Abdeljalil Salma, Saibi Walid, Ben Hmad Ines, Baklouti Abir, Ben Mahmoud Feten, Belghith Hafedh, Gargouri Ali
Laboratory of Biomass Valorisation and Protein Production in Eucaryotes, Centre of Biotechnology of Sfax (CBS)/University of Sfax, Sfax, Tunisia.
Plant Protection and Improvement Laboratory, Centre of Biotechnology of Sfax (CBS)/University of Sfax, Sfax, Tunisia.
Biotechnol Appl Biochem. 2014 Jul-Aug;61(4):432-40. doi: 10.1002/bab.1195. Epub 2014 Mar 25.
The current study investigated the production of cellulases and xylanases from the rare fungus Stachybotrys microspora under solid-state fermentation (SSF) on wheat bran (WB). A comparison of both activities was first performed in submerged cultures using various concentrations of WB, glucose, and cellulose as substrates. The maximal activity of β-glucosidases and xylanases was obtained with 2% and 4% WB, respectively, whereas cellulose yielded the highest endoglucanase production. The SSF conditions were therefore consequently optimized. A moisture content of 70% gave the most significant levels of enzyme production. Inoculation by spores led to better results than by preculture, with 10(5) spores per gram of dried matter as the best inoculum dose for all activities tested. Interestingly, the WB-based medium need not to be supplemented by an exogeneous nitrogen source. Considering the richness of S. microspora secreted proteins as lytic hydrolases, the crude extracellular enzyme extracts were successfully tested in two different biotechnological fields: protoplasting of fungi and subsequent extraction of their DNA, paper pulp hydrolysis to produce fermentable sugars.
本研究调查了在以麦麸（WB）为底物的固态发酵（SSF）条件下，稀有真菌小孢葡萄穗霉产生纤维素酶和木聚糖酶的情况。首先在液体培养中，以不同浓度的WB、葡萄糖和纤维素为底物，对这两种酶的活性进行了比较。β-葡萄糖苷酶和木聚糖酶的最大活性分别在WB浓度为2%和4%时获得，而纤维素能产生最高水平的内切葡聚糖酶。因此，对固态发酵条件进行了优化。70%的水分含量产生的酶产量最高。孢子接种比预培养的效果更好，每克干物质接种10(5)个孢子是所有测试活性的最佳接种剂量。有趣的是，基于WB的培养基无需添加外源氮源。鉴于小孢葡萄穗霉分泌的蛋白质作为裂解水解酶十分丰富，粗细胞外酶提取物在两个不同的生物技术领域成功进行了测试：真菌原生质体的制备及其后续DNA的提取、纸浆水解以生产可发酵糖。
