Mannanases Miscellaneous

D-Mannanases occurring in Actinomyces griseinus are synthesized independently of other glycanases, and it was possible to stimulate the synthesis of D-mannanases while inhibiting that of D-glucanases. A correlation exists between the total lytic activity and the D-mannanase activity. 

The occurrence, purification, properties, and modes of action of D-mannanases have been reviewed.  

An endo-p-D-mannanase activity in the endosperm of germinating fenugreek Trigonella foenum-graecum) seeds is required to hydrolyse the storage galacto-mannan. The level of e/iJo-P-D-mannanase activity is controlled in vivo by the aleurone layer. 

Germinating lettuce Lactuca sativa) seeds synthesize large amounts of an endo-P-D-mannanase that hydrolyses D-mannose-containing polysaccharides in the endosperm cell walls. This enzyme appears to mobilize the cell-wall polysaccharides as a source of nutrient for the growing embryo. 

The D-mannanase activities of some wood-rotting fungi have been investigated.  

Yokogawa, S. Kawata, and Y. Yoshimura, Agric. and Biol. Chem. (Japan), 1976, 40, 661. E. Moczar and C. Sepulchre, Biochimie, 1975, 57, 1241. 

Proteins of a crude enzyme preparation obtained from the cultivation medium of the basidiomycete Phellinus abietis were separated by gel filtration and ion-exchange chromatography. The preparation contained a minimum of three enzymes capable of splitting a-D-mannosidic bonds a-D-mannosidase, exo-D-mannanase, and endo-D-mannanase, which were separated. Some properties of the D-mannanase complex of the crude enzyme preparation were examined. The D-mannanase complex exhibited two pH optima, its temperature optimum being at 45 C. 

The phytopathogen Xanthomonas campestris when grown on several polysaccharide substrates produced j8-D-mannanases (see p. 496).  

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