Terrestrial fungi

Abstract Recent chemical studies on the marine soft corals and terrestrial plants have lesnlted in the isolation of several novel componnds. The soft corals, Pseudopterogorgia elisabethae and Cladiella species yielded several novel terpenoids, exhibiting antimicrobial activities. New steroids were isolated from terrestrial fungi, Mucor plumbeus and Coprims micaceus. Phytochemical studies on the Buxus hyrcana, collected from Iran, have yielded steroidal bases. This revdew describes the new natiual products exhibiting different bioactivities from the aforementioned sources. 

Fungi and yeasts are also members of the marine heterotrophic eukaryotes. They are generally found living on or within tissues of other organisms or on detrital POM. Fungi are important primarily in coastal water where they serve as decomposers of terrestrial vascular plant detritus. Yeasts occur as parasites of copepods. 

Mycosporine and diketopiperazine types ofpeptides are typical of fimgi but are also found in other taxa, on land and in the sea. Their wide occurrence may be explained by the chemical propensity of amino acids to couple, forming these chemically stable rings (Chart 8.3.P). Similarity of metabolites from terrestrial and marine fungi (Chart 8.3.P) is no surprise in view of the commonness of marine-adapted fungi. 

Several sulfide diketopiperazines were isolated from marine bacteria. Gliovictin (74) composed 27% of media extract of cultured broths of the marine deuteromycete Asteromyces cruciatus [82], Compound 74 was previously found in terrestrial fungi of the genera Helminthosporium and Penicillium [83]. Maremycins A and B (75 and 76) were additional diketopiperazines obtained from the cultured broth of the marine Streptomyces sp. and the structures of these compounds were elucidated by spectral methods and chemical means [84]. 

Nitrification. Nitrification, the oxidation of NH4+ to N03 , is mediated by bacteria and fungi in both the terrestrial and aquatic portions of watersheds. It is an important process in controlling the form of N released to surface waters by watersheds, as well as in controlling the acid-base status of surface waters (Figure 1). Nitrification is a strongly acidifying process, producing 2 moles of H for each mole of N (NH4+) nitrified. 

Organohalogens are present in many terrestrial environments sediments, soils, plants, fungi, lichen, volcanoes, biomass combustion, bacteria, insects, and higher organisms. The high concentration and dispersal of chloride in minerals, soils,... 

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