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1.
Sci Rep ; 11(1): 10386, 2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34001915

RESUMO

Conservation agriculture (CA)-based practices have been promoted and recouped, as they hold the potential to enhance farm profits besides a consistent improvement in soil properties. A 7 years' field experiment consisting of three crop establishment practices viz., zero-till flatbed (ZTFB), permanent beds (PNB), conventional system (CT) along with the three-nutrient management; nutrient expert-based application (NE), recommended fertilization (RDF), and farmers' fertilizer practice (FFP), was carried out from 2013 to 2020. The CA-based practices (ZTFB/PNB) produced 13.9-17.6% greater maize grain-equivalent yield (MGEY) compared to the CT, while NE and RDF had 10.7-20% greater MGEY than the FFP. PNB and ZTFB gave 28.8% and 24% additional net returns than CT, while NE and RDF had 22.8% and 17.4% greater returns, respectively over FFP. PNB and ZTFB had 2.3-4.1% (0.0-0.20 m soil layers) lower bulk density than the CT. Furthermore, microbial biomass carbon (MBC) increased by 8-19% (0.0-0.50 m soil layers) in ZTFB/PNB over the CT, and by 7.6-11.0% in NE/RDF over FFP. Hence, CA-based crop establishment coupled with the NE or RDF could enhance the yields, farm profits, soil properties of the maize-chickpea rotation, thereby, could sustain production in the long run.

2.
Sci Rep ; 11(1): 1564, 2021 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-33452276

RESUMO

Reduction of excess nutrient application and balanced fertilizer use are the key mitigation options in agriculture. We evaluated Nutrient Expert (NE) tool-based site-specific nutrient management (SSNM) in rice and wheat crops by establishing 1594 side-by-side comparison trials with farmers' fertilization practices (FFP) across the Indo-Gangetic Plains (IGP) of India. We found that NE-based fertilizer management can lower global warming potential (GWP) by about 2.5% in rice, and between 12 and 20% in wheat over FFP. More than 80% of the participating farmers increased their crop yield and farm income by applying the NE-based fertilizer recommendation. We also observed that increased crop yield and reduced fertilizer consumption and associated greenhouse gas (GHG) emissions by using NE was significantly influenced by the crop type, agro-ecology, soil properties and farmers' current level of fertilization. Adoption of NE-based fertilizer recommendation practice in all rice and wheat acreage in India would translate into 13.92 million tonnes (Mt) more rice and wheat production with 1.44 Mt less N fertilizer use, and a reduction in GHG of 5.34 Mt CO2e per year over farmers' current practice. Our study establishes the utility of NE to help implement SSNM in smallholder production systems for increasing crop yields and farmers' income while reducing GHG emissions.

3.
Saudi J Ophthalmol ; 35(4): 350-352, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-35814993

RESUMO

Fat necrosis is a benign non-suppurative inflammation of adipose tissue most commonly occurring in breast, subcutaneous tissue or intraabdominal fat post trauma, surgery, radiation. Transcaruncularorbitotomy provides a safe, rapid, and cosmetically pleasing approach to the medial wall and orbital apex. Intraorbital fat necrosis as its complication has not been documented in literature. The authors report the case of an elderly lady who presented with localized pain, swelling following a transcaruncular orbitotomy for excision biopsy of an orbital vascular mass. The etiology, clinical presentation, intraoperative finding, imaging, and possible mechanisms contributing to the pathogenesis of postsurgical orbital fat necrosis has been suggested.

