RESUMO
BACKGROUND: Whether patients with moderate left atrioventricular valve regurgitation (LAVVR) after surgical repair of complete atrioventricular septal defect (CAVSD) should be observed or undergo reoperation remains unclear. METHODS: Moderate LAVVR was diagnosed in 87 of 220 patients who underwent CAVSD repair: 47 during the initial hospital stay and 40 after a median of 7 months (interquartile range, 2-18 months) after the initial operation. RESULTS: Of these 87 patients who had moderate LAVVR, 15 died, for an overall mortality of 17%. The regurgitation became severe in 39 patients (45%) within a median of 2 months (interquartile range, 1-7 months) leading to 33 reoperations and 10 deaths. In 23 of 87 patients (26%), regurgitation remained at a moderate level over a median follow-up period of 8 months (interquartile range, 1-48 months). In 25 of 87 patients (29%), the regurgitation decreased to mild after a median of 9 months (interquartile range, 5-19 months). The only independent risk factor for increased severity of regurgitation and reoperation was the echocardiographic appearance of the jet centered around the cleft rather than central at the time of diagnosis of moderate regurgitation (odds ratio, 3.5; 95% CI, 1.5-9.0; P = .007). CONCLUSIONS: Moderate LAVVR after CAVSD repair is often linked to death and reoperation, but regurgitation remains stable in one-quarter of patients and improves in one-third. The deterioration usually occurs within the first year after surgery. The initial observation of patients with residual or new moderate regurgitation for up to 1 year or until further deterioration seems reasonable, as long as the regurgitation is centrally located.
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BACKGROUND: There are limited data on outcomes after implantation of the CardioCel 3D 60° patch in great vessel repair. After anecdotally witnessing an increase in negative outcomes, we reviewed our experience using this patch in our neonate and infant patients undergoing aortic arch repair. METHODS: Aortic arch repair with implantation of the CardioCel 3D 60° patch was performed in 24 patients between July 2018 and July 2021. Dominant cardiac morphologies were hypoplastic left heart syndrome (66%), atrioventricular canal defects (13%), and other (21%). Median age at implantation was 44 days (interquartile range [IQR], 6-112 days). Recurrent obstruction was defined as the need for reoperation or catheter intervention or recurrent peak pressure gradient of descending aorta ≥25 mm Hg on echocardiography. RESULTS: Five deaths occurred after a median of 217 days (IQR, 69-239 days). Twelve patients (50%) had recurrent obstruction. Three patients (13%) required redo aortic arch operation after a median of 148 days (IQR, 128-193 day), with extensive fibrous coating of the patch interior causing obstruction. Eleven patients (46%) required at least 1 balloon angioplasty on their aorta after a median of 102 days (IQR, 83-130 days) after repair, and 3 needed >1 catheter intervention. The estimated probability of having recurrent obstruction was 85% at 6 months and 71% at the 1-year follow (P = .06). CONCLUSIONS: Recurrent aortic obstruction occurred in half of our patients shortly after repair. The use of the CardioCel 3D 60° patch for aortic arch reconstruction in neonates and infants should be reevaluated.
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Background: We sought to evaluate the outcomes in patients who underwent the arterial switch operation (ASO) over a 20-year period at a single institution. Methods: The current study is a retrospective review of 180 consecutive patients who underwent the ASO for biventricular surgical correction of dextro-transposition of the great arteries (d-TGA) between 2002 and 2022. Results: Among 180 patients, 121 had TGA-intact ventricular septum, 47 had TGA-ventricular septal defect and 12 had Taussig-Bing Anomaly (TBA). The median follow-up time was 6.7 years (interquartile range: 3.9-8.7 years). There were five early (2.8%) and one late (0.6%) mortality. Survival was 96.6% at one year and beyond. Reoperations were performed in 31 patients (17%). Taussig Bing Anomaly was found to increase the risk of reoperation by 17 times (P < .0001). A total of 37 (21%) patients underwent 53 reinterventions (14 surgical procedures, 39 catheter interventions) specifically addressing pulmonary artery (PA) stenosis. Freedom from PA reintervention was 97%, 87%, 70%, and 55% at 1, 5, 10, and 15 years, respectively. By bivariable analysis, TBA (P = .003, odds ratio [OR]: 6.4, 95% confidence interval [CI]: 1.9-21.7), mild PA stenosis at discharge (P ≤ .001, OR: 6.1, 95% CI: 2.7-13.6), and moderate or severe PA stenosis at discharge (P ≤ .001, OR: 12.7, 95% CI: 5-32.2) were identified as predictors of reintervention on PA. In the last follow-up of 174 survivors, 24 patients (14%) had moderate or greater PA stenosis, two (1%) had moderate neoaortic valve regurgitation, and 168 were New York Heart Association status I. Conclusions: Our results demonstrated excellent survival and functional status following the ASO for d-TGA; however, patients remain subject to frequent reinterventions especially on the pulmonary arteries.
