Kinetic models of ribonucleic acid fermentation and continuous culture by Candida tropicalis no.121

Abstract

During ribonucleic acid fermentation, the fermentative processes were researched at pH controlled at 4.0 and under natural conditions. Unstructured models in a 50-L airlift fermentor were established for batch RNA production at pH 4.0 using the Verhulst equation for microbial growth, the Luedeking-Piret equation for product formation and a Luedeking-Piret-like equation for substrate uptake. Parameters of the kinetic models were determined using origin 7.5. Based on the models estimated above, another batch fermentation experiment was conducted in a 300-L airlift fermentor, which demonstrated that the models could be useful for RNA production on an industrial scale. Additionally, continuous fermentation based on kinetic models was proposed to make full use of substrates and reduce the cost of waste water treatment. As a result, although the DCW and RNA concentration were 11.5 and 1.68 g L(-1), which were lower than that of batch fermentation, the sugar utilization increased by 14.3%, while the waste water decreased by more than 90%.

Genome Sequence of Candida tropicalis no. 121, Used for RNA Production

“…121 was a high-yield strain used for RNA production in our laboratory and Nanjing BioTogether Co. Ltd. Under optimal conditions, the maximum RNA and dry cell weight (DCW) concentrations were >2.5 and 15 g liter -1 (5, 6), higher than those for Kluyveromyces marxianus (7). At the present, the genome sequence of C. tropicalis MYA-3404 is available at the National Center for Biotechnology Information (NCBI) (8).…”

Enhanced Ribonucleic Acid Production by High-Throughput Screening Based on Fluorescence Activation and Transcriptomic-Guided Fermentation Optimization in Saccharomyces cerevisiae

“…Ying and Li achieved a volumetric productivity of 2.84 and 1.68 g/L RNA, respectively, by batch and continuous fermentation of Candida tropicalis. 22 It has been observed and reported that yeast cellular RNA content increases with the yeast cell growth rate. 23 However, the mechanism of high RNA accumulation in S. cerevisiae is unclear.…”

“…However, these previous studies were only carried out at the shake flask level, and determination of RNA was performed at the early stage of the logarithmic stage (samples for RNA determination were taken at OD 600 ≈ 1.0), which was not applicable to industrial scale production of RNA. Ying and Li achieved a volumetric productivity of 2.84 and 1.68 g/L RNA, respectively, by batch and continuous fermentation of Candida tropicalis …”

Fed-Batch Fermentation of Saccharomyces pastorianus with High Ribonucleic Acid Yield

“…The production of glutathione in S. cerevisiae increased to 253% by continuously feeding cysteine during fed-batch fermentation [ 19 ]. Higher biomass and RNA production in S. cerevisiae and C. tropicalis were achieved with the fed-batch fermentation strategy [ 20 , 21 ].…”