scholarly journals Purification and Properties of the Raw Starch Degrading α-amylase of Mutant strain: Bacillus cereus 1306

2004 ◽  
Vol 2 (2) ◽  
pp. 46-54
Author(s):  
Manoj Trivedi ◽  
S. K. Mandal

The raw starch-degrading α-amylase Produced by Bacillus cereus 1306 was purified to homogeneity by acetone precipitation and gel filtration chromatography.The Molecular weight of α-amylase was estimated to be 58KDa. The enzyme displayed maximum activity 85 Units/ml at pH 7.0 and an incubation temperature of 37˚C and Stable in the pH range of 5.0-9.0. Activity was inhibited in the presence of Hg2+,Cu2+,Fe3+ but no inhibition was observed in the presence of Zn2+. Medium containing CaCl2.2H2O enhanced amylase production over that on Ca2+-deficient medium. The detergent Tween-80 and Triton X-100 increased Biomass but Significantly Suppressed amylase production. The enzyme released large amount of glucose and maltose on hydrolysis of starch.

2010 ◽  
Vol 53 (1) ◽  
pp. 35-45 ◽  
Author(s):  
Arlem Nascimento de Oliveira ◽  
Luiz Antonio de Oliveira ◽  
Jerusa Souza Andrade

Amylase production and partial characterization of crude enzyme preparations from two rhizobia strains (R-926 and R-991) were evaluated. For both the strains, maximal amylase activities were achieved during the early-to-mid- exponential growth phase; both were active over a pH range from 4.5 to 8.5 and temperature from 30 to 50 ºC. None of the ions studied (K+, Na+, Ca2+, Hg2+, Mg2+, Mn2+, Cu2+ and Zn2+) was required for the catalytic activity of strain R-926; amylase activity of strain R-991 was stimulated in the presence of K+, Hg2+ and Zn2+. The surfactants SDS, Triton X-100 and Tween-80 did not have a pronounced inhibitory effect on enzyme activities; SDS and Tween-80 caused the highest stimulatory effects. Amylase activities from the rhizobia strains were reduced by up to 30% in the presence of EDTA; amylase activity of R-926 was also inhibited by HgCl2, suggesting that Ca2+and cysteine residues could be important for activity of this strain.


1993 ◽  
Vol 289 (2) ◽  
pp. 453-461 ◽  
Author(s):  
M Hrmova ◽  
G B Fincher

Three (1->3)-beta-D-glucan glucanohydrolase (EC 3.2.1.39) isoenzymes GI, GII and GIII were purified from young leaves of barley (Hordeum vulgare) using (NH4)2SO4 fractional precipitation, ion-exchange chromatography, chromatofocusing and gel-filtration chromatography. The three (1->3)-beta-D-glucanases are monomeric proteins of apparent M(r)32,000 with pI values in the range 8.8-10.3. N-terminal amino-acid-sequence analyses confirmed that the three isoenzymes represent the products of separate genes. Isoenzymes GI and GII are less stable at elevated temperatures and are active over a narrower pH range than is isoenzyme GIII, which is a glycoprotein containing 20-30 mol of hexose equivalents/mol of enzyme. The preferred substrate for the enzymes is laminarin from the brown alga Laminaria digitata, an essentially linear (1->3)-beta-D-glucan with a low degree of glucosyl substitution at 0-6 and a degree of polymerization of approx. 25. The three enzymes are classified as endohydrolases, because they yield (1->3)-beta-D-oligoglucosides with degrees of polymerization of 3-8 in the initial stages of hydrolysis of laminarin. Kinetic analyses indicate apparent Km values in the range 172-208 microM, kcat. constants of 36-155 s-1 and pH optima of 4.8. Substrate specificity studies show that the three isoenzymes hydrolyse substituted (1->3)-beta-D-glucans with degrees of polymerization of 25-31 and various high-M(r), substituted and side-branched fungal (1->3;1->6)-beta-D-glucans. However, the isoenzymes differ in their rates of hydrolysis of a (1->3;1->6)-beta-D-glucan from baker's yeast and their specific activities against laminarin vary significantly. The enzymes do not hydrolyse (1->3;1->4)-beta-D-glucans, (1->6)-beta-D-glucan, CM-cellulose, insoluble (1->3)-beta-D-glucans or aryl beta-D-glycosides.


