Optimization of beta-carotene production of Rhodotorula mucilaginosa isolated from the waste leather factory

Yeasts have a special value for human in biotechnology because of the production of pigments. Rhodotorula species produce high amounts of beta-carotene. The aim of this study was to maximize the production of beta-carotene at least prices from native yeast species.   The four isolation evaluated were isolated from specific environments during three stages of sampling from the waste leather factory.  Subsequently, two isolates of Aa1 and Aa4 were identified using the biochemical test and PCR technique. The production of beta-carotene was determined by the identified isolates and a standard strain in different conditions of salt, nitrogen source, carbon source, aeration, temperature, and pH. Optical absorption of the pigment was read through spectrophotometer at 470 nm.   Among the four isolates, only the isolate Aa1 is capable to produce carton-free pigment. The genetic identification of the two isolates Aa1 and Aa4 confirmed 98% similarity to those of Rhodotorula mucilaginosa and Debaryomyces hanseni, respectively. The results showed that the maximum production of beta-carotene was obtained after optimization of 75.6 μg/ml for Rhodotorula mucilaginosa and 32.7 μg/ml for Rhodotorula glutinis (standard strain).   The isolation of native species and the optimization of its functional activities in the laboratory is not only useful in the production of high-quality industrial products, but also the use of the native species is highly economical.