In this work, the semi-continuous succinic acid fermentation by Actinobacillus succinogenes CGMCC1593 from cane molasses with a novel two-stage and two-stream system was studied, in order to increase the succinic acid...In this work, the semi-continuous succinic acid fermentation by Actinobacillus succinogenes CGMCC1593 from cane molasses with a novel two-stage and two-stream system was studied, in order to increase the succinic acid productivity.The fermentation conditions of the first stage, such as initial sugar concentration, medium addition volume, and time interval of each loading were optimized.Under the optimized condition the maximum succinic acid productivity (2.38 g·L-1·h-1) was increased by 111% and 114% compared with those obtained in batch and fed batch fermentation, respectively.In addition, the maximum succinic acid concentration (46.0 g·L-1)increased by 12.9% compared with that in batch fermentation, and reached a compatible level of that obtained in fed batch fermentation (36 h, 48.8 g·L-1).This process was operated stably for 39 circles without any decreases in both succinic acid concentration and productivity.During the 39 operation circles, the fermentation time of each batch (stage 1 and stage 2), the average succinic acid concentration, succinic acid productivity, succinic acid yield, and sugar conversion rate were 21—24 h, 43.5 g·L-1, 2.07 g·L-1·h-1, 0.79 g·g-1, and 96.4%, respectively.展开更多
以人参、赤芍和桂皮等混合中药渣为发酵原料,采用全混式厌氧反应器,在中温(35±1)℃,通过半连续厌氧发酵工艺,研究其发酵过程中不同有机负荷,沼气日产气量、甲烷含量、p H值、挥发性有机酸(VFA)和总无机碳(TIC)等参数变化相互关系...以人参、赤芍和桂皮等混合中药渣为发酵原料,采用全混式厌氧反应器,在中温(35±1)℃,通过半连续厌氧发酵工艺,研究其发酵过程中不同有机负荷,沼气日产气量、甲烷含量、p H值、挥发性有机酸(VFA)和总无机碳(TIC)等参数变化相互关系。结果表明:厌氧消化过程呈现5个阶段,即发酵启动期、增长期、稳定期、超负荷期和恢复期;反应器高效稳定运行可承受的中药渣最大有机负荷为8.0 g TS·(L·d)^(-1),系统p H值稳定在7.0左右,沼气日产气量8.38 L,容积产气率为1.68 L·(d·L)^(-1),原料产沼气能力262 m L·(TS g·d)^(-1),VS去除率为20.69%。有机负荷为10.0 g TS·(L·d)^(-1)时超负荷运行,沼气产量急剧下降,系统运行稳定性被破坏。因此,在中药渣厌氧消化过程中一定要控制有机负荷在最佳数值,实时监测反应器运行过程中的各参数变化,及时做出调整,保证工程的高效稳定运行。展开更多
采用自吸式发酵罐液态深层半连续法发酵食醋,该方法生产效率高、生产周期短,但食醋风味不足。在传统液态法食醋发酵工艺基础上,通过筛选原料、添加糖化曲和多菌协同酒精发酵,可以提高食醋不挥发酸的含量,改善食醋风味。研究结果表明:以...采用自吸式发酵罐液态深层半连续法发酵食醋,该方法生产效率高、生产周期短,但食醋风味不足。在传统液态法食醋发酵工艺基础上,通过筛选原料、添加糖化曲和多菌协同酒精发酵,可以提高食醋不挥发酸的含量,改善食醋风味。研究结果表明:以小麦为原料调浆液化完成后,加入6.5%(质量分数)增香糖化曲,35℃保温糖化1 h,接种5%(体积分数)乳酸菌与0.28 g/100 m L酵母菌共同酒精发酵,控制温度32℃发酵4 d,最后接种醋酸菌。将该工艺应用在摇瓶水平上液态法发酵食醋,得到的食醋中不挥发酸含量可达0.47 g/100 m L。将该工艺应用于5 L自吸罐液态半连续发酵得到的食醋成品,总酸度≥6 g/100 m L,不挥发酸含量≥0.5 g/100 m L,达到了国标对固态醋不挥发酸含量的要求。展开更多
文摘In this work, the semi-continuous succinic acid fermentation by Actinobacillus succinogenes CGMCC1593 from cane molasses with a novel two-stage and two-stream system was studied, in order to increase the succinic acid productivity.The fermentation conditions of the first stage, such as initial sugar concentration, medium addition volume, and time interval of each loading were optimized.Under the optimized condition the maximum succinic acid productivity (2.38 g·L-1·h-1) was increased by 111% and 114% compared with those obtained in batch and fed batch fermentation, respectively.In addition, the maximum succinic acid concentration (46.0 g·L-1)increased by 12.9% compared with that in batch fermentation, and reached a compatible level of that obtained in fed batch fermentation (36 h, 48.8 g·L-1).This process was operated stably for 39 circles without any decreases in both succinic acid concentration and productivity.During the 39 operation circles, the fermentation time of each batch (stage 1 and stage 2), the average succinic acid concentration, succinic acid productivity, succinic acid yield, and sugar conversion rate were 21—24 h, 43.5 g·L-1, 2.07 g·L-1·h-1, 0.79 g·g-1, and 96.4%, respectively.
文摘以人参、赤芍和桂皮等混合中药渣为发酵原料,采用全混式厌氧反应器,在中温(35±1)℃,通过半连续厌氧发酵工艺,研究其发酵过程中不同有机负荷,沼气日产气量、甲烷含量、p H值、挥发性有机酸(VFA)和总无机碳(TIC)等参数变化相互关系。结果表明:厌氧消化过程呈现5个阶段,即发酵启动期、增长期、稳定期、超负荷期和恢复期;反应器高效稳定运行可承受的中药渣最大有机负荷为8.0 g TS·(L·d)^(-1),系统p H值稳定在7.0左右,沼气日产气量8.38 L,容积产气率为1.68 L·(d·L)^(-1),原料产沼气能力262 m L·(TS g·d)^(-1),VS去除率为20.69%。有机负荷为10.0 g TS·(L·d)^(-1)时超负荷运行,沼气产量急剧下降,系统运行稳定性被破坏。因此,在中药渣厌氧消化过程中一定要控制有机负荷在最佳数值,实时监测反应器运行过程中的各参数变化,及时做出调整,保证工程的高效稳定运行。
文摘采用自吸式发酵罐液态深层半连续法发酵食醋,该方法生产效率高、生产周期短,但食醋风味不足。在传统液态法食醋发酵工艺基础上,通过筛选原料、添加糖化曲和多菌协同酒精发酵,可以提高食醋不挥发酸的含量,改善食醋风味。研究结果表明:以小麦为原料调浆液化完成后,加入6.5%(质量分数)增香糖化曲,35℃保温糖化1 h,接种5%(体积分数)乳酸菌与0.28 g/100 m L酵母菌共同酒精发酵,控制温度32℃发酵4 d,最后接种醋酸菌。将该工艺应用在摇瓶水平上液态法发酵食醋,得到的食醋中不挥发酸含量可达0.47 g/100 m L。将该工艺应用于5 L自吸罐液态半连续发酵得到的食醋成品,总酸度≥6 g/100 m L,不挥发酸含量≥0.5 g/100 m L,达到了国标对固态醋不挥发酸含量的要求。
