Identification of newly zeaxanthin-producing bacteria isolated from sponges in the gulf of thailand and their zeaxanthin production

摘要

Sponge-associated bacteria have been found to produce a variety of bioactive compounds including natural pigments. Here, we report the molecular identification of zeaxanthinproducing sponge-associated bacteria isolated from sponges in the Gulf of Thailand and the effect of environmental factors on zeaxanthin production from a bacterium. Three colorful spongeassociated bacteria (CHOB06-6, KODA19-6, andMAKB08-4) were identified based on the 16S rDNA profile. The 16S rDNA sequence-based analyses revealed that CHOB 06-6 and MAKB 08-4 were the closest relatives to Sphingomonas phyllosphaerae FA2T, and KODA19-6 was a relative of Shingomonas (Blastomonas) natatoria DSM 3183T. After all bacteria were cultivated in a modified Zobell medium, S. natatoria KODA19-6 was found to produce the highest zeaxanthin at 0.62 mg/l. pH and temperature considerably affected its zeaxanthin production. Its optimal condition for zeaxanthin production was found at a pH of 7 and 30 °C. The bacterium had a maximum specific growth rate (μmax) of 0.061/h with zeaxanthin productivity (Qp) of 6.27 μg/l.h. Therefore, this newly zeaxanthin-producing bacterium has a potential to produce natural zeaxanthin for the food, feed, pharmaceutical, and cosmetic industries.