南海深海沉积物中52株真菌的初步分离鉴定及其代谢产物活性

Isolation, identification and evaluation of 52 fungi from the deep-sea sediments of South China Sea

【背景】深海环境复杂多样,蕴含着丰富的真菌资源,为深海真菌结构新颖代谢产物化学及生物活性研究提供了新契机。【目的】对南海深海环境来源真菌进行初步鉴定和代谢产物活性初步研究,旨在筛选和发现潜在的药源真菌新资源,为南海深海真菌资源的进一步开发利用奠定基础。【方法】基于内转录间隔区(ITS)序列测定对分离得到的52株真菌进行初步鉴定,利用纸片扩散法、Solis改良法和DPPH自由基清除法对真菌粗浸膏进行了抗菌(ABA)、卤虫致死(BSL)和抗氧化活性(ABTS)筛选。【结果】52株真菌分布在16个属,其中枝孢菌属(Cladosporium)、曲霉属(Aspergillus)为优势菌群,分别占菌株总数的25.00%、23.08%;32株真菌发酵产物具有抑制至少1种指示菌的活性,其中8株对所有指示菌均有抑制作用;23株具有一定强度的卤虫致死活性,占总数的44.23%,其中有2株活性较显著,IC50值为68.59μg/mL和78.83μg/mL;30株具有DPPH自由基清除活性,占总数的57.69%,其中有9株活性较显著,EC50值低于100μg/mL。【结论】初步认知了南海部分海域深海沉积环境真菌分布和代谢产物活性特征,发现了一批潜在的活性真菌资源,为后续深海真菌代谢产物化学多样性及其功能研究提供支撑。

[Background] Deep-sea environment is complex and diverse with abundant fungi that provide new opportunities to study the chemical and biological activity of deep-sea fungal metabolites. ]Objective[ To isolate, identify and evaluate fungi from the South China Sea deep-sea sediment, to discover new potential drug source fungi and lay the foundation for further utilization of deep-sea fungi from the South China Sea. ]Methods] Based on intergenic transcribed spacer sequencing, 52 fungi isolated from deep-sea sediment were identified. All fungal crude extracts were tested for antibacterial, brine shrimp lethal and antioxidative activities by using Kirby-Bauer test, Solis＇ method and DPPH radical scavenging method. [Results] These fungi could be clarified into 16 genera, in which Cladosporium sp. and Aspergillus sp. were in majority, accounting for 25.00% and 23.08%, respectively; 32 strains inhibited 1 indicative bacterium at least, 8 of which inhibited all 4 indicative bacteria; 23 strains exhibited medium brine shrimp lethality, accounting for 44.23% of all isolated strains, 2 of which exhibited obvious activities with ICs0 of 68.59, 78.83 gg/mL; 30 strains showed DPPH radical scavenging activity, accounting for 57.69%, 9 of which with ECs0 values lower than 100 gg/mL. [Conclusion] This study revealed the distribution and metabolite activities of deep-sea fungi from South China Sea and found a number of potential active fungi, and provides support for subsequent investigation on chemical diversities and biological activities of deep-sea fungi.