4.
Int J Biol Macromol ; 164: 3340-3348, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32871119

RESUMO

The bioactive form of thermostable and alkali stable pectinase of Bacillus pumilus dcsr1 is a homodimer of the molecular mass of 60 kDa with a pI of 4.6. The enzyme is optimally active at 50 °C and pH 10.5, and its Michaelis constant (Km), maximum rate of reaction (Vmax), activation energy (Ea), and temperature quotient (Q10) values (for citrus pectin) are 0.29 mg mL-1, 116 µmole mg-1 min-1, 74.73 KJmol-1 and 1.57, respectively. The enzyme has a shelf life of one and a half years at room temperature as well as 4 °C. The activity of the enzyme is stimulated by Mn2+ and Ca2+ and inhibited by Hg+, Cd2+, Co2+, Zn2+, Fe2+, Pb2+, EDTA and urea to a varied extent. The conformational studies of the enzyme revealed a high ß-sheet content in the bioactive dimer, and high α-helix in the inactive monomer. The Circular Dichroism (CD) spectra of the dimer in the presence of inhibitors suggested a marked decrease in ß-sheet, and a significant increase in α-helix, suggesting a key role of ß-sheets in the enzyme catalysis. Based on the end product analysis, the enzyme is an exopolygalacturonase with a unique ability of transglycosylation. When ramie fibers were treated with the enzyme, removal of gummy material (pectin) was visible, confirming its applicability in the degumming process.


Assuntos
Bacillus pumilus/enzimologia , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/isolamento & purificação , Bacillus/enzimologia , Bacillus pumilus/metabolismo , Proteínas de Bactérias/química , Boehmeria/química , Boehmeria/metabolismo , Cisteína Endopeptidases/química , Cisteína Endopeptidases/isolamento & purificação , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Cinética , Peso Molecular , Pectinas/química , Poligalacturonase/química , Polissacarídeo-Liases/química , Especificidade por Substrato , Temperatura
5.
Skeletal Radiol ; 48(1): 163-165, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29876592

RESUMO

The transverse acetabular ligament is an unusual location for ganglion cysts. Only a few cases have been reported in the literature. They can be asymptomatic and represent an incidental finding or can cause an atypical pattern of hip joint/groin pain. We report a case of ganglion cyst arising from the TAL causing entrapment of the anterior branch of the obturator nerve with associated acute denervation of the abductor longus (AL), adductor brevis (AB), and gracilis muscles.


Assuntos
Cistos Glanglionares/complicações , Cistos Glanglionares/diagnóstico por imagem , Síndromes de Compressão Nervosa/diagnóstico por imagem , Síndromes de Compressão Nervosa/etiologia , Nervo Obturador/lesões , Adulto , Cistos Glanglionares/cirurgia , Humanos , Ligamentos Articulares , Masculino , Síndromes de Compressão Nervosa/cirurgia , Radiografia Intervencionista , Sucção , Tomografia Computadorizada por Raios X
6.
Int J Health Care Qual Assur ; 31(1): 76-91, 2018 Feb 12.
Artigo em Inglês | MEDLINE | ID: mdl-29504841

RESUMO

Purpose The purpose of this paper is to appraise Pai and Chary's (2016) conceptual framework for measuring patient-perceived hospital service quality (HSQ). Design/methodology/approach A structured questionnaire was used to obtain data from teaching, public and corporate hospital patients. Several tests were conducted to assess the instrument's reliability and validity. Pai and Chary's (2016) nine dimensions for measuring HSQ were examined in this paper. Findings The tests confirm that Pai and Chary's (2016) conceptual framework is reliable and valid. The study also establishes that the nine dimensions measure HSQ. Practical implications The framework empowers managers to assess service quality in any hospital settings, corporate, public and teaching, using an approach that is superior to the existing HSQ scales. Originality/value This paper helps researchers and practitioners to assess HSQ from patient perspectives in any hospital setting.


Assuntos
Hospitais/normas , Satisfação do Paciente , Percepção , Qualidade da Assistência à Saúde/normas , Inquéritos e Questionários/normas , Adolescente , Adulto , Fatores Etários , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reprodutibilidade dos Testes , Fatores Sexuais , Fatores Socioeconômicos , Adulto Jovem
7.
Int J Biol Macromol ; 108: 185-192, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29174359

