Your browser doesn't support javascript.
Show: 20 | 50 | 100
Results 1 - 20 de 4.066
Electron. j. biotechnol ; 52: 30-34, July. 2021. ilus, tab, graf
Article in English | LILACS | ID: biblio-1283487


BACKGROUND: This study aimed to develop an amplification method of urea detection based on pHsensitive liposomes. RESULTS: The urease covalently immobilized on the magnetic particles and the pH-sensitive liposomes encapsulating ferricyanide were added to the cyclic-voltammeter cell solution where urea was distributed. The conversion of urea into carbonic acid seemed to induce a pH decrease that caused a reduction in the electrostatic repulsion between the headgroups of weakly acidic 1,2-dipalmitoyl-sn-glycero3-succinate. The reduction induced the liposomes to release potassium ferricyanide that was encapsulated inside. The effects of urea concentration and pH value were investigated. A specific concentration (0.5 mg/mL) of the urea solution was set to observe the response. The activity of urease was reversible with respect to the pH change between 7 and 5. The sensitivity of this detection was almost identical to the comparable techniques such as an enzyme-linked immunosorbent assay and a field-effect transistor. CONCLUSIONS: In summary, the methodology developed in this study was feasible as a portable, rapid, and sensitive method.

Urea/analysis , Liposomes/chemistry , Urease/chemistry , Enzyme-Linked Immunosorbent Assay , Enzymes, Immobilized , Hydrogen-Ion Concentration
Electron. j. biotechnol ; 52: 85-92, July. 2021. graf, tab
Article in English | LILACS | ID: biblio-1283600


BACKGROUND: Nonribosomal peptide synthases (NRPS) can synthesize functionally diverse bioactive peptides by incorporating nonproteinogenic amino acids, offering a rich source of new drug leads. The bacterium Escherichia coli is a well-characterized production host and a promising candidate for the synthesis of nonribosomal peptides, but only limited bioprocess engineering has been reported for such molecules. We therefore developed a medium and optimized process parameters using the design of experiments (DoE) approach. RESULTS: We found that glycerol is not suitable as a carbon source for rhabdopeptide production, at least for the NRPS used for this study. Alternative carbon sources from the tricarboxylic acid cycle achieved much higher yields. DoE was used to optimize the pH and temperature in a stirred-tank reactor, revealing that optimal growth and optimal production required substantially different conditions. CONCLUSIONS: We developed a chemically defined adapted M9 medium matching the performance of complex medium (lysogeny broth) in terms of product concentration. The maximum yield in the reactor under optimized conditions was 126 mg L-1, representing a 31-fold increase compared to the first shaking-flask experiments with M9 medium and glycerol as the carbon source. Conditions that promoted cell growth tended to inhibit NRPS productivity. The challenge was therefore to find a compromise between these factors as the basis for further process development.

Peptide Synthases/metabolism , Bioreactors/microbiology , Escherichia coli , Temperature , Biotechnology , Carbon/metabolism , Models, Statistical , Electrophoresis, Polyacrylamide Gel , Bioengineering , Hydrogen-Ion Concentration
Rev. cient. odontol ; 9(2): e058, abr.-jun. 2021. ilus, tab
Article in Spanish | LILACS, LIPECS | ID: biblio-1254597


Objetivo: Comparar el pH de cuatro marcas de geles aclaradores a base de peróxido de hidrógeno de altas concentraciones (30%-35%) Whiteness HP Maxx (HPM), Lase Peroxide (LP), Whiteness HP Automixx (HPA)y Dash (DA), a través del tiempo de aplicación clínica (inicio, 15', 30' y 45'). Materiales y métodos: El estudio fue experimental in vitro. Se evaluaron 40 muestras (dientes bovinos) divididos en 4 grupos, uno para cada marca comercial de gel. Se preparó cada gel de acuerdo con las instrucciones del fabricante y se colocó una cantidad necesaria en la superficie vestibular; posteriormente, se registró el pH del gel con un pHmetro digital al inicio, 15, 30 y 45 minutos. Los datos se analizaron con las pruebas Anova, Friedman y Wilcoxon. Resultados: Hubo una tendencia a la disminución del pH desde el tiempo inicial de aplicación hasta el tiempo final, con excepción del grupo de la marca DA, el cual mostró que los valores del pH fueron aumentando a través del tiempo. En la marca HPM, existe una diferencia significativa entre el tiempo inicial de aplicación del gel y el resto de tiempos. En la marca LP, a partir de los 15' de aplicación, sí hay diferencia significativa entre los tiempos. En cuanto a la marca HPA, existieron diferencias significativas entre el tiempo inicial de aplicación y los demás tiempos. Finalmente, con la marca DA se encontró únicamente una diferencia significativa entre el tiempo inicial de aplicación y el tiempo final. Conclusiones: El pH de los geles aclaradores disminuyó a través del tiempo de aplicación clínica en todas las marcas estudiadas, con excepción de la marca Dash 30%, la cual mostró un aumento. (AU)

