RESUMO
Xylanase is widely used in various industries such as food processing, paper, textiles, and leather tanning. In this study, Bacillus cereus L-1 strain was isolated and identified as capable of producing low molecular weight xylanase through 16 s rRNA sequencing. Maximum xylanase yield of 15.51 ± 2.08 U/mL was achieved under optimal fermentation conditions (5% inoculum, 20 g/L xylan, pH 6.0, for 24 h). After purification via ammonium sulfate precipitation and High-S ion exchange chromatography, electrophoretic purity xylanase was obtained with a 28-fold purification and specific activity of 244.97 U/mg. Xylanase had an optimal pH of 6.5 and temperature of 60 °C and displayed thermostability at 30 °C and 40 °C with 48.56% and 45.97% remaining activity after 180 min, respectively. The xylanase retained more than 82.97% of its activity after incubation for 24 h at pH 5.0 and was sensitive to metal ions, especially Mg2+ and Li+. Purified xylanase showed a molecular weight of 23 kDa on SDS-PAGE, and partial peptide sequencing revealed homology to the endo-1,4-beta-xylanase with a molecular weight of 23.3 kDa through LC/MS-MS (liquid chromatography-tandem mass spectrometry). This study suggests that the purified xylanase is easier to purify and enriches low molecular weight xylanases from bacteria source.
Assuntos
Bacillus cereus , Endo-1,4-beta-Xilanases , Bacillus cereus/genética , Bacillus cereus/metabolismo , Peso Molecular , Estabilidade Enzimática , Temperatura , Fermentação , Endo-1,4-beta-Xilanases/genética , Endo-1,4-beta-Xilanases/metabolismo , Concentração de Íons de HidrogênioRESUMO
The exploration of polysaccharides from microorganisms is of great importance. In this study, a new type of exopolysaccharide excreted by Fusarium merismoides A6 (FM-EPS) was isolated, and the extraction conditions were optimized using a response surface methodology (RSM). The extraction temperature at 0 °C, a precipitation time of 7.83 h, and an ethanol precipitation concentration of 77.64% were predicted and proved to be the best extraction conditions with the maximum extraction yield of 0.74 g/mL. Then, two fractions of F. merismoides A6 exopolysaccharides (FM-EPS1 and FM-EPS2) were obtained through DEAE Sepharose fast flow column chromatography. As indicated by monosaccharide composition analysis, both fractions mainly consisted of mannose, glucose, galactose, and ribose, with an average molecular weight of 5.14 × 104 and 6.50 × 104 g/mol, respectively. FT-IR and NMR spectroscopy indicated the FM-EPSs had both α- and ß-glycosidic bonds. Moreover, the determination of antioxidant and antiproliferative activities in vitro proved that FM-EPSs had good antioxidant activities and antiproliferation activities. FM-EPS1 showed stronger antioxidant activities than FM-EPS2. FM-EPS2 showed antiproliferation activities on HeLa and HepG2 cells, while FM-EPS1 had no obvious antiproliferative activity. Therefore, FM-EPSs could be explored as potential antioxidant and anticancer agent applied in food, feed, nutraceutical, pharmaceutical, cosmetics, and chemical industries.
Assuntos
Antioxidantes , Fusarium , Espectroscopia de Infravermelho com Transformada de Fourier , Polissacarídeos/química , Fusarium/químicaRESUMO
ABSTRACT Introduction: It is common for athletes to have accidental injuries in training. Sports injuries damage the health of athletes, dampen their enthusiasm, and affect their normal life and training. Objective: To explore preventive measures against athletes' sports injuries by understanding their sports injuries. Methods: We used the literature data method, a questionnaire, an interview, and mathematical statistics to determine the cause of sports injury accidents of athletes. Results: The locations of sports injuries were fingers, ankle and knee joints, lower back, thighs, etc. Common types of injuries were joint sprains, muscle strains, and soft tissue injuries. Conclusion: Scientific physical training can prevent sports injuries and effectively reduce injuries and accidents caused by sports. Level of evidence II; Therapeutic studies - investigation of treatment results.
