Enzyme Research最新文献_第4页

Pseudomonas aeruginosa Exopolyphosphatase Is Also a Polyphosphate: ADP Phosphotransferase 铜绿假单胞菌胞外磷酸酶也是一种多磷酸ADP磷酸转移酶

Enzyme Research Pub Date : 2015-10-21 DOI: 10.1155/2015/404607

Paola Beassoni, L. A. Gallarato, Cristhian Boetsch, M. N. Garrido, Á. T. Lisa

{"title":"Pseudomonas aeruginosa Exopolyphosphatase Is Also a Polyphosphate: ADP Phosphotransferase","authors":"Paola Beassoni, L. A. Gallarato, Cristhian Boetsch, M. N. Garrido, Á. T. Lisa","doi":"10.1155/2015/404607","DOIUrl":"https://doi.org/10.1155/2015/404607","url":null,"abstract":"Pseudomonas aeruginosa exopolyphosphatase (paPpx; EC 3.6.1.11) catalyzes the hydrolysis of polyphosphates (polyP), producing polyPn−1 plus inorganic phosphate (Pi). In a recent work we have shown that paPpx is involved in the pathogenesis of P. aeruginosa. The present study was aimed at performing the biochemical characterization of this enzyme. We found some properties that were already described for E. coli Ppx (ecPpx) but we also discovered new and original characteristics of paPpx: (i) the peptide that connects subdomains II and III is essential for enzyme activity; (ii) NH4 + is an activator of the enzyme and may function at concentrations lower than those of K+; (iii) Zn2+ is also an activator of paPpx and may substitute Mg2+ in the catalytic site; and (iv) paPpx also has phosphotransferase activity, dependent on Mg2+ and capable of producing ATP regardless of the presence or absence of K+ or NH4 + ions. In addition, we detected that the active site responsible for the phosphatase activity is also responsible for the phosphotransferase activity. Through the combination of molecular modeling and docking techniques, we propose a model of the paPpx N-terminal domain in complex with a polyP chain of 7 residues long and a molecule of ADP to explain the phosphotransferase activity.","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2015-10-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76940615","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis. 来自海洋杆菌EMB8的氯活化嗜盐α-淀粉酶:高效淀粉水解的生产优化和纳米固定化。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-01-18 DOI: 10.1155/2015/859485

Sumit Kumar, S K Khare

{"title":"Chloride Activated Halophilic α-Amylase from Marinobacter sp. EMB8: Production Optimization and Nanoimmobilization for Efficient Starch Hydrolysis.","authors":"Sumit Kumar, S K Khare","doi":"10.1155/2015/859485","DOIUrl":"https://doi.org/10.1155/2015/859485","url":null,"abstract":"Halophiles have been perceived as potential source of novel enzymes in recent years. The interest emanates from their ability to catalyze efficiently under high salt and organic solvents. Present work encompasses production optimization and nanoimmobilization of an α-amylase from moderately halophilic Marinobacter sp. EMB8. Media ingredients and culture conditions were optimized by \"one-at-a-time approach.\" Starch was found to be the best carbon source at 5% (w/v) concentration. Glucose acted as catabolic repressor for amylase production. Salt proved critical for amylase production and maximum production was attained at 5% (w/v) NaCl. Optimization of various culture parameters resulted in 48.0 IU/mL amylase production, a 12-fold increase over that of unoptimized condition (4.0 IU/mL). α-Amylase was immobilized on 3-aminopropyl functionalized silica nanoparticles using glutaraldehyde as cross-linking agent. Optimization of various parameters resulted in 96% immobilization efficiency. Starch hydrolyzing efficiency of immobilized enzyme was comparatively better. Immobilized α-amylase retained 75% of its activity after 5th cycle of repeated use. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2015 ","pages":"859485"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/859485","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33373589","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

An efficient and improved methodology for the screening of industrially valuable xylano-pectino-cellulolytic microbes. 筛选具有工业价值的木聚糖-果胶-纤维素分解微生物的有效改进方法。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-01-26 DOI: 10.1155/2015/725281