Objective: The aim of this in vitro study was to evaluate the pH of four bleaching agents based on high concentration hydrogen peroxide (30-35%) Whiteness HP Maxx (HPM), Lase Peroxide (LP), Whiteness HP Automixx (HPA) and Dash (DA) in different clinical periods (baseline, 15', 30' and 45'). Materials and methods: 40 specimens (bovine teeth) were divided into 4 groups; one group for each bleaching agent. Each bleaching agent was prepared according to the manufacturer's instructions and was applied on the vestibular surface. The pH of the bleaching agent was measured with a digital pH meter at baseline, 15, 30 and 45 minutes. ANOVA, Friedman and Wilcoxon tests were applied. Results: The pH values showed a trend to decreasing from the initial time of application to the final time, except for the DA group, which showed increasing pH values over time. The HPM group showed significant differences between baseline and the remaining periods. The LP group LP showed significant difference between 15' and the other periods. The HPA group showed significant differences between baseline and the remaining periods. Finally, the DA group, showed a significant difference between baseline and 45'. Conclusions: The pH values of 3 of the bleaching agents decreased over time, with the exception of Dash which increased in the different time periods. (AU)

Tooth Bleaching , Hydrogen-Ion Concentration , Hydrogen Peroxide , In Vitro Techniques , Epidemiology, Experimental
Electron. j. biotechnol ; 51: 79-87, May. 2021. tab, ilus, graf
Article in English | LILACS | ID: biblio-1343441


BACKGROUND: At present, cellulases are the most important enzymes worldwide, and their demand has been increasing in the industrial sector owing to their notable hydrolysis capability. RESULTS: In the present study, contrary to conventional techniques, three physical parameters were statistically optimized for the production of cellulase by thermophilic fungi by using response surface methodology (RSM). Among all the tested thermophilic strains, the best cellulase producing fungus was identified as Talaromyces thermophilus ­ both morphologically and molecularly through 5.8S/ITS rDNA sequencing. The central composite design (CCD) was used to evaluate the interactive effect of the significant factors. The CCD was applied by considering incubation period, pH, and temperature as the model factors for the present investigation. A second-order quadratic model and response surface method revealed that the independent variables including pH 6, temperature 50 C, and incubation period 72 h significantly influenced the production of cellulases. The analysis of variance (ANOVA) indicated that the established model was significant (P 0.05) and showed the high adequacy of the model. The actual and predicted values of CMCase and FPase activity showed good agreement with each other and also confirmed the validity of the designed model. CONCLUSIONS: We believe the present findings to be the first report on cellulase production by exploiting Kans grass (Saccharum spontaneum) as a substrate through response surface methodology by using thermophilic fungus, Talaromyces thermophilus.

Talaromyces/metabolism , Cellulases/biosynthesis , Analysis of Variance , Saccharum , Fermentation , Hot Temperature , Hydrogen-Ion Concentration
Rev. cuba. hematol. inmunol. hemoter ; 37(1): e1338, ene.-mar. 2021. tab, graf
Article in Spanish | LILACS, CUMED | ID: biblio-1251717


Introducción: Las hemoglobinopatías se consideran errores monogénicos hereditarios y están caracterizados por defectos en la molécula de hemoglobina. En Cuba, la detección prenatal de hemoglobinopatías se realiza a través de la electroforesis de hemoglobina para identificar parejas de alto riesgo. El programa brinda: asesoramiento genético, diagnóstico prenatal molecular e interrupciones selectivas de fetos afectados, a solicitud de las parejas. Objetivo: Determinar la frecuencia de hemoglobinopatías en mujeres embarazadas residentes en Cuba. Métodos: Se realizó un estudio descriptivo, retrospectivo y de corte transversal para determinar la frecuencia de hemoglobinopatías en 1 342 917 mujeres embarazadas captadas en el periodo 2009-2019. El método diagnóstico de la pesquisa fue la electroforesis de hemoglobina en geles de agarosa a pH alcalino. La confirmación se realizó por electroforesis de hemoglobina en gel de agarosa a pH ácido; ambos métodos mediante la tecnología HYDRASYS. Resultados: La frecuencia global de embarazadas con hemoglobinopatías fue de 3,5 por ciento. Se detectó hemoglobinopatías en 47 465 mujeres; 38 698 con variante S heterocigoto, 8 706 variantes de hemoglobina C y 158 de otras variantes. Se detectaron 44 283 esposos con hemoglobinopatías, 3 099 parejas de alto riesgo y se realizaron 2 689 diagnósticos prenatales moleculares. Se confirmaron 522 fetos afectados y 382 parejas solicitaron la interrupción del embarazo. El subprograma alcanzó 99,24 por ciento de cobertura en el país. Conclusión: La alta frecuencia de hemoglobinopatías en Cuba justifica la importancia de continuar el subprograma de detección de portadores para prevenir la aparición de las formas graves de la enfermedad(AU)

Introduction: Hemoglobinopathies are hereditary monogenic errors characterized by defects in the hemoglobin molecule. In Cuba, prenatal detection of hemoglobinopathies is performed by hemoglobin electrophoresis to identify high-risk couples. The program offers genetic counseling, prenatal molecular diagnosis and selective pregnancy termination in case of affected fetuses at the request of couples. Objective: Determine the frequency of hemoglobinopathies among pregnant women living in Cuba. Methods: A descriptive cross-sectional retrospective study was conducted to determine the frequency of hemoglobinopathies in 1 342 917 pregnant women recruited in the period 2009-2019. Screening was based on the diagnostic method of hemoglobin electrophoresis in alkaline pH agarose gels. Confirmation was performed with hemoglobin electrophoresis in acid pH agarose gel. Both methods used HYDRASYS technology. Results: Overall frequency of pregnant women with hemoglobinopathies was 3.5 percent. Hemoglobinopathies were detected in 47 465 women: 38 698 with variant S heterozygote, 8 706 with variants of hemoglobin C y 158 with other variants. 44 283 husbands with hemoglobinopathies and 3 099 high-risk couples were detected, and 2 689 prenatal molecular diagnostic tests were conducted. A total 522 affected fetuses were confirmed, and 382 couples requested pregnancy termination. The subprogram achieved 99.24 percent coverage in the country. Conclusion: The high frequency of hemoglobinopathies in Cuba justifies the importance of continuing the carrier detection subprogram to prevent the emergence of severe forms of the disease(AU)