Assuntos
Transposição das Grandes Artérias , Artéria Pulmonar , Reoperação , Transposição dos Grandes Vasos , Humanos , Estudos Retrospectivos , Masculino , Feminino , Transposição dos Grandes Vasos/cirurgia , Transposição dos Grandes Vasos/mortalidade , Reoperação/estatística & dados numéricos , Transposição das Grandes Artérias/mortalidade , Artéria Pulmonar/cirurgia , Lactente , Taxa de Sobrevida , Recém-Nascido , Resultado do Tratamento , Seguimentos , Complicações Pós-Operatórias/mortalidade , Pré-Escolar , CriançaRESUMO
BACKGROUND: Although some previous studies have reported the impact of cultural factors on individuals' cognition and decision making, a shortage of research has led to this comparison study for Chinese and Korean elderly, a growing population with depression. This study aimed to explore depression levels in Chinese and South Korean elderly individuals by focusing on testing the generalizability of the Geriatric Depression Scale (GDS). METHODS: The data of 493 community-dwelling Chinese and Korean elderly individuals over the age of 60 years were used to examine GDS. To test the dimensionality, item quality, and reliability of the GDS, the item response theory, Rasch analysis was performed. The detection of differential item functioning (DIF) of the GDS between the two countries was determined by performing a hybrid ordinal logistic regression. RESULTS: The four-dimensional framework of the GDS, categorized into agitation, cognitive concerns, dysphoria, and vigor/withdrawal was fit for measuring depression levels in Chinese and Korean elderly individuals. In addition, good item quality and reliability of the GDS indicate that almost all items in this scale contribute to measuring the intended trait. Meanwhile, 18 out of 28 items of the GDS were detected as country-related DIF with five items having a large effect size. CONCLUSIONS: Although China and Korea are close geographically and culturally, the item bias shown by severe country-related DIF implies that different cultural backgrounds impact how the elderly interpret GDS items. The cultural issues related to the specific DIF items, the implication to accuracy of individual scores estimation, and the optimal decision to treat individuals were discussed.
Assuntos
Depressão , Vida Independente , Idoso , China/epidemiologia , Depressão/diagnóstico , Depressão/epidemiologia , Avaliação Geriátrica , Humanos , Escalas de Graduação Psiquiátrica , Reprodutibilidade dos Testes , República da Coreia/epidemiologiaRESUMO
Objectives: Emerging studies found the potential effects of acupuncture for treating chronic pain and mental disorders, namely, depressive and anxiety disorders. Acupuncture is widely used for treating culture-related anger syndrome, Hwa-byung. This pilot trial aimed to investigate the feasibility of a clinical trial testing acupuncture for the psychosomatic symptoms of Hwa-byung. Methods: A total of 26 patients with Hwa-byung planned to be randomly assigned to the acupuncture or sham acupuncture groups. About 10 treatment sessions were applied over 4 weeks. The 100-mm visual analog scale was used to measure the six major Hwa-byung symptoms: stuffiness in the chest, heat sensations, pushing-up in the chest, feeling a mass in the throat, feelings of unfairness, and hard feelings. The criteria for assessing the success of this pilot trial were defined as improvement in three or more of the six Hwa-byung symptoms after treatment, with an effect size >0.2. Results: A total of 15 patients were finally included and randomly assigned to the acupuncture group (n = 7) or the sham acupuncture group (n = 8). After 10 treatment sessions, the Cohen's d effect sizes for acupuncture compared to sham acupuncture were >0.2 for each one of the six major Hwa-byung symptoms, which met our a priori criteria for success. Also, the effect size for the somatic symptoms of "stuffiness in the chest" was 0.81 (95% CI -0.40, 2.20), referring to a large effect size. Conclusions: Our results suggest that acupuncture treatment would be regarded as an acceptable intervention for a full-scale study of psychosomatic symptoms in patients with Hwa-byung. Trial Registration: cris.nih.go.kr, identifier: KCT0001732.
