Isolation and Characterization of an actinomycete strain producing an antifungal metabolite effective against Candida albicans Chandrashekar Adithya, Muralidharan Anuraag, Koteshwara Ananthamurthy, Alex Angel Treasa, Subrahmanyam V. M.* Department of Pharmaceutical Biotechnology, Manipal College of Pharmaceutical Sciences, Manipal Academy of Higher Education, Manipal-576104, Karnataka, India *Corresponding Author E-mail: vm.subra@manipal.edu
Online published on 24 December, 2019. Abstract Novel antifungals are challenging to find as potential target may have close human orthologs. Among the pathogenic fungi, Candida albicans is the most prevalent pathogen. Screening of actinomycetes for antifungals has been an aggressive area of research since decades. For discovering newer metabolites against Candida albicans, work was oriented in isolation of actinomycetes for evaluating the antifungal activity of their cultural extracts. A total of 115 strains were isolated from different soil samples using Starch Casein Agar. Mueller Hinton Agar and Glucose Soybean Meal were used as suitable assay and cultivation medium. Only 11.30% isolates were significantly active and isolate M-23 was found promising. Metabolite production reached maximum on the 7th day of incubation at 30⁰C using modified Glucose Soybean Meal medium. The culture supernatant and its ethyl acetate extract fraction had inhibitory zone diameters of 25mm and 30mm. Effect of addition sodium acetate as precursor was insignificant. M-23 was identified as Streptomyces coelicolor by 16SrDNA sequencing. The metabolite was partially characterized using various physicochemical tests. The UV spectrum showed three absorbances in 360-405nm region. The crude extract gave an IC50 of 256.5μg/ml against vero cell lines. This strain can find use in the production of newer antifungals. Top Keywords Actinomycetes, Antifungal, Streptomyces coelicolor. Top |