Page 41 - 《广西植物》2020年第3期
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3 期      候师师等: 海南西海岸四种真红树根系土壤放线菌物种多样性及其延缓衰老活性初筛                                            3 2 1

       Abstract: Four true mangrove rhizosphere soils in the intertidal zone of the west coast of Hainan were studied to analyze
       the species diversity composition and metabolite activity of mangrove rhizosphere actinomycetesꎬ in order to accumulate
       abundant actinomycetes for better exploitation and utilization of marine microbial resources. In this studyꎬ seven samples
       of true mangrove rhizosphere soil were selected as research objects and nine different media were used as the isolation
       media. Pure culture method and three ̄zone scribing method were used to isolate and purify the strains. The species diver ̄
       sity composition was analyzed by combinating with the morphological characteristics of actinomycetes and the 16S rRNA
       gene sequence results. The actinomycete fermentation broth was extracted with ethyl acetateꎬ and its anti ̄aging activity
       was tested using Caenorhabditis elegans model. The results were as follows: (1) A total of 22 strains of actinomycetes
       were isolatedꎬ belonging to four ordersꎬ seven families and nine genera consist of Amycolatopsisꎬ Curtobacteriumꎬ Deme ̄

       quinaꎬ Isoptericolaꎬ Lysinimicrobiumꎬ Microbacteriumꎬ Rhodococcusꎬ Sinomonasꎬ Streptomycesꎬ and Streptomyces was the
       dominant flora of this study with eleven strains isolatedꎬ and five strains of IMDGX 6012ꎬ IMDGX 6028ꎬ IMDGX 6118ꎬ
       IMDGX 6326ꎬ IMDGX 6119 were identified as potential new species actinobacteria. The highest similarities among the
       strains and the effective published strains Amycolatopsis lexingtonensisꎬ A. niigatensisꎬ Curtobacterium albidumꎬ C. cit ̄
       reumꎬ Demequina salsinemoris were 97.75%ꎬ 98.15%ꎬ 98.32%ꎬ 98.44%ꎬ 98.45%ꎬ respectively. The above five rhizo ̄
       sphere actinobacteria belong to rare actinobacteria and were preliminarily identified as potential new species. (2) The re ̄
       sults of anti ̄aging of fermentation products showed that the metabolites of eight strains of actinobacteria could signifi ̄
       cantly prolong the lifespan of nematodes (P<0.05)ꎬ including one strains of Curtobacteriumꎬ one strains of Demequinaꎬ
       one strain of Sinomonas and five of which were from Streptomycesꎬ indicating that Streptomyces had potential to produce
       anti ̄aging active substances. IMDGX 6028 and IMDGX 6118ꎬ as potential new species of Amycolatopsis and Curtobacte ̄
       riumꎬ had extremely significant anti ̄aging activity (P<0.01). When the crude metabolite concentration was 500 μg
           ̄1
       mL ꎬ the survival time of C. elegans was increased by 22.2% and 26.6%ꎬ respectivelyꎬ compared with the blank
       group. The results indicate that there are abundant resources of culturable actinobacteria and the potential to discover
       new species and anti ̄aging activity strains in the true mangrove rhizosphere soils in the west coast of Hainan.
       Key words: mangrove plantsꎬ rhizosphere actinobacteriaꎬ species diversityꎬ anti ̄aging activity

       放线菌是挖掘新型次生代谢产物的重要菌种                           东海岸相比ꎬ西海岸红树林面积小ꎬ群落类型相对
   资源ꎮ 红树林处于海岸潮间带ꎬ独特的理化环境                            简单ꎬ目前对于该区域红树根系放线菌的研究鲜
   和丰富的腐殖质为创造微生物多样性提供了有利                             有报道ꎮ 加上近年来人类活动对红树林资源造成
   条件(Sangkanu et al.ꎬ2017)ꎬ已经被公认为分离放                了实际威胁ꎬ及时对该区域红树林根系放线菌实
   线菌的理想环境(Sweetline et al.ꎬ2012)ꎮ 因此ꎬ红              现高值化开发利用ꎬ并以此为契机进一步推动西
   树林放线菌一直是国内外科研人员争相研究的对                             海岸红树林生态系统建设ꎬ对于我国发展海洋生
   象ꎮ Lee et al.(2014) 从马来西亚热带红树林沉积                  态文明具有重要意义ꎮ 同时对红树林根系放线菌
   物中分离获得 87 株放线菌ꎬ其中 5 株被认为是新                        种类多样性的研究ꎬ对于我国海洋微生物资源现
   种ꎮ 洪葵研究组从中国 8 个红树林站点采集的                           状的整体评价也具有一定参考价值ꎮ
   112 份土壤和 99 个植物样品中分离出2 041株放                          近年来我国人口呈负增长趋势ꎬ老龄化形势
   线菌ꎬ归于 8 亚目 11 科 25 属ꎬ部分菌株次生代谢                     日益严峻ꎬ预计到 21 世纪中叶ꎬ老龄人口将高达
   产物具有抗菌、抗肿瘤、治疗神经退行性疾病和糖                            4.5 亿ꎬ占总人口的 1 / 3(曾尔亢等ꎬ2012)ꎬ解决人
   尿病多种药理活性(Hong et al.ꎬ2009)ꎮ 我国红树                  口老龄化问题刻不容缓ꎮ 目前临床用于抗衰老的
   物种资源丰富ꎬ海南岛是我国红树植物聚集地之                             药物大多是合成药物( Messing et al.ꎬ 2013)ꎬ存在
   一ꎬ共有红树植物 38 种(辛欣等ꎬ2016)ꎮ 其中ꎬ位                     安全和功效的不确定性ꎬ从微生物中挖掘新化合
   于东部海岸的东寨港和清澜港红树林保护区作为                             物一直以来受到各国科学家的青睐ꎮ 放线菌被认
   海南最大的红树林分布区ꎬ成为热点研究地区ꎬ已                            为是最适合挖掘新化合物的微生物之一ꎬ从放线
   分离出具有抗菌、抗肿瘤及杀线虫活性的多种菌                             菌挖掘获得的新化合物包括生物碱、类固醇、萜类

   株(雷湘兰ꎬ2006ꎻ黄惠琴等ꎬ2013ꎻ李静等ꎬ2016)ꎮ                   化合物、聚酮等ꎬ这些化合物在人类疾病治疗和病
   海南西海岸红树林主要分布于临高、儋州等地ꎬ与                            虫害防治均有报道( Singh et al.ꎬ 2017)ꎬ然而这些
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