Regulation On The Secondary Metabolism Of Marine Algicolous Trichoderma Fungi

Multifarious secondary metabolites have been obtained from Trichoderma species of various origin, including terpenoids, polyketides, and alkaloids. Studies on the secondary metabolites of marine algicolous fungi(MAFs) began in the 1990 s, and over 20% of the secondary metabolites from marine-derived fungi were produced by MAFs, which have attracted a great attention for natural product researchers. Marine algicolous Trichoderma species have the characteristics of the Trichoderma, MAFs and marine-derived Trichoderma. Until 2016, only 6 strains of marine algicolous Trichoderma were chemically studied. Thus, it is significant to further explore the secondary metabolism of marine algicolous Trichoderma species.Study on secondary metabolic regulation of marine algicolous Trichoderma species revealed that marine algicolous Trichoderma species can grow in seawater and freshwater, even at 70.0 g/L Na Cl. However, under the Na Cl(30 g/L) and seawater conditions, marine algicolous Trichoderma species growed better. In Na Cl(70.0 g/L), Na Br(86.3 mg/L), p H = 8.0, and seawater(salinity = 3.0% and p H = 8.0) conditions, their crude extracts contain more heteroatoms and unsaturated groups(vinyl and/or aryl). The intracellular and extracellular secretions of ten strains marine algicolous Trichoderma were also found to be toxic to Artemia salina and inhibitory against microalgae and phytopathogenic fungi. Moreover, some broth extracts were evaluated to be significantly toxic to the larvae of mollusc Littorina brevicula at 10 μg/m L.Due to the high activity, Trichoderma dl36 was selected for large-scaled fermentation. As a result, six compounds were obtained by column chromatography on silica gel and Sephadex LH-20, preparative thin layer chromatography(p TLC), and semi-preparative high performance liquid chromatography(HPLC). The structures were elucidated by spectroscopic methods, involving 1H NMR、13C NMR,and DEPT.Overall, the secondary metabolisms of ten marine algicolous Trichoderma strains and the products from one of them have been explored. The results make a contribution to knowing the secondary metabolisms of marine algicolous Trichoderma species, and lay the foundation for further exploring it.