Abstract：
In this study, we investigated a deleterious mutation in the β-xylosidase gene, xylA (AkxylA), in Aspergillus luchuensis mut. kawachii IFO 4308 by constructing an AkxylA disruptant and complementation strains of AkxylA and xylA derived from A. luchuensis RIB2604 (AlxylA), which does not harbor the mutation in xylA. Only the AlxylA complementation strain exhibited significantly higher growth and substantial β-xylosidase activity in medium containing xylan, accompanied by an increase in XylA expression. This resulted in lower xylobiose and higher xylose concentrations in the mash of barley shochu. These findings suggest that the mutation in xylA affects xylose levels during the fermentation process. Because the mutation in xylA was identified not only in the genome of strain IFO 4308 but also the genomes of other industrial strains of A. luchuensis and A. luchuensis mut. kawachii, these findings enhance our understanding of the genetic factors that affect the fermentation characteristics.
摘要：
在这项研究中,我们研究了β-木糖苷酶基因的有害突变，木A（AkxylA），在鲁川曲霉中。KawachiiIFO4308通过构建来自A.luchuensisRIB2604（AlxylA）的AkxylA和木A的AkxylA破坏和互补菌株，它没有xylA的突变。只有AlxylA互补菌株在含有木聚糖的培养基中表现出显着的更高的生长和显着的β-木糖苷酶活性，伴随着XylA表达的增加。这导致大麦烧酒中的木二糖浓度较低，木糖浓度较高。这些发现表明xylA中的突变影响发酵过程中的木糖水平。因为xylA中的突变不仅在菌株IFO4308的基因组中被鉴定出来，而且在其他工业菌株的基因组中也被鉴定出来。Kawachii,这些发现增强了我们对影响发酵特性的遗传因素的理解。
