Diversity and distribution of fungal communities within the hot springs of soda lakes in the Kenyan rift valley

Abstract

Fungi are highly diverse and versatile, with members growing under different environmental conditions including extreme environments. Although fungal communities in some extreme environments have been investigated in recent years, little is known about their structure and richness within the hot springs of soda lakes in Kenya. The aim of the study was to determine the biogeography and diversity of fungi from the hot springs of four Soda lakes. Water, sediment and microbial mat samples were collected in triplicates from Lakes Bogoria, Magadi, Elmenteita and Little Magadi in Kenya. 454-Pyrosequencing was used to sequence amplicons of Internal Transcribed Spacer (ITS) gene region of the total community DNA in order to explore the fungal community composition in twenty four samples collected. Sequences were analyzed using QIIME pipeline Version 1.8.0, while hierarchical clustering, non-metric dimensional scaling (NMDS) and diversity indices were carried out using the R programming language and the Vegan package. A total of 139,023 quality sequence reads were obtained from which, 2,179 operational taxonomic units (OTUs) were realized at 3% genetic distance. Three known phyla (Ascomycota [83.3%], Basidiomycota [15.8%], Glomeromycota [0.02%]) were identified. Richness, abundance and taxonomic analyses identified Agaricomycetes as the most abundant and diverse class within Basidiomycota. Sequences matching with Ascomycota had high affinities with seven known classes, with Sordariomycetes and Dothideomycetes being the most abundant and diverse classes. The most abundant OTUs showed the highest sequence similarity to Cladosporium sp., Cladosporium cladosporioides, Pleosporales sp., Aureobasidium pullulans and Aspergillus oryzae. Key words: Hot springs, fungi, 454 pyrosequencing, diversity, extreme environments.