RESUMO

In this study, two xylanase genes (GH10 and GH11) derived from Malbranchea cinnamomea, designated as XYN10A_MALCI and XYN11A_MALCI, respectively, were expressed in Pichia pastoris X33. The maximum level of xylanase expression was found to be 24.3U/ml for rXYN10A_MALCI and 573.32U/ml for rXYN11A_MALCI. The purified recombinant rXYN11A_MALCI was stable at 70°C and catalytically active against a variety of substituted (arabinoxylans) as well as unsubstituted xylans. The hydrolytic potential of recombinant xylanases for enhancing the hydrolysis of acid/alkali pretreated lignocellulosics (rice straw and bagasse) by the commercial cellulase Cellic CTec2 was assessed which revealed that both rXYN10A_MALCI and rXYN11A_MALCI act synergistically with commercial cellulases and resulted in 1.54 and 1.58 folds improved hydrolysis of acid treated rice straw and alkali treated rice straw using cocktail comprising of Cellic CTec2 and XYN11A_MALCI (8:2 ratio) when compared to Cellic CTec2 alone at same protein loading rate of (∼5.7mg/g biomass).


Assuntos
Ascomicetos/enzimologia , Ascomicetos/genética , Expressão Gênica , Lignina/química , Xilosidases/genética , Xilosidases/metabolismo , Catálise , Clonagem Molecular , Estabilidade Enzimática , Concentração de Íons de Hidrogênio , Hidrólise , Proteínas Recombinantes , Especificidade por Substrato , Temperatura , Xilosidases/química , Xilosidases/isolamento & purificação
8.
Int J Biol Macromol ; 104(Pt A): 107-116, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28591592

RESUMO

Codon adaptation index (CAI) of a 1263bp long endoglucanase encoding gene from the thermophilic mould Myceliopthora thermophile BJA has been improved from 0.44 to 0.76 by in vitro gene synthesis. The codon optimized endoglucanase gene (Mt-egl) has been constitutively expressed in Pichia pastoris under the regulation of GAP promoter. Recombinant endoglucanase (rMt-egl), purified by size exclusion chromatography, has been confirmed to be a monomeric protein of ∼47kDa. rMt-egl is optimally active at pH 10 and 50°C, displaying stability in broad pH and temperature ranges, with a t1/2 of 60 and 15min at 90 and 100°C, respectively. This retained ∼70% of activity after 3h incubation at pH 5-12. The Km, Vmax, kcat and kcat/Km of rMt-egl were 5mgmL-1, 20µmolesmin-1mg-1, 1.02×103s-1 and 204s-1mg-1mL-1, respectively. Homology modeling and bioinformatics analysis confirmed catalytically important role of glutamate 234 and 344. rMt-egl released high amounts of reducing sugars from wheat bran and corn cobs (421 and 382mgg-1), thus making it a useful biocatalyst for producing bioethanol and fine chemicals from agro-residues.


Assuntos
Agricultura , Celulase/química , Celulase/metabolismo , Sordariales/enzimologia , Açúcares/metabolismo , Temperatura , Sequência de Aminoácidos , Detergentes/farmacologia , Estabilidade Enzimática , Fermentação , Concentração de Íons de Hidrogênio , Resíduos Industriais , Cinética , Metais/farmacologia , Modelos Moleculares , Conformação Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Solventes/farmacologia
9.
Int J Biol Macromol ; 99: 274-281, 2017 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-28238910

RESUMO

For saccharifying starch in one step, a chimeric biocatalyst (Amy-Glu) was generated from engineered α-amylase (Ba-Gt-amy) of Bacillus acidicola and glucoamylase (Glu) gene of Aspergillus niger. In order to join two enzymes, a linker peptide of 25 amino acids was used. Chimeric Amy-Glu was expressed in E. coli. Glu is of 75kDa, while Amy-Glu is of 145kDa. Both Amy-Glu and Glu displayed similar pH profile with good activity in the acidic pH range like that of Ba-Gt-amy with optimum at pH 4.0. All three enzymes (Ba-Gt-amy, Amy-Glu and glucoamylase) exhibited activity in the temperature range between 40 and 70°C with optimum at 60°C. Amy-Glu and Glu have T1/2 of 90 and 70min at 60 and 70°C, respectively. The Km, Vmax and Kcat values of Glu (soluble starch) are 0.34mgmL-1, 606µmolmg-1min-1 and 727s-1, while for Amy-Glu are 0.84mgmL-1, 13,886µmolmg-1min-1 and 4.2×104s-1, respectively. The end product analysis suggested that Amy-Glu retains the activity of both parental enzymes and forms maltodextrins along with glucose as the major products. Amy-Glu saccharifies wheat and corn starches more efficiently than the Ba-Gt-amy and glucoamylase.


