Díaz-Godínez G, Soriano-Santos J, Augur C, Viniegra-González G
Area de Biotecnología del Centro de Investigación en Ciencias Biológicas, Universidad Autónoma de Tlaxcala, Ixtacuixtla Tlaxala, México.
J Ind Microbiol Biotechnol. 2001 May;26(5):271-5. doi: 10.1038/sj.jim.7000113.
Exopectinase production by Aspergillus niger was compared in submerged fermentation (SmF) and solid-state fermentation (SSF). SSF was carried out using polyurethane foam (PUF) as the solid support. The purpose was to study the effect of sucrose addition (0 or 40 g/l) and water activity level (A(w)=0.99 or 0.96) on the level of enzyme activity induced by 15 g/l of pectin. Mycelial growth, as well as extracellular protease production, was also monitored. Sucrose addition in SmF resulted in catabolite repression of exopectinase activity. However, in SSF, an enhancement of enzyme activity was observed. Protease levels were minimal in SSF experiments with sucrose and maximal in SmF without sucrose. Exopectinase yields (IU/g X) were negligible in SmF with sucrose. The high levels of exopectinase with sucrose and high A(w) in SSF can be explained by a much higher level of biomass production without catabolite repression and with lower protease contamination.
比较了黑曲霉在深层发酵（SmF）和固态发酵（SSF）中果胶外切酶的产生情况。固态发酵使用聚氨酯泡沫（PUF）作为固体支持物。目的是研究添加蔗糖（0或40 g/l）和水分活度水平（A(w)=0.99或0.96）对15 g/l果胶诱导的酶活性水平的影响。还监测了菌丝体生长以及细胞外蛋白酶的产生。在深层发酵中添加蔗糖导致果胶外切酶活性的分解代谢物阻遏。然而，在固态发酵中，观察到酶活性增强。在添加蔗糖的固态发酵实验中蛋白酶水平最低，而在不添加蔗糖的深层发酵中蛋白酶水平最高。在添加蔗糖的深层发酵中果胶外切酶产量（IU/g X）可忽略不计。固态发酵中添加蔗糖且水分活度高时果胶外切酶水平较高，这可以通过在没有分解代谢物阻遏且蛋白酶污染较低的情况下更高水平的生物量生产来解释。