RESUMO Introdução: Não é raro que atletas tenham ferimentos acidentais em seus treinamentos. Lesões esportivas causam danos à saúde dos atletas e reduzem seu entusiasmo, afetando suas vidas normais e seu treino. Objetivo: Explorar medidas preventivas contra lesões esportivas para compreender como tais ferimentos ocorrem. Métodos: Este trabalho utilizou pesquisa bibliográfica, questionário, entrevista, e cálculo estatístico matemático para determinar a causa das lesões esportivas acidentais de atletas. Resultados: As lesões esportivas ocorreram em dedos, articulações de tornozelo e joelho, região lombar, coxas e etc. Tipos comuns de lesão incluíram torção de articulações, estiramento muscular, e feridas em tecidos moles. Conclusão: O treino físico com base científica pode prevenir lesões esportivas e efetivamente reduzir os ferimentos e acidentes causados pelo esporte. Nível de evidência II; Estudos terapêuticos - investigação de resultados de tratamento.
RESUMEN Introducción: No es raro que los deportistas sufran lesiones accidentales en sus entrenamientos. Lesiones deportivas causan daños a la salud de los atletas y reducen su entusiasmo, afectando sus vidas normales y su entrenamiento. Objetivo: Explorar medidas preventivas contra lesiones deportivas para comprender cómo tales heridas ocurren. Métodos: Este trabajo utilizó investigación bibliográfica, cuestionario, entrevista y cálculo estadístico matemático pata determinar la causa de las lesiones deportivas accidentales de atletas. Resultados: Las lesiones deportivas ocurrieron en los dedos, articulaciones de los tobillos y rodillas, región lumbar, muslos, etc. Entre los tipos de lesiones más comunes se encuentran los esguinces articulares, las distensiones musculares y las heridas en los tejidos blandos. Conclusión: El entrenamiento físico con base científica puede prevenir lesiones deportivas y efectivamente reducir las heridas y accidentes causados por el deporte. Nivel de evidencia II; Estudios terapéuticos - investigación de resultados de tratamiento.
RESUMO
The fat mass- and obesity-associated gene (FTO) is significantly associated with obesity, but the associations of FTO with obesity-related traits are not fully described. We aimed to investigate the association of the FTO single nucleotide polymorphism (SNP) rs6499640 with lipid levels in Chinese children. A total of 3503 children aged 6-18 years were included in the present study. Lipid levels were analyzed and the SNP rs6499640 was genotyped using the TaqMan Allelic Discrimination Assay. Statistically significant associations were found between rs6499640 and low-density lipoprotein cholesterol (LDL-C) (p = 0.008), total cholesterol (TC) (p = 0.005), and triglycerides (TG) (p < 0.001) in girls under a dominant model adjusted for age and BMI. No statistical significance was found between the SNP and lipid levels in boys. We demonstrated for the first time that the SNP rs6499640 in FTO is associated with LDL-C, TC, and TG in Chinese girls. Our study identified a new risk locus for lipid levels in children.
RESUMO
To identify the specificity of base substitutions, a novel experimental system was established based on rifampicin-resistant (Rif r) mutant screening and sequencing of the defined region of the rpoB gene in E. coli. We focused on comparing mutational spectra of base substitutions induced by either low energy nitrogen ion beam implantation or 60Co-gamma rays. The most significant difference in the frequency of specific kinds of mutations induced by low energy nitrogen ion beam was that CG -> TA transitions were significantly increased from 32 to 46, AT -> TA transversions were doubled from 7 to 15 in 50 mutants, respectively. The preferential base substitutions induced by nitrogen ion beam implantation were CG -> TA transitions, AT -> GC transitions, AT -> TA transversions, which account for 92.13 percent (82/89) of the total. The mutations induced by 60Co-gamma rays were preferentially GC -> AT and AT -> GC transitions, which totaled 84.31 percent (43/51).