scholarly journals Enhanced Thermostability of a Fungal Alkaline Protease by Different Additives

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Nilesh P. Nirmal ◽  
R. Seeta Laxman

A fungal strain (Conidiobolus brefeldianus MTCC 5184) isolated from plant detritus secreted a high activity alkaline protease. Thermostability studies of the fungal alkaline protease (FAP) revealed that the protease is stable up to 50°C with 40% residual activity after one hour. Effect of various additives such as sugars, sugar alcohols, polyols, and salts, on the thermostability of FAP was evaluated. Among the additives tested, glycerol, mannitol, xylitol, sorbitol, and trehalose were found to be very effective in increasing the stability of FAP, which was found to be concentration dependent. Fivefold increase in residual activity of FAP was observed in the presence of trehalose (50%) and sorbitol (50%) at 50°C for 4 h, compared to FAP without additive. Other additives like calcium at 20 mM and 10–15% ammonium sulphate showed lower stability improvement than trehalose and sorbitol. NaCl, MgCl2, K2HPO4, and glycine were found to be poor stabilizers and showed only a marginal improvement. PEG 6000 did not show any increase in stability but was found to be slightly inhibitory.

Polymers ◽  
2021 ◽  
Vol 13 (15) ◽  
pp. 2452
Author(s):  
Chia-Jung Hsieh ◽  
Ju-Chuan Cheng ◽  
Chia-Jung Hu ◽  
Chi-Yang Yu

Capturing and storing CO2 is of prime importance. The rate of CO2 sequestration is often limited by the hydration of CO2, which can be greatly accelerated by using carbonic anhydrase (CA, EC 4.2.1.1) as a catalyst. In order to improve the stability and reusability of CA, a silica-condensing peptide (R5) was fused with the fastest known CA from Sulfurihydrogenibium azorense (SazCA) to form R5-SazCA; the fusion protein successfully performed in vitro silicification. The entrapment efficiency reached 100% and the silicified form (R5-SazCA-SP) showed a high activity recovery of 91%. The residual activity of R5-SazCA-SP was two-fold higher than that of the free form when stored at 25 °C for 35 days; R5-SazCA-SP still retained 86% of its activity after 10 cycles of reuse. Comparing with an uncatalyzed reaction, the time required for the onset of CaCO3 formation was shortened by 43% and 33% with the addition of R5-SazCA and R5-SazCA-SP, respectively. R5-SazCA-SP shows great potential as a robust and efficient biocatalyst for CO2 sequestration because of its high activity, high stability, and reusability.


2009 ◽  
Vol 15 (6) ◽  
pp. 545-552 ◽  
Author(s):  
Erzheng Su ◽  
Tao Xia ◽  
Liping Gao ◽  
Qianying Dai ◽  
Zhengzhu Zhang

Tannase was effectively immobilized on alginate by the method of crosslinking-entrapment-crosslinking with a high activity recovery of 76.6%. The properties of immobilized tannase were investigated. Its optimum temperature was determined to be 35 ° C, decreasing 10 °C compared with that of free enzyme, whereas the optimum pH of 5.0 did not change. The thermal and pH stabilities of immobilized tannase increased to some degree. The kinetic parameter, Km, for immobilized tannase was estimated to be 11.6 × 10-4 mol/L. Fe2+ and Mn2+ could activate the activity of immobilized tannase. The immobilized tannase was also applied to treat the tea beverage to investigate its haze-removing effect. The content of non-estern catechins in green tea, black tea and oolong tea increased by 52.17%, 12.94% and 8.83%, respectively. The content of estern catechins in green tea, oolong tea and black tea decreased by 20.0%, 16.68% and 5.04%, respectively. The anti-sediment effect of green tea infusion treated with immobilized tannase was significantly increased. The storage stability and reusability of the immobilized tannase were improved greatly, with 72.5% activity retention after stored for 42 days and 86.9% residual activity after repeatedly used for 30 times.


