Saccharification of cellolulose by the cellulolytic enzyme system of Thermonospora sp. I. Stability of cellulolytic activities with respect to time, temperature, and pH

Abstract

PI? ilcidelp h iu , Pen n sy 1 L W n ici I 9 I 04 SummaryThe stabilities and optima with respect to temperature and pH of the P-glucosidase, Avicelase, and carboxymethylcellulase (CMCase) activities of Thermomonospora sp., in the culture filtrate, culture whole broth, and filtrate after sonication of culture solids, are reported. The P-glucosidase is cell associated and has an optimal activity at about pH 6.5 and 55°C. In the whole culture broth, it has a half-life of about 8 hr at 55°C and less than 1 hr at 60°C. while the half-life of the activity in the sonicated, cell-free filtrate is less than 1 hr at 55°C. The Avicelase and CMCase activities occur in the extracellular culture fluid and have optima at about pH 7.0 and 5.9, and 65 and 7O"C, respectively. The CMCase activity is stable over 24 hr at 60"C, but declines by 50% in the same period at 65°C. The Avicelase activity declines by 15% over 24 hr at 55°C. and by 50% at 60°C. The highest pH studied (pH 7.3) was the most destabilizing for all three activities. The thermostable characteristics of the cellulases from 7herniomonosporcr appear to make them suitable for commercial saccharification processes operating at elevated temperatures.

Controlling simultaneous production of endoglucanase and beta-glucosidase by Fusarium oxysporum in submerged culture

“…2). While the temperature optimum of endoglucanase were within the range reported for mesophilic microorganisms (Hagerdal et al, 1982;Garg and Neelakantan, 1982;Macris, 1984;Sidhu et al, 1986) the optimum of l~-glucosidase competed favourably with those reported for certain thermophilic cellulolytic microorganisms (Hagerdal et al, 1982;McHale and Coughlan, 1981;Sen et al, 1982). Besides temperature optima, the thermostability of the enzymes investigated in this work is an important characteristic.…”

Bio‐control and plant growth promotion potential of siderophore producing endophytic Streptomyces from Azadirachta indica A. Juss.

“…All the three strains had cellulase activity that can be helpful in reducing fungal infection. Many actinomycetes were reported to have cellulase activity such as Thermomonospora sp., and Streptomyces transformant [23,24]. Strains AzR-049 and 051 were potentially more antagonistic (inhibition ranges in between 12 to 14 mm) to the Alternaria alternata, than isolate AzR-010 (only 9 mm, p < 0.05), this suggests that the two strains AzR-049 and 051 have strong antagonistic activity towards this particular pathogen ( Table 2, Fig.…”

Purification and characterization of an exoglucanase from Streptomyces flavogriseus

“…has been. studied in considerable detail, there is only one report which deals with fractionation of the enzyme complex (Hagerdal et al 1978). Three major fractions with cellulolytic activity were obtained by preparative electrofocusing.…”

“…Only one thermophilic species, Thermomonospora sp. Hagerdal et al 1978Hagerdal et al , 1980Moreira et al 198 l), and one mesophilic species, Streptomyces jlavogriseus (Ishaque andKluepfel 1980, 1981), have been examined in any detail.…”