Mutation and Breeding High Productive Mutant of Lipid from Rhodotorula Glutinis by Low Ion Implantation

Abstract

In order to obtain an industrial strain with higher lipid yield, the wild strain Rhodotorula glutinis 31596 cells were mutated through a novel mutagen, nitrogen ion beam, with the energy of 10 keV and dose ranging from 20×2.6×1013 ions/ cm2 to 120 × 2.6×1013 ions/cm2 and with interval dose 20×2.6×1013 ions/cm. One mutant, D30 with high yield of lipid was isolated; its lipid yield was increased by 34 % than that of original. And it was found that genetic characteristics of D30 were rather stable through successive transfer of cultures. In the study of screening process, Soxhlet extraction method and acid-heating + ultrasonic extraction were compared. As a result, the cerulenin screening is chosen as qualitative analysis method and acid-heating + ultrasonic as qualitative analysis method. Additionally, the fermentation characteristic of high-yield mutation strain D30 was studied, when fermentation time was 96 h, its lipid yield increased to 3.10 g/L. Finally, GC was used to analyze the composition of the lipid, and the most represented fatty acids of mutant D30 were C16:0(11.4%), C16:1(5.66%), C18:1(49.3%), and C18:2(27.0%).