Abstract: Mesophilic xylanases derived from Acremonium cellulolyticus. A mesophilic xylanase I, derived from the mold Acremonium cellulolyticus, capable of non-specifically hydrolyzing xylan mainly into xylose, xylobiose and xylotriose, having an optimal pH at 3.5 and an optimal temperature for action at 55.degree. C. as determined by saccharifying activity for soluble xylan as a substrate and a molecular weight of 30,000 as determined by SDS-polyacrylamide gel electrophoresis. A mesophilic xylanase II having an optimal pH a 3.8, an optimal temperature for action at 55.degree. C. and a molecular weight of 25,500. A mesophilic xylanase III having an optimal pH at 3.5, an optimal temperature for action at 50.degree. C. and a molecular weight of 33,500.

Abstract: A .beta.-glucooligosaccharide-containing composition comprising at least one material selected from food, drink and medicine, and at least one selected from a glucooligosaccharide comprising at least one .beta.-1,6 bond and a reduced product thereof. A method of improving intestinal floras, comprising administering to a human or animal for ingestion a physiologically effective amount of at least one selected from a glucooligosaccharide comprising at least one .beta.-1,6 bond and a reduced product thereof. The ingestion of the .beta.-glucooligosaccharide and/or the reduced product thereof can bring about promotion of the selective growth of useful bacteria such as Bifidobacteria and lactic acid bacteria, inhibition of the growth of harmful bacteria or putrefactive bacteria, and hence improvement in the intestinal floras.

Abstract: A dental plaque-degrading composition containing endodextranase produced by Arthrobacter globiformis W31 exhibiting high degradation efficacy to insoluble glucan produced by Streptococcus mutans IFO 13955, the dental plaque-degrading composition additionally containing .alpha.-amylase of various origins. These compositions are useful for preventing the settlement of Streptococcus mutans in the oral cavity and the formation of new dental plaque and for preventing the dental caries, and provided in the form of dentifrices, denture detergents, troches, mouth washes, chewing gums or candies.