Assuntos
Glucana 1,4-alfa-Glucosidase/química , Glucana 1,4-alfa-Glucosidase/genética , Engenharia de Proteínas , Proteínas Recombinantes de Fusão/química , Proteínas Recombinantes de Fusão/genética , Amido/metabolismo , alfa-Amilases/genética , Aspergillus niger/enzimologia , Bacillus/enzimologia , Biocatálise , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Glucana 1,4-alfa-Glucosidase/metabolismo , Hidrólise , Proteínas Recombinantes de Fusão/metabolismo
10.
Bioprocess Biosyst Eng ; 40(5): 651-662, 2017 May.
Artigo em Inglês | MEDLINE | ID: mdl-28039507

RESUMO

The recombinant alkalistable and moderately thermostable bifunctional endoglucanase gene (BhCell-Xyl) of polyextremophilic bacterium Bacillus halodurans TSLV1 has been expressed in Pichia pastoris under constitutive GAP as well as inducible AOX promoters. A higher titre of recombinant BhCell-Xyl was attained after induction (4.8 U mL-1) as compared to that of the constitutive production (2.1 U mL-1). The recombinant P. pastoris strains integrated two copies of BhCell-Xyl under AOX and GAP promoters. The pure recombinant BhCell-Xyl is a glycoprotein of 66 kDa, which is optimally active at 60 °C and pH 6.0 and 8.0. Glycosylated BhCell-Xyl exhibits higher thermostability than that of the native enzyme. The analysis of amino acids of BhCell-Xyl revealed that multiple factors are responsible for its thermostability. Kinetics and in silico analysis of the enzyme suggested that BhCell-Xyl has one active site for both endocellulase and endoxylanase activities. The BhCell-Xyl possesses a carbohydrate binding domain and saccharifies lignocellulosic agro-residues to xylo-oligosaccharides and cello-oligosaccharides, suggesting its potential application in generating fermentable sugars from renewable agro-residues for biofuel and fine chemical industries.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/química , Celulase/química , Glucuronatos/química , Lignina/química , Oligossacarídeos/química , Bacillus/genética , Proteínas de Bactérias/genética , Celulase/genética , Estabilidade Enzimática , Temperatura Alta , Concentração de Íons de Hidrogênio , Proteínas Recombinantes/química , Proteínas Recombinantes/genética
11.
Appl Microbiol Biotechnol ; 101(6): 2357-2369, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27924363

RESUMO

The 3'-deleted amylopullulanase gene from the extreme thermophile Geobacillus thermoleovorans (Gt-apuΔC) was expressed extracellularly in Pichia pastoris under both methanol-inducible AOX1 and constitutive GAP promoters. The expression of the gene (Gt-apuΔC) was higher under GAP promoter (36.2 U ml-1, α-amylase; 33.5 U ml-1, pullulanase) than that under AOX1 promoter (32.5 and 28.6 U ml-1). The heavily glycosylated Gt-apuΔC from the recombinant P. pastoris displays higher substrate specificity, thermal stability and starch saccharification efficiency than that expressed in Escherichia coli. The enzyme hydrolyses maltotriose and maltotetraose unlike that expressed in E. coli. The enzyme action on wheat bran liberates maltose and glucose without detectable amount(s) of maltooligosaccharides. The sugars released from wheat bran (glucose and maltose) could be fractionated by ultrafiltration, as confirmed by TLC and HPLC analysis. This is the first report on the production of recombinant amylopullulanase extracellularly in P. pastoris.


