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1.
Junfang Wu Anna Wuolikainen Miles Trupp Pär Jonsson Stefan L. Marklund Peter M. Andersen Lars Forsgren Anders Öhman 《Metabolomics : Official journal of the Metabolomic Society》2016,12(6):101
Introduction
Amyotrophic lateral sclerosis (ALS) and Parkinson’s disease (PD) are two severe neurodegenerative disorders for which the disease mechanisms are poorly understood and reliable biomarkers are absent.Objectives
To identify metabolite biomarkers for ALS and PD, and to gain insights into which metabolic pathways are involved in disease.Methods
Nuclear magnetic resonance (NMR) metabolomics was utilized to characterize the metabolite profiles of cerebrospinal fluid (CSF) and plasma from individuals in three age, gender, and sampling-date matched groups, comprising 22 ALS, 22 PD and 28 control subjects.Results
Multivariate analysis of NMR data generated robust discriminatory models for separation of ALS from control subjects. ALS patients showed increased concentrations of several metabolites in both CSF and plasma, these are alanine (CSF fold change = 1.22, p = 0.005), creatine (CSF-fc = 1.17, p = 0.001), glucose (CSF-fc = 1.11, p = 0.036), isoleucine (CSF-fc = 1.24, p = 0.002), and valine (CSF-fc = 1.17, p = 0.014). Additional metabolites in CSF (creatinine, dimethylamine and lactic acid) and plasma (acetic acid, glutamic acid, histidine, leucine, pyruvate and tyrosine) were also important for this discrimination. Similarly, panels of CSF-metabolites that discriminate PD from ALS and control subjects were identified.Conclusions
The results for the ALS patients suggest an affected creatine/creatinine pathway and an altered branched chain amino acid (BCAA) metabolism, and suggest links to glucose and energy metabolism. Putative metabolic markers specific for ALS (e.g. creatinine and lactic acid) and PD (e.g. 3-hydroxyisovaleric acid and mannose) were identified, while several (e.g. creatine and BCAAs) were shared between ALS and PD, suggesting some overlap in metabolic alterations in these disorders.2.
Wenwen Zhang Zhaohui Chen Mengmeng Wu Zhong Shi Feng Zhu Guoqiang li Ting Ma 《Biotechnology letters》2016,38(6):991-997
Objective
To improve the production of welan gum and obtain a carotenoid-free strain while reducing the fermentation and post-treatment costs.Results
The vitreoscilla globin (vgb) gene combined with the β-galactosidase (lacZ) promoter was inserted into the phytoene synthase (crtB) gene region of the chromosome in Alcaligenes sp. ATCC31555. When the recombinant strain was grown in a 5 l fermentor, welan gum was produced at 24 ± 0.4 g l?1 compared to 21 g ± 0.4 g l?1 in the wild type. Furthermore, the carotenoid-free welan gum produced using Alcaligenes sp. ATCC31555 VHb strain was less expensive with improved properties.Conclusions
Alcaligenes sp. ATCC31555 VHb strain was a better neutral welan-producing strain with a higher production than the wild-type strain.3.
Objective
A potential thermotolerant l-leucine dehydrogenase from Laceyella sacchari (Ls-LeuDH) was over-expressed in E. coli, purified and characterized.Results
Ls-LeuDH had excellent thermostability with a specific activity of 183 U/mg at pH 10.5 and 25 °C. It retained a high activity in 200 mM carbonate buffer from pH 9.5 to 11. The optimal temperature for Ls-LeuDH was 60 °C.Conclusion
It is the first time that a thermostable and highly active LeuDH originating from L. sacchari has been characterized. It may be useful for medical and pharmaceutical applications.4.
