摘要
为提高微生物降解反式茴脑获得茴香酸的产量,对假单胞菌Pseudomonas sp.NT2的发酵参数进行优化,以提高降解过程的转化率。利用单因素试验考察碳氮源种类及浓度、反式茴脑添加量、发酵温度、接种量、初始pH以及装液量对茴香酸生成量、反式茴脑降解率的影响,通过Plackett-Burman试验和最陡爬坡试验确定影响茴香酸生成量的显著因素并获取中心点,最后采用Box-Behnken模型进行响应面优化得到最佳发酵条件并验证。结果表明氯化铵浓度、初始pH和装液量是显著影响因素,最佳发酵条件为:柠檬酸钠10 g/L,氯化铵1.26 g/L,反式茴脑添加量1%,发酵温度30℃,接种量4%,初始pH 7.9,装液量42 mL/250 mL。优化后茴香酸生成量为7.24 g/L,为优化前的3.5倍,茴香酸摩尔生成率为80.72%,反式茴脑降解率为89.81%,分别比优化前提高了270.28%和97.78%。综上,假单胞菌NT2是生物转化生产茴香酸的潜力菌株。响应面优化可以显著提高反式茴脑的降解率和茴香酸产量,这为大规模生产茴香酸奠定了基础。
In order to increase the yield of anisic acid by microbial degradation of trans-anethole,the fermentation parameters of Pseudomonas sp. NT2 were optimized to enhance the transformation rate of degradation process. Firstly single factor experiments were used to determine the optimum basic medium and fermentation conditions including carbon and nitrogen sources and their concentrations,trans anethole addition,temperature,inoculation dose,initial pH and liquid medium volume. Then key factors affecting the yield of anisic acid and their optimal range were determined respectively by Plackett-Burman Design and the steepest ascent tests. Finally,the Box Behnken model and response surface methodology were applied to analyze the dominant factors,and optimal fermentation conditions were obtained and verified. The results showed that NH4Cl concentration,initial pH and liquid medium volume were the critical factors. The optimal fermentation conditions were sodium citrate concentration 10 g/L,NH4Cl concentration 1. 26 g/L,trans anethole addition 1%,fermentation temperature 30 ℃,inoculation quantity 4%,initial pH 7. 9,liquid medium volume 42 mL/250 mL. After optimization,the anisic acid production reached 7. 24 g/L,3. 5 times that before optimization;the molar rate of anisic acid production rate was 80. 72% and the trans anethole degradation rate was 89. 81%,raising 270. 28% and 97. 78 respectively. Therefore,strain NT2 was the potential to produce a high yield of anisic acid. Response surface optimization could significantly improve the degradation rate of trans anethole and the yield of anisic acid,which laid the foundation for the large scale production of anisic acid.
作者
张健
郑景辉
高程海
林瑜
李学坚
冯玉燕
郑雪莹
银江林
ZHANG Jian;ZHENG Jinghui;GAO Chenghai;LIN Yu;LI Xuejian;FENG Yuyan;ZHENG Xueying;YIN Jianglin(Guangxi University of Chinese Medicine, Nanning 530200)
出处
《工业微生物》
CAS
2021年第2期22-30,共9页
Industrial Microbiology
基金
广西高校中青年教师基础能力提升项目(2017KY0288)
广西中医药大学海洋研究院开放课题项目(XP019069)。
