Abstract

Despite recent studies, relatively few are known about the diversity of fungal communities in the deep Atlantic Ocean. In this study, we investigated the diversity of fungal communities in 15 different deep-sea sediments from the South Atlantic Ocean with a culture-dependent approach followed by phylogenetic analysis of ITS sequences. A total of 29 fungal strains were isolated from the 15 deep-sea sediments. These strains belong to four fungal genera, including Aspergillus, Cladosporium, Penicillium, and Alternaria. Penicillium, accounting for 44.8% of the total fungal isolates, was a dominant genus. The antiaflatoxigenic activity of these deep-sea fungal isolates was studied. Surprisingly, most of the strains showed moderate to strong antiaflatoxigenic activity. Four isolates, belonging to species of Penicillium polonicum, Penicillium chrysogenum, Aspergillus versicolor, and Cladosporium cladosporioides, could completely inhibit not only the mycelial growth of Aspergillus parasiticus mutant strain NFRI-95, but also the aflatoxin production. To our knowledge, this is the first report to investigate the antiaflatoxigenic activity of culturable deep-sea fungi. Our results provide new insights into the community composition of fungi in the deep South Atlantic Ocean. The high proportion of strains that displayed antiaflatoxigenic activity demonstrates that deep-sea fungi from the Atlantic Ocean are valuable resources for mining bioactive compounds.

 抽象的

尽管最近进行了研究，但人们对大西洋深海真菌群落的多样性知之甚少。在这项研究中，我们采用依赖培养的方法调查了南大西洋 15 种不同深海沉积物中真菌群落的多样性，然后对 ITS 序列进行系统发育分析。从15个深海沉积物中总共分离出29株真菌。这些菌株属于四个真菌属，包括曲霉属、枝孢属、青霉属和链格孢属。青霉属为优势属，占真菌分离株总数的44.8%。研究了这些深海真菌分离株的抗黄曲霉毒素产生活性。令人惊讶的是，大多数菌株表现出中度至强的抗黄曲霉毒素生成活性。属于Penicillium polonicum 、 Penicillium chrysogenum、Aspergillus versicolor和Cladosporium cladosporioides的4个菌株不仅能完全抑制寄生曲霉突变株NFRI-95的菌丝生长，而且能完全抑制黄曲霉毒素的产生。据我们所知，这是第一份研究可培养深海真菌的抗黄曲霉毒素活性的报告。我们的结果为南大西洋深处真菌的群落组成提供了新的见解。高比例的表现出抗黄曲霉毒素活性的菌株表明，来自大西洋的深海真菌是开采生物活性化合物的宝贵资源。