Assuntos
Proteínas de Bactérias/química , Geobacillus/química , Glucose/química , Glicosídeo Hidrolases/química , Maltose/química , Pichia/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Fibras na Dieta/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Geobacillus/enzimologia , Glucose/metabolismo , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Glicosilação , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Maltose/metabolismo , Pichia/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade da Espécie , Especificidade por Substrato
12.
Biotechnol Prog ; 33(1): 70-80, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27689686

RESUMO

Chitinase from the thermophilic mould Myceliopthora thermophila BJA (MtChit) is an acid tolerant, thermostable and organic solvent stable biocatalyst which does not require any metal ions for its activity. To produce high enzyme titres, reduce fermentation time and overcome the need for induction, this enzyme has been heterologously expressed under GAP promoter in the GRAS yeast, Pichia pastoris. The production medium supplemented with the permeabilizing agent Tween-20 supported two-fold higher rMtChit production (5.5 × 103 U L-1 ). The consensus sequences S(132)xG(133)G(134) and D(168)xxD(171)xD(173)xE(175) in the enzyme have been found to represent the substrate binding and catalytic sites, respectively. The rMtChit, purified to homogeneity by a two-step purification strategy, is a monomeric glycoprotein of ∼48 kDa, which is optimally active at 55°C and pH 5.0. The enzyme is thermostable with t1/2 values of 113 and 48 min at 65 and 75°C, respectively. Kinetic parameters Km , Vmax , kcat , and kcat /Km of the enzyme are 4.655 mg mL-1 , 34.246 nmol mg-1  s-1 , 3.425 × 106 min-1 , and 1.36 × 10-6 mg mL-1  min-1 , respectively. rMtChit is an unique exochitinase, since its action on chitin liberates N-acetylglucosamine NAG. The enzyme inhibits the growth of phytopathogenic fungi like Fusarium oxysporum and Curvularia lunata, therefore, this finds application as biofungicide at high temperatures during summer in tropics. © 2016 American Institute of Chemical Engineers Biotechnol. Prog., 33:70-80, 2017.


Assuntos
Acetilglucosamina/biossíntese , Fungos/crescimento & desenvolvimento , Hexosaminidases/biossíntese , Proteínas Recombinantes/biossíntese , Quitina/biossíntese , Quitina/metabolismo , Fermentação , Fungos/patogenicidade , Hexosaminidases/genética , Cinética , Pichia/genética , Proteínas Recombinantes/genética , Sordariales/enzimologia , Sordariales/genética , Especificidade por Substrato
13.
Int J Biol Macromol ; 94(Pt A): 36-44, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27697488

RESUMO

Thermophilc mold Sporotrichum thermophile secretes an acidstable and thermostable phytase, which finds application as a food and feed additive because of its adequate thermostability, acid stability, protease insensitivity and broad substrate spectrum. Low extracellular phytase production by the mold is a major bottleneck for its application on a commercial scale. We have successfully overcome this problem by constitutive secretary expression of codon optimized rStPhy under glyceraldehyde phosphate dehydrogenase (GAP) promoter in Pichia pastoris. A ∼41-fold improvement in rStPhy production has been achieved. Circular Dichroism (CD) spectra revealed that rStPhy is composed of 26.65% α-helices, 5.26% ß-sheets and 68.09% random coils at pH 5.0 and 60°C, the optima for the enzyme activity. The melting temperature (Tm) of the enzyme is ∼73°C. The 3D structure of rStPhy displayed characteristic signature sequences (RHGXRXP and HD) of HAP phytase. The catalytically important amino acids (Arg74, His75, Arg78, His368 and Asp369) were identified by docking and site directed mutagenesis. Fluorescence quenching by N-bromosuccinimide (NBS) and CsCl exposed tryptophan residues surrounded by negative charges, which play a key role in maintaining structural integrity of rStPhy.