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Psychological anxiety and physiological stress hormone management is closely related to an athlete's performance, especially in shooting competitions. Thus, we aimed to investigate the changes in saliva stress hormones according to anxiety scores of Korean elite shooters immediately before a shooting competition. Seventy-two Korean national shooting athletes (Rifle = 62, Pistol = 8, Shotgun = 2) were recruited for the present study. The physiological stress hormones were assessed based on cortisol and immunoglobulin A level in saliva. The psychological stress was assessed based on Beck Anxiety Inventory (BAI) questionnaire. Cortisol concentration and cortisol secretion rate were significant higher in severe anxiety group. Secretory immunoglobulin A (SIgA) concentration and SIgA secretion rate did not significant different in among the groups. A positive correlation was found between BAI score and cortisol concentration. These findings provide preliminary evidence indicating that psychological anxiety affects physiological stress and therefore may have a negative effect on athletes' performance. Thus, research is needed to develop a strategy to reduce physiological stress in these athletes.
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Poly(lactic acid) (PLA) nanocomposites were synthesized by a solution blending and coagulation method using alkylated graphene oxide (AGO) as a reinforcing agent. Turbiscan confirmed that the alkylation of GO led to enhanced compatibility between the matrix and the filler. The improved dispersity of the filler resulted in superior interfacial adhesion between the PLA chains and AGO basal plane, leading to enhanced mechanical and rheological properties compared to neat PLA. The tensile strength and elongation at break, i.e., ductility, increased by 38% and 42%, respectively, at the same filler content nanocomposite (PLA/AGO 1 wt %) compared to nonfiller PLA. Rheological analysis of the nanocomposites in the molten state of the samples was performed to understand the filler network formed inside the matrix. The storage modulus increased significantly from PLA/AGO 0.5 wt % (9.6 Pa) to PLA/AGO 1.0 wt % (908 Pa). This indicates a percolation threshold between the two filler contents. A steady shear test was performed to examine the melt flow characteristics of PLA/AGO nanocomposites at 170 °C, and the viscosity was predicted using the Carreau-Yasuda model.
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The enzyme from halophilic microorganisms often has unique properties such as organic-solvent-tolerance. In this study, a novel organic-solvent-tolerant α-amylase gene was cloned from the mild halophile Exiguobacterium sp. DAU5. The open reading frame (ORF) of the enzyme consisted of 1,545 bp and encoded 514 amino acids, the primary sequence revealed that it belongs to the glycoside hydrolase (GH) family 13. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) showed an AmyH monomer of 57 kDa. The enzyme exhibited maximal activity at 40 °C in pH 8.5 glycine-NaOH buffer, and the activity was strongly inhibited by Zn(2+), Cu(2+), and Fe(2+). The α-amylase AmyH exhibited high hydrolysis activity toward soluble starch, and the major hydrolysis products were maltose, maltotriose, and maltopentaose; the AmyH could not efficiently hydrolyze oligosaccharides smaller than maltoheptaose, nor could it act on the ß-1,4 or α-1,6 glucosidic bonds in xylan or pullulan, respectively. In addition, the α-amylase exhibited better tolerance to organic solvents, as it was stable in the presence of dimethylsulfoxide (DMSO), methanol, ethanol, and acetone. Base on all of these results, the enzyme could be useful for practical application in the bakery industry and in biotechnological processes that occur in the presence of organic solvents.