Humans , Female , Pregnancy , Prenatal Diagnosis , Family Characteristics , Electrophoresis , Genetic Counseling , Hemoglobinopathies , Hydrogen-Ion Concentration , Mass Screening , Retrospective Studies
Rev. cuba. pediatr ; 93(1): e1205, ene.-mar. 2021. tab
Article in Spanish | LILACS, CUMED | ID: biblio-1251747


Introducción: El ensayo de muestras matutinas de orina pudiera mejorar el estudio de la función tubular en niños y adolescentes. Objetivo: Describir las tubulopatías diagnosticadas en niños y adolescentes después del ensayo de muestras matutinas de orina. Métodos: Se completó un estudio retrospectivo y analítico en el Laboratorio de Estudio de la Función Renal, Servicio de Laboratorio Clínico, Hospital Pediátrico Docente "Juan Manuel Márquez", con 70 informes de la función tubular hechos en muestras matutinas de orina de 56 probandos (varones: 50,0 por ciento; edad promedio: 4,3 ± 5,5 años; edades < 12 meses: 41,1 por ciento) atendidos entre 2015-2019 (ambos inclusive) que contenían los valores del filtrado glomerular, la excreción urinaria absoluta y fraccional de las sustancias de interés, la brecha aniónica, la presión parcial de los gases, y la acidez titulable, el pH, la densidad y la osmolaridad de los fluidos pertinentes. Los resultados obtenidos se integraron dentro de las construcciones de caso de varias tubulopatías. Resultados: La función tubular estaba conservada en el 41,1 por ciento de los probandos. La inmadurez tubular explicó los hallazgos en otros dos niños. La hipercalciuria idiopática (16,0 por ciento), la diabetes insípida de causa nefrogénica (8,9 por ciento) y la insuficiencia renal aguda (5,3 por ciento) fueron los hallazgos más frecuentes. En 14 de los probandos se diagnosticaron 10 tubulopatías que recorrieron el raquitismo carencial, la hipofosfatasia, la enfermedad de Leigh, el síndrome de Bartter, la enfermedad de Dent y la acidosis tubular I, II y IV. Conclusiones: El estudio tubular en muestras matutinas de orina permite el diagnóstico de importantes tubulopatías en las edades pediátricas(AU)

Introduction: The morning urine sample assay may improve the study of tubular function in children and adolescents. Objective: Describe the tubulopathies diagnosed in children and adolescents after the trial of morning urine samples. Methods: A retrospective and analytical study was completed at the Renal Function´s Study Laboratory, in the Clinical Laboratory Service at "Juan Manuel Marquez" Teaching Pediatric Hospital, with 70 reports of tubular function made in morning urine samples of 56 testees (males: 50.0 percent; average age: 4.3 ± to 5.5 years; ages< 12 months: 41.1 percent) attended from 2015 to 2019 (both inclusive) containing glomerular filtration values, absolute and fractional urinary excretion of substances of interest, anionic gap, partial gas pressure, and titrable acidity, pH, density and osmolarity of relevant fluids. The results obtained were integrated into the case constructions of various tubulopathies. Results: Tubular function was preserved in 41.1 percent of the testees. Tubular immaturity explained the findings in two other children. Idiopathic hypercalciuria (16.0 percent), nephrogenic diabetes insipidus (8.9 percent) and acute renal failure (5.3 percent) were the most frequent findings. In 14 of the testees, 10 tubulopathies were diagnosed were through deficiency rickets, hypophosphatasia, Leigh's disease, Bartter syndrome, Dent disease and tubular acidosis I, II and IV.. Conclusions: The tubular study with morning urine samples allows the diagnosis of important tubulopathies in the pediatric ages(AU)

Humans , Male , Female , Infant , Child, Preschool , Osmolar Concentration , Diabetes Insipidus, Nephrogenic , Acute Kidney Injury , Clinical Laboratory Services , Hydrogen-Ion Concentration
Electron J Biotechnol ; 49: 56-63, Jan. 2021. tab, ilus, graf
Article in English | LILACS | ID: biblio-1291900


