用5种不同的培养基分离、培养海洋沉积物中的放线菌,并用16S rRNA基因序列对部分放线菌株进行系统发育分析。【结果】根据菌落表型共分离到1215株放线菌。选择271株具有代表性的菌株进行16S rRNA分析,结果表明,251株(92.26%)属于放线菌门,覆盖11个科,15个属;其余20株属于厚壁门和变形菌门;有7株为潜在的新种。【结论】大连渤海老虎滩海域的沉积物中存在较为丰富的放线菌和新种资源,这些菌株为将来开发新的微生物代谢产物奠定了基础。 相似文献