The partial characterization of extracellular proteases from Streptomyces clavuligerus NRRL 3585 and 644 mutant was investigated. The enzyme production was carried out in batch fermentation using soy bean filtrate as nitrogen source. Maximum activity was obtained after 96h of fermentation with an initial pH of 7.0. The enzyme was partially purified by ammonium sulphate precipitation. Enzymes from the two strains retained 37% of their initial activities at pH 8.0 after 2 h incubation at 25ºC. Enzyme half-life at pH 8.0 and 60ºC was 40.30 and 53.32 min, respectively for both strains (partially purified extract). The optimum pH was obtained at pH 7.0-8.0 and 8.4 for enzymes produced for 3585 and 644 strains (crude extract), respectively, and 8.4 and 8.0 for enzymes from the partially purified extract 3585 and 644 strains, respectively. The optimum temperature for the crude extract was 21ºC for both strains. However, for the partially preparation the optimum temperature was 50ºC and 40°C for S. clavuligerus NRRL 3585 and 644 strains respectively.
Galactans from albumen glands and from freshly collected egg masses of intermediary hosts of bilharzia in Brazil (Biomphalaria glabrata, Biomphalaria tenagophila and Biomphalaria straminea) were investigated. All these galactans had D-galactopyranose characterized as the sole sugar component. No evidence was found for the presence of L-galactopyranose in these polymers, using specific enzymes. Methanolysis of the methylated galactans and periodate oxidation data indicated a multibranched structure for these galactans. Yields of O-methyl sugars showed a equimolecular proportion of non-reducing end groups and disubstituted residues linked through positions 3 and 6 and a predominance of /?-(l ->3)-over /?-(l ->6)-linkages. In view of the structural identity presently observed in the galactans from all our sources, as compared to the distinctive structure proposed for the galactan after five days of egg masses laying [M. Iacomini et al, Arq. Biol. Tecnol, 23, 329 (1980)], it is inferred that the enzymic system for galactan degradation is still inactive in freshly collected egg masses.l\ Galactans from snails were isolated as early Moretto et al.S) 'based on oxidative degraas 1885,1* but structural studies were madejust dation results, proposed another structural recently. conception for the albumen gland galactans of O'Colla2) applied the Barry degradation to Megalobulimus genus, as being a multibranchthe albumen gland galactan from Helix po-ed structure containing also linear segments matia and showed that the alternative struc-ofj8-(l.->3)-or j8-(l ->6)-linkages. This kind of tures proposed by Bell and Baldwin3] for this model was in accordance with the methylation polymer were an over-simplification and that data previously obtained for S. oblongus the galactan had a dichotomously branched galactan.5) structure, consisting of alternate j8-(l->3)-Bell and Baldwin3) also verified that the and /?-(l-^-linkages. Correa et al.,4) using galactan from H. pomatia confdimd n-and lthe same kind of degradation, suggested a galactose residues in a 6:1 ratio. Correa et similar structure for the albumen gland galac-al.4) also suggested that galactose residues not tan ofBiomphalaria glabrata. Further, Duarte susceptible to the action of D-galactose oxiand Jones5} showed that the methylation data dase could be a evidence of the L-isomer in the of Strophocheilus oblongus albumen gland ga-galactan of B. glabrata. lactan were not completely compatible with a On the other hand, the polymer isolated dichotomously branched structure. Recently, from egg masses of Ampullarius sp. differedSegura and Duarte,6) Iacomini et al.1] and from the albumen gland polysaccharides al-
Ga1actans from albumen glands and from freshly collected egg masses of intermediary hosts 'of bilharzia in Brazil (Biomphalaria glabrata, Biomphalaria tenagophila.and Biomphalaria straminea) were investigated. All these galactans had D•galactopyranose characterized as the sole sugar component. No evidence was found for the presence of L-galactopyranose in these polymers, using specific enzymes. Methanolysis of the methylated galactans and periodate oxidation data indicated a multibranched structure for these galactans. Yields of O-methyl sugars showed aequimolecular proportion of non-reducing end groups and disubstituted residues linked through positions 3 and 6 and a predominance of fJ-(l-.3)-over fJ-(l-.6)-linkages. In view of the structural identity presently observed in the galactans from all our sources, as compared to the distinctive structure proposed for the galactan after five days of egg masses laying [M. Iacomini et al., Arq. Bioi. Tecnol., 23, 329 (1980)], it is inferred that the enzymic system for galactan degradation is still inactive in freshly collected egg masses.
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