Assuntos
Bacillales/enzimologia , Compostos Orgânicos/farmacologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Solventes/farmacologia , alfa-Amilases/genética , alfa-Amilases/metabolismo , Bacillales/genética , Clonagem Molecular , Estabilidade Enzimática , Escherichia coli/genética , Expressão Gênica , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Metais/farmacologia , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Solubilidade , Amido/química , Amido/metabolismo , Temperatura , alfa-Amilases/química , alfa-Amilases/isolamento & purificaçãoRESUMO
The bacterial strain Paenibacillus xylanilyticus KJ-03 was isolated from a sample of soil used for cultivating Amorphophallus konjac. The cellulase gene, cel5A was cloned using fosmid library and expressed in Escherichia coli BL21 (trxB). The cel5A gene consists of a 1,743 bp open reading frame and encodes 581 amino acids of a protein. Cel5A contains N-terminal signal peptide, a catalytic domain of glycosyl hydrolase family 5, and DUF291 domain with unknown function. The recombinant cellulase was purified by Ni-affinity chromatography. The cellulase activity of Cel5A was detected in clear band with a molecular weight of 64 kDa by zymogram active staining. The maximum activity of the purified enzyme was displayed at a temperature of 40 °C and pH 6.0 when carboxymethyl cellulose was used as a substrate. It has 44% of its maximum activity at 70 °C and retained 66% of its original activity at 45 °C for 1 h. The purified cellulase hydrolyzed avicel, CMC, filter paper, xylan, and 4-methylumbelliferyl ß-D-cellobiose, but no activity was detected against p-nitrophenyl ß-D-glucoside. The end products of the hydrolysis of cellotetraose and cellopentaose by Cel5A were detected by thin layer chromatography, while enzyme did not hydrolyze cellobiose and cellotriose.
Assuntos
Celulase/isolamento & purificação , Celulase/metabolismo , Paenibacillus/enzimologia , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Celulase/química , Celulase/genética , Cromatografia de Afinidade , Cromatografia em Camada Fina , Clonagem Molecular , Escherichia coli/química , Escherichia coli/genética , Escherichia coli/metabolismo , Concentração de Íons de Hidrogênio , Hidrólise , Paenibacillus/genética , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Especificidade por SubstratoRESUMO
The bacteria with hydrolysis activity to glucomannan were isolated from the rhizosphere of Amorphophallus konjac through enrichment cultivation. One strain with strong activity in degrading glucomannan was identified preliminarily as Paenibacillus azotofixans YUPP-5 according to the sequence analysis of 16S rDNA. This strain is able to hydrolyze many polysaccharide with ß-1,4 linkage, including glucomannan, galactomannan, xylan, carboxymethyl cellulose, and chitin. One hydrolytic enzyme band of approximately 70 kDa was examined from the supernatants of YUPP-5 by using zymogram with mixture polysaccharides as substrate. The encoding gene had an open reading frame of 2157 bp, which deduced cyclodextrin glycosyltransferase (CGTase), including 718 amino acids with a signal peptide in the N-terminal region. When the gene was expressed in Escherichia coli BL21, the recombinant CGTase exhibited strong activity in degrading polysaccharides with ß-1,4 linkage, and in forming cyclodextrin by using carboxymethyl cellulose as substrate. This CGTase exhibited some new functions. Finally, the hydrolytic oligosaccharides from galactomannan or glucomannan were detected by thin layer chromatography. Pentasaccharide, tetrasaccharide, trisaccharide, and disaccharide could be examined as reaction time went on.
