AUTHOR=Hu Ping , Mao Junxia , Zeng Yan , Sun Zhihong , Deng Huan , Chen Chen , Sun Weizhong , Tang Zhiru 

TITLE=Isolation, Identification, and Function of Rhodotorula mucilaginosa TZR2014 and Its Effects on the Growth and Health of Weaned Piglets

JOURNAL=Frontiers in Microbiology

VOLUME=13

YEAR=2022

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2022.922136

DOI=10.3389/fmicb.2022.922136

ISSN=1664-302X

ABSTRACT=<p>A red yeast isolated from orange and grape soil and identified by the 26S rDNA sequence analysis revealed that it was <italic>Rhodotorula mucilaginosa</italic> and named TZR<sub>2014</sub>. Its biomass and carotenoid production reached a maximum when using the fermentation medium with pH 6.0, containing 5% glucose, 1% peptone, and 1.5% yeast powder. TZR<sub>2014</sub> was resistant to 55°C for 15 min, 0.2% pig bile salts for 4 h, and artificial gastric and intestinal fluids. A total of thirty 28-day weaned pigs were divided into three groups, and the piglets were fed a basal diet (CON), a basal diet and orally administered 1 ml 1.0 × 10<sup>10</sup> CFU/ml <italic>Candida utilis</italic> DSM 2361 three times (<italic>C. utilis</italic>), or a basal diet and orally administered 1 ml 1.0 × 10<sup>10</sup> CFU/mL TZR<sub>2014</sub> three times daily (<italic>R. mucilaginosa</italic>) for 4 weeks. Compared with the piglets in the CON group, those in the <italic>C. utilis</italic> or <italic>R. mucilaginosa</italic> group reported an increased average daily weight gain and average daily feed intake (<italic>P</italic> &lt; 0.05) and a decreased feed/gain (<italic>P</italic> &lt; 0.05). The diarrhea rate of piglets in the <italic>R. mucilaginosa</italic> group was lower than that in the CON and <italic>C. utilis</italic> groups (<italic>P</italic> &lt; 0.05). Compared with that in the CON and <italic>C. utilis</italic> groups, the <italic>R. mucilaginosa</italic> group reported an increased ileum villus height (<italic>P</italic> &lt; 0.05), serum concentration of total antioxidant content, total superoxide dismutase, and glutathione peroxidase and pepsin and lipase activities in the intestinal content, while it reported a decreased serum concentration of malondialdehyde and pH of the intestinal tract (<italic>P</italic> &lt; 0.05). The relative abundances of <italic>Proteobacteria</italic> and <italic>Megasphaera</italic> of caecum in the <italic>R. mucilaginosa</italic> group were lower than those in the CON and <italic>C. utilis</italic> group<italic>s</italic> (<italic>P</italic> &lt; 0.05). The relative abundances of <italic>Prevotella, Ruminococcaceae, Succinivibrio, Rikenellaceae RC9 gut group</italic>, and <italic>Roseburia</italic> of caecum in the <italic>R. mucilaginosa</italic> group were higher than those in the CON and <italic>C. utilis</italic> group<italic>s</italic> (<italic>P</italic> &lt; 0.05). <italic>R. mucilaginosa</italic> TZR<sub>2014</sub> can produce carotenoids and adapts to the animal's gastrointestinal environment. Oral <italic>R. mucilaginosa</italic> TZR<sub>2014</sub> improved growth performance, enhanced antioxidant capacity, strengthened gastrointestinal digestion, and maintained the intestinal microbiological balance of piglets.</p>