Molecular identification and biological activity of a red sea bacterial isolate

Abstract

Marine microorganisms residing in the Red Sea have been recognized as valuable sources of novel natural products with potential medical applications. One distinct bacterial isolate coded MMM3 was isolated from the marine tunicate Phallusia nigra, gathered from the Egyptian coast of the Red Sea. The present study aimed to identify and assess the isolated strain’s biological activities. After genomic extraction and PCR amplification, the bacterial strain was identified through 16 S rRNA gene sequencing as Heyndrickxia ginsengihumi and deposited in (NCBI) GenBank database under the accession code PX237387. The tested isolate was cultivated in R2A liquid medium for ten days at 25 °C in a shaking incubator set at 220 rpm. The crude extract exhibited effective COX-2 inhibition and antioxidant activity with IC₅₀ value of 107.07 and 451.75 µg/ml, respectively. The crude extract exerted antifungal effect (inhibition zone of 9 mm) against Candida albicans ATCC 10,231. In addition, the crude extract demonstrated significant cytotoxic activities against HepG2, A-549, MCF-7 and HCT-116 cell lines with IC50 values of 54.67 ± 1.05, 60.19 ± 1.23, 108.79 ± 2.08, and 73.57 ± 1.48 µg/mL, respectively. Regarding the chemical characterization of the crude extract, LC-MS analysis indicated diverse secondary metabolites including linoleic acid, myristoyl glucose-3-phosphate, and 2-acetoxy-4-pentadecylbenzoic acid. The identified metabolites suggest a synergistic contribution to the biological activities of the isolated strain, highlighting its potential as a source of bioactive compounds. The results indicated that the bacteria isolated from Red Sea coast is a promising source of bioactive molecules with medical applications.