Assuntos
Glucosiltransferases/metabolismo , Paenibacillus/enzimologia , Polissacarídeos/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sequência de Bases , Biotecnologia , Clonagem Molecular , Meios de Cultura , Ciclodextrinas/metabolismo , Estabilidade Enzimática , Escherichia coli/genética , Escherichia coli/metabolismo , Glucosiltransferases/química , Glucosiltransferases/genética , Glucosiltransferases/isolamento & purificação , Hidrólise , Mananas/química , Mananas/metabolismo , Dados de Sequência Molecular , Paenibacillus/classificação , Paenibacillus/genética , Paenibacillus/crescimento & desenvolvimento , Polissacarídeos/química , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análise de Sequência de DNA , Especificidade por SubstratoRESUMO
A gene encoding a beta-1,3-1,4-glucanase (CelA) belonging to family 5 of glycoside hydrolases was cloned and sequenced from the Bacillus subtilis A8-8. The open-reading-frame of celA comprised 1499 base pairs and the enzyme was composed of 500 amino acids with a molecular mass of 55 kDa. The recombinant beta-1,3-1,4 glucanase was purified by GST-fusion purification system. The pH and temperature optima of the enzyme were 8.0 and 60 degrees C, respectively. The enzyme was stable within pH 6.0-9.0. It was stable up to 60 degrees C and retained 30% of its original activity at 70 degrees C for 60 min. It hydrolyzed lichenan, CMC, xylan, laminarin, avicel and pNPC, but was inactive towards cellobiose. The enzyme activity was markedly activated by Co2+ and Mn2+, but was strongly inactivated by Fe3+. The truncated gene, devoid of cellulose-binding domain (CBD) showed 60% of activity and bound to avicel.
Assuntos
Bacillus subtilis/enzimologia , Bacillus subtilis/genética , Endo-1,3(4)-beta-Glucanase/química , Domínio Catalítico , Celulose/química , Clonagem Molecular , Cobalto/química , Glucanos/química , Concentração de Íons de Hidrogênio , Hidrólise , Manganês/química , Polissacarídeos/química , Proteínas Recombinantes/química , Temperatura , Xilanos/químicaRESUMO
We cloned 2-keto-3-deoxy-gluconate kinase (KDGK), which catalyzes the phosphorylation of 2-keto-3-deoxygluconate (KDG) to 2-keto-3-deoxy-6-phophogluconate (KDPG) from Serratia marcescens KCTC 2172. The nucleotide sequence revealed a single open reading frame containing 1,208 bp and encoding for 309 amino acids, with a molecular weight of 33,993 Da. The enzyme was purified via GST affinity chromatography. The putative KdgT binding site was detected upstream of the initial codon. The KDG kinase utilized 2-ketogluconate (KG) and KDG as substrates. The optimal temperature and pH for KDGK activity were 50ºC and 8.0, respectively.
Assuntos
Gluconatos/metabolismo , Serratia marcescens/genética , Serratia marcescens/metabolismo , Gelatinases/biossíntese , Glutationa Transferase/biossíntese , Glutationa Transferase/metabolismo , Lipase/biossíntese , Maltose/metabolismoRESUMO
Acinetobacter baumannii BD5 was isolated from waters of Baek-du mountain, and the lipase gene was cloned using a PCR technique. The deduced amino acid sequence of the lipase and lipase chaperone were found to encode proteins of 325 aa and 344 aa with a molecular mass of 35 kDa and 37 kDa, respectively. The lipase gene was cloned and expressed in Escherichia coli BL21 (trxB) as an inclusion body, which was subsequently solubilized by urea, and then purified using Ni-affinity chromatography. After being purified, the lipase was refolded by incubation at 4oC in the presence of a 1:10 molar ratio of lipase:chaperone. The maximal activity of the refolded lipase was observed at a temperature of 35 degrees and pH 8.3 when p-NP caprate (C10) was used as a substrate; however, 28% of the activity observed at 35 degrees was still remaining at 0 degrees . The stability of the purified enzyme at low temperatures indicates that it is a cold-adapted enzyme. The refolded lipase was activated by Ca2+, Mg2+, and Mn2+, whereas Zn2+ and Cu2+ inhibited it. Additionally, 0.1% Tween 20 increased the lipase activity by 33%, but SDS and Triton X-100 inhibited the lipase activity by 40% and 70%, respectively.
