Extremely halophilic archaea and eubacteria are responsible for free radical scavenging activity of solar salts of Goa, India

Abstract

Free radical scavenging activity of natural solar salt of Goa was evaluated by the DPPH method. It ranged between 0.0793 mu g AAE /g and 0.145 mu g AAE/g. Our results showed that this antioxidant activity of salt was contributed by extremely halophilic Alteromonas, Gluconobacter and members of haloarcheal genera such as Halobacterium, Haloferax, Haloarcula, Halococcus, Halorubrum, Natrialba, Natrinema and Natronococcus, associated with it. This is the first record of Alteromonas, Gluconobacter, Natrialba, Natrinema, and Natronococcus as free radical scavengers. A positive correlation of R = 0.89, pless than or equal to 0.001 between the total antioxidant capacity and the phenolic content was observed in five Haloarchaeal genera selected for studies. Among which, Haloferax sp. GUSF-1 (KF796625) exhibited percent DPPH RSA of 31.5 plus or minus 0.43, total antioxidant capacity of 1.176 plus or minus 0.75 mg AAE/g and phenolic content of 0.784 plus or minus 0.004 mg GAE /g cells. This free radical scavenging potential of solar salts due to presence of these microbes, possibly reflects its use in moderation, as soil conditioner and fertiliser for coastal fruit bearing trees such as Cocos nucifera, Mangifera indica and Artocarpus heterophyllus in Goa, India.