pH与溶氧控制对解淀粉芽胞杆菌发酵粗甘油生产2,3-丁二醇的影响

Effects of pH and oxygen supply on production of 2,3-butanediol from biodiesel-derived glycerol by Bacillus amyloliquefaciens

摘要:

首次利用一株安全菌株解淀粉芽胞杆菌发酵生物柴油副产物粗甘油生产2,3-丁二醇。溶氧和pH是影响微生物法生产2,3-丁二醇的最主要因素。结果表明，发酵过程中不控制pH更有利于2,3-丁二醇合成；采用三阶段控制搅拌转速策略，2,3-丁二醇产量最大值达到?38.1?g/L，生产强度达到1.06?g/(L·h)，与恒定转速获得的最好结果相比，分别提高了14.8%和63.1%。采用脉冲流加发酵时，2,3-丁二醇产量达到71.2 g/L，2,3-丁二醇生产强度达到0.99 g/(L·h)，这是目前报道的利用粗甘油合成2,3-丁二醇的最高产量。

Abstract:

Bacillus amyloliquefaciens B10-127 was used to produce 2,3-butanediol (2,3-BD) from residual glycerol obtained from biodiesel synthesis. Important variables for 2,3-BD fermentation, pH and dissolved oxygen, were studied. When pH was maintained constant, the yield of 2,3-BD was inhibited. The highest 2,3-BD yields were achieved by fermentation without any pH control with an optimized initial pH 6.5. Batch fermentative production of 2,3-BD by B. amyloliquefaciens was investigated using various oxygen supply methods by changing agitation speed. Based on the analysis of three kinetic parameters including specific cell growth rate (μ), specific glucose consumption rate (qs) and specific 2,3-BD formation rate (qp), a three-stage agitation speed control strategy was proposed, aimed at achieving high concentration, high yield and high productivity of 2,3-BD. Maximum concentration of 2,3-BD reached 38.1 g/L, with the productivity of 1.06 g/(L·h), which were 14.8% and 63.1% over the best results from constant agitation speeds. In a pulse fed-batch fermentation, 2,3-BD concentration and productivity were significantly improved to 71.2 g/L and 0.99 g/(L·h), respectively. To our knowledge, these results were the highest for 2,3-BD production from biodiesel-derived glycerol.