Purification of an exo-1,3-β-glucanase from Candida utilis

1976 ◽  
Vol 54 (11) ◽  
pp. 927-934 ◽  
Author(s):  
T. G. Villa ◽  
V. Notario ◽  
T. Benítez ◽  
J. R. Villanueva

An exo-1,3-β-glucanase (EC 3.2.1.—) has been purified from the culture fluid of the yeast Candida utilis, and its biochemical properties have been studied. The amino acid analysis revealed a high content of acidic amino acids. The purified enzyme had 20% carbohydrate and a net negative charge showing higher affinity for laminarin than for p-nitrophenyl-β-D-glucopyranoside and yeast cell-wall 1,3-β-glucans. In addition, the enzyme hydrolyzed the substrates starting from the nonreducing ends, releasing glucose as the exclusive hydrolysis product. The enzyme activity was strongly inhibited by lactones and also by some heavy-metal ions.

2012 ◽  
Vol 46 (5) ◽  
pp. 292-294 ◽  
Author(s):  
A. S. Berlyand ◽  
A. P. Snyakin ◽  
A. A. Prokopov

2005 ◽  
Vol 52 (10-11) ◽  
pp. 151-156 ◽  
Author(s):  
J. Mikes ◽  
M. Siglova ◽  
A. Cejkova ◽  
J. Masak ◽  
V. Jirku

Wastewaters from a chemical industry polluted by heavy metal ions represent a hazard for all living organisms. It can mean danger for ecosystems and human health. New methods are sought alternative to traditional chemical and physical processes. Active elimination process of heavy metals ions provided by living cells, their components and extracellular products represents a potential way of separating toxic heavy metals from industrial wastewaters. While the abilities of bacteria to remove metal ions in solution are extensively used, fungi have been recognized as a promising kind of low-cost adsorbents for removal of heavy-metal ions from aqueous waste sources. Yeasts and fungi differ from each other in their constitution and in their abilities to produce variety of extracellular polymeric substances (EPS) with different mechanisms of metal interactions. The accumulation of Cd(2+), Cr(6+), Pb(2+), Ni(2+) and Zn(2+) by yeasts and their EPS was screened at twelve different yeast species in microcultivation system Bioscreen C and in the shaking Erlenmayer's flasks. This results were compared with the production of yeast EPS and the composition of yeast cell walls. The EPS production was measured during the yeast growth and cell wall composition was studied during the cultivations in the shaking flasks. At the end of the process extracellular polymers and their chemical composition were isolated and amount of bound heavy metals was characterized. The variable composition and the amount of the EPS were found at various yeast strains. It was influenced by various compositions of growth medium and also by various concentrations of heavy metals. It is evident, that the amount of bound heavy metals was different. The work reviews the possibilities of usage of various yeast EPS and components of cell walls in the elimination processes of heavy metal ions. Further the structure and properties of yeasts cell wall and EPS were discussed. The finding of mechanisms mentioned above is necessary to identify the functional groups entered in the metals elimination processes.


CrystEngComm ◽  
2022 ◽  
Author(s):  
Yin-Xia Sun ◽  
Geng Guo ◽  
Wenmin Ding ◽  
Wenyu Han ◽  
Juan Li ◽  
...  

Heavy metal ions were common pollutants in water pollution. Amino acids, as important substances in organisms, participate in many life activities. The detection of heavy metal ions and amino acids...


1971 ◽  
Vol 17 (7) ◽  
pp. 865-869 ◽  
Author(s):  
B. Sue Criswell ◽  
Judith H. Marston ◽  
Wayne A. Stenback ◽  
S. H. Black ◽  
Herman L. Gardner

The fine structure of Haemophilus vaginalis 594 (ATCC 14018) was examined by electron microscopy, and the biochemical composition of its cell wall was determined. For comparison, similar studies were done with a Gram-positive bacterium, Bacillus megaterium KM, and a Gram-negative bacterium, Escherichia coli B. Both Haemophilus vaginalis 594 and Escherichia coli B possessed a multiple-layered cell wall containing 11 to 14 amino acids, a low mucopeptide content, and no teichoic acid. In contrast, Bacillus megaterium KM had a thick, amorphous cell wall with five amino acids, high mucopeptide content, and detectable amounts of teichoic acid. Haemophilus vaginalis 594 resembled Escherichia coli, a member of the Gram-negative group of organisms. The structural and biochemical properties of Haemophilus vaginalis, which are described in detail, may prove useful in determining the ultimate taxonomic position of this species.