Avtar Singh, Amanjot Kaur, Anita Dua, Ritu Mahajan

{"title":"An efficient and improved methodology for the screening of industrially valuable xylano-pectino-cellulolytic microbes.","authors":"Avtar Singh, Amanjot Kaur, Anita Dua, Ritu Mahajan","doi":"10.1155/2015/725281","DOIUrl":"https://doi.org/10.1155/2015/725281","url":null,"abstract":"Xylano-pectino-cellulolytic enzymes are valuable enzymes of the industrial sector. In our earlier study, we have reported a novel and cost effective methodology for the qualitative screening of cellulase-free xylano-pectinolytic microorganisms by replacing the commercial, highly expensive substrates with agricultural residues, but the microorganisms with xylanolytic, pectinolytic, cellulolytic, xylano-pectinolytic, xylano-cellulolytic, pectino-cellulolytic, and xylano-pectino-cellulolytic potential were obtained. The probability of getting the desired combination was low, so efforts were made to further improve this cost effective methodology for obtaining the high yield of the microbes capable of producing desired combination of enzymes. By inclusion of multiple enrichment steps in sequence, using only practically low cost substrates and without any nutrient media till primary screening stage, this improved novel protocol for screening gave only the desired microorganisms with xylano-pectino-cellulolytic activity. Using this rapid, efficient, cost effective, and improved methodology, microbes with required combination of enzymes can be obtained and the probability of getting the desired microorganisms is cent percent. This is the first report presenting the methodology for the isolation of xylano-pectino-cellulolytic positive microorganisms at low cost and consuming less time. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2015 ","pages":"725281"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/725281","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33393832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 23

Effect of Diffusion on Discoloration of Congo Red by Alginate Entrapped Turnip (Brassica rapa) Peroxidase. 海藻酸盐包埋芜菁过氧化物酶扩散对刚果红变色的影响。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-02-05 DOI: 10.1155/2015/575618

Afaf Ahmedi, Mahmoud Abouseoud, Amrane Abdeltif, Couvert Annabelle

{"title":"Effect of Diffusion on Discoloration of Congo Red by Alginate Entrapped Turnip (Brassica rapa) Peroxidase.","authors":"Afaf Ahmedi, Mahmoud Abouseoud, Amrane Abdeltif, Couvert Annabelle","doi":"10.1155/2015/575618","DOIUrl":"https://doi.org/10.1155/2015/575618","url":null,"abstract":"Enzymatic discoloration of the diazo dye, Congo red (CR), by immobilized plant peroxidase from turnip \"Brassica rapa\" is investigated. Partially purified turnip peroxidase (TP) was immobilized by entrapment in spherical particles of calcium alginate and was assayed for the discoloration of aqueous CR solution. Experimental data revealed that pH, reaction time, temperature, colorant, and H2O2 concentration play a significant role in dye degradation. Maximum CR removal was found at pH 2.0, constant temperature of 40°C in the presence of 10 mM H2O2, and 180 mg/L of CR. More than 94% of CR was removed by alginate immobilized TP after 1 h of incubation in a batch process under optimal conditions. About 74% removal efficiency was retained after four recycles. Diffusional limitations in alginate beads such as effectiveness factor η, Thiele modulus Φ, and effective diffusion coefficients (D e ) of Congo red were predicted assuming a first-order biodegradation kinetic. Results showed that intraparticle diffusion resistance has a significant effect on the CR biodegradation rate. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2015 ","pages":"575618"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/575618","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33097579","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Immobilization of Papain on Chitin and Chitosan and Recycling of Soluble Enzyme for Deflocculation of Saccharomyces cerevisiae from Bioethanol Distilleries. 几丁质和壳聚糖对木瓜蛋白酶的固定化及可溶酶的回收用于生物乙醇蒸馏的酿酒酵母菌脱絮。

Enzyme Research Pub Date : 2015-01-01 DOI: 10.1155/2015/573721

Douglas Fernandes Silva, Henrique Rosa, Ana Flavia Azevedo Carvalho, Pedro Oliva-Neto

{"title":"Immobilization of Papain on Chitin and Chitosan and Recycling of Soluble Enzyme for Deflocculation of Saccharomyces cerevisiae from Bioethanol Distilleries.","authors":"Douglas Fernandes Silva, Henrique Rosa, Ana Flavia Azevedo Carvalho, Pedro Oliva-Neto","doi":"10.1155/2015/573721","DOIUrl":"https://doi.org/10.1155/2015/573721","url":null,"abstract":"Yeast flocculation (Saccharomyces cerevisiae) is one of the most important problems in fuel ethanol production. Yeast flocculation causes operational difficulties and increase in the ethanol cost. Proteolytic enzymes can solve this problem since it does not depend on these changes. The recycling of soluble papain and the immobilization of this enzyme on chitin or chitosan were studied. Some cross-linking agents were evaluated in the action of proteolytic activity of papain. The glutaraldehyde (0.1-10% w·v(-1)), polyethyleneimine (0.5% v·v(-1)), and tripolyphosphate (1-10% w·v(-1)) inactivated the enzyme in this range, respectively. Glutaraldehyde inhibited all treatments of papain immobilization. The chitosan cross-linked with TPP in 5 h of reaction showed the yield of active immobilized enzyme of 15.7% and 6.07% in chitosan treated with 0.1% PEI. Although these immobilizations have been possible, these levels have not been enough to cause deflocculation of yeast cells. Free enzyme was efficient for yeast deflocculation in dosages of 3 to 4 g·L(-1). Recycling of soluble papain by centrifugation was effective for 14 cycles with yeast suspension in time perfectly compatible to industrial conditions. The reuse of proteases applied after yeast suspension by additional yeast centrifugation could be an alternative to cost reduction of these enzymes. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2015 ","pages":"573721"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/573721","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33010457","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 19

