Application of Exhausting Gas Mass Spectrometer in Metabolic Regulation of Lactic Acid Fermentation

Lactic acid,as a widely occurring hydroxycarboxylic acid,plays important roles in food,pharmaceutical,textile,leather and chemical industries.In this work,exhausting gas mass spectrometer was successfully introduced into lactic acid fermentation.Furthermore,combining the dynamic changes of macroscopic physiological parameters and fermentation conditions,the prime parameters could be determined under various states through multi-parameters relevant analysis method.The fermentation process of impurities in the synthesis of metabolic process was illuminated.Based on exhausting gas analysis by process-mass-spectrometer for micro-aerobic fermentation process,the oxygen supply levels were accurately controlled and optimized;when the the oxygen consumption rate was controlled at 0.70 mmol/(L·h),the highest L-lactic acid production rate reached 2.78 g/(L·h).At the same time,through the correlation analysis of physiological parameters,residual sugar consumption and by-products formation under the matrix medium of corn starch hydrolysis sugar solution,we established the fermentation process fast on-line control method based on physiological parameters dynamic changes,and realized the yield and quality online control strategy of L-lactic acid fermentation.