eng Oriental Scientific Publishing Company Biosciences Biotechnology Research Asia 0973-1245 2016-06-10 11 Spl.Edn.1 271 278 10.13005/bbra/1420 11850 article R. Muthezhilan 1 R. Ragul 1 Angelin C. Pushpam 1 R. Lakshmi Narayanan 3 A. Jaffar Hussain 2 Department of Marine Biotechnology, AMET University (U/S 3 of UGC Act 1956), Kanathur, Chennai 603112, India. Centre for Marine Bioprospecting, AMET University (U/S 3 of UGC Act 1956), Kanathur, Chennai 603112, India. Centre for advanced study in Marine Biology, Annamalai University, Parangipettai - 608502, India. The use of synthetic dyes have been found to be unsafe to human health and there only some limited kinds of such dyes are permitted to be use. Hence there is an urgent need of natural food colorants to alternate the existing one. In general, the natural colors are quite common and rich in pigment producing microorganisms such as bacteria, yeast, fungi etc., among which the yeast are easily grown unicellular eukaryotes. In this present study, morphologically 30 different Marine yeast strains from 12 different samples collected from 6 different saltern areas of Kelambakkam, East Coast of Tamil Nadu, India and they were named as AMBY101 to AMBY130. Among the 30 strains 3 strains were capable of producing pigment. The pigments were extracted from all the three yeast strains using methanol as solvent and they were screened for antimicrobial activity against human pathogens such as Escherichia coli, Enterococcus faecalis, Vibrio cholerae, V. parahaemolyticus, Salmonella sp. and Shigella sp (obtained from AMET Microbial Culture Collection Centre). Based on the zone of inhibition, cell density and pigment production the marine yeast strain AMBY109 was potentially chosen for further study. The morphological and chemotaxonomic characteristics were confirmed that the potential marine yeast strain AMBY109 was belonging to Rhodotorula Sp. Response surface methodology (Box behnken design) were used to produce the pigment from the potential strain under different physicochemical parameters. Based on box behnken design and analysis of variance, the optimum culture conditions were found as: pH (8.54), temperature (34.290C), salinity (20.15ppt) and incubation period (48.24 hrs). With the optimum condition pigment production was predicted 0.7263 by this model and pigment production was observed 0.7152. From the results the study has suggested to use these readily absorbable natural pigments from Rhodotorula Sp. for an alternative of synthetic colorants in food industry. https://www.biotech-asia.org/vol11_nospl_edn1/isolation-optimization-and-extraction-of-microbial-pigments-from-marine-yeast-rhodotorula-sp-amby109-as-food-colourants/ Pigments; Marine Yeast; Rhodotorula sp.; Food colorants