Cecilia V. Tapia Germán Hermosilla Paula Fortes Claudio Alburquenque Sergio Bucarey Hugo Salinas Paula I. Rodas María Cristina Díaz Fabien Magne 《Mycopathologia》2017,182(3-4):339-347
Objective
To study Candida albicans genotypes using RAPD and their susceptibility to fluconazole in healthy pregnant women and in vulvovaginal candidiasis (VVC) patients after topical treatment with clotrimazole.Methods
Vaginal swabs were collected at t = 0 and t = 1 (1 month later) in pregnant women (control group, n = 33), and before (t = 0), at 1 month (t = 1) and at 2 months (t = 2) after clotrimazole treatment in pregnant women with VVC.Results
Candida albicans was isolated in 30% of healthy pregnant women and 80% of patients with VVC. A high genetic heterogeneity was observed in C. albicans genotypes between individuals. In patients with VVC, topical antifungal treatment with clotrimazole was clinically effective, but only in a 62% C. albicans was eradicated. In patients in which C. albicans was not eradicated, this microorganism persisted for 1 or 2 months after the antifungal treatment. The persistent colonies were not associated with a specific genotype, but they were associated with higher MICs in comparison with colonies isolated from the control group.Conclusions
Therapy with topical clotrimazole, despite a good clinical outcome, could not eradicate completely C. albicans allowing the persistence of genotypes, with higher MICs to fluconazole. More studies with higher number of patients are needed to validate this preliminary finding.5.
Objectives
To construct an Escherichia coli strain capable of producing riboflavin with high titer and yield.Results
A low copy number plasmid pLS01 containing a riboflavin operon under the control of a constitutive promoter was constructed and introduced into Escherichia coli MG1655. Subsequently, the pfkA, edd and ead genes were disrupted, and the resulting strain LS02T produced 667 mg riboflavin/l in MSY medium supplied with 10 g glucose/l in flask cultivation. In a fed-batch process, riboflavin production of the strain reached 10.4 g/l with a yield of 56.8 mg riboflavin/g glucose.Conclusion
To our knowledge, this is the first report of engineered E. coli strains that can produce more than 10 g riboflavin/l in fed-batch cultivation, indicating that E. coli has potential for riboflavin production.6.
7.
Dorothea Lesche Roland Geyer Daniel Lienhard Christos T. Nakas Gaëlle Diserens Peter Vermathen Alexander B. Leichtle 《Metabolomics : Official journal of the Metabolomic Society》2016,12(10):159
Background
Centrifugation is an indispensable procedure for plasma sample preparation, but applied conditions can vary between labs.Aim
Determine whether routinely used plasma centrifugation protocols (1500×g 10 min; 3000×g 5 min) influence non-targeted metabolomic analyses.Methods
Nuclear magnetic resonance spectroscopy (NMR) and High Resolution Mass Spectrometry (HRMS) data were evaluated with sparse partial least squares discriminant analyses and compared with cell count measurements.Results
Besides significant differences in platelet count, we identified substantial alterations in NMR and HRMS data related to the different centrifugation protocols.Conclusion
Already minor differences in plasma centrifugation can significantly influence metabolomic patterns and potentially bias metabolomics studies.8.
Objectives
To investigate the contribution of direct electron transfer mechanisms to electricity production in microbial fuel cells by physically retaining Shewanella oneidensis cells close to or away from the anode electrode.Results
A maximum power output of 114 ± 6 mWm?2 was obtained when cells were retained close to the anode using a dialysis membrane. This was 3.5 times more than when the cells were separated away from the anode. Without the membrane the maximum power output was 129 ± 6 mWm?2. The direct mechanisms of electron transfer contributed significantly to overall electron transfer from S. oneidensis to electrodes, a result that was corroborated by another experiment where S. oneidensis cells were entrapped in alginate gels.Conclusion