Improved Enzyme Catalytic Characteristics upon Glutaraldehyde Cross-Linking of Alginate Entrapped Xylanase Isolated from Aspergillus flavus MTCC 9390. 黄曲霉MTCC 9390海藻酸包埋木聚糖酶戊二醛交联催化性能的改进

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-08-12 DOI: 10.1155/2015/210784

Bharat Bhushan, Ajay Pal, Veena Jain

引用次数: 49

Long-Range PCR Amplification of DNA by DNA Polymerase III Holoenzyme from Thermus thermophilus. 嗜热热菌DNA聚合酶III全酶的远程PCR扩增。

Enzyme Research Pub Date : 2015-01-01 Epub Date: 2015-01-19 DOI: 10.1155/2015/837842

Wendy Ribble, Shawn D Kane, James M Bullard

{"title":"Long-Range PCR Amplification of DNA by DNA Polymerase III Holoenzyme from Thermus thermophilus.","authors":"Wendy Ribble, Shawn D Kane, James M Bullard","doi":"10.1155/2015/837842","DOIUrl":"https://doi.org/10.1155/2015/837842","url":null,"abstract":"DNA replication in bacteria is accomplished by a multicomponent replicase, the DNA polymerase III holoenzyme (pol III HE). The three essential components of the pol III HE are the α polymerase, the β sliding clamp processivity factor, and the DnaX clamp-loader complex. We report here the assembly of the functional holoenzyme from Thermus thermophilus (Tth), an extreme thermophile. The minimal holoenzyme capable of DNA synthesis consists of α, β and DnaX (τ and γ), δ and δ' components of the clamp-loader complex. The proteins were each cloned and expressed in a native form. Each component of the system was purified extensively. The minimum holoenzyme from these five purified subunits reassembled is sufficient for rapid and processive DNA synthesis. In an isolated form the α polymerase was found to be unstable at temperatures above 65°C. We were able to increase the thermostability of the pol III HE to 98°C by addition and optimization of various buffers and cosolvents. In the optimized buffer system we show that a replicative polymerase apparatus, Tth pol III HE, is capable of rapid amplification of regions of DNA up to 15,000 base pairs in PCR reactions. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2015 ","pages":"837842"},"PeriodicalIF":0.0,"publicationDate":"2015-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2015/837842","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33060976","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Optimization of Enzymatic Saccharification of Alkali Pretreated Parthenium sp. Using Response Surface Methodology. 利用响应面方法优化碱处理帕氏藻的酶糖化过程

Enzyme Research Pub Date : 2014-01-01 Epub Date: 2014-05-12 DOI: 10.1155/2014/764898

K Pandiyan, Rameshwar Tiwari, Surender Singh, Pawan K S Nain, Sarika Rana, Anju Arora, Shashi B Singh, Lata Nain

{"title":"Optimization of Enzymatic Saccharification of Alkali Pretreated Parthenium sp. Using Response Surface Methodology.","authors":"K Pandiyan, Rameshwar Tiwari, Surender Singh, Pawan K S Nain, Sarika Rana, Anju Arora, Shashi B Singh, Lata Nain","doi":"10.1155/2014/764898","DOIUrl":"10.1155/2014/764898","url":null,"abstract":"Parthenium sp. is a noxious weed which threatens the environment and biodiversity due to its rapid invasion. This lignocellulosic weed was investigated for its potential in biofuel production by subjecting it to mild alkali pretreatment followed by enzymatic saccharification which resulted in significant amount of fermentable sugar yield (76.6%). Optimization of enzymatic hydrolysis variables such as temperature, pH, enzyme, and substrate loading was carried out using central composite design (CCD) in response to surface methodology (RSM) to achieve the maximum saccharification yield. Data obtained from RSM was validated using ANOVA. After the optimization process, a model was proposed with predicted value of 80.08% saccharification yield under optimum conditions which was confirmed by the experimental value of 85.80%. This illustrated a good agreement between predicted and experimental response (saccharification yield). The saccharification yield was enhanced by enzyme loading and reduced by temperature and substrate loading. This study reveals that under optimized condition, sugar yield was significantly increased which was higher than earlier reports and promises the use of Parthenium sp. biomass as a feedstock for bioethanol production. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2014 ","pages":"764898"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4036719/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32400330","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Purification and characterization of melanogenic enzyme tyrosinase from button mushroom. 钮扣菇产黑素酶酪氨酸酶的纯化及特性研究。

