Microbial pentosanases. I. A survey of microorganisms for the production of enzymes that attack the pentosans of wheat flour.

Abstract

A water soluble pentosan extracted from wheat flour was purified by precipitation with ethanol and treatment with pancreatin. Such preparations contained 78 to 82% pentosan and 0.5 to 1% protein. The pentosan of "squeegee" starch also was obtained by removing the starch with pancreatin. The product contained 60 to 75% pentosan and 1 to 3% protein. A number of fungi, streptomycetes, and bacteria produced extracellular enzymes that hydrolyzed the water soluble pentosan. Some of these were tested against the pentosan of "squeegee" starch and found to attack it also. The fungi and streptomycetes possessed adaptive pentosanases whereas 40% of the active bacteria had constitutive pentosanases. Xylose and, to a lesser extent, arabinose stimulated production of the adaptive pentosanases of the molds and streptomycetes while xylose, but not arabinose, was effective with the bacilli. The more active genera were Alternaria, Aspergillus, Fusarium, Trichothecium, Trichoderma, and Bacillus.