BACKGROUND: 2R,3R-butanediol dehydrogenase (R-BDH) and other BDHs contribute to metabolism of 3R/3S-Acetoin (3R/3S-AC) and 2,3-butanediol (2,3-BD), which are important bulk chemicals used in different industries. R-BDH is responsible for oxidizing the hydroxyl group at their (R) configuration. Bacillus species is a promising producer of 3R/3S-AC and 2,3-BD. In this study, R-bdh gene encoding R-BDH from Bacillus sp. DL01 was isolated, expressed and identified. RESULTS: R-BDH exerted reducing activities towards Diacetyl (DA) and 3R/3S-AC using NADH, and oxidizing activities towards 2R,3R-BD and Meso-BD using NAD+ , while no activity was detected with 2S,3S-BD. The R-BDH showed its activity at a wide range of temperature (25 C to 65 C) and pH (5.0­8.0). The R-BDH activity was increased significantly by Cd2+ when DA, 3R/3S-AC, and Meso-BD were used as substrates, while Fe2+ enhanced the activity remarkably at 2R,3R-BD oxidation. Kinetic parameters of the R-BDH from Bacillus sp. DL01 showed the lowest Km, the highest Vmax, and the highest Kcat towards the racemic 3R/3S-AC substrate, also displayed low Km towards 2R,3R-BD and Meso-BD when compared with other reported R-BDHs. CONCLUSIONS: The R-BDH from Bacillus sp. DL01 was characterized as a novel R-BDH with high enantioselectivity for R-configuration. It considered NAD+ and Zn2+ dependant enzyme, with a significant affinity towards 3R/3S-AC, 2R,3R-BD, and Meso-BD substrates. Thus, R-BDH is providing an approach to regulate the production of 3R/3S-AC or 2,3-BD from Bacillus sp. DL01.

Bacillus subtilis/enzymology , Alcohol Oxidoreductases/isolation & purification , Alcohol Oxidoreductases/metabolism , Temperature , Kinetics , Hydrogen-Ion Concentration , Acetoin
Neotrop. ichthyol ; 19(1): e200126, 2021. tab, graf
Article in English | ID: biblio-1154962


Patterns of species replacement and richness differences along environmental gradients or ecoregions shed light on different ecological and evolutionary mechanisms acting on community structure. Communities of aquatic ecosystems of different watersheds are supposed to host distinct species and lineages. Quantifying and understanding the degree to which these differences are affected by environmental and biogeographical factors remains an open question for these environments, particularly in the Neotropical region. We investigated patterns of taxonomic and phylogenetic composition of headwater streams of the Paraná and Paraguai River basins to understand how local and biogeographical factors affect the assembly of fish communities. We also quantified taxonomic and phylogenetic beta diversity by decomposing them into nestedness and turnover components. We found that local environmental factors are the main factors influencing the composition of stream fish communities. Whereas pH affected both taxonomic and phylogenetic turnover, water velocity was responsible for phylogenetic turnover and pH was the main driver of phylogenetic nestedness. Our results indicate an effect of local environmental factors in determining the structure of headwater stream fish communities through a combination of a species sorting mechanism (water velocity and pH) and phylogenetic habitat filtering (pH).(AU)

Padrões de substituição de espécies ou diferenças de riqueza ao longo de gradientes ambientais ou ecoregiões lançam luz sobre diferentes processos e mecanismos ecológicos atuando na estruturação das comunidades. Supõe-se que comunidades aquáticas pertencentes a diferentes bacias pertençam a linhagens evolutivas distintas. Quantificar e entender o grau em que tais diferenças são resultado de fatores ambientais locais e/ou processos biogeográficos ainda é uma questão pouco explorada. Neste estudo nós investigamos os padrões de composição taxonômica e filogenética em riachos de cabeceira das bacias dos Rios Paraná e Paraguai, para entender como fatores locais e biogeográficos afetam a estruturação das comunidades de peixes. Nós quantificamos a diversidade beta taxonômica e filogenética decompondo estas em aninhamento e substituição. Encontramos que os fatores ambientais locais são os principais determinantes da composição das comunidades de peixes destes riachos. Enquanto o pH afetou tanto a substituição de linhagens e de espécies, a velocidade da água foi responsável por uma substituição de linhagens, enquanto o pH foi o principal responsável pelo aninhamento de linhagens. Nossos resultados indicam a importância dos fatores locais através da combinação entre mecanismos de preferência de nicho (velocidade da água e pH) e filtragem ambiental de linhagens (pH).(AU)

Animals , Phylogeny , Classification , Ecosystem , Fishes , Rivers , Hydrogen-Ion Concentration
Chinese Journal of Biotechnology ; (12): 1415-1424, 2021.
Article in Chinese | WPRIM | ID: wpr-878643


Coupling sugar is a kind of new sweetener which can substitute sucrose. It has a good application prospect in food, medicine and other fields because of its good coloration, water retention and anti caries. The purpose of this study was to find cheap and easily available donor and acceptor, and to optimize the preparation process of coupling sugar by using β-cyclodextrin glycosyltransferase from Bacilluscirculans 251. Using sucrose as acceptor, the factors of preparing coupling sugar was optimized, including enzyme dosage, starch types, temperature, pH, ratio of starch/sucrose, and cooperation of isoamylase and β-CGTase. When 105 g/L potato starch and 95 g/L sucrose was used as substrates, the yield of coupling sugar reached 88.4%, which was catalyzed by 13.5 U/g immobilized β-CGTase and 45.0 U/g isoamylase under the conditions of pH 5.5 and 40 °C for 21 h. In this study, isoamylase and β-CGTase were used to prepare coupling sugar innovatively. This method had obvious advantages in yield and cost, which laid both theoretical and experimental foundation for the industrial enzymatic preparation of coupling sugars.

