Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by y...Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by yeast strains which have great potential in paper and pulp industry in removing the hemicellulose from the treated or untreated pulp. In this study, P. hubeiensis NCIM 3574 isolated in our laboratory produced significant levels of extracellular cellulase free xylanase (2480 IU/g DSS) in solid state fermentation (SSF) using wheat bran and xylan. It also produced high levels of β-xylosidase (198 IU/g DSS) when grown in SSF using ground nut oil cake and xylan. These highest activities were obtained when fermented Koji was extracted with 1% NaCl supplemented with 0.5% of Triton X-100. These are the highest activities reported so far from yeast strains in the available literature. The crude xylanase preparation of P. hubeiensis produced xylooligosaccharides (XOS) without xylose proving its potential for XOS production with no further requirement of downstream processing. The XOS as prebiotic show beneficial effect on gut microflora such as Lactobacilli and Bifidobacteria which suppress the activity of pathogenic organisms. This xylanase also has a potential application as a bio-bleaching agent in paper and pulp industry.展开更多
The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are describedand illustrated for a culture homothallic strain collected from Wuhan,Hubei,China.The asexual reproduction is by partheno...The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are describedand illustrated for a culture homothallic strain collected from Wuhan,Hubei,China.The asexual reproduction is by parthenospores,aplanospores and akinetes.The major events of the sexual cycle,including the genuflection of reproductive cells,gametangial development,gamete formation,gamete fusion,zygote formation,zygospore development,and zygospore germination are observed.展开更多
本文描述了贵州剑河八郎寒武系第二统第四阶"清虚洞组"剑河生物群的高肌虫化石。化石壳体呈圆形,背边平直,前、后背角均钝,壳前背部具有"V"形槽。符合Qingquanella Cui et Huo,1985的属征,与模式种湖北清泉虫Q.hube...本文描述了贵州剑河八郎寒武系第二统第四阶"清虚洞组"剑河生物群的高肌虫化石。化石壳体呈圆形,背边平直,前、后背角均钝,壳前背部具有"V"形槽。符合Qingquanella Cui et Huo,1985的属征,与模式种湖北清泉虫Q.hubeiensis相似,将其厘定为湖北清泉虫相似种Q.cf.hubeiensis。本属产于湖北水井沱组、石牌组及陕西辛集组,黔东地区"清虚洞组"发现清泉虫Qingquanella,增加了清泉虫的产地信息、新的类群,其壳体形态由切卵变圆形,生态环境由浅水向深水变化,为高肌虫的形态分类、早期演化与辐射分异提供新的材料。展开更多
文摘Xylanase is an important enzyme with potential application in the degradation of xylan component in the lignocellulosic biomass. There are very few reports on the production of cellulase free xylanases especially by yeast strains which have great potential in paper and pulp industry in removing the hemicellulose from the treated or untreated pulp. In this study, P. hubeiensis NCIM 3574 isolated in our laboratory produced significant levels of extracellular cellulase free xylanase (2480 IU/g DSS) in solid state fermentation (SSF) using wheat bran and xylan. It also produced high levels of β-xylosidase (198 IU/g DSS) when grown in SSF using ground nut oil cake and xylan. These highest activities were obtained when fermented Koji was extracted with 1% NaCl supplemented with 0.5% of Triton X-100. These are the highest activities reported so far from yeast strains in the available literature. The crude xylanase preparation of P. hubeiensis produced xylooligosaccharides (XOS) without xylose proving its potential for XOS production with no further requirement of downstream processing. The XOS as prebiotic show beneficial effect on gut microflora such as Lactobacilli and Bifidobacteria which suppress the activity of pathogenic organisms. This xylanase also has a potential application as a bio-bleaching agent in paper and pulp industry.
文摘The morphology and reproduction cycles of a new species,Zygnemopsis hubeiensis Wei are describedand illustrated for a culture homothallic strain collected from Wuhan,Hubei,China.The asexual reproduction is by parthenospores,aplanospores and akinetes.The major events of the sexual cycle,including the genuflection of reproductive cells,gametangial development,gamete formation,gamete fusion,zygote formation,zygospore development,and zygospore germination are observed.
文摘本文描述了贵州剑河八郎寒武系第二统第四阶"清虚洞组"剑河生物群的高肌虫化石。化石壳体呈圆形,背边平直,前、后背角均钝,壳前背部具有"V"形槽。符合Qingquanella Cui et Huo,1985的属征,与模式种湖北清泉虫Q.hubeiensis相似,将其厘定为湖北清泉虫相似种Q.cf.hubeiensis。本属产于湖北水井沱组、石牌组及陕西辛集组,黔东地区"清虚洞组"发现清泉虫Qingquanella,增加了清泉虫的产地信息、新的类群,其壳体形态由切卵变圆形,生态环境由浅水向深水变化,为高肌虫的形态分类、早期演化与辐射分异提供新的材料。
