一株耐NMMO纤维素酶菌株的筛选及发酵优化

在常规筛选方法的基础上,利用在富集培养基中加入10 g/L NMMO,从土壤中筛选获得一株耐NMMO的高活性纤维素酶菌株Galactomyces sp. CCZU11-1。经研究,最适产酶培养条件为：碳源为甘蔗渣（5 g/L）,氮源为(NH4)2SO4（5 g/L）,表面活性剂为Tween-80（8 g/L）,培养温度为30 ℃,初始培养pH值为5.5。在此条件下菌株培养7天后,FPA及CMCase分别为13.5 IU/mL和24.6 IU/mL。在培养体系和反应体系中分别加入200 g/L NMMO,Galactomyces sp. CCZU11-1纤维素酶仍具有良好的活性,表明其具有较高的耐NMMO性能及应用前景。     

海带内生真菌Galactomyces geotrichum次生代谢产物改善小鼠的学习记忆能力

报道了海带内生真菌白地霉Galactomyces geotrichum次生代谢产物的乙酸乙酯萃取物具有改善小鼠学习、记忆能力的作用。以D-半乳糖所致的阿尔兹海默病(AD)小鼠为模型,采用Morris水迷宫实验测定了不同剂量组的上述萃取物对小鼠血清、肝脏和脑部组织中的超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)、过氧化氢酶(CAT)活性和丙二醛(MDA)的含量及脑组织中乙酰胆碱转移酶(Ch AT)和乙酰胆碱酯酶(Ach E)的活性的影响。Morris水迷宫结果显示,试验各剂量组的逃避潜伏期的时间均显著缩短(p0.05),而空间探索能力也有所改善;与模型组相比,低、中、高剂量组血清、肝脏与脑部组织的SOD、GSH-Px、CAT活力升高,而MDA含量降低,脑部组织中Ach E活力下降、Ch AT活力上升。上述发现说明,该次代谢产物的乙酸乙酯萃取物对AD模型小鼠具有明显改善学习记忆能力的作用。     

Decolorization of Brilliant Blue G dye mediated by degradation of the microbial consortium of Galactomyces geotrichum and Bacillus sp.

A consortium-GB containing two microorganisms Galactomyces geotrichum MTCC 1360 and Bacillus sp. VUS was able to degrade sulfur-containing dye Brilliant Blue G, optimally at pH 9 and temperature at 50 °C. The ability of consortium-GB to work at higher temperature and pH ranges will help in using this consortium for removal of the dye from textile effluent. Malt extract, peptone and beef extract were found to be the best additional carbon and nitrogen sources. Brilliant Blue G caused enhancement of the riboflavin reductase among the enzyme activities studied. Biodegradation was confirmed by analyzing the product using UV–vis, HPLC, and FTIR. The GC–MS study revealed a pathway of Brilliant Blue G with release of (4-ethoxy-phenyl)-phenyl-amine and 3-ethylaminomethyl-benzenesulfonic acid as final metabolites formed by the consortium-GB. GC–MS analysis indicated the formation of 3-{[ethyl-(3-methyl-cyclohexa-2,5-dienyl)-amino]-methyl}-benzenesulfonic acid as a product by G. geotrichum MTCC 1360 alone and (4-benzylidene-3-methyl-cyclohexa-2,5-dienylidene)-methyl-amine by Bacillus sp. VUS alone. Phytotoxicity revealed nontoxic nature of the metabolites. These results indicate the high potential of the consortium-GB to serve as an excellent biomass for the use in Brilliant Blue G dye removal.