1983 ◽  
Vol 50 (1) ◽  
pp. 77-89 ◽  
Author(s):  
Patrick F. Fox ◽  
Leszek Stepaniak

SummaryAeration increased the growth and lipase production in milk byPseudomonas fluorescensstrain AFT 36, isolated from refrigerated bulk milk. A heat-stable lipase was isolated from a shaken milk culture of this microorganism by DEAE-chromatography and gel filtration in Sepharose 6B. The lipase-rich fraction from DEAE cellulose contained 3 lipases that were separated by gel filtration; only the principal lipase, which represented ∼ 71 % of total lipolytic activity, was characterized. The purified enzyme showed maximum activity on tributyrin at pH 8·0 and 35 °C; it had aKmon tributyrin of 3·65 mM. and was inhibited by concentrations of substrate > ∼ 17 mM. The enzyme was very stable over the pH range 6–9; it was relatively heat-labile in phosphate buffer in the temperature range 60–80 °C, where it was stabilized significantly by Ca2+. It was, however, very stable at 100–150 °C: theDvalues at 150 °C were ∼ 22 s and 28 s in phosphate buffer and synthetic milk serum respectively; the correspondingZvalues in the temperature range 100–150 °C were ∼ 40 and ∼ 42 °C and theEafor inactivation were 7·65 × 104J mol-1and 6·97 × 104J mol-1respectively.


1985 ◽  
Vol 229 (1) ◽  
pp. 251-257 ◽  
Author(s):  
S Hedeager-Sørensen ◽  
A J Kenny

Carboxypeptidase P has been purified by immunoaffinity chromatography from pig kidneys. A single-step assay with Z-Pro-Met (where Z represents benzyloxycarbonyl) as substrate was used, methionine being determined by using L-amino acid oxidase and horseradish peroxidase. The enzyme constitutes about 1.5% of the kidney microvillar proteins. Triton X-100-solubilized and papain-released forms of the enzyme were isolated. The former had an apparent subunit Mr of 135 000, and the latter form contained two polypeptide chains of Mr 128 000 and 95 000. The undenatured forms were dimeric proteins. In common with other microvillar hydrolases, carboxypeptidase P was a glycoprotein and each subunit contained one Zn atom. MnCl2 (1 mM) in the assay was necessary for maximum activity; in its absence, 0.5 mM-ZnSO4 produced a limited activation, but was inhibitory at higher concentrations. The Km for Z-Pro-Met, in the presence of MnCl2, was 4.1 mM, and the kcat. for freshly prepared enzyme was 1230 min-1. The enzyme lost activity during storage at −20 degrees C. In a limited survey of peptides, hydrolysis was observed only with substrates containing a proline, alanine or glycine residue in the P1 position, and these included angiotensins II and III. The best substrate in this series was Val-Ala-Ala-Phe.


1987 ◽  
Vol 248 (3) ◽  
pp. 871-876 ◽  
Author(s):  
M E Hoey ◽  
N Allison ◽  
A J Scott ◽  
C A Fewson

L-Mandelate dehydrogenase was purified from Acinetobacter calcoaceticus by Triton X-100 extraction from a ‘wall + membrane’ fraction, ion-exchange chromatography on DEAE-Sephacel, (NH4)2SO4 fractionation and gel filtration followed by further ion-exchange chromatography. The purified enzyme was partially characterized with respect to its subunit Mr (44,000), pH optimum (7.5), pI value (4.2), substrate specificity and susceptibility to various potential inhibitors including thiol-blocking reagents. FMN was identified as the non-covalently bound cofactor. The properties of L-mandelate dehydrogenase are compared with those of D-mandelate dehydrogenase, D-lactate dehydrogenase and L-lactate dehydrogenase from A. calcoaceticus.