Glucosyltransferases , Hydrogen-Ion Concentration , Isoamylase , Starch
Chinese Journal of Biotechnology ; (12): 580-592, 2021.
Article in Chinese | WPRIM | ID: wpr-878583


A novel β-glucosidase BglD2 with glucose and ethanol tolerant properties was screened and cloned from the deep-sea bacterium Bacillus sp. D1. The application potential of BglD2 toward polydatin-hydrolyzing was also evaluated. BglD2 exhibited the maximal β-glucosidase activity at 45 °C and pH 6.5. BglD2 maintained approximately 50% of its origin activity after incubation at 30 °C and pH 6.5 for 20 h. BglD2 could hydrolyze a variety of substrates containing β (1→3), β (1→4), and β (1→6) bonds. The activity of β-glucosidase was enhanced to 2.0 fold and 2.3 fold by 100 mmol/L glucose and 150 mmol/L xylose, respectively. BglD2 possessed ethanol-stimulated and -tolerant properties. At 30 °C, the activity of BglD2 enhanced to 1.2 fold in the presence of 10% ethanol and even remained 60% in 25% ethanol. BglD2 could hydrolyze polydatin to produce resveratrol. At 35 °C, BglD2 hydrolyzed 86% polydatin after incubation for 2 h. Thus, BglD2 possessed glucose and ethanol tolerant properties and can be used as the potential candidate of catalyst for the production of resveratrol from polydatin.

Enzyme Stability , Glucose , Glucosides/pharmacology , Hydrogen-Ion Concentration , Stilbenes/pharmacology , Substrate Specificity , Temperature , Xylose , beta-Glucosidase/genetics
Chinese Journal of Biotechnology ; (12): 448-460, 2021.
Article in Chinese | WPRIM | ID: wpr-878574


Resource utilization is an effective way to cope with the rapid increase of kitchen waste and excess sludge, and volatile fatty acids produced by anaerobic fermentation is an important way of recycling organic waste. However, the single substrate limits the efficient production of volatile fatty acids. In recent years, volatile fatty acids produced by anaerobic co-fermentation using different substrates has been widely studied and applied. In this paper, we analyze the characteristics of fermentation to produce acid using kitchen waste and excess sludge alone or mixture. Influences of environmental factors and microbial community structure on the type and yield of volatile fatty acids in the anaerobic fermentation system are discussed in detail. Moreover, we propose future research directions, to provide a reference for recycling kitchen waste and excess sludge.

Anaerobiosis , Bioreactors , Fatty Acids, Volatile , Fermentation , Hydrogen-Ion Concentration , Microbiota , Organic Chemicals , Sewage
Chinese Journal of Biotechnology ; (12): 218-227, 2021.
Article in Chinese | WPRIM | ID: wpr-878556


β-N-acetylglucosaminidases (NAGases) can convert natural substrates such as chitin or chitosan to N-acetyl-β-D glucosamine (GlcNAc) monomer that is wildly used in medicine and agriculture. In this study, the BcNagZ gene from Bacillus coagulans DMS1 was cloned and expressed in Escherichia coli. The recombinant protein was secreted into the fermentation supernatant and the expression amount reached 0.76 mg/mL. The molecular mass of purified enzyme was 61.3 kDa, and the specific activity was 5.918 U/mg. The optimal temperature and pH of the BcNagZ were 75 °C and 5.5, respectively, and remained more than 85% residual activity after 30 min at 65 °C. The Mie constant Km was 0.23 mmol/L and the Vmax was 0.043 1 mmol/(L·min). The recombinant BcNagZ could hydrolyze colloidal chitin to obtain trace amounts of GlcNAc, and hydrolyze disaccharides to monosaccharide. Combining with the reported exochitinase AMcase, BcNagZ could produce GlcNAc from hydrolysis of colloidal chitin with a yield over 86.93%.

Acetylglucosamine , Acetylglucosaminidase , Bacillus coagulans , Chitin , Chitinases , Hydrogen-Ion Concentration , Recombinant Proteins/genetics
ABCD arq. bras. cir. dig ; 34(1): e1566, 2021. tab
Article in English | LILACS | ID: biblio-1248504


ABSTRACT Background: The catheter of the esophageal pH monitoring is associated with nasal and throat discomfort, and different behave in patients. The capsule of the wireless pH monitoring may cause chest pain and complications. Aim: To compare the wireless and conventional pH monitoring concerning the degree of discomfort and limitations in daily activities, complications, ability to diagnose pathological reflux, and costs. Methods: Twenty-five patients with symptoms of gastroesophageal reflux were prospectively submitted, in a simultaneous initial period, to 24-hour catheter esophageal pH monitoring and 48-hour wireless system. After removing each system, patients underwent a specific clinical questionnaire. Results: Fifteen patients (60%) pointed a higher discomfort in the introduction of the capsule (p=0.327). Discomfort and limitations in daily activities were lower on 2nd day (p<0.05); however, continued to be expressive (32% to 44%). Chest pain occurred in 13 (52%) patients. The diagnostic gain of pathological reflux was 12% with the wireless system (p=0.355). Conclusions: 1) There is no significant difference between the discomfort mentioned in the introduction of the capsule and the catheter; 2) during reflux monitoring, the wireless system provides significant less discomfort and limitations in daily activities; 3) there is no significant difference between the two methods in the ability to diagnose pathological reflux; 4) wireless pH monitoring has higher cost.

