Antioxidant and Antibacterial Activity of Β-Carotene Pigment Extracted From Parococcus Homiensis Strain BKA7 Isolated from Air of Basra, Iraq

Abstract

Carotenoids are widely used in natural and have different colors as yellow, orange, red and pink. Carotenoids having many applications as antioxidant, antibacterial and food additives. In this study an orange pigment produced from Parococcus homiensis strain BKA7 was isolated from air  in  Basra city, Iraq. Identified this strain by the 16SrNA gene analysis and recorded in Gene Bank as new strain with accession number LC495622.1. The optimum growth and pigment production by this strain were by Nutrient broth supplement with 0.5%yeast extract and 2% glycerol, incubation temperature 30 C^º, initial pH 9 , 1% inoculum , 150 rpm as culture shacking  and 72 hours as period of incubation. The carotenoid was extracted by methanol solvent and its analyzed by spectrophotometric within 400-600nm and wave length maximum was found at 460nm three peak spectra. The extract was separated using TLC, and three spots were found at Rf 0.98 which revealed the present of β-carotene while Rf 0.81 and Rf 0.47 were revealed to the present of xanthophyll. The β-carotene was purified by silica column chromatochraphy and confirmed by HPLC with a concentration of 574.00 µg/gm. The β- carotene have strong antioxidant activity, the maximum antioxidant was 72% at concentration 10mg/ml comparing with BHT 96% and Ascorbic acid 88% using DPPH method. The β-carotene showed high antibacterial activity with concentrations ranged 1200µg/ml against some pathogens strains. It was observed that β-carotene have a significantly stronger impact on Gram-positive than Gram-negative bacteria.