2017 ◽  
Vol 7 (4) ◽  
pp. 1 ◽  
Author(s):  
Sreedevi Basavaraju ◽  
Chandrasekhar Kathera ◽  
Pramoda Kumari Jasti

The alkaline protease produced by Bacillus cereus UV-15 mutant was purified by precipitation with ammonium sulphate and gel filtration through sephadex G-100. The enzyme has shown to have a molecular weight of 29kDa by SDS polyacrylamide gel electrophoresis. The extracted protease enzyme was purified by 16.64 fold through ammonium sulphate precipitation and chromatography separation in Sephadex G-100. The purified protease had a specific activity of 2915 (U/mg). The zymogram also revealed a clear hydrolytic zone due to proteolytic activity, which coincided with the band obtained with SDS–PAGE. The enzyme was remained active and stable at pH 8-11, with an optimum at pH 10.0. The protease was stable in the temperature ranging from 40°C to 60°C, but gradually decreased at temperature 70°C. The optimum temperature for protease activity was determined at 60°C. The enzyme showed stability towards non-ionic and anionic surfactants, and oxidizing agents. At 1% concentration of Tween-20 and Tween-80, the enzyme retained 78% and 94% relative activity respectively. Alkaline protease retained 95% activity toward 0.5% concentration of the anionic detergent SDS. The enzyme showed compatibility at 50°C with commercial detergents such as Ariel, Surf excel, Rin, wheel, Tide and Nirma. In the presence of Ariel and Rin the enzyme retained about 72 and 75% of the original activity respectively. The supplementation of the enzyme in detergents could improve the cleansing performance towards the blood stains and suggested to be used as a detergent additive. The enzyme also removed goat hide hairs completely after 15 hr of incubation. These characteristics may make the enzyme suitable for several industrial applications, especially in leather industries.


2018 ◽  
Vol 7 (2) ◽  
pp. 173-179
Author(s):  
Widyastuti Widjaksana ◽  
◽  
Puji Widayati ◽  
Yunilda Alwi ◽  
Lindawati N ◽  
...  

2015 ◽  
Vol 3 (1) ◽  
pp. 36 ◽  
Author(s):  
Md. Arafat Al Mamun ◽  
Md. Murad Khan ◽  
Md. Nahinur Rahmam Akand ◽  
Shakila Nargis Khan ◽  
Md. Mozammel Hoq

<p>An alkaline protease from <em>Bacillus licheniformis</em> MZK05M9 (<em>Bl</em>M9), a mutant strain developed in our laboratory, has been partially purified and characterized for its robustness and eco-friendly application potential in processing of hides and skins for leather manufacturing and detergent industries. The enzyme was purified 2.70 fold with specific activity of 1624U/mg in comparison to crude enzyme extract by using ammonium sulfate precipitation, dialysis and Sephadex G-75 column chromatography. The molecular mass of the enzyme was 27.2 kDa as judged by SDS–PAGE. The purified protease had a pH optimum of 8.5 and temperature optimum of 55°C. According to the inhibition profiles obtained with the various protease inhibitors, it was confirmed that the partially purified protease belongs to the serine protease type. The activity of partially purified enzyme was enhanced by calcium, magnesium, barium, potassium and manganese ions and strongly inhibited by mercury ion. In addition, the protease showed remarkable stability in the presence of 1% SDS; 1, 3 and 5% Triton X-100 and H<sub>2</sub>O<sub>2</sub>, which comprise the common bleach-based detergent formulation. The enzyme was found equally efficient to a commercial enzyme Oropon K (one of the commercial enzymes imported into Bangladesh for bating purpose) in bating of animal hide as proved by different comparative qualitative tests such as tensile strength, percent of elongation, stitch tears strength, water vapor permeability, grain crack strength and tongue tear  strength tests. In addition, the stability profile (pH, temperature and surfactants) and blood stain removal data also revealed its suitability for application in detergent industry.</p>


2010 ◽  
Vol 14 (04) ◽  
pp. 335-342 ◽  
Author(s):  
Amineh Aghabali ◽  
Nasser Safari

TPPMnOAc and four different kinds of manganese tetraphenylporphyrin acetates were synthesized using different numbers of methoxy substituents in various positions of the phenyl rings. These porphyrins were used as catalysts in the epoxidation of various alkenes with tetra-n-butylammonium hydrogen monopersulfate (n- Bu 4 NHSO 5) as the oxidant and imidazole as the axial base. The following order of catalytic activity was obtained: TPPMnOAc ≥ T (2,3- OMeP ) PMnOAc > T (4- OMeP ) PMnOAc > T (3,4- OMeP ) PMnOAc > T (2,4,6- OMeP ) PMnOAc . By studying the UV-vis spectra in the reaction solution, the stability of the applied methoxy porphyrins and the effect of this factor on obtained yields were investigated. Lower catalytic activity in some of the methoxy porphyrins emphasized steric effects and special hydrogen bonding among the reaction elements. However, the stability of T (2,3- OMeP ) PMnOAc under our reaction condition was considerable and high activity was observed. By adding small amounts of alcohol to the reaction solution, the effect of the solvent mixture was previewed and steps were taken to identify the active intermediate of the catalyst in these conditions.