Enzyme Research Pub Date : 2014-01-01 Epub Date: 2014-08-14 DOI: 10.1155/2014/120739

Kamal Uddin Zaidi, Ayesha S Ali, Sharique A Ali

{"title":"Purification and characterization of melanogenic enzyme tyrosinase from button mushroom.","authors":"Kamal Uddin Zaidi, Ayesha S Ali, Sharique A Ali","doi":"10.1155/2014/120739","DOIUrl":"https://doi.org/10.1155/2014/120739","url":null,"abstract":"Melanogenesis is a biosynthetic pathway for the formation of the pigment melanin in human skin. A key enzyme, tyrosinase, catalyzes the first and only rate-limiting steps in melanogenesis. Since the discovery of its melanogenic properties, tyrosinase has been in prime focus and microbial sources of the enzyme are sought. Agaricus bisporus widely known as the common edible mushroom, it's taking place in high amounts of proteins, enzyme, carbohydrates, fibers, and low fat contents are frequently cited in the literature in relation to their nutritional value. In the present study tyrosinase from Agaricus bisporus was purified by ammonium sulphate precipitation, dialysis followed by gel filtration chromatography on Sephadex G-100, and ion exchange chromatography on DEAE-Cellulose; the enzyme was purified, 16.36-fold to give 26.6% yield on total activity in the crude extract and final specific activity of 52.19 U/mg. The SDS-PAGE electrophoresis showed a migrating protein band molecular weight of 95 kDa. The purified tyrosinase was optimized and the results revealed that the optimum values are pH 7.0 and temperature 35°C. The highest activity was reported towards its natural substrate, L-DOPA, with an apparent Km value of 0.933 mM. This indicated that tyrosinase purified from Agaricus bisporus is a potential source for medical applications. ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2014 ","pages":"120739"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/120739","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32647428","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 45

Aspergillus 6V4, a Strain Isolated from Manipueira, Produces High Amylases Levels by Using Wheat Bran as a Substrate. 以麦麸为底物制备高淀粉酶的曲霉6V4菌株

Enzyme Research Pub Date : 2014-01-01 Epub Date: 2014-03-02 DOI: 10.1155/2014/725651

Jessyca Dos Reis Celestino, Ana Caroline Duarte, Cláudia Maria de Melo Silva, Hellen Holanda Sena, Maria do Perpétuo Socorro Borges Carriço Ferreira, Neila Hiraishi Mallmann, Natacha Pinheiro Costa Lima, Chanderlei de Castro Tavares, Rodrigo Otávio Silva de Souza, Erica Simplício Souza, João Vicente Braga Souza

{"title":"Aspergillus 6V4, a Strain Isolated from Manipueira, Produces High Amylases Levels by Using Wheat Bran as a Substrate.","authors":"Jessyca Dos Reis Celestino, Ana Caroline Duarte, Cláudia Maria de Melo Silva, Hellen Holanda Sena, Maria do Perpétuo Socorro Borges Carriço Ferreira, Neila Hiraishi Mallmann, Natacha Pinheiro Costa Lima, Chanderlei de Castro Tavares, Rodrigo Otávio Silva de Souza, Erica Simplício Souza, João Vicente Braga Souza","doi":"10.1155/2014/725651","DOIUrl":"https://doi.org/10.1155/2014/725651","url":null,"abstract":"The aim of this study was screening fungi strains, isolated from manipueira (a liquid subproduct obtained from the flour production of Manihot esculenta), for amylases production and investigating production of these enzymes by the strain Aspergillus 6V4. The fungi isolated from manipueira belonged to Ascomycota phylum. The strain Aspergillus 6V4 was the best amylase producer in the screening assay of starch hydrolysis in petri dishes (ASHPD) and in the assay in submerged fermentation (ASbF). The strain Aspergillus 6V4 produced high amylase levels (335 UI/L) using wheat bran infusion as the exclusive substrate and the supplementation of this substrate with peptone decreased the production of this enzyme. The moisture content of 70% was the best condition for the production of Aspergillus 6V4 amylases (385 IU/g) in solid state fermentation (SSF). ","PeriodicalId":11835,"journal":{"name":"Enzyme Research","volume":"2014 ","pages":"725651"},"PeriodicalIF":0.0,"publicationDate":"2014-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1155/2014/725651","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"32255327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 5