RESUMO Racional: O cateter da pHmetria esofágica associa-se ao desconforto nasal e na garganta, e comportamento diferente nos pacientes. A cápsula da pHmetria sem cateter pode causar dor torácica e complicações. Objetivo: Comparar as pHmetrias sem cateter e a convencional, em relação ao desconforto e limitações das atividades diárias, complicações, capacidade de diagnosticar refluxo patológico, e custos. Métodos: Vinte e cinco pacientes com sintomas de refluxo gastroesofágico foram prospectivamente submetidos, em um período inicial simultâneo, à pHmetria esofágica com cateter durante 24 h e à pHmetria sem cateter durante 48 h. Após a retirada de cada método, pacientes responderam o questionário clínico específico. Resultados: Quinze pacientes (60%) relataram maior desconforto na introdução da cápsula (p=0,327). Desconforto e limitações das atividades diárias foram menores no 2º dia (p< 0,05); entretanto, continuaram sendo expressivos (32% a 44%). Dor torácica ocorreu em 13 (52%) pacientes. O ganho diagnóstico no refluxo patológico foi de 12% com o sistema sem cateter (p=0,355). Conclusões: 1) Não há diferença significativa entre o desconforto relatado na introdução da cápsula e do cateter; 2) durante a monitorização do refluxo, o sistema sem cateter proporciona significativo menor desconforto e limitações das atividades diárias; 3) não há diferença significativa entre os dois métodos na capacidade de diagnosticar o refluxo patológico; 4) pHmetria sem cateter tem custo maior.

Humans , Gastroesophageal Reflux/diagnosis , Esophageal pH Monitoring , Surveys and Questionnaires , Catheters , Hydrogen-Ion Concentration
REME rev. min. enferm ; 25: e1382, 2021. graf
Article in English, Portuguese | LILACS, BDENF | ID: biblio-1340533


RESUMO Objetivo: relatar casos de cateteres nasoenterais mal posicionados, após inserção às cegas à beira leito. Método: são apresentados três casos, os quais ocorreram em uma instituição hospitalar localizada no estado de São Paulo. Os cateteres foram inseridos pelo enfermeiro conforme protocolo institucional, para posicionamento em nível entérico. Ausculta epigástrica e mensuração do pH foram os métodos empregados na confirmação do posicionamento dos cateteres e posteriormente foi realizado o exame de Raios-X, considerado exame de referência para confirmar o posicionamento de cateteres nasoenterais. Resultados: dos três cateteres mal posicionados, dois estavam com a extremidade distal projetada para a junção esofagogástrica e uma não foi visibilizada, apesar de a ausculta ter sido positiva e os valores de pH terem sido superiores a seis. Conclusão: os resultados revelaram importantes limitações de ambos os métodos na verificação do posicionamento de cateteres nasoenterais que foram inseridos recentemente às cegas à beira leito.

RESUMEN Objetivo: reportar casos de catéteres nasoenterales mal posicionados tras inserción ciega a pie de cama. Método: se presentan tres casos, ocurridos en un hospital ubicado en el estado de São Paulo. Los catéteres fueron insertados por el enfermero según protocolo institucional, para su colocación a nivel entérico. La auscultación epigástrica y la medición del pH fueron los métodos utilizados para confirmar la posición de los catéteres y posteriormente se realizó el examen de rayos X, considerado un examen de referencia para confirmar la posición de los catéteres nasoenterales. Resultados: de los tres catéteres mal posicionados, dos tenían el extremo distal proyectado a la unión esofagogástrica y uno no se visualizaba, a pesar de que la auscultación era positiva y los valores de pH superiores a seis. Conclusión: los resultados revelaron importantes limitaciones de ambos métodos para verificar la posición de los catéteres nasoenterales recientemente insertados a ciegas a la cabecera de la cama.

ABSTRACT Objective: to report cases of poorly positioned nasoenteral catheters after blind insertion at the bedside. Method: three cases are presented, which occurred in a hospital located in the state of São Paulo. The catheters were inserted by the nurse according to institutional protocol, for placement at the enteric level. Epigastric auscultation and pH measurement were the methods used to confirm the positioning of the catheters and subsequently the X-Ray exam was performed, considered a reference exam to confirm the positioning of nasoenteral catheters. Results: of the three poorly positioned catheters, two were with the distal end projected to the esophagogastric junction and one was not visualized, despite the auscultation being positive and the pH values being higher than six. Conclusion: the results revealed important limitations of both methods in verifying the positioning of nasoenteral catheters that were recently inserted blindly at the bedside.

Humans , Catheters , Patient Care , Intubation, Gastrointestinal/methods , X-Rays , Enteral Nutrition , Hydrogen-Ion Concentration
Electron. j. biotechnol ; 48: 1-12, nov. 2020. tab, graf, ilus
Article in English | LILACS | ID: biblio-1254671


