scholarly journals Fed-batch fermentation of nipa sap to acetic acid by Moorella thermoacetica (f. Clostridium thermoaceticum)

2017 ◽  
Vol 23 (4) ◽  
pp. 507-514 ◽  
Author(s):  
Dung Nguyen ◽  
Harifara Rabemanolontsoa ◽  
Shiro Saka

An efficient process for conversion of nipa sap to acetic acid was developed. Nipa sap was hydrolyzed with invertase and provided glucose as well as fructose as main sugars. Batch fermentation of glucose and fructose was inadequate with increased substrate concentration. By contrast, fed-batch technique on hydrolyzed nipa sap with high feeding rate drastically increased acetic acid concentration and productivity to be 42.6 g/L and 0.18 g/(L/h), respectively. All the sugars in hydrolyzed nipa sap were consumed, with acetic acid yield of 0.87 g/g sugar. Overall, nipa sap as hydrolyzed with invertase was efficiently fermented to acetic acid, which is a valuable chemical and a potential biorefinery intermediate.

1991 ◽  
Vol 36 (3) ◽  
Author(s):  
Takaomi Ito ◽  
Hiroyuki Sota ◽  
Hiroyuki Honda ◽  
Kazuyuki Shimizu ◽  
Takeshi Kobayashi

2011 ◽  
Vol 63 (3) ◽  
pp. 907-914 ◽  
Author(s):  
Huijun Dong ◽  
Junyun Jiang ◽  
Tongshun Yan ◽  
Junjie Zhao

To develop the effective control method for fed-batch culture of cyclosporin A production, we chose fructose, L-valine and (NH4)2HPO4 as feeding nutrients and compared their productivities in relation to different concentrations. The feeding rate of three kinds of feeding materials was controlled to maintain the suitable residual concentration. The fed-batch fermentation results indicated that the optimal concentrations of fructose, L-valine and (NH4)2HPO4 were about 20 g/L, 0.5 g/L and 0.6 g/L for cyclosporin A production, respectively. The cultivation of Beauveria nivea could produce cyclosporin A up to 6.2 g/L for 240 hrs through a continuous feeding-rate-controlled-batch process under the optimal feeding conditions.


2020 ◽  
Author(s):  
Rongkang Hu ◽  
Dongming Lan ◽  
Ruiguo Cui ◽  
Haomin Hong ◽  
Yachun Niu ◽  
...  

Abstract Background: Methanol can be used by Pichia pastoris as the sole carbon source and inducer to produce recombinant proteins in high-cell-density fermentations, but also damages cells due to reactive oxygen species (ROS) accumulation from methanol oxidation. Here, we study the relationship between methanol feeding and ROS accumulation by controlling constant methanol feeding rate during the induction phase.Results: Higher methanol feeding rate increased the level of ROS accumulation caused by methanol oxidation. While the cell growth rate was proportional to the rate of methanol feeding rate, but maximum total protein production and highest enzyme activity were achieved at methanol feeding rate 4 mL/(L·h) as compared to that with 5 mL/(L·h). Moreover, oxidative demage induced by over accumulation of ROS in P. pastoris during the methanol induction phase caused cell death and reduced protein expression ability. ROS scavenging system analysis reveals that the higher methanol feeding rate, especially 5 mL/(L·h), resulted in increased intracellular catalase activity and decreased glutathione content significantly. Finally, Spearman's correlation analysis further reveals that the reduced glutathione might be beneficial for maintaining cell viability and increasing protein production under oxidative stress caused by toxic accumulation of ROS accumulation.Conclusion: Our findings suggest an integrated strategy to control the feeding of the essential substrate based on analyzing its response to oxidative stress caused by toxic accumulation of ROS accumulation, as well as develop strategy to optimize fed-batch fermentation.


2012 ◽  
Vol 18 (5) ◽  
pp. 791
Author(s):  
Xiaoyun DING ◽  
Bin ZHUGE ◽  
Huiying FANG ◽  
Hong ZONG ◽  
Xiaoxiao LIU ◽  
...  

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