Carotenoid biosynthesis is associated with low-temperature adaptation in Rhodosporidium kratochvilovae

Abstract

Background Low temperatures greatly limit the growth of microorganisms. Low-temperature adaptation in microorganisms involves multiple mechanisms. Carotenoids are naturally occurring lipid-soluble pigments that act as antioxidants and protect cells and tissues from the harmful effects of free radicals and singlet oxygen. However, studies on the regulation of carotenoid biosynthesis at low temperatures in microorganisms are limited. In this study, we investigated the correlation between carotenoids and low-temperature adaptation in the cold-adapted strain of Rhodosporidium kratochvilovae YM25235. Results Carotenoid biosynthesis in YM25235 was inhibited by knocking out the bifunctional lycopene cyclase/phytoene synthase gene (RKCrtYB) using the established CRISPR/Cas9 gene-editing system based on endogenous U6 promoters. The carotenoids were extracted with acetone, and the content and composition of the carotenoids were analyzed by spectrophotometry and HPLC. Then, the levels of reactive oxygen species (ROS) and the growth rate in YM25235 were determined at a low temperature. The results indicated that the carotenoid biosynthesis and ROS levels were increased in the YM25235 strain at a low temperature and inhibition of carotenoid biosynthesis was associated with higher ROS levels and a significant decrease in the growth rate of YM25235 at a low temperature. Conclusions The regulation of carotenoid biosynthesis was associated with low-temperature adaptation in YM25235. Our findings provided a strong foundation for conducting further studies on the mechanism by which YM25235 can adapt to low-temperature stress.

Comprehensive Response of Rhodosporidium kratochvilovae to Glucose Starvation: A Transcriptomics-Based Analysis

“…It is generally observed that most abiotic stresses cause ROS accumulation in cells. One of our previous studies also confirmed a negative correlation between the increase in carotenoid biosynthesis and ROS accumulation at low temperatures [48]. The lack of a carbon source inevitably induces ROS production [13,26], a phenomenon similar to that encountered in this study.…”

“…Rhodosporidium kratochvilovae YM25235 (isolated from Chenghai Lake, Yunnan, China) is a red yeast that produces polyunsaturated fatty acids (PUFAs) and carotenoids [ 44 , 45 , 46 ]. Our previous research focused on the adaptability of the YM25235 strain to a low temperature [ 47 , 48 ]. However, in industrial applications, the growth of microorganisms is usually limited by nutrient availability [ 49 ].…”

Integrated Transcriptomics and Metabolomics Analysis Reveal the Regulatory Mechanisms Underlying Sodium Butyrate-Induced Carotenoid Biosynthesis in Rhodotorula glutinis

“…The levels of these substances are regulated to normal levels by enzymatic and non-enzymatic antioxidant systems [37]. Notably, β-carotene is the principal non-enzymatic antioxidant found in red yeast cells; in another study, we found a correlation between carotenoid biosynthesis and ROS accumulation in red yeast [38]. In this study, the experimental group (Y79_96SB) exhibited high ROS levels and increased carotenoid synthesis efficiency at 96 h (Figures 2c and 3a).…”

Involvement of Versatile Bacteria Belonging to the Genus Arthrobacter in Milk and Dairy Products

“…Carotenoids are lipophilic compounds accumulated in the cell membrane where the variation in chemical structure and thickness of carotenoids may affect the regulations of these compounds [ 54 ]. They present significant biological properties, for example, acting as antioxidants and protecting cells and tissues from the harmful effects of free radicals and singlet oxygen [ 55 ]. In addition, these compounds were reported to engage in photoprotection, and membrane stabilization [ 56 , 57 , 58 ].…”