Assuntos
6-Fitase/biossíntese , Proteínas Fúngicas/biossíntese , 6-Fitase/química , 6-Fitase/genética , Estabilidade Enzimática , Proteínas Fúngicas/química , Proteínas Fúngicas/genética , Expressão Gênica , Temperatura Alta , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Simulação de Acoplamento Molecular , Mutagênese Sítio-Dirigida , Pichia , Regiões Promotoras Genéticas , Ligação Proteica , Estrutura Secundária de Proteína , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Sporothrix/enzimologia
14.
Appl Biochem Biotechnol ; 181(4): 1283-1303, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-27787770

RESUMO

Streptomyces badius DB-1 produces α-amylase extracellularly, and its production was enhanced 5.1-fold (from 9.47 ± 0.51 to 48.23 ± 1.45 U mL-1) due to optimization by one-variable-at-a-time and statistical approaches. Soluble starch emerged as the most influential factor that strongly affected enzyme production. The purified enzyme is a monomer with a molecular mass of ~57 kDa and optimally active at 50 °C and pH 6.0. The enzyme hydrolyzes soluble as well as raw starches into simpler sugars with a high proportion (>40.0 %) of maltotetraose. It is optimally active at moderate temperature and generates maltooligosaccharides from starch, thus, useful as an antistale in bread making. It also plays a role in increasing the formation of maltooligosaccharides due to transglycosylation activity, thus, finds application in functional foods. This is the first report on the production of raw starch-digesting α-amylase by S. badius with transglycosylation activity.


Assuntos
Biotecnologia/métodos , Amido/metabolismo , Streptomyces/enzimologia , alfa-Amilases/metabolismo , Técnicas de Cultura Celular por Lotes , Biotecnologia/economia , Pão/microbiologia , Análise Custo-Benefício , Estabilidade Enzimática , Fermentação , Glicosilação , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Maltose/química , Metais/farmacologia , Peso Molecular , Oligossacarídeos/biossíntese , Oligossacarídeos/química , Amido/química , Estatística como Assunto , Streptomyces/crescimento & desenvolvimento , Streptomyces/isolamento & purificação , Temperatura , alfa-Amilases/biossíntese , alfa-Amilases/química
15.
Extremophiles ; 20(6): 831-842, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27558695

RESUMO

The thermostable bifunctional CMCase and xylanase encoding gene (rBhcell-xyl) from Bacillus halodurans TSLV1 has been expressed in Escherichia coli. The recombinant E. coli produced rBhcell-xyl (CMCase 2272 and 910 U L-1 xylanase). The rBhcell-xyl is a ~62-kDa monomeric protein with temperature and pH optima of 60 °C and 6.0 with T1/2 of 7.0 and 3.5 h at 80 °C for CMCase and xylanase, respectively. The apparent K m values (CMC and Birchwood xylan) are 3.8 and 3.2 mg mL-1. The catalytic efficiency (k cat/K m ) values of xylanase and CMCase are 657 and 171 mL mg-1 min-1, respectively. End-product analysis confirmed that rBhcell-xyl is a unique endo-acting enzyme with exoglucanase activity. The rBhcell-xyl is a GH5 family enzyme possessing single catalytic module and carbohydrate binding module. The action of rBhcell-xyl on corn cobs and wheat bran liberated reducing sugars, which can be fermented to bioethanol and fine biochemicals.


Assuntos
Bacillus/enzimologia , Proteínas de Bactérias/genética , Celulases/genética , Microbiologia Industrial , Xilosidases/genética , Bacillus/genética , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Celulases/química , Celulases/metabolismo , Produtos Agrícolas , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Xilosidases/química , Xilosidases/metabolismo
16.
Mol Biotechnol ; 58(11): 707-717, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-27568390

