Abstract：
Ganoderma lucidum polysaccharides (GLP) attract growing attention due to their remarkable bioactivities, but the low content in raw materials remains a bottleneck severely restricting their application. We previously found a higher polysaccharides accumulation in Ganoderma lucidum cultured in continuous cropping soil, and soil symbiotic fungi are presumed as the key among many factors. Herein, 33 symbiotic fungi were isolated from the soil, and fungal elicitors were prepared to investigate their biotic eliciting effect on GLP biosynthesis. Most elicitors were found to significantly improve GLP production, among which the NO.16 molecularly identified as Penicillium citrinum, exhibited the optimum eliciting effect with GLP yield increasing by 3.4 times. Differences in the biosynthetic pathway genes expressions and the monosaccharide components of GLP were further analyzed. The transcriptions of the main genes of GLP biosynthetic pathway were up-regulated under PCE treatments, suggesting it improves GLP production by activating transcriptions of the biosynthetic pathway genes. Moreover, PCE eliciting significantly altered the monosaccharide compositions of GLP with Gal, Man, GalA, GlcA, and Fuc increasing by 8.17 %, 5.68 %, 5.41 %, 2.66 %, and 1.51 % respectively, but Glc decreased by 23.43 %, which may result in the activity change. It can serve as a new strategy to improve GLP production.
摘要：
灵芝多糖(GLP)因其显著的生物活性而受到越来越多的关注,但是原材料含量低仍然是严重限制其应用的瓶颈。我们以前发现在连作土壤中培养的灵芝中多糖积累较高，土壤共生真菌被认为是众多因素中的关键。在这里，从土壤中分离出33种共生真菌，并制备了真菌诱导子，以研究其对GLP生物合成的生物诱导作用。发现大多数激发子可以显着提高GLP的产量，其中NO.16分子鉴定为柑橘青霉，表现出最佳的诱导效果，GLP产量增加3.4倍。进一步分析生物合成途径基因表达和GLP单糖组分的差异。在PCE处理下,GLP生物合成途径的主要基因转录上调,提示它通过激活生物合成途径基因的转录来提高GLP的产生。此外，PCE引发显着改变了GLP与Gal的单糖组成，伙计,GalA,GlcA,Fuc增长8.17%，5.68%,5.41%,2.66%,和1.51%，但是Glc下降了23.43%，这可能会导致活动的变化。它可以作为提高GLP生产的新策略。
