Efficient production of RNA in Saccharomyces cerevisiae through inducing high level transcription of functional ncRNA-SRG1.

RNA (Ribonucleic Acid) is an essential component of organisms and is widely used in the food and pharmaceutical industries. Saccharomyces cerevisiae, recognized as a safe strain, is widely used for RNA production. In this study, the S. cerevisiae W303-1a was used as a starting strain and molecular modifications were made to the functional ncRNA-SRG1 to evaluate the effect on RNA production. At the same time, its transcriptionally associated helper genes (Spt2, Spt6 and Cha4) were overexpressed and the culture medium was supplemented with serine to induce SRG1 transcription, to increase SRG1 transcription levels and investigate its effect on intracellular RNA levels. The results showed that the intracellular RNA content of the recombinant strain W303-1a-SRG1 was 10.27 %, an increase of 11.15 % compared to the starting strain (W303-1a, with an intracellular RNA content of 9.24 %). On this basis, a gene co-overexpression strain-W303-1a-SRG1-Spt6 was constructed. Simultaneously, the addition of 2 % serine strategy was used to increase the transcription level of SRG1 and RNA content of the recombinant strain. The intracellular RNA of the recombinant strain reached 11.41 %, an increase of 23.38 % compared to the starting strain (W303-1a, without serine supplementation). In addition, the growth performance of the strain was assessed by measuring the SRG1 transcription level in the strain and plotting the growth curve. Therefore, we found that improving the transcription level of ncRNA can be used as a new idea to construct S. cerevisiae with high RNA content, which provides a strong help for subsequent research in related fields. This work provides a new strategy for increasing the nucleic acid content of S. cerevisiae.