ABSTRACT

The objective of this research was to identify and select the bacteria from samples of marine water that produce antimicrobial agents and to optimize different growth conditions for the production of a significant quantity of antibacterial metabolites that are effective against the test pathogens. The present study focus on the isolation of bacteria from marine water of Bheemli beach Bay of Bengal, Visakhapatnam, Andhra Pradesh, India. The isolated bacteria were labelled initially as C1, C6 and C7 identified by 16S rRNA sequencing as Bacillus paramycoides (Bp), Lysinibacillus fusiformis (Lf) and Bacillus oshimensis (Bo). These bacteria had shown to be the most potent strains in exhibiting the considerable growth inhibition of the test organisms. By adjusting one parameter at a time, the effects of factors such as temperature, pH, incubation time, sodium chloride concentration and the effect of carbon and nitrogen sources on the production of antibacterial metabolites were examined. It was observed that environmental factors had a significant impact on the isolate's ability to secrete metabolites. The suitable conditions for optimum synthesis of bioactive compounds were identified as incubation period for Bacillus paramycoides (72 hrs), Lysinibacillus fusiformis (96 hrs) and Bacillus oshimensis (72 hrs) and other conditions of pH 7.0, temperature 30o C, NaCl 2% concentration with the nutritional components of ribose ascarbon source and sodium nitrate as nitrogen source were same for all these three isolates. The results of the study showed that the growth of test microorganisms was inhibited by these isolated bacterial strains namely Bacillus paramycoides, Lysinibacillus fusiformis and Bacillus oshimensis in the primary screening and the inhibition was further increased by optimizing the conditions required for the cultivation. Keywords: Antibacterial activity, Bioactive compounds, Marine bacteria, Optimization
Publication date: 01/08/2026

https://www.ijbpas.com/pdf/2026/August/MS_IJBPAS_2026_10399.pdf

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https://doi.org/10.31032/IJBPAS/2026/15.8.10399