PROPERTIES OF THERMOSTABLE HEMICELLULOLYTIC ENZYMES FROM THERMOMONOSPORA STRAIN-29 GROWN IN SOLID-STATE FERMENTATION ON COFFEE PROCESSING SOLID-WASTE

During decaffeination of Coffee Processing Plant Solid Wastes (CPSW) b y actinomycetes, Thermomonospora, Strain 29 exhibited high titers of c ellulase and xylanase. This organism, originally isolated on soybean s eed coat was grown in solid state fermentation on CPSW supplemented wi th mineral salts. Enzymes recovered were arabinosidase, xylanase, and beta-D-xylosidase. Higher activity of the former two enzymes was in th e extracellular broth, whereas the beta-D-xylosidase activity was high est in the cell fraction. The enzymes were characterized after precipi tation with (NH4)2SO4, dialysis, and gel filtration. Production of all three enzymes was inhibited by monomeric sugars and sugar alcohols bu t not by arabinoxylan, xylans, or xylan containing water insoluble car bohydrates. The optimum pH for the activity was 6.5, 7.0, and 7.5 for beta-xylosidase, xylanase and arabinosidase (alpha-L-arabinofuranosida se, alpha-arabinosidase, alpha-L-arabinosidase) respectively. These en zymes were stable in the pH range of 6.5 to 8.0. All three enzymes wer e thermostable up to 80-degrees-C. At 55-degrees-C, arabinosidase had the longest half life of 120 h. However, at 40-degrees-C, xylanase had the longest half life (504 h). At either temperature, Beta-D-xylosida se had the shortest half life. The molecular weights (kDa), and Kms (m M) were estimated to be 95, 0.27; 45, 12.4; and 106, 0.67 for arabinos idase, xylanase, and beta-xylosidase respectively. Step wise addition of the three enzymes showed higher saccharification of lignocellulosic s.