Enhanced β-carotene production by Rhodotorula glutinis using high hydrostatic pressure

High hydrostatic pressure (HHP) technology was used for improving the ability of beta-carotene biosynthesis of Rhodotorula glutinis R68. After the treatments of five repeated cycles at 300 MPa for 15 min, the barotolerant mutant PR68 was obtained. After 72 h of culture, the biomass of mutant PR68 was 21.6 g/L, decreased by 8.5% compared to the parent strain R68, but its beta-carotene production reached 19.4 mg/L, increased by 52.8% compared to the parent strain R68. The result of restriction fragment length polymorphism analysis suggested that mutant strain PR68 was likely to change in nucleic acid level, and thus enhanced beta-carotene production in this strain was a result of gene mutation induced by HHP treatment. HHP technology seems a promising approach for improving industrial microbes.