Candida tropicalis strain:No.1254 Transcriptome or Gene expression. Candida tropicalis strain:No.1254

Here we report enhancement of cell growth and cell membrane permeability of Candida tropicalis after treatment with low intensity ultrasonic irradiation with a sweeping frequency mode. Four factors, that is, yeast growth phases, ultrasonic power density, ultrasonic frequency and processing time were investigated to obtain optimal treatment conditions. Fortunately, remarkable increasement of Candida tropicalis biomass was observed after treatment with ultrasound compared with the control (without ultrasonic treatment). The optimal conditions for ultrasonic treatment for the maximum biomass addition were determined as follows: 28+-2 kHz ultrasound irradiation with power density 120 W/L, yeast cultured at mid-logarithmic phase, and treatment for 1 hour. Under these conditions, the Candida tropicalis biomass addition reaches to 148.48%, higher than that previously reported. Furthermore, Illumina transcriptome sequencing was performed to compare the gene expression profile of Candida tropicalis treated with ultrasound under the optimal conditions and that untreated as a control. The results show ultrasonic treatment has effects of expressional regulations on diverse cellular components, biological processes and molecular functions of the yeast.