Centella asiatica, commonly known as Asiatic pennywort and Gotukola, harbors a wide variety of phytochemicals. This complex phytochemical composition of the plant makes it suitable for broad medicinal and commercial applications. The plant body provides a habitat for the growth and survival of various microorganisms and has its microbiome. In this study, efforts were made to isolate and identify bacterial inhabitants from the leaves of the plant. The bacterial isolates were further tested for osmotolerance activity which enables them to survive and grow in high salt concentrations. The high salt concentration is one of the important abiotic parameters which affects the growth of living organisms negatively. High salt concentration induces abiotic stress on the plant by producing an excessive amount of reactive oxygen species which leads to damage to biomolecules and osmotic shock. However, certain living organisms especially bacteria come under the group called osmotolerant and have molecular and biochemical machinery which help in the alleviation of this salt stress and enable them to survive in high salt concentrations. During the study, various bacteria were isolated from the phylloplane of C. asiatica using specific microbial cultural methods. The isolated bacterial populations were subjected to identification and characterization. Various morphological and biochemical methods were applied to characterize the bacterial isolates. The characterized bacteria were further grown on media plates containing an increasing amount of salts such as sodium chloride, mannitol, and sorbitol which help in the isolation of osmotolerant bacteria. The osmotolerant bacteria were finally identified using advanced molecular methods like 16s rRNA sequencing. The results of this study show that the plant has varieties of bacterial inhabitants in its phylloplane and all three bacterial isolates were known and identified for having osmotolerance activity.
Key words: Abiotic stress, Centella asiatica, Osmotolerance, 16s rRNA sequencing
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