Structure and properties of aCephalosporium acremonium ?-galactosidase

Запрометова, О. М.; Ulezlo, I. V.; Lakhtin, V. M.

doi:10.1007/bf01073373

Cited by 5 publications

(1 citation statement)

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“…While the experiments described here were all carried out on a shake flask scale, we have recently successfully attempted to scale up this cultivation method to pilot plant dimensions. This also allows purification of larger amounts of enzyme than de- The purification of a-galactosidase from T. reesei is described here for the first time, although this enzyme has been Elution Time [min] studied from several other sources (1, 3, 4-6, 26,31,32).…”

Section: Discussionmentioning

confidence: 99%

Conditions of formation, purification, and characterization of an alpha-galactosidase of Trichoderma reesei RUT C-30

Zeilinger

Kristufek

Arisan-Atac

et al. 1993

Appl Environ Microbiol

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Trichoderma reesei RUT C-30 formed an extracellular a-galactosidase when it was grown in a batch culture containing lactose or locust bean gum as a carbon source. Short-chain a-galactosides (melibiose, raffinose, stachyose), as well as the monosaccharides galactose, dulcitol, arabinose, and arabitol, also induced at-galactosidase activity both when they were used as carbon sources (at a concentration of 1%) in batch cultures and in resting mycelia (at concentrations in the millimolar range). The addition of 50 mM glucose did not affect the induction of ac-galactosidase formation by galactose. a-Galactosidase from T. reesei RUT C-30 was purified to homogeneity from culture fluids of galactose-induced mycelia. The active enzyme was a 50 ± 3-kDa, nonglycosylated monomer which had an isoelectric point of 5.2. It was active against several a-galactosides (p-nitrophenyl-t-D-galactoside, melibiose, raffinose, and stachyose) and galactomannan (locust bean gum) and was inhibited by the product galactose. It released galactose from locust bean gum and exhibited synergism with T. reesei 1-mannanase. Its activity was optimal at pH 4, and it displayed broad pH stability (pH 4 to 8). Its temperature stability was moderate (60 min at 50°C resulted in recovery of 70%o of activity), and its highest level of activity occurred at 60°C. Its action on galactomannan was increased by the presence of 13-mannanase. Hemicelluloses are the second most abundant polysaccharides in nature, and they seem to be linked to lignin in wood (23). The major constituents of hemicellulose are the hetero-1,4-0-D-xylans and the hetero-1,4-,B-D-mannans (galactoglucomannans and glucomannans). While heteroxylans are found mainly in grasses, cereals, and hardwoods, P-mannans are more abundant in softwoods (8, 23). The biotechnological interest in the hydrolysis of hemicelluloses for the pulp and paper industry and the feedstock industry has recently revived interest in the enzymology of hemicellulose degradation. In the case of galactomannans, this enzymatic hydrolysis requires the concerted action of the following hydrolytic enzymes: endo-1

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Section: Discussionmentioning

confidence: 99%