S. oneidensis transfers electrons primarily by direct electron transfer as opposed to mediated electron transfer.9.
Xiangrong Dong Yanping Wang Fengyuan Yang Shanshan Zhao Bing Tian Tao Li 《Biotechnology letters》2017,39(1):65-70
Objectives
Lycopene biosynthetic genes from Deinococcus radiodurans were co-expressed in Lactococcus lactis to produce lycopene and improve its tolerance to stress.Results
Lycopene-related genes from D. radiodurans, DR1395 (crtE), DR0862 (crtB), and DR0861 (crtI), were fused in line with S hine-Dalgarno (SD) sequences and co-expressed in L. lactis. The recombinant strain produced 0.36 mg lycopene g-1 dry cell wt after 48 h fermentation. The survival rate to UV irradiation of the recombinant strain was higher than that of the non-transformed strain.Conclusion
The L. lactis with co-expressed genes responsible for lycopene biosynthesis from D. radiodurans produced lycopene and exhibited increased resistance to UV stress, suggesting that the recombinant strain has important application potential in food industry.10.
Xuexia Zhu Jingwen Yang Xingxing Zhang Lu Zhang Xiaojun Wang Yuan Huang Zhou Yang 《Biotechnology letters》2017,39(1):85-90
Objective
To explore the combined effects of temperature and Daphnia-associated infochemicals on colony formation of Scenedesmus obliquus to faciliate harvesting the algal biomass.Results
A three-parameter modified Gaussian model fitted the changes of the number of cells per particle in S. obliquus induced by Daphnia culture filtrate well under any temperature. Decreases in temperature enhanced the induced–colony formation of Scenedesmus. The maximum colony size at 15–25 °C was significantly larger than those at 30–35 °C. An additional 1 or 2 days at low temperature was needed to reach the maximum colony size, which indicates the best harvest time for algal biomass.Conclusion
Induced-colony formation of Scenedesmus by Daphnia culture filtrate at 15–25 °C is recommended to settle algal cells. This condition facilitates harvesting the biomass.11.
Linpei Zhang Hao Huang Hao Wang Jian Chen Guocheng Du Zhen Kang 《Biotechnology letters》2016,38(12):2103-2108
Objectives
To improve the production and molecular mass of the glycosaminoglycan hyaluronan (HA) in Bacillus subtilis by engineering hyaluronan synthase (HAS) from Streptococcus zooepidemicus.Results
By mutating regions within HAS intracellular domains, five positive variants exhibiting higher HA production (from 1.22 to 2.24 g l?1) and molecular mass values (from 1.20 to 1.36 × 106 Da) were constructed and characterized. Overexpression of the V5 variant and the genes tuaD and glmU increased HA production and molecular mass to 2.8 g l?1 and 2.4 × 106 Da, respectively.Conclusions
This study provides a novel strategy for improving HA production and its molecular mass.12.
Objectives
To enhance succinic acid production in Corynebacterium glutamicum by increasing the supply of NADH and the rate of glucose consumption by decreasing H+-ATPase activity.Results
A mutant of C. glutamicum NC-3-1 with decreased H+-ATPase activity was constructed. This increased the rate of glycolysis and the supply of NADH. Fermentation of C. glutamicum NC-3-1 gave 39 % higher succinic acid production (113 and 81 g/l), a 29 % higher succinic acid yield (0.94 and 0.73 g succinic acid/g glucose) and decreased by-products formation compared to that of C. glutamicum NC-3 in 5 l bioreactor.Conclusion
The point mutation in C. glutamicum NC-3-1 increased the rate of glycolysis and resulted in higher succinic acid production, higher succinic acid yield and significantly decreased formation of by-products.13.
