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

Here we report the enhancement of both cellular permeability and cell growth rate of Candida tropicalis after treatment with the ultrasonic irradiation of low intensity using a mode of sweeping frequency (UILS) genenated by a self-developed ultrasonic device in our lab. After the ultrasonic treatment, remarkable biomass enhancement of the yeast was observed; the hyphae became significantly longer; the seeped cellular protein and nucleic acid from the yeast increased and the cellular Ca2+ content became lower. Illumina transcriptome sequencing showed that the ultrasonic treatment affected the expression of genes involved in diverse cellular components, biological processes and molecular functions. RT-PCR and Western blotting further confirmed the up-/down-regulation of genes in the ultrasound-treated yeasts. The optimal conditions of the ultrasonic treatment for the maximum biomass addition were determined as follows: the yeast was treated for 1 hour at the mid logarithmic phase, the frequency was 28±2 kHz and the power density was 120 W/L. Under these conditions, the Candida tropicalis biomass increased by 142.5% compared with the untreated yeast.

本研究报道了利用实验室自主研发的超声装置产生的扫频模式低强度超声辐照（UILS）处理热带假丝酵母（Candida tropicalis）后，其细胞通透性与细胞生长速率均得到提升的结果。经超声处理后，该酵母菌的生物量显著提升；菌丝长度明显增加；渗漏出的细胞蛋白与核酸含量升高，而细胞内钙离子含量降低。Illumina转录组测序结果显示，超声处理会影响参与多种细胞组分、生物学过程及分子功能的基因的表达。逆转录聚合酶链式反应（RT-PCR）与蛋白质印迹法（Western blotting）进一步验证了经超声处理的酵母菌中相关基因的上调与下调表达。本研究确定了实现最大生物量提升的超声处理最优条件：在对数生长期中期对酵母菌进行1小时处理，超声频率为28±2 kHz，功率密度为120 W/L。在此条件下，热带假丝酵母的生物量较未处理组提升了142.5%。