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2,3 - butanediol is an important chemical raw materials and liquid fuels, conversion of biomass to produce 2,3 - butanediol is a viable alternative to traditional chemical synthesis. Because of the growing shortage of oil resources, the use of low-cost wood fiber as raw material fermentation production of 2,3 - butanediol more competitive and application value as the initial raw material, corn stalks, research pretreatment of cellulase to The key technical parameters of the various aspects of a single batch fermentation, fed-batch fermentation, simultaneous saccharification and fermentation, the findings have important significance for the promotion of non-food raw materials of biological conversion and utilization of. Corn stover pretreatment technology research, the results showed that: dilute acid treatment can remove most of the hemicellulose, dilute alkali treatment can remove most of the lignin. Enzymatic Hydrolysis of Cellulose experimental results show that: the higher the single sugar content in the corn stover enzymatic hydrolyzate of alkali treatment, mainly due to the high removal of lignin, and Yun Zhang cellulose ingredients easier cellulase degradation, a dilute alkali pretreatment is an effective pretreatment. Pretreatment process introduced inorganic salts, When the the representation inorganic salts of Na 2 SO 4 concentrations of less than 20g / L had no significant effect on the subsequent fermentation. The acetic acid and ethanol is the major fermentation byproducts, when the concentration of more than 20 g / L and 5 g / L, the interested strains were grown to produce significant inhibition. Fermentation suitable initial pH of 6.0 to 6.5, the total sugar concentration of 80 ~ 100g / L by Klebsiella oxytoca Klebsiella oxytoca ZU-03 straw cellulose hydrolyzate single batch fermentation experiments showed that, in the total concentration of sugar 80g / L, 30 ° C conditions 64 h of fermentation, the total sugar utilization can reach 99.36%, 2,3 - butanediol, the mass concentration of 37.20g / L, in a yield of 0.468 g / g to achieve the theoretical yield 93.6 %. Was achieved in this process of use of five-carbon sugars derived from hemicellulose and cellulose, and hexose. Single batch fermentation substrate inhibition bottlenecks can be overcome by fed-batch strategy. Research show that 12h start time is more appropriate feeding the suitable single complement quantity is 15g / L. Ingredients the better feeding N ratio of 16, 204 h continuous fermentation product concentration 100.14g / L, the highest yield 108.13g / L, relative to the single-batch fermentation, a 190.7% increase in production by fed-batch operation obtain a higher concentration of product, and for reducing the cost of downstream separation of practical value. Simultaneous saccharification and fermentation (Simultaneous saccharification and fermentation, SSF) production of 2,3 - butanediol integration of enzymatic hydrolysis and fermentation of two important aspects, not only eliminates the need for enzymatic liquid handling steps, and improve production efficiency, reduce costs . Klebsiella oxytoca ZU-03 simultaneous saccharification and fermentation of fiber raw materials to produce 2,3 - butanediol suitable temperature is 31 ℃, initial pH value of 6.0, the appropriate amount of cellulase 25 FPIU / g substrate, cellobiose sugar enzyme dosage of 20 CBIU / g substrate, SSF for 36 h, 2,3 - butanediol, the concentration in the fermentation broth was 23.30 g / L, the yield was 0.23 g / g substrate. Corn straw hydrolyzate fermentation production of 2,3 - butanediol, re-use of agricultural waste. And compared to the chemical synthesis, biological conversion process is relatively mild, and therefore less wear and tear on equipment and energy demand. The fermentation useful compound, 2,3 - butanediol. The study of this process to promote biological conversion and use of biodegradable waste to open up a new direction.
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