Labyrinthulomycota from Brazilian mangrove swamps and coastal waters

Abstract

Abstract The phylum Labyrinthulomycota is composed of three distinct groups of fungus-like organisms: the labyrinthulids, the thraustochytrids and the aplanochytrids. They are present in marine and brackish waters as saprobes and/or parasites. In recent years, there was an increased interest in studying these organisms due to the ability that some have to produce large amounts of lipids, particularly polyunsaturated fatty acids. However, in spite of their importance and diversity, in Brazil only four species were reported in the 1970s. Due to their ecological and economic importance globally and the limited knowledge of them in the country, this study aimed to evaluate the diversity of the Labyrinthulomycota in mangrove swamps and coastal waters of São Paulo State, Brazil. The specimens were isolated from water and leaf samples using different methodologies, and purified in an agar medium prepared with half-strength sterile seawater, peptone, yeast extract and glucose. After purification, they were identified by means of morphology and phylogenetic analysis of the SSU rDNA region. A total of 193 specimens representing five genera were observed, 26 specimens were incorporated into the culture collections and 29 sequences of the SSU rDNA region were deposited in GenBank. Labyrinthula sp., Aurantiochytrium sp., Parietichytrium sarkarianum and Thraustochytrium striatum are new records for Brazil, contributing to our knowledge of the diversity of fungus-like organisms in the country.