BACKGROUND: The potential waste canola oil-degrading ability of the cold-adapted Antarctic bacterial strain Rhodococcus sp. AQ5-07 was evaluated. Globally, increasing waste from food industries generates serious anthropogenic environmental risks that can threaten terrestrial and aquatic organisms and communities. The removal of oils such as canola oil from the environment and wastewater using biological approaches is desirable as the thermal process of oil degradation is expensive and ineffective. RESULTS: Rhodococcus sp. AQ5-07 was found to have high canola oil-degrading ability. Physico-cultural conditions influencing its activity were studied using one-factor-at-a-time (OFAT) and statistical optimisation approaches. Considerable degradation (78.60%) of 3% oil was achieved by this bacterium when incubated with 1.0 g/L ammonium sulphate, 0.3 g/L yeast extract, pH 7.5 and 10% inoculum at 10°C over a 72-h incubation period. Optimisation of the medium conditions using response surface methodology (RSM) resulted in a 9.01% increase in oil degradation (87.61%) when supplemented with 3.5% canola oil, 1.05 g/L ammonium sulphate, 0.28g/L yeast extract, pH 7.5 and 10% inoculum at 12.5°C over the same incubation period. The bacterium was able to tolerate an oil concentration of up to 4.0%, after which decreased bacterial growth and oil degradation were observed. CONCLUSIONS: These features make this strain worthy of examination for practical bioremediation of lipid-rich contaminated sites. This is the first report of any waste catering oil degradation by bacteria originating from Antarctica.

Rhodococcus/physiology , Rapeseed Oil/metabolism , Waste Products , Biodegradation, Environmental , Adaptation, Physiological , Cold Temperature , Waste Water , Hydrogen-Ion Concentration , Antarctic Regions
Electron. j. biotechnol ; 48: 13-22, nov. 2020. tab, ilus, graf
Article in English | LILACS | ID: biblio-1254675


BACKGROUND: There is a large amount of industrial wastewater produced by the mushroom industry during the canning processing each year, which could provide abundant carbon, nitrogen and inorganic salts for microbial growth. The aim of this study was to optimize the culture conditions for Bacillus licheniformis cultured in the Agaricus bisporus industrial wastewater to produce the agricultural microbial fertilizer. RESULTS: In this work, the maximal biomass of B. licheniformis could be obtained under the following culture conditions: 33.7°C, pH 7.0, 221 rpm shaking speed, 0.5% wastewater, 2 (v:v, %) inoculum dose, loading liquid of 60 mL/250 mL and a culture time of 24 h, and the average experimental value obtained was 1.35 ± 0.04 × 109 Obj/mL, which was within the 95% confidence interval of the predicted model (1.29­1.38 × 109 Obj/mL), and met the national microbial fertilizers' standard in China. Furthermore, the field experiment results showed that the fermentation broth of B. licheniformis could significantly improve the yield of Anoectochilus roxburghii. CONCLUSIONS: Agaricus bisporus industrial wastewater can be used to produce agricultural microbial fertilizer.

Orchidaceae/physiology , Fertilizers/microbiology , Bacillus licheniformis/physiology , Agaricus , Fermentation , Waste Water , Flow Cytometry , Hydrogen-Ion Concentration , Industrial Waste
Electron. j. biotechnol ; 48: 46-52, nov. 2020. graf, tab
Article in English | LILACS | ID: biblio-1254708


BACKGROUND: Fructose and single cell protein are important products for the food market. Abundant amounts of low-grade dates worldwide are annually wasted. In this study, highly concentrated fructose syrups and single cell protein were obtained through selective fermentation of date extracts by Saccharomyces cerevisiae. RESULTS: The effect of air flow (0.1, 0.5, 0.75, 1, 1.25 and 1.5 vvm) and pH (4.5, 4.8, 5, 5.3 and 5.6) was investigated. Higher air flow led to lower fructose yield. The optimum cell mass production of 10 g/L was achieved at air flow of 1.25 vvm with the fructose yield of 91%. Similar cell mass production was obtained in the range pH of 5.0­5.6, while less cell mass was obtained at pH less than 5. Controlling the pH at 4.5, 5.0 and 5.3 failed to improve the production of cell mass which were 5.6, 5.9 and 5.4 g/L respectively; however, better fructose yield was obtained. CONCLUSIONS: Extension of the modified Gompertz enabled excellent predictions of the cell mass, fructose production and fructose fraction. The proposed model was also successfully validated against data from literatures. Thus, the model will be useful for wide application of biological processes.

Saccharomyces cerevisiae/physiology , Phoeniceae , Fructose/biosynthesis , Aerobiosis , Mathematical Concepts , Fermentation , Garbage , Hydrogen-Ion Concentration
Electron. j. biotechnol ; 47: 83-88, sept. 2020. graf, ilus
Article in English | LILACS | ID: biblio-1253097


BACKGROUND: L-tert-Leucine has been widely used in pharmaceutical, chemical, and other industries as a vital chiral intermediate. Compared with chemical methods, enzymatic methods to produce L-tert-leucine have unparalleled advantages. Previously, we found a novel leucine dehydrogenase from the halophilic thermophile Laceyella sacchari (LsLeuDH) that showed good thermostability and great potential for the synthesis of L-tertleucine in the preliminary study. Hence, we manage to use the LsLeuDH coupling with a formate dehydrogenase from Candida boidinii (CbFDH) in the biosynthesis of L-tert-leucine through reductive amination in the present study. RESULT: The double-plasmid recombinant strain exhibited higher conversion than the single-plasmid recombinant strain when resting cells cultivated in shake flask for 22 h were used. Under the optimized conditions, the double-plasmid recombinant E. coli BL21 (pETDute-FDH-LDH, pACYCDute-FDH) transformed 1 mol·L-1 trimethylpyruvate (TMP) completely into L-tert-leucine with greater than 99.9% ee within 8 h. CONCLUSIONS: The LsLeuDH showed great ability to biosynthesize L-tert-leucine. In addition, it provided a new option for the biosynthesis of L-tert-leucine.