Objectives
To improve the stability and sweetness of the sweet-tasting protein, monellin, by using site-directed mutagenesis and a Pichia pastoris expression system with a GAPDH constitutive promoter.Results
Both wild-type and E2 N mutant of single-chain monellin gene were cloned into the PGAPZαA vector and expressed in Pichia pastoris. The majority of the secreted recombinant protein, at 0.15 g/l supernatant, was monellin. This was purified by Sephadex G50 chromatography. The sweetness threshold of wild-type and E2 N were 30 μg/ml and 20 μg/ml, respectively. Compared with the proteins expressed in Escherichia coli, the thermostability of both proteins was improved. The N-terminal sequence is determinative for the sweetness of the proteins expressed in yeast strains.Conclusions
Site-directed mutagenesis, modification of the N-terminus of monellin, and without the need of methanol induction in P. pastoris expression system, indicate the possibility for large-scale production of this sweet-tasting protein.14.
Objectives
With the view of designing a single biocatalyst for biorefining, carbazole dioxygenase was cloned from Pseudomonas sp. and expressed in Rhodococcus sp.Results
The recombinant, IGTS8, degraded both carbazole and dibenzothiophene at 400 mg/l in 24 h. Maximum carbazole degradation was in 1:1 (v/v) hexadecane/aqueous phase. Anthracene, phenanthrene, pyrene, fluoranthene and fluorine were also degraded without affecting the aliphatic component.Conclusions
Recombinant Rhodococcus sp. IGTS8 can function as a single biocatalyst for removing major contaminants of fossil fuels viz. dibenzothiophene, carbazole and polyaromatic compounds.15.
Objectives
To characterize a novel ene-reductase from Meyerozyma guilliermondii and achieve the ene-reductase-mediated reduction of activated C=C bonds.Results
The gene encoding an ene-reductase was cloned from M. guilliermondii. Sequence homology analysis showed that MgER shared the maximal amino acid sequence identity of 57 % with OYE2.6 from Scheffersomyces stipitis. MgER showed the highest specific activity at 30 °C and pH 7 (100 mM sodium phosphate buffer), and excellent stereoselectivities were achieved for the reduction of (R)-carvone and ketoisophorone. Under the reaction conditions (30 °C and pH 7.0), 150 mM (R)-carvone could be completely converted to (2R,5R)-dihydrocarvone within 22 h employing purified MgER as catalyst, resulting in a yield of 98.9 % and an optical purity of >99 % d.e.Conclusion
MgER was characterized as a novel ene-reductase from yeast and showed great potential for the asymmetric reduction of activated C=C bonds of α,β-unsaturated compounds.16.
Timothy D. Leathers Joseph O. Rich Melinda S. Nunnally Amber M. Anderson 《Biotechnology letters》2018,40(1):157-163
Objective
To test the inactivation of the antibiotic, virginiamycin, by laccase-induced culture supernatants of Aureobasidium pullulans.Results
Fourteen strains of A. pullulans from phylogenetic clade 7 were tested for laccase production. Three laccase-producing strains from this group and three previously identified strains from clade 5 were compared for inactivation of virginiamycin. Laccase-induced culture supernatants from clade 7 strains were more effective at inactivation of virginiamycin, particularly at 50 °C. Clade 7 strain NRRL Y-2567 inactivated 6 µg virginiamycin/ml within 24 h. HPLC analyses indicated that virginiamycin was degraded by A. pullulans.Conclusions
A. pullulans has the potential for the bioremediation of virginiamycin-contaminated materials, such as distiller’s dry grains with solubles (DDGS) animal feed produced from corn-based fuel ethanol production.17.
Christina Tan David Rubenson Ajay Srivastava Rajeev Mohan Michael R. Smith Kristen Billick Samuel Bardarian J. Thomas Heywood 《Cardiovascular ultrasound》2017,15(1):18
Background
Left ventricular outflow tract velocity time integral (LVOT VTI) is a measure of cardiac systolic function and cardiac output. Heart failure patients with low cardiac output are known to have poor cardiovascular outcomes. Thus, extremely low LVOT VTI may predict heart failure patients at highest risk for mortality.Methods
Patients with heart failure and extremely low LVOT VTI were identified from a single-center database. Baseline characteristics and heart failure related clinical outcomes (death, LVAD) were obtained at 12 months. Correlation between clinical endