海水来源的548株真菌的近海及远海分布模式及其抑菌活性分析

Distribution pattern and antibacterial activity of 548 fungi from offshore and pelagic seawater

摘要:

【目的】海洋真菌是新颖天然产物的理想来源。本研究旨在加深对可培养海洋真菌多样性的了解，以及挖掘具有应用潜力的海洋真菌。【方法】采用膜过滤法分离近海和远海海水样品中的真菌，通过菌株分离纯化、ITS基因序列测序，分析浅海带、半深海带和深海带海水样品中可培养真菌的多样性。在此基础上，采用固体平板法筛选具有抑菌活性的菌株。【结果】本研究共获得548株纯培养真菌，它们分属于2个门6个纲11个目19个科24个属44个种，其中包含海洋真菌种15个和潜在新分类单元3个。在纲水平上，座囊菌纲（Dothideomycetes）包含种的数量最多（13个），其次为粪壳菌纲（Sordariomycetes）（11个）和散囊菌纲（Eurotiomycetes）（11个）。在属水平上，青霉属（Penicillium）、枝孢属（Cladosporium）、外瓶霉属（Exophiala）和拟青霉属（Simplicillium）的分离频率较高。44个真菌种呈现出5种不同的地理分布特征，包括在浅海带、半深海带和深海带均有分布（15个种），仅分布于浅海带（5个种），不存在于浅海带（12个种），不存在于半深海带（5个种），以及不存在于深海带（7个种）。44个真菌种中，12个种具有不同程度的抑菌作用，其中Hortaea werneckii所呈现的抑菌谱最广，而Simplicillium cylindrosporum对Staphylococcus aureus MCCC1A0646抑菌活性最强。【结论】本研究初步揭示了近、远海海水中可培养真菌的多样性及其地理分布模式，并丰富了海洋真菌菌种资源。

Abstract:

[Objective] Marine fungi are ideal producers of novel natural products. This paper aims to deepen the understanding of the diversity of culturable marine fungi and identify potential useful marine fungi.[Methods] Fungi were isolated from offshore and pelagic seawater by membrane filtration. Through the isolation and purification of strains and internal transcribed spacer (ITS) sequencing, the diversity of culturable fungi in neritic water, bathyal water, and abyssal water was analyzed. The solid plate method was used to screen strains with antibacterial activity.[Results] A total of 548 fungi were isolated and they fell into 44 species, 24 genera, 19 families, 11 orders, 6 classes, and 2 phyla, including 15 marine species and 3 novel taxa. At the class level, Dothideomycetes dominated (13 species), followed by Sordariomycetes (11 species) and Eurotiomycetes (11 species). At the genus level, Penicillium, Cladosporium, Exophiala, and Simplicillium were dominant. The 44 species presented 5 geographic distribution pattern:presence in neritic, bathyal, and abyssal areas (15 species), presence only in neritic area (5 species), absence in neritic area (12 species), absence in bathyal area (5 species), and absence in abyssal area (7 species). A total of 12 species had antibacterial activity. Among them, Hortaea werneckii showed the broadest antibacterial spectrum, and Simplicillium cylindrosporum demonstrated the strongest inhibition on Staphylococcus aureus MCCC1A0646.[Conclusion] This study reveals the diversity and distribution pattern of culturable fungi in the offshore and pelagic seawater and enriches the resource of marine fungi.