Assuntos
Acinetobacter baumannii/genética , Proteínas de Bactérias/metabolismo , Temperatura Baixa , Lipase/metabolismo , Acinetobacter baumannii/enzimologia , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Clonagem Molecular , DNA Bacteriano/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Lipase/genética , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Alinhamento de Sequência , Análise de Sequência de DNARESUMO
A microbe isolated from a soil sample obtained on Deog-yu Mountain in Korea, was found to produce an extracellular lipase. This microbe, which was designated as DYL129, was identified as an Acinetobacter sp. based on phylogenetic analysis of its 16S rDNA. A genomic library was constructed by using DYL129 fragment digested with HindIII and a recombinant plasmid, pLip-1, was selected for further analysis by colony polymerase chain reaction (PCR). Sequencing of a 3.8-kb insert in the pLip-1 clone revealed the presence of one incomplete and three complete open reading frames (ORFs). The ORFs were predicted to encode a partial lipase, two putative lipases and a 50S ribosomal protein. Genome-walking PCR also identified transcripts encoding a complete lipase chaperone and three lipaseA proteins. The lipase structural gene present in Acinetobacter sp. DYL129 was similar to the lipase structural gene found in Acinetobacter calcoaceticus BD413 (lipBA). However, the three lipase genes were located downstream of the chaperone gene in Acinetobacter sp. DYL129 (lipBA (1) A (2) A (3)), which differs from the location of these genes in A. calcoaceticus BD413. Although the amino acid sequences of these lipases (LipA(1), LipA(2), and LipA(3)) differed, both strains had a common "GHSHG" consensus motif, which is the conserved active-site pentapeptide of lipaseA. Moreover, all three lipases were found to share a conserved domain, the so-called alpha/beta hydrolase fold.
Assuntos
Acinetobacter/enzimologia , Lipase/genética , Lipase/metabolismo , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Acinetobacter/genética , Acinetobacter/isolamento & purificação , Acinetobacter calcoaceticus/genética , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Sequência Consenso , Sequência Conservada , DNA Bacteriano/química , DNA Bacteriano/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Estabilidade Enzimática , Ordem dos Genes , Concentração de Íons de Hidrogênio , Coreia (Geográfico) , Lipase/química , Dados de Sequência Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Homologia de Sequência de Aminoácidos , Microbiologia do Solo , TemperaturaRESUMO
To obtain predominant bacteria degrading crude oil, we isolated some bacteria from waste soybean oil. Isolated bacterial strain had a marked tributyrin (C4:0) degrading activity as developed clear zone around the colony after incubation for 24h at 37 degrees C. It was identified as Klebsiella sp. Y6-1 by analysis of 16S rRNA gene. Crude biosurfactant was extracted from the culture supernatant of Klebsiella sp. Y6-1 by organic solvent (methanol:chloroform:1-butanol) after vacuum freeze drying and the extracted biosurfactant was purified by silica gel column chromatography. When the purified biosurfactant dropped, it formed degrading zone on crude oil plate. When a constituent element of the purified biosurfactant was analyzed by TLC and SDS-PAGE, it was composed of peptides and lipid. The emulsification activity and stability of biosurfactant was measured by using hydrocarbons and crude oil. The emulsification activity and stability of the biosurfactant showed better than the chemically synthesized surfactant. It reduced the surface tension of water from 72 to 32 mN/m at a concentration of 40 mg/l.