RESUMO

The recombinant acidstable α-amylase (Ba-amy) of acidophilic bacterium Bacillus acidicola TSAS1 has been produced extracellularly using a combination of cloning (E. coli and P. pastoris) and physico-chemical treatment strategies. A total of 150,000 U/L of Ba-amy were attained under constitutive promoter in P. pastoris, which is 15-fold higher than that of the wild strain B. acidicola (10,000 U/L). The recombinant P. pastoris integrated two copies of Ba-amy under GAP promoter. The pure Ba-amy expressed in P. pastoris is a glycoprotein of 66 kDa, which is optimally active at pH 4.0 and 60 °C with a T 1/2 of 25 min at 70 °C. The K m, V max and K cat values of the recombinant Ba-amy are 1.66 mg/mL, 53.6 µmol/mg/min and 106.8/s, respectively. The enzyme generates maltose (30 %), maltotriose (20 %) and other higher maltooligosaccharides from starch, thus, useful in baking as an antistale. This is the first report on the optimization of extracellular production of recombinant acidic α-amylase of an acidophilic bacterium.


Assuntos
Bacillus/enzimologia , Cálcio/metabolismo , Oligossacarídeos/biossíntese , alfa-Amilases/genética , alfa-Amilases/metabolismo , Bacillus/genética , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Peso Molecular , Pichia/genética , Regiões Promotoras Genéticas , Proteínas Recombinantes/metabolismo , Amido/metabolismo , Temperatura
17.
Appl Microbiol Biotechnol ; 100(13): 5661-79, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27142298

RESUMO

Pullulan hydrolyzing enzymes are endoacting, classified based on the substrate specificity and hydrolysis products as pullulanases (type I and II) and pullulan hydrolases (type I, II and III). Pullulanases and pullulan hydrolase type I are produced by bacteria and archaea. Among bacteria, many mesophilic, thermophilic and hyperthermophilic bacteria produce pullulanases and neopullulanases. While pullulan hydrolase type II and type III are produced by fungi and archaea, respectively. These are multi-domain proteins with three conserved catalytic acidic residues of the glycosyl hydrolases. The recent advances in molecular biology and protein engineering via mutagenesis and truncation led to improvement in thermostability, catalytic activity and substrate specificity. Pullulanases are debranching enzymes, which are widely employed in starch saccharification that minimizes the use of glucoamylase (approx. 50 %) and reduces the total reaction time of the industrial starch conversion process. The thermostable amylopullulanases are useful in one-step starch liquefaction and saccharification, which replaces amylolytic enzymes like α-amylase and glucoamylase, thus resulting in the reduction in the cost of sugar production. The enzymes also find application in making resistant starches and as an antistale in bread making. Panose and isopanose containing syrups are useful as prebiotics, while panose has also been reported to display anticarcinogenic activity. This review focuses on the distinguishing features of these enzymes based on the analysis of amino acid sequences and domain structure, besides highlighting recent advances in the molecular biology and protein engineering for enhancing their thermostability, catalytic activity and substrate specificity. This review also briefly summarizes the potential applications of pullulanases and pullulan hydrolases.


Assuntos
Archaea/enzimologia , Bactérias/enzimologia , Glucanos/metabolismo , Glicosídeo Hidrolases/química , Hidrolases/química , Engenharia de Proteínas , Archaea/química , Archaea/genética , Bactérias/química , Bactérias/genética , Biocatálise , Estabilidade Enzimática , Glicosídeo Hidrolases/genética , Glicosídeo Hidrolases/metabolismo , Hidrolases/genética , Hidrolases/metabolismo , Especificidade por Substrato
18.
Int J Biol Macromol ; 89: 659-68, 2016 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27174908

RESUMO

Carbonic anhydrase (CA) is a biocatalyst that catalyzes the hydration of CO2 to bicarbonate and protons, thus useful in mitigating green house effect by sequestering CO2 from various point sources. An alkalistable and moderately thermostable α- carbonic anhydrase encoding gene (BhCA) from Bacillus halodurans TSLV1 has been cloned and expressed in Escherichia coli. A 31.4-fold enhancement in CA production was achieved due to cloning and expression in E. coli. About 50% of the CA produced was secreted when recombinant E. coli with BhCA-pET22b was cultivated in a medium with EDTA and lysozyme because of the efficient pelB leader sequence. rBhCA is a ∼75kDa homodimeric protein with a Tm of 72°C and T1/2 values of 66 and 24min at 50 and 60°C, respectively. SDM analysis revealed that H137, H139, H156 and H110 present in the active site play an important role in catalysis. Mineralization of CO2 using rBhCA led to the accelerated precipitation of CaCO3 in calcite form. rBhCA also functions as an efficient virtual peroxidase when Zn(2+) is substituted with Mn(2+).