1989 ◽  
Vol 67 (9) ◽  
pp. 666-669 ◽  
Author(s):  
Ijeoma Ahonkhai ◽  
Masahiro Kamekura ◽  
Donn J. Kushner

The aspartate transcarbamylase (ATCase) in cell-free extracts of the moderately halophilic eubacterium, Vibrio costicola, was stable in 1.5 M NaCl, but not in 0.5 M NaCl on prolonged storage at 4 °C in concentrated extracts. At lower salt concentrations, activity was lost rapidly. ATCase activity was optimal at about 1.5 M NaCl or 1.0 M KCl, although high activity was detected at 0.15 M NaCl. In the presence of 0.03 M aspartate both succinate and maleate inhibited ATCase activity. CTP inhibited the activity of the enzyme at low salt concentrations (0.15 to 0.3 M). Much less inhibition occurred at higher salt concentrations. Precipitating the enzyme with ammonium sulphate resulted in loss of CTP inhibition. The ATCase of V. costicola differs from those of a nonhalophile (Saccharomyces cerevisiae) and an extremely halophilic archaebacterium (Halobacterium cutirubrum) in its salt-response patterns of activity and regulation.Key words: halophilic, aspartate transcarbamylase, Vibrio costicola.


2005 ◽  
Vol 37 (10) ◽  
pp. 702-708 ◽  
Author(s):  
Yan-Hong Li ◽  
Rui Guo ◽  
Qiu-Yu Yin ◽  
Ming Ding ◽  
Si-Liang Zhang ◽  
...  

Abstract Two novel endo-β-1,4-glucanases, EG45 and EG27, were isolated from the gastric juice of mollusca, Ampullaria crossean, by anion exchange, hydrophobic interaction, gel filtration and a second round of anion exchange chromatography. The purified proteins EG45 and EG27 appeared as a single band on sodium dodecylsulfate polyacrylamide gel electrophoresis with a molecular mass of 45 kDa and 27 kDa, respectively. The optimum pH for CMC activity was 5.5 for EG45 and 4.4-4.8 for EG27. The optimum temperature range for EG27 was broad, between 50 °C and 60 °C; for EG45 it was 50 °C. The analysis on the stability of these two endo-β-1,4-glucanases showed that EG27 was acceptably stable at pH 3.0-11.0 even when the incubation time was prolonged to 24 h at 30 °C, whereas EG45 remained relatively stable at pH 5.0-8.0. About 85% of the activity of EG27 could be retained upon incubation at 60 °C for 24 h. However, less than 10% residual activity of EG45 was detected at 50 °C. Among different kinds of substrates, both enzymes showed a high preference for carboxymethyl cellulose. EG45, in particular, showed a carboxymethyl cellulose hydrolytic activity of 146.5 IU/mg protein. Both enzymes showed low activities to xylan (from oat spelt) and Sigmacell 101, and they were inactive to p-nitrophenyl-β-D-cellobioside, salicin and starch.


2007 ◽  
Vol 50 (3) ◽  
pp. 557-564 ◽  
Author(s):  
Graziela Batista Ferreira ◽  
Alex Ferreira Evangelista ◽  
João Baptista Severo Junior ◽  
Roberto Rodrigues de Souza ◽  
José Carlos Curvelo Santana ◽  
...  

This work aimed to establish the relationship between the compositions and pH of ATPS PEG 6000/CaCl2 and the proteins partition from maize malt and also to simplify the process optimization in ATPS for a statistical model, established by response surface methodology (RSM). Results showed that these were no influence of pH on the phase diagrams and on the composition of tie line length of PEG 6000/CaCl2 ATPS. SRM analyses showed that elevated pH and larger tie line length were the best conditions for recovering of maize malt proteins. The maximum partition coefficient by PEG 6000/CaCl2 ATPS was about 4.2 and was achieved in ATPS in a single purification step. The theoretical maximum partition coefficient was between 4.1-4.3. The process was very suitable for continuous aqueous two-phase purification due to the stability of proteins (e.g. and -amylases) and could increase their content into middle.


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