ABSTRACT
Biorefinery of chemicals from straw is an effective approach to alleviate the environmental pollution caused by straw burning. In this paper, we prepared gellan gum immobilized Lactobacillus bulgaricus T15 gel beads (LA-GAGR-T15 gel beads), characterized their properties, and established a continuous cell recycle fermentation process for D-lactate (D-LA) production using the LA-GAGR-T15 gel beads. The fracture stress of LA-GAGR-T15 gel beads was (91.68±0.11) kPa, which was 125.12% higher than that of the calcium alginate immobilized T15 gel beads (calcium alginate-T15 gel beads). This indicated that the strength of LA-GAGR-T15 gel beads was stronger, and the strain was less likely to leak out. The average D-LA production was (72.90±2.79) g/L after fermentation for ten recycles (720 h) using LA-GAGR-T15 gel beads as the starting strain and glucose as the substrate, which was 33.85% higher than that of calcium alginate-T15 gel beads and 37.70% higher than that of free T15. Subsequently, glucose was replaced by enzymatically hydrolyzed corn straw and fermented for ten recycles (240 h) using LA-GAGR-T15 gel beads. The yield of D-LA reached (1.74±0.79) g/(L·h), which was much higher than that of using free bacteria. The wear rate of gel beads was less than 5% after ten recycles, which indicated that LA-GAGR is a good carrier for cell immobilization and can be widely used in industrial fermentation. This study provides basic data for the industrial production of D-LA using cell-recycled fermentation, and provides a new way for the biorefinery of D-LA from corn straw.
Subject(s)
Fermentation , Lactobacillus delbrueckii , Zea mays , Lactic Acid , Alginates/chemistry , GlucoseABSTRACT
The WUSCHEL related-homeobox (WOX) family is one of the plant-specific transcription factor families, playing important roles in plant growth and development. In this study, 51 WOX gene family members were identified from the genome data of Brassica juncea by searching and screening with HUMMER, Smart and other software. Their protein molecular weight, amino acids numbers, and isoelectric point were analyzed by using Expasy online software. Furthermore, bioinformatics software was used to systematically analyze the evolutionary relationship, conservative region, and gene structure of the WOX gene family. The mustard WOX gene family was divided into three subfamilies: ancient clade, intermediate clade, and WUS clade/modern clade. Structural analysis showed that the type, organization form and gene structure of the conservative domain of WOX transcription factor family members in the same subfamily were highly consistent, while there was a certain diversity among different subfamilies. 51 WOX genes are distributed unevenly on 18 chromosomes of mustard. Most of the promoters of these genes contain cis acting elements related to light, hormone and abiotic stress. Using transcriptome data and real-time fluorescence quantitative PCR (qRT-PCR) analysis, it was found that the expression of mustard WOX gene was spatio-temporal specific, among which BjuWOX25, BjuWOX33, and BjuWOX49 might play an important role in the development of silique, and BjuWOX10, BjuWOX32, and BjuWOX11, BjuWOX23 respectively might play an important role in the response to drought and high temperature stresses. The above results may facilitate the functional study of mustard WOX gene family.
Subject(s)
Mustard Plant/genetics , Multigene Family/genetics , Transcription Factors/metabolism , Plants/genetics , Promoter Regions, Genetic , Phylogeny , Gene Expression Regulation, Plant , Plant Proteins/metabolismABSTRACT
Objective:To prepare the multilayer alginate chitosan microspheres loading vascular endothelial growth factor (VEGF) and vancomycin (VAN), and to study in vitro release characteristics.Methods:The microspheres were prepared by emulsion cross-linking and self-assembly techniques.The effects of sodium alginate concentration, calcium chloride concentration, oil/water ratio and span80 concentration on the entrapment efficiency(EE) and drug loading(DL) of VEGF and VAN were investigated by orthogonal experimental design to optimize the preparation process.The surface morphology and particle size of microspheres were observed by scanning electron microscope (SEM).Self-assembly was detected by Fourier transform infrared spectroscope (FTIR).The EE, DL and in vitro release of VEGF and VAN were detected by ELISA double antibody sandwich method and ultraviolet spectrophotometry,and the cumulative release curve was drawn.Results:The prepared microspheres were yellowish brown powder.The SEM results showed that the microspheres were spherical, the surface was smoothy, and the dispersity was better.The average particle size was about 50 μm.Sodium alginate concentration of 1.0 g·mL-1, CaCl2 concentration of 8 g·mL-1, oil to water ratio of 3∶1, and span80 concentration of 2% were the best formula.The EE of VEGF and VAN were 49.63% and 16.67%, respectively.In vitro, the cumulative release last 16.5 d and 12.5 d respectively and the amount reached up to 95%.Conclusion:The multilayer alginate chitosan microspheres loading VEGF and VAN present several advantages, such as smaller particle size, higher EE and better controlled release.
