温度和发酵时间对厨余垃圾发酵产乳酸及其光学异构体的影响

Effect of Temperature and Fermentation Time on Yield and Optical Purity of Lactic Acid from Kitchen Waste Fermentation

通过间歇实验,探讨了温度和发酵时间对非灭菌的厨余垃圾发酵产乳酸及其光学异构体的影响.结果表明,控制温度在35℃时,发酵液中乳酸浓度远高于45℃和55℃,发酵120h后,总乳酸的产率和产量最大,分别达到0.59gL-1d-1和0.62gg(VS)-1,以有机碳表示的乳酸占发酵液中总有机碳的78%;控制发酵时间小于120h,L-乳酸在35℃、45℃和55℃三个温度条件下都是主要的异构体形式;35℃和55℃时,发酵72h后,随着发酵时间的延长,L-乳酸浓度在总乳酸中的比例呈下降趋势;45℃时,L-乳酸浓度随着发酵时间的延长逐渐增加,L-乳酸在总乳酸中的比例在发酵144h后达到97%.

Batch experiments were carried out to analyze the effect of temperature and fermentation time on lactic acid yield and optical characteristics during the non-sterilized fermentation of kitchen wastes. The results showed that the maximum total lactic acid production rate （0.59 g L^-1 d^-1） and yield （0.62 g per gram VS） were obtained at 35 ℃ after fermented for 120 h. Lactic acid （ calculated as organic carbon） accounted for 78% of the total organic carbon in the fermentation liquid. The L-lactic acid was the predominant isomer form when the fermentation time was less than 120 h. At 35 ℃ and 55 ℃, L-lactic acid concentration decreased with the fermentation time, while at 45 ℃, it increased with the fermentation time and the ratio of Llactic acid to total lactic acid reached 97% after fermented for 144 h. Fig 4, Tab 1, Ref 21