Diversity of cultivable actinomycetes associated with lichen of Xishuangbanna, Baimang Snow Mountain, and South Bank of the Baltic Sea

Abstract:

[Background] Apart from symbiotic fungi and algae, the lichens symbiosis system also includes some symbiotic actinomycetes. [Objective] To collect lichen samples from Xishuangbanna, Baimang Snow Mountain of Yunnan and South Bank of the Baltic Sea in Germany, and to analyze the diversity of pure cultivate actinomycetes associated with lichens. [Methods] Three actinomycetes selective media were used to isolate actinomycetes through plate dilution method. The taxonomic status of pure cultured actinomycetes was determined by comparing 16S rRNA gene sequence similarity and constructing phylogenetic tree. [Results] A total of 1 123 strains were isolated and 417 strains were identified. Among them, 107 strains of actinomycetes, including 18 potential new taxa, were isolated and purified from 17 lichen samples of Xishuangbanna which distributed in 7 orders, 14 families and 33?genera. Streptomyces was distributed widely. One hundred and three actinomycetes were separated from 7 lichen samples of Baimang Snow Mountain which belonging to 4 orders, 5 families and 9 genera. Sixteen possible new species were acquired. Streptomyces was the dominant genus, accounting for 39% of the total number of the actinomycetes. Total 65 strains of actinomycetes were obtained from 5 lichen samples of South Bank of the Baltic Sea which distributed among 4 orders, 8 families and 18 genera. Five potential new taxa and Streptomyces were the prime group. [Conclusion] In this study, the diversity of actinomycetes associated with lichens in Xishuangbanna was more abundant than Baimang Snow Mountain and South Bank of the Baltic Sea. Members of streptomycetes were predominant, and potential new taxa accounting for 15.5% of total actinomycetes associated with lichens in Baimang Snow Mountain. The floristic composition of actinomycetes associated with lichens in the three regions was different, which was closely related to the geographical environment and completely different climate of the three regions.