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›› 2013, Vol. 47 ›› Issue (4): 7-11.

• 研究报告 • Previous Articles     Next Articles

Promotion and Inhibition Effects of Phenolic Acids on Clostridium Acetobutylicum Fermentation

ZHANG Lian-hua1,2, WANG Lan1, CHEN Hong-zhang1
  

  1. 1. Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China; 2. University of Chinese Academy of Sciences, Beijing 100049, China
  • Received:1900-01-01 Revised:1900-01-01 Online:2013-07-30 Published:2013-07-30

Abstract: Phenol acids generated during lignocellulose pretreatment process can affect the growth and metabolism of Clostridium acetobutylicum. Promotion and inhibition effects of ferulic acid, vanillic acid, syringic acid and p-hydroxybenzoic acid on butanol fermentation were investigated. The results showed that low concentration of phenolic acids (lower than 100 mg/L) played a promotion role in butanol fermentation. Butanol yield was increased by 21.72% when 60 mg/L hydroxybenzoic acid was added into fermentation culture, whereas biomass reached 4.50 times that of the control group when 100 mg/L vanillic acid was added. However as the inhibitor concentrations increased (higher than 100 mg/L), the effect of inhibition became more obvious. Butanol production was inhibited 96.67% when 1 000 mg/L of vanilla acid was added, and the biomass of all experimental groups failed to detect. A way of direct butanol fermentation without detoxification steps by increasing the inoculation rate to enhance bacterial inhibition point was established. Butanol yield of 9.16 g/L, which was the normal fermentation level, was obtained by 30% inoculation. These four phenolic acids had similar effects on butanol fermentation, but differed in their toxicity to bacteria. The toxicity of phenolic acids was significantly correlated with their ionization constants and molecular weight, and the correlation coefficients were 0.816 and 0.876, respectively, by quantitative structure activity relationships (QSAR) method, i.e. the smaller ionization constants and molecular weight, the greater the toxicity. But the toxicity presented no significant negative correlation with the hydrophobic.