Study of Antioxidants from Marine Bacteria

Abstract

newlineMarine habitats constantly expose marine organisms to different stresses indicating these organisms could have an effective antioxidant mechanism to combat stress making them a potential source of novel antioxidant compounds.156 isolates obtained from marine soil samples were screened for antioxidant production by TLC and DPPH assay. The HPTLC analysis of the lyophilized CFS of the selected organisms viz. 6-3 and 8-1 exhibited a different banding pattern of the antioxidants. The isolates were identified as Janibacter sp TKB-1 and Pseudomonas sp KKB-1. After screening of different media for optimal production, Janibacter showed optimal antioxidant production in SWYE and Pseudomonas showed optimum antioxidant production in SWC medium. The ascorbic acid equivalence of the extracts was found to be 214 µg/ml for Janibacter and 211.5 µg/ml for Pseudomonas by DPPH assay. The FRAP assay and H2O2 scavenging assay showed 334 µg/ml and 230 µg/ml of ascorbic acid equivalence for Janibacter and 753 µg/ml and 226 µg/ml of ascorbic acid equivalence for Pseudomonas respectively. The comparative analysis of these isolates with known antioxidant producing Lactobacilli cultures revealed that the isolates exhibit antioxidant activity equivalent to the standard cultures. To study the effect of stress on antioxidant activity, Janibacter and Pseudomonas were exposed to metal stress viz. CuSO4 and Cd(NO3)2. In presence of Cd(NO3)2 the cell density decreased with concentration, giving a 7 to 8-fold increase in the antioxidant activity, suggesting enhanced antioxidant production. The FT-IR and H1 NMR studies revealed the presence of the ester, ether functional groups and aromatic ring and aliphatic chain. The cytotoxicity of the extracts were nontoxic in accordance with the IC50 value of std tannin. The antiageing potential of the extracts was studied and a moderate antielastase activity and antihyaluronidase activity was observed indicating their application as effective antiwrinkling and moisturizing agent. newline newline