ABSTRACT
To study the value of lung ultrasound score (LUS) in assessing the clinical outcome of patients with ventilator-associated pneumonia (VAP).A total of 99 VAP patients were enrolled in a prospective study.All patients met the diagnostic criterion of VAP based on the 2013 guidelines and admitted into our ICU from Jun 2013 to Jun 2015.All parameters were recorded on the diagnostic day (day 1) and day 5,including LUS,clinical pulmonary infection score (CPIS),chest X ray (CXR),Acute Physiology and Chronic Health Evaluation Ⅱ (APACHE Ⅱ) score,Sequential Organ Failure Assessment (SOFA) score,etc.According to the CPIS,patients were divided into 2 groups(CPIS less than 6 and more or equal to 6).CPIS and LUS were similar on day 1 between two groups (P ＞ 0.05).However,on day 5,significant differences of CPIS and LUS were found between groups with CPIS ＜ 6 and CPIS≥6 (P =0.019 and P ＜ 0.001 respectively).LUS decreased on day 5 in CPIS ＜ 6 group and increased in CPIS ≥6 group.In CPIS ＜ 6 group,there was a positive correlation between LUS and CPIS on day 1 (r =0.375,P =0.003) and day 5 (r =0.590,P ＜ 0.001).CPIS ≥6 groupshowed the same trend on day 1 (r =0.484,P =0.002) and day 5 (r =0.407,P =0.011).LUS can be used to dynamically evaluate the clinical outcome of VAP.
ABSTRACT
ObjectiveTo evaluate the value of lung ultrasound score (LUS) on assessing the severity and prognosis in patients with acute respiratory distress syndrome (ARDS), and to investigate its correlation with oxygenation index, acute physiology and chronic health evaluationⅡ (APACHEⅡ) score, sequential organ failure assessment (SOFA) score, and clinical pulmonary infection score (CPIS), and other traditional parameters.Methods A prospective double-blind cohort study was conducted. Sixty-two ARDS patients conformed to the Berlin diagnostic criteria admitted to intensive care unit (ICU) of Beijing Huaxin Hospital from October 2013 to December 2014 were enrolled, including 14 cases with mild, 18 moderate, and 30 severe ARDS; among them 37 cases were of ARDS with pulmonary origin, and 25 non-pulmonary ARDS; 35 patients survived, and 27 died. The clinical data and scores of all patients were recorded by one specialized observer, including baseline data, hemodynamic parameters, lactate, respiratory parameters, and APACHEⅡ, SOFA and CPIS scores. Another observer of recording was responsible for the results of lung ultrasound, LUS, and echocardiogram. The correlation between LUS and oxygenation index as well as APACHEⅡ, SOFA and CPIS scores was analyzed by bivariate correlation analysis. Receiver operator characteristic curve (ROC) was plotted, and the predictive value, sensitivity and specificity of mild ARDS, moderate ARDS, severe ARDS and mortality by LUS were calculated. Results LUS had a negative correlation with oxygenation index (r = -0.755,P 19.0 had a high mortality, sensitivity for predicting death was 84.0%, and specificity of 89.0%.Conclusion Bedside LUS, which is simple and easily available, could evaluate the changes in pulmonary ventilation area of ARDS, and its degree of severity, and prognosis including prediction of mortality of the patients.