Assuntos
Microbiologia de Alimentos , Klebsiella/metabolismo , Óleo de Soja , Tensoativos/metabolismo , Eletroforese em Gel de Poliacrilamida , Emulsões , Klebsiella/isolamento & purificação , Tensoativos/isolamento & purificaçãoRESUMO
Bacillus amyloliquefaciens strain LP03 isolated from soil, produced an antagonistic compound that strongly inhibited the growth of plant-pathogenic fungi and a lipopeptide biosurfactant. Also, isolated strain LP03 had a marked crude oil-emulsifying activity as it developed a clear zone around the colony after incubation for 24 h at 37 degrees C. LP03 was identified as Bacillus amyloliquefaciens by analysis of partial 16 S rRNA gene and partial gyrA gene sequence. The lipopeptide was purified by acid precipitation of cell-free culture broth, extraction of the precipitates with methanol, silica gel column chromatography, and reverse-phase, high-pressure liquid chromatography. The purified biosurfactant was analyzed biochemical structure by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) and electrospray ionization mass spectrometry/mass spectrometry (ESI-MS/MS). The masses of the two peaks were observed by HPLC chromatography. Their masses were determined to be 1,044 and 1,058 m/z with MALDI-TOF mass spectrometry. As constituents of the peptide and lipophilic part of the m/z 1,022.6, seven amino acids (Glu-Leu-Met-Leu-Pro-Leu-Leu) and beta-hydroxy-C13 fatty acid were determined by ESI-MS/MS. The lipopeptide of 1,022.6 Da differed from surfactins in the substitution of leucine, valine and aspartic acid in positions 3, 4, and 5 by methionine, leucine, and proline, respectively. Novel lipopeptide was designated as bamylocin A.
Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Bacillus/química , Emulsificantes/isolamento & purificação , Emulsificantes/farmacologia , Lipoproteínas/isolamento & purificação , Lipoproteínas/farmacologia , Bacillus/classificação , Bacillus/isolamento & purificação , Fracionamento Químico , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , DNA Girase/genética , DNA Fúngico/química , DNA Fúngico/genética , DNA Ribossômico/química , DNA Ribossômico/genética , Ácidos Graxos/análise , Fungos/efeitos dos fármacos , Coreia (Geográfico) , Peso Molecular , Petróleo/metabolismo , RNA Ribossômico 16S/genética , Análise de Sequência de Proteína , Microbiologia do Solo , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por MatrizRESUMO
A chitinase encoding gene from Bacillus sp. DAU101 was cloned in Escherichia coli. The nucleotide sequencing revealed a single open reading frame containing 1781 bp and encoding 597 amino acids with 66 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and zymogram. The chitinase was composed of three domains: a catalytic domain, a fibronectin III domain, and a chitin binding domain. The chitinase was purified by GST-fusion purification system. The pH and temperature optima of the enzyme were 7.5 and 60 degrees C, respectively. The metal ions, Zn(2+), Cu(2+), and Hg(2+), were strongly inhibited chitinase activity. However, chitinase activity was increased 1.4-fold by Co(2+). Chisb could hydrolyze GlcNAc(2) to N-acetylglucosamine and was produced GlcNAc(2), when chitin derivatives were used as the substrate. This indicated that Chisb was a bifunctional enzyme, N-acetylglucosaminase and chitobiosidase. The enzyme could not hydrolyze glycol chitin, glycol chitosan, or CMC, but hydrolyzed colloidal chitin and soluble chitosan.
Assuntos
Bacillus/enzimologia , Quitinases/metabolismo , Sequência de Aminoácidos , Antifúngicos/análise , Fusão Gênica Artificial , Bacillus/genética , Cátions/metabolismo , Quitinases/genética , Quitinases/isolamento & purificação , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Estrutura Terciária de Proteína , Análise de Sequência de DNA , Especificidade por Substrato , TemperaturaRESUMO
In the course of screening for reactive oxygen species scavengers from natural products, an antioxidant was isolated from the mycelial culture broth of Phellinus linteus and identified as hispidin. The hispidin content was reached its maximum level at 12 days after onset of inoculation. About 2.5 mg/mL of hispidin was produced by P. linteus in a yeast-malt medium (pH 5.8, 25 degrees C). Hispidin inhibited 22.6 and 56.8% of the super oxide anion radical, 79.4 and 95.3% of the hydroxyl radical, and 28.1 and 85.5% of the DPPH radical at 0.1 and 1.0 mM, respectively. The positive control alpha-tocopherol scavenged 25.6 and 60.3%, 74.6 and 96.3%, and 32.7 and 77.5% of each radical, respectively, at the same concentrations. However, hispidin showed no significant activity on the hydrogen peroxide radical.