1988 ◽  
Vol 255 (3) ◽  
pp. 833-841 ◽  
Author(s):  
J D Erfle ◽  
R M Teather ◽  
P J Wood ◽  
J E Irvin

A 1,3-1,4-beta-D-glucanase (lichenase, 1,3-1,4-beta-D-glucan 4-glucanohydrolase, EC 3.2.1.73) from Bacteroides succinogenes cloned in Escherichia coli was purified 600-fold by chromatography on Q-Sepharose and hydroxyapatite. The cloned enzyme hydrolysed lichenin and oat beta-D-glucan but not starch, CM(carboxymethyl)-cellulose, CM-pachyman, laminarin or xylan. The enzyme had a broad pH optimum with maximum activity at approx. pH 6.0 and a temperature optimum of 50 degrees C. The pH of elution from a chromatofocusing column for the cloned enzyme was 4.7 (purified) and 4.9 (crude) compared with 4.8 for the mixed-linkage beta-D-glucanase activity in B. succinogenes. The Mr of the cloned enzyme was estimated to be 37,200 by gel filtration and 35,200 by electrophoresis. The Km values estimated for lichenin and oat beta-D-glucan were 0.35 and 0.71 mg/ml respectively. The major hydrolytic products with lichenin as substrate were a trisaccharide (82%) and a pentasaccharide (9.5%). Hydrolysis of oat beta-D-glucan yielded a trisaccharide (63.5%) and a tetrasaccharide (29.6%) as the major products. The chromatographic patterns of the products from the cloned enzyme appear to be similar to those reported for the mixed-linkage beta-D-glucanase isolated from Bacillus subtilis. The data presented illustrate the similarity in properties of the cloned mixed-linkage enzyme and the 1,3-1,4-beta-D-glucanase from B. subtilis and the similarity with the 1,4-beta-glucanase in B. succinogenes.


2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Soni Tiwari ◽  
Neha Shukla ◽  
Pooja Mishra ◽  
Rajeeva Gaur

Ten bacterial strains isolated from the soil samples in the presence of cyclohexane were screened for amylase production. Among them, culture RG-01 was adjudged as the best amylase producer and was identified asBacillus tequilensisfrom MTCC, Chandigarh. The isolate showed maximum amylase production (8100 U/mL) in the presence of starch, peptone, and Ca2+ions at 55°C pH 7.0 within 24 h of incubation. The enzyme was stable in the presence of n-dodecane, isooctane, n-decane, xylene, toluene, n-hexane, n-butanol, and cyclohexane, respectively. The presence of benzene, methanol, and ethanol marginally reduced the amylase stability, respectively. The enzyme was showed it 100% activity at 55°C and pH 7.0 with 119% and 127% stability at 55°C and pH 7.0, respectively. The enzyme was also stable in the presence of SDS, Tween-40, Tween-60, and Tween-80 (1%) and was found stimulatory effect, respectively. Only Triton-X-100 showed a moderate inhibitory effect (5%) on amylase activity. This isolate (Bacillus tequilensisRG-01) may be useful in several industrial applications owing to its thermotolerant and organic solvents and surfactants resistance characteristics.


1978 ◽  
Vol 45 (2) ◽  
pp. 159-172 ◽  
Author(s):  
Patrick F. Fox ◽  
Catherine M. Hearn

Summaryα-Lactalbumin and SDS in addition to β-lactoglobulin introduced pH sensitivity to the heat stability–pH curve of serum protein free casein micelles particularly by increasing stability in the pH range 6·4–6·7. Bovine serum albumin, ovalbumin and lysozyme caused marked destabilization of milk and casein micelle suspensions throughout the pH range 6·4–7·4. Tetramethyl ammonium bromide caused destabilization of milk at pH values > 7·0, but had no effect in the region of maximum stability while the non-ionic detergents Triton X-100 and Tween 80 had no effect on heat stability.


