YEAST IN SOUTHWEST MONSOON RAINWATER

Abstract

Strong evidence of the presence of bacteria and fungi in the tropospheric boundary layer is available in the literature. We report successful isolation of unique morphotypes of wild ascomycetous yeasts from rainwater samples collected directly in sterile containers, taking extreme care to avoid ambient contamination. Direct and quick visualization of fresh rainwater samples under a phase contrast microscope indicated the sporadic presence of yeast cells. Further confirmation of the presence of yeast was obtained by plating of rainwater on a medium with antibiotics to generate pure colonies. We described their characteristics while molecular identification revealed it as Candida tropicalis. Yeast species  could contribute valuable knowledge about yeast transportation in the atmosphere. However, knowledge is insufficient about the yeast deposited from the atmosphere and its transportation across the atmosphere. We report and discuss these interesting and exciting results which are useful in understanding the microbiological dimension of meteorology and the southwest monsoon rainfall in the light of present discourse on global warming and climate change. We offer a tentative model for a possible source, role, and fate of the yeasts in rainwater.