Leucine Dehydrogenase/metabolism , Bacillales/enzymology , Leucine/biosynthesis , Temperature , Recombinant Proteins , Escherichia coli , Hydrogen-Ion Concentration
Electron. j. biotechnol ; 47: 29-35, sept. 2020. tab, graf
Article in English | LILACS | ID: biblio-1253015


BACKGROUND: Salep is obtained by grinding dried orchid tubers and used as a valuable ingredient in the food industry. Because of the glucomannan content of salep, it is thought to have prebiotic potential. However, there is little information in studies concerning the fermentation characteristics and potential prebiotic properties of salep. The objective of this study was to investigate the effect of salep on bifidobacterial growth by measuring the highest optical density (OD), calculating the specific growth rates, and determining the production of lactic acid and short-chain fatty acids (acetic, propionic, and butyric acid) as a result of bacterial fermentation. RESULT: The OD and pH values obtained in this study showed that salep was utilized as a source of assimilable carbon and energy by the Bifidobacterium species (BS). All Bifidobacterium strains produced lactic, acetic, propionic, and butyric acid, indicating that salep is readily fermented by these bacteria. Salep at 1% (w/v) showed a similar effect on bifidobacterial growth as that promoted by 1% (w/v) glucose used as a traditional carbon source. CONCLUSIONS: Bifidobacterium species can develop in media containing salep as well as in glucose and exhibit the potential to be used as new sources of prebiotics.

Powders/metabolism , Bifidobacterium/growth & development , Bifidobacterium/metabolism , Fatty Acids, Volatile/biosynthesis , Propionates/analysis , Propionates/metabolism , Food Industry , Acetic Acid/analysis , Acetic Acid/metabolism , Lactic Acid/analysis , Lactic Acid/metabolism , Probiotics , Butyric Acid/analysis , Butyric Acid/metabolism , Fatty Acids, Volatile/analysis , Prebiotics , Fermentation , Hydrogen-Ion Concentration
Int. j. morphol ; 38(4): 1112-1119, Aug. 2020. tab, graf
Article in English | LILACS | ID: biblio-1124903


Monosodium glutamate (MSG) is a flavor enhancer widely used in the food industry, with obesogenic properties, in addition to causing alterations in the oral cavity. The aim of the study was to observe the morphofunctional changes in the parotid gland after the administration of MSG in rats. 18 newborn male Sprague Dawley rats were used, divided into three groups (Control group; MSG1 group: 4 mg/g weight of monosodium glutamate, 5 doses, kept for 8 weeks, and MSG2 group: 4 mg/g weight of MSG, 5 doses, kept for 16 weeks). The body mass index (BMI) was calculated, and the salivary flow, pH, a-amylase activity, Na, Cl, K and Ca were analyzed by quantitative analysis. After euthanasia by ketamine/xylazine overdose, parotid volume was analyzed and stereology was performed. MSG administration caused an increase in BMI and a decrease in parotid volume as well as a reduction in salivary flow and pH and an increase in a-amylase activity, also increasing the salivary sodium and chlorine levels. Alterations in the normal stereological parameters of the gland were observed. Exposure to MSG caused morphofunctional alterations at parotid gland.

El glutamato monosódico (MSG), es un potenciador del sabor ampliamente utilizado en la industria alimentaria. Diversos estudios han propuesto la relación entre éste y el desarrollo de obesidad, además de provocar alteraciones en la cavidad oral. El objetivo del estudio fue observar los cambios morfofuncionales a nivel de la glándula parótida, posterior a la administración de MSG en ratas. Se utilizaron 18 ratas neonatas Sprague Dawley machos, divididas en tres grupos según su tiempo de exposición y dosis a MSG (Grupo Control, Grupo MSG1: 4 mg/g peso de glutamato monosódico, 5 dosis, mantenidas 8 semanas, Grupo MSG2: 4 mg/g peso de MSG, 5 dosis, mantenidas 16 semanas. Fue calculado el índice de masa corporal (BMI), además de ser analizado el flujo salival, pH, actividad de α-amilasa, y Na, Cl, K y Ca mediante análisis semicuantitativo. Luego de la eutanasia por sobredosis de ketamina/xilasina, las glándulas parótidas fueron extraídas y analizado su volumen y fueron procesadas para histología, y estudio estereológico. La administración de MSG causó aumento en BMI y disminución del volumen parotídeo, además de disminución del flujo y pH salival, así como aumento en actividad de la a-amilasa, aumentando además los niveles de sodio y cloro salival. Fueron observadas alteraciones a nivel de los parámetros estereológicos normales de la glándula. La exposición a MSG causó alteraciones morfofuncionales a nivel parotídeo, observándose una disminución del volumen de la glándula, acompañado de alteraciones en el adenómero y conductos estriados de la glándula, implicados en la producción, secreción y modificación de la saliva, la cual se vio alterada, en el flujo, pH, y en sus componentes.

Animals , Male , Rats , Parotid Gland/drug effects , Sodium Glutamate/administration & dosage , Flavoring Agents/administration & dosage , Saliva/chemistry , Sodium/analysis , Sodium Glutamate/pharmacology , Time Factors , Body Mass Index , Chlorine/analysis , Analysis of Variance , Rats, Wistar , alpha-Amylases/analysis , Flavoring Agents/pharmacology , Hydrogen-Ion Concentration