Du Chenyu, Lin Sze Ki Carol, Koutinas Apostolis, Wang Ruohang, Webb Colin
Satake Centre for Grain Process Engineering, School of Chemical Engineering and Analytical Science, The University of Manchester, P.O. Box 88, Manchester M60 1QD, UK.
Appl Microbiol Biotechnol. 2007 Oct;76(6):1263-70. doi: 10.1007/s00253-007-1113-7. Epub 2007 Jul 25.
The biosynthesis of succinic acid from wheat flour was investigated in a two-stage bio-process. In the first stage, wheat flour was converted into a generic microbial feedstock either by fungal fermentation alone or by combining fungal fermentation for enzyme and fungal bio-mass production with subsequent flour hydrolysis and fungal autolysis. In the second stage, the generic feedstock was converted into succinic acid by bacterial fermentation by Actinobacillus succinogenes. Direct fermentation of the generic feedstock produced by fungal fermentation alone resulted in a lower succinic acid production, probably due to the low glucose and nitrogen concentrations in the fungal broth filtrate. In the second feedstock production strategy, flour hydrolysis conducted by mixing fungal broth filtrate with wheat flour generated a glucose-rich stream, while the fungal bio-mass was subjected to autolysis for the production of a nutrient-rich stream. The possibility of replacing a commercial semi-defined medium by these two streams was investigated sequentially. A. succinogenes fermentation using only the wheat-derived feedstock resulted in a succinic acid concentration of almost 16 g l(-1) with an overall yield of 0.19 g succinic acid per g wheat flour. These results show that a wheat-based bio-refinery employing coupled fungal fermentation and subsequent flour hydrolysis and fungal autolysis can lead to a bacterial feedstock for the efficient production of succinic acid.
在一个两阶段生物过程中研究了从小麦粉生物合成琥珀酸。在第一阶段，小麦粉通过单独的真菌发酵，或者通过将用于酶和真菌生物质生产的真菌发酵与随后的面粉水解和真菌自溶相结合，转化为一种通用的微生物原料。在第二阶段，通过产琥珀酸放线杆菌的细菌发酵将通用原料转化为琥珀酸。仅由真菌发酵产生的通用原料的直接发酵导致琥珀酸产量较低，这可能是由于真菌肉汤滤液中葡萄糖和氮浓度较低。在第二种原料生产策略中，将真菌肉汤滤液与小麦粉混合进行面粉水解产生了富含葡萄糖的物流，而真菌生物质则进行自溶以生产富含营养的物流。依次研究了用这两种物流替代商业半限定培养基的可能性。仅使用小麦衍生原料的产琥珀酸放线杆菌发酵产生的琥珀酸浓度接近16 g l(-1)，每克小麦粉的总产率为0.19 g琥珀酸。这些结果表明，采用耦合真菌发酵以及随后的面粉水解和真菌自溶的基于小麦的生物精炼厂可以产生用于高效生产琥珀酸的细菌原料。
