Screening of lipid high producing mutant from rhodotorula glutinis by low ion implantation and study on optimization of fermentation medium

Abstract

In order to obtain lipid producing strain with high-yield, the wild type stain Rhodotorula glutinis was treated by low ion implantation, and optimization of fermentation medium for higher lipid yield was carried out using mutant strain. It was found that the strain had a higher positive mutation rate when the output power was 10 keV and the dose of N ? implantation was 80 9 2.6 9 10 13 ions/cm 2 . Then a high-yield mutant strain D30 was obtained through cid-heating coupling ultrasonic method and lipid yield was 3.10 g/L. Additionally, the surface response method was used to optimize fermentation medium. The three significant factors (glucose, peptone, KH 2 PO 4 ) were optimized using response surface methodology (RSM), and the optimized parameters of fermentation medium were as follows: glucose 73.40 g/L, peptone 1.06 g/L and KH 2 PO 4 3.56 g/L. Finally the fermentation characteristic of high-yield mutation strain D30 was studied, when fermentation time was 10 days, which lipid yield increased to 7.81 g/L. Fatty acid composition of the lipid was determined by GC, 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 %).

Production of microbial carotenoids by Rhodotorula lactosa isolated in the Brazilian tropical savanna / Produção de carotenoides microbianos por Rhodotorula lactosa isolada na savana tropical brasileira

“…The constant pH 4 profile was also observed for the production of lipids by R. glutinis, during 10 to 11 days of fermentation, the pH and the production of lipids and biomass were simultaneously decreased, due to the yeast autolysis process, in turn, due to scarcity of nutrients [35]. In our studies, no decrease in these responses was observed up to 168 h.…”

Rhodotorula glutinis—potential source of lipids, carotenoids, and enzymes for use in industries

“…Profile of fatty acids synthesized by the R. glutinis primarily depends on the yeast strain and composition of the culture medium (Zhang et al 2011 ) (Table 2 ). However, the composition of the lipids can also be adjusted by modifying the molar ratio C/N in the culture medium (Braunwald et al 2013 ), temperature of cultivation (Suutari et al 1990 ), and by genetic modification of yeast (Shichang et al 2013 ). A significant impact on the profile of fatty acids synthesized by the R. glutinis yeast has also time of cultivation (Mast et al 2014 ; Zhang et al 2011 ).…”

“…Lipids synthesized by R. glutinis can be also enriched in linoleic acid through genetic modification. Shichang et al ( 2013 ) used for this purpose implantation of nitrogen ions. The obtained mutant D30 synthesized almost 3-fold more linoleic acid (27 %) compared to the parental strain R. glutinis 31,596 (9.93 %), while significantly reduced oleic acid (from 61.8 to 49.3 %) and palmitic acid (from 5.66 to 11.0 %).…”

Kinetic Models and Effects of Mn(II) Ion on Ethanol Production from Cornstalks

“…Mn 2+ is an essential trace element for microbial growth that improves the activity of cellulase and yeast (Saxena and Tanner 2011;Lakkana et al 2012). The increase in activity and cellulose content is favorable for fermentation (Li et al 2013;Deesuth et al 2015). The results showed that the ethanol yield from cornstalks was improved by adding appropriate amounts of Mn 2+ , which was economically feasible.…”

“…The media were prepared as described by Li et al (2013). Medium I was used for slant medium, and it was composed of 10% wort with 2% agar and 2% peptone.…”