Assuntos
Bacillus/enzimologia , Anidrases Carbônicas/química , Proteínas Recombinantes/química , Bacillus/química , Carbonato de Cálcio/química , Dióxido de Carbono/química , Anidrases Carbônicas/genética , Anidrases Carbônicas/metabolismo , Catálise , Domínio Catalítico , Escherichia coli/genética , Regulação Enzimológica da Expressão Gênica , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo
19.
Bioprocess Biosyst Eng ; 39(10): 1515-25, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-27215773

RESUMO

Carbonic anhydrase (CA) was produced from the polyextremophilic (halotolerant, moderately thermophilic and alkaliphilic) bacterium Aeribacillus pallidus TSHB1 isolated from water and sediment samples of Choti Anhoni hot spring of Pipariya, Madhya Pradesh (India), is being reported to be suitable for carbon sequestration. Growth and CA production were inhibited at higher CO2 concentration (5-10 %). Under optimized culture variables (tryptone 0.8 %, yeast extract 0.08 %, glucose 1 %, micronutrient solution 1 %, inoculums size 1.10 %, agitation 200 at pH 8, and temperature 55 °C), 3.7-fold higher CA production was attained than that under unoptimized conditions. The zymogram analysis of the partially purified CA revealed an activity band corresponding to 32 kDa. The enzyme is stable in the pH range between 8.0 and 11.0 with T 1/2 of 40, 15, and 8 min at 60, 70, and 80 °C, respectively. The CA of A. pallidus displayed a marked enhancement in the rate of CaCO3 precipitation from aqueous CO2. The CA-aided formation of CaCO3 was 42.5 mg mg(-1) protein. Scanning electron microscopy revealed the formation of rhomboid calcite crystals. This is the first report on the production and applicability of CA from the polyextremophilic A. pallidus in carbon sequestration.


Assuntos
Bacillaceae/enzimologia , Proteínas de Bactérias/química , Materiais Biomiméticos/química , Anidrases Carbônicas/química , Estabilidade Enzimática
20.
Int J Health Care Qual Assur ; 29(3): 300-23, 2016 Apr 18.
Artigo em Inglês | MEDLINE | ID: mdl-27120508

RESUMO

Purpose - Although measuring healthcare service quality is not a new phenomenon, the instruments used to measure are timeworn. With the shift in focus to patient centric processes in hospitals and recognizing healthcare to be different compared to other services, service quality measurement needs to be tuned specifically to healthcare. The purpose of this paper is to design a conceptual framework for measuring patient perceived hospital service quality (HSQ), based on existing service quality literature. Design/methodology/approach - Using HSQ theories, expanding existing healthcare service models and literature, a conceptual framework is proposed to measure HSQ. The paper outlines patient perceived service quality dimensions. Findings - An instrument for measuring HSQ dimensions is developed and compared with other service quality measuring instruments. The latest dimensions are in line with previous studies, but a relationship dimension is added. Practical implications - The framework empowers managers to assess healthcare quality in corporate, public and teaching hospitals. Originality/value - The paper helps academics and practitioners to assess HSQ from a patient perspective.


Assuntos
Administração Hospitalar/normas , Satisfação do Paciente , Indicadores de Qualidade em Assistência à Saúde/organização & administração , Inquéritos e Questionários/normas , Comunicação , Meio Ambiente , Pessoal de Saúde/normas , Humanos , Avaliação de Processos e Resultados em Cuidados de Saúde , Percepção , Relações Profissional-Paciente , Qualidade da Assistência à Saúde , Confiança
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