Studies on the diversity, distribution and ecological role of Saprolegniales (Oomycota) in freshwater ecosystems are currently receiving attention due to a greater understanding of their role in carbon cycling in various aquatic ecosystems. In this study, we characterized several Saprolegniales species isolated from Anzali lagoon, Gilan province, Iran, using morphological and molecular methods. Four species of Saprolegnia were identified, including S. anisospora and S. diclina as first reports for Iran, as well as Achlya strains, which were closely related to A. bisexualis, A. debaryana and A. intricata. Evaluation of the ligno-, cellulo- and chitinolytic activities was performed using plate assay methods. Most of the Saprolegniales isolates were obtained in autumn, and nearly 50% of the strains showed chitinolytic and cellulolytic activities. However, only a few Saprolegniales strains showed lignolytic activities. This study has important implications for better understanding the ecological niche of oomycetes, and to differentiate them from morphologically similar, but functionally different aquatic fungi in freshwater ecosystems.

中文翻译：

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伊朗安扎里泻湖中腐菌属的分类和功能多样性

由于腐臭菌（Oomycota）在淡水生态系统中的多样性，分布和生态作用的研究由于其在各种水生生态系统中碳循环中的作用的深入了解而受到关注。在这项研究中，我们使用形态学和分子学方法对从伊朗吉兰省安扎里泻湖中分离出的几种腐霉属进行了鉴定。四个品种的水霉鉴定，包括S. anisospora和S.霉作为伊朗第一次报告，以及绵霉的菌株，其中密切相关A. bisexualis，A. debaryana和A. intricata。使用平板测定法对木质素，纤维素和壳多糖的活性进行评估。大部分腐霉菌分离物是在秋天获得的，近50％的菌株表现出几丁质分解和纤维素分解活性。然而，只有少数Saprolegniales菌株表现出的木质素降解活动。这项研究对更好地了解卵菌的生态位，并将其与形态相似但功能不同的淡水生态系统水生真菌区分开来具有重要意义。