Melanin production and antibacterial activity by melanin produced by actinomycetes strain PNST-01 and PRBS-12

Abstract

The objectives of this research were to characterize growth and melanin production on different culture media, effect of copper ion and cobalt ion on growth and melanin production including antibacterial activity of crude melanin. The results revealed that actinomycetes strain PNST-01 have good growth on ISP-7 medium, synthetic medium, while strain PRBS-12 grow very well on ISP-3 medium, complex medium. Both strains produced high amount of melanin showing brownish colony on ISP-7 medium but there is no melanin pigment production on ISP-1 medium and ISP-6 medium. Moreover, the growth rate was reduced and both strains could not produce melanin pigment on ISP-7 medium without supplement with copper chloride and cobalt chloride. Crude melanin extract of strain PNST-01 showed antimicrobial activity against Bacillus cereus ATCC 11778, Bacillus subtilis ATCC 6633 and Staphylococcus aureus ATCC 25923 but could not inhibit Escherichia coli, Shigella dysenteriae, Salmonella typhi, Klebsiella pneumoniae, Serratia marcescens, Pseudomonas aeruginosa and Streptococcus pyogenes . While crude melanin extract of strain PRBS-12 gave antimicrobial activity only on B. cereus ATCC 11778 and B. subtilis ATCC 6633. Based on the study, the results can be used as key information for further development of melanin production and application in various industries.