Antibacterial and anticancer activity of marine Streptomyces parvus: optimization and application

Abstract

A total of 17 actinomycetes were isolated and screened against five bacterial pathogens. Forty-one per cent of the isolates were active against the tested pathogens. The most potent isolate was identified as Streptomyces parvus by using a 16S rRNA sequence analysis. S. parvus produced active compound(s) against a number of Gram negative and Gram positive bacteria. The obtained inhibition zones were 14, 19, 20 and 20 mm against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa and Aeromonas hydrophila, respectively. Moreover, the anticancer activity of S. parvus was tested against four different cell lines: human liver cancer cell line, mouse lymphoma cell line, breast cancer cell line and human colon cancer cell line. The inhibition activities were 53%, 56%, 57% and 42%, respectively. To achieve a maximum production of the bioactive compound, Plackett–Burman design was applied. The productivity increased up to 1.3-fold, when S. parvus was grown in optimized medium composed of: 10 g L−1 starch, 1.5 g L−1 KNO3, 0.75 g L−1 K2HPO4, 0.75 g L−1 MgSO4∙7H2O, 0.015 g L−1 FeSO4, 2 mL (103 colony-forming units mL−1) inoculum size with pH 8 for 7 d of incubation. The main constitutes of S. parvus crude extract were determined by gas–liquid chromatography mass spectrometry. They were found to be ethane, 1,1-diethoxy; di-n-octyl phthalate; ethanol, 2,2-diethoxy; 9,12-octadecadienoic acid; methyl ester (E,E) and benzoic acid.

Keywords

• Streptomyces parvus
• antibacterial
• anticancer
• antifouling
• Plackett–Burman design
• immobilization