Antimicrobial Activity of Submerged Culture Extracts from Xylaria striata

[ Objective ] The paper was to explore the antimicmbial activities of extracts from Xylaria striata via submerged culture. [ Methods ] The antibacterial activities of X. striata extracts against 10 kinds of bacteria were determined using Oxford cup method and mJcroplate assay, and the antifungal activities against nine kinds of pathogenic fungi were determined using mycelial growth rate method. [ Results ] The inhibition zone diameters of the mycelium extract against tested bacte- ria ranged from 13.0 to 17.5 mm, and that of the fermentation broth extract ranged from 10.5 to 12.7 ram. Enterobacter cloacae was the most sensitive to both my- celium extract and fermentation broth extract, with the inhibition zone diameters of 17.1 and 12.7 mm and the minimum inhibitory concentrations of 2.5 and 5 mg/mL, respectively. The inhibitory effects of the mycelium extract and the fermentation broth extract against Fusarium graminearum were the greatest, and the in- hibition rates were 89.88% and 69.53%, respectively. [ Conclusion] X. striata has potential antimicrobial activity and deserves to be further studied.

Biodegrading Wheat Bran with Agaricus blazei and Its Effects on Intestinal Development Identified with Mice

Agaricus blazei Murill is a well known edible/medicinal mushroom used for immune-nutrient food therapies.The biodegradation of different substrates with this fungus may result in different metabolites and degraded compounds,which may enrich the function of the food therapies.In this study,soluble compounds from the culture of A.blazei grown in liquid media with whole wheat bran and its water filtrate,respectively,were compared.Total soluble sugar,arabinoxylan,protein,and amino acids were significantly higher in the fungal culture resulted from the medium with whole wheat bran （43.54,1.56,0.59,and 2.19 mg mL^-1,respectively） than that from the medium with the bran filtrate （17.28,0.37,0.13,and 1.13 mg mL^-1,respectively）.The biodegraded wheat bran with cultured mycelia was fed to Mus musculus Linnaeus as supplementation or as dietary fiber exclusive ingredient.As non-specific food therapies,feeding effects on mice intestinal development were indicated indirectly in growth performance,intestinal absorption and serum parameters.Compared to feeding uncultured wheat bran,feeding mice with culture mixes of A.blazei resulted in remarkably increase in villus height and villus height/crypt depth ratio,which were increased by 25.4 and 31.0%,respectively,when applied as supplementation,and by 44.3 and 43.4%,respectively,when applied as dietary fiber.These increases are concomitant with the higher level of D-xylose in blood serum about 16.9 and 29.2% as supplementation and dietary fiber,respectively.The results implying that culturing A.blazei with whole wheat bran enhanced extracellular metabolism of the fungus and extensive degradation of wheat bran insoluble fibrous compounds.Furthermore,feeding the culture mix including metabolites and degraded wheat bran improved intestinal villus development,proving the nutritional benefits of the A.blazei mycelial cultures.