1976 ◽  
Vol 159 (3) ◽  
pp. 555-562 ◽  
Author(s):  
V Notario ◽  
T G Villa ◽  
J R Villanueva

β-Glucanase present in cell-free extracts from Candida utilis was isolated and purified 562-fold by procedures that include adsorption on DEAE-Sephadex A-50 and filtration through columns of Sephadex G-50, G-100 and G-200, Bio-Gel P-10, and Concanavalin A-Sepharose 4B. The purified enzyme appeared homogeneous on polyacrylamide-gel electrophoresis and in ultracentrifugation studies (S20,w = 1.74S). The enzyme behaved as an acidic glycoprotein (pI4.1) with 68% carbohydrate and a high content of acidic amino acids. The mol.wt. was estimated to be 20000 from gel filtration and polyacrylamide-gel electrophoresis and 36000 from sedimentation experiments. Studies on the hydrolysis of different substrates showed that the enzyme is an unspecific β-glucanase able to break down both (1 leads to 3)-eta- and (1 leads to 6)-β-linkages by an exo-splitting mechanism. Glucono-δ-lactone, Zn2+ and Hg2+ inhibited the enzyme activity.


2020 ◽  
Author(s):  
Pilla Sankara Krishna ◽  
Sarada Raghunathan ◽  
Shyam Sunder Prakash Jogadhenu

Abstract Background: Bacillus okhensis, isolated from saltpan near port of Okha, India, was initially reported to be a halo-alkali tolerant bacterium.We previously sequenced it’s 4.86 Mb genome, here we analyze its genome and physiological responses to high salt and high pH stress. Results: B. okhensis is a halo-alkaliphile with optimal growth at pH 10 and 5% NaCl. 16S rDNA phylogenetic analysis resulted in habitat based segregation of 106 Bacillus species into 3 major clades with all alkaliphiles in one clade clearly suggesting a common ancestor for alklaliphilic Bacilli. We observed that B. okhensis has been adapted to survive at halo-alkaline conditions, by acidification of surrounding medium using fermentation of glucose to organic acids. Comparative genome analysis revealed that the surface proteins which are exposed to external high pH environment of B. okhensis were evolved with relatively higher content of acidic amino acids than their orthologues of B. subtilis. It posess relatively more genes involved in the metabolism of osmolytes and sodium dependent transporters in comparison to B. subtilis. Growth of B. okhensis is Na+ dependent, with a minimum requirement of 4% NaCl at neutral pH but 0.5% NaCl is enough at pH 10. It tolerated sudden increase of salt concentration of its medium, and exhibited an elongated cellular phenotype. But, could not tolerate a sudden shift of pH from 7 to 11, and cell envelope got damaged, confirming the pH regulation through cell wall reinforcement is key to survival at high-pH condition. We observed that hydroxyl ions damage the cell, but not Na+ ions, becuase at high pH Na+ ions were not accumulated inside. Conclusion: B. okhensis uses acidification of the external medium and pH dependent cell wall reinforcement to survive sodic environments. Interestingly, its growth is highly Na+ dependent and the genome encodes for a high proportion of acidic amino acids in majority of surface proteins in comparison to their orthologues of B. subtilis, a direct evidence of adaptive evolution.


2020 ◽  
Vol 11 (2) ◽  
pp. 310-314
Author(s):  
O. V. Fedotov ◽  
Z. L. Usikova

The results of the modification of methods for producing enzymatic preparations (EP) of peroxidases and catalases of extra- and intracellular finding from fungal cultures are presented. Strains of Flammulina velutipes F-vv, Lentinula edodes 523 and Pleurotus ostreatus P-01 were used as producers of oxidoreductases. The producers were cultured in glucose-peptone medium, modified for each strain. Protein fractionation was carried out by leaching with ammonium sulfate at a saturation of 40–70% for peroxidases and 80% for catalases. The obtained solutions of protein fractions were additionally subjected to purification by dialysis, gel filtration on Molselect G-50 and G-75 granules, and also freeze drying. The yield of enzymatic preparations per unit mass of mycelium and the volume of culture fluid were calculated. The individual characteristics of EP – enzymatic activity, the mass percentage of protein and associated amino acids, the ratio of the latter in groups depending on the nature of the radicals (amphotericity) of protein molecules are established. It was proved that the amino acid content in the proteins of fungal EP catalases and peroxidases indicates their acidic nature and this is confirmed by the pH values of aqueous solutions. Examination and toxicity testing of enzymatic preparations were carried out in certified laboratories, which confirmed their characteristics and compliance with safety requirements. The therapeutic properties of amino acids that are part of proteins or are in a free state in enzyme preparations are analyzed. In this way, the methods have been developed for producing enzymatic preparations of peroxidases and catalases of extra- and intracellular location, which allow new antioxidant enzymes with individual properties to be obtained, and, as a result, bring prospects for use in various industries and scientific research.


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