2011 ◽  
Vol 58 (2) ◽  
Author(s):  
Suyue Zheng ◽  
Hexiang Wang ◽  
Guoqing Zhang

A protease with a molecular mass of 30 kDa and the N-terminal sequence of GLQTNAPWGLARSS, was isolated from fresh fruiting bodies of the wild edible mushroom Termitomyces albuminosus. The purification protocol included ion exchange chromatography on DEAE-cellulose, Q-Sepharose, SP-Sepharose and FPLC-gel filtration on Superdex 75. The protein was unadsorbed on DEAE-cellulose and Q-Sepharose, but adsorbed on SP-Sepharose. The optimal pH and temperature of the purified enzyme were 10.6 and 60 °C, respectively. The enzyme was stable in the presence of 2 % (v/v) Tween 80 and 4 M urea. More than 80 % of the enzyme activity was retained in 2 % (v/v) Triton X 100, 54 % in 10 mM EDTA and 31 % in 2 % (w/v) SDS. The enzyme was strongly inhibited by phenylmethylsulfonyl fluoride (PMSF), but not inhibited by dithiothreitol (DTT), pepstatin or lima bean trypsin inhibitor suggesting that it was a serine protease but not a trypsin-like one. The protease was inhibited by Hg(2+), Cu(2+), and Fe(3+) ions. The K(m) and V(max) values of the purified enzyme for casein were 8.26 mg ∙ ml(-1) and 0.668 mg ∙ ml(-1) ∙ min(-1), respectively.


1981 ◽  
Vol 198 (3) ◽  
pp. 467-473 ◽  
Author(s):  
I M Cesari ◽  
A J G Simpson ◽  
W H Evans

1. Incubation of Schistosoma mansoni for 5 min in a phosphate-buffered medium, pH 7.4, released tegumental material containing the following phosphohydrolase activities: alkaline phosphatase, 5′-nucleotidase, glycerol-2-phosphatase, glucose 6-phosphatase, phosphodiesterase and ATPase. 2. Maximum activity of these enzymes was measured at pH 9.5; however, the phosphodiesterase and ATPase activities were also appreciable at pH 7.0. 3. Solubilization of the released tegumental material in 1% Triton X-100 followed by gel filtration distinguished three peaks of enzyme activity: an ATPase (mol.wt. greater than 1000 000), a phosphodiesterase (mol.wt. 1 000 000) and an alkaline phosphomonoesterase with broad specificity (mol.wt. 232 000). 4. The ATPase activity was highly activated by 10 mM-Mg2+ or 1 mM-Ca2+ and was inhibited by chelating agents. Ouabain, Na+ and K+ had little effect on enzyme activity, whereas activity was increased by 50% in the presence of calmodulin. The phosphodiesterase activity was highest in the presence of 100 mM-Na+ or -K+, and 10 mM-Mg2+ or -Ca2+. Alkaline phosphatase activity was also stimulated by 100 mM-Na+ or -K+, and 10 mM-Mg2+; however Ca2+ inhibited at greater than 1 mM. 5. Surface iodination of parasites followed by detergent solubilization and gel filtration of the released tegumental membranes indicated that these enzymes were not accessible. A major surface component, apparent mol.wt. 80 000, was iodinated. 6. Rabbit anti-(mouse liver 5′-nucleotidase) antibodies did not inhibit the phosphohydrolase activities. However, an immunoglobulin G fraction from sera of mice chronically infected with S. mansoni partially inhibited alkaline phosphatase activity, but was without effect on the phosphodiesterase and ATPase activities. 7. The location of the enzymes in the double membrane of the tegument and their significance in host-parasite interactions is discussed.


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