北海竹林盐场极端嗜盐真菌的多样性及其抑菌活性研究

Diversity and Antibacterial Activity of Extremely Halophilic Fungi from Beihai Zhulin Salt Field

为探讨北海竹林盐场极端嗜盐真菌的物种多样性及其抑菌活性,采用高盐培养基分离盐场饱和盐度采样点的可培养真菌,并基于ITS基因序列进行菌株鉴定;使用耐甲氧西林金黄色葡萄球菌(Methicillin-resistant Staphylococcus aureus,MRSA)、表皮葡萄球菌(Staphylococcus epidermidis,SE)、无乳链球菌(Streptococcus agalactiae,SA)和海豚链球菌(Strepstococcus iniae,SI)作为指示菌,利用96孔板法评价真菌发酵提取物的抑菌活性。本研究分离得到可培养极端嗜盐真菌16株,鉴定为6科6属12种,其中枝孢菌属(Cladosporium,3种)、黑孢霉属(Nigrospora,3种)和镰刀菌属(Fusarium,3种)是优势属。菌株F.incarnatum GXIMD00527和F.chlamydosporum GXIMD00541的发酵产物对4种指示菌有较强的抑菌活性[90%Minimal Inhibitory Concentration(MIC90)<6.25μg/mL],Alternaria alternata GXIMD00532、Cladosporium cladosporioides GXIMD00533和Curvularia hawaiiensis GXIMD00538的发酵产物对MRSA有抑菌活性(MIC90≤25μg/mL)。本研究丰富了广西嗜盐海洋真菌的物种多样性,为北部湾海洋微生物资源的开发利用奠定了基础。

In order to investigate the species diversity and antibacterial activity of extremely halophilic fungi in Beihai Zhulin Salt Field,high salt medium was used to isolate culturable fungi from saturated salinity sampling points in salt field,and the strains were identified based on ITS gene sequence.Methicillin resistant Staphylococcus aureus(MRSA),Staphylococcus epidermidis(SE),Streptococcus agalactiae(SA)and Strepstococcus iniae(SI)were used as indicator bacteria to evaluate the antibacterial activity of fungal fermentation extracts by 96 well plate method.In this study,16 strains of culturable extreme halophilic fungi were isolated and identified as 12 species,6 genera and 6 families.Among them,Cladosporium(3 species),Nigrospora(3 species)and Fusarium(3 species)were the dominant genera.The fermentation products of F.incarnatum GXIMD00527 and F.chlamydosporum GXIMD00541 had strong antibacterial activity against four indicator bacteria(90%Minimal Inhibitory Concentration,MIC 90<6.25μg/mL).The fermentation products of Alternaria alternata GXIMD00532,Cladosporium cladosporioides GXIMD00533 and Curvularia hawaiiensis GXIMD00538 had antibacterial activity against MRSA(MIC 90≤25μg/mL).This study enriches the species diversity of halophilic marine fungi in Guangxi and lays a foundation for the development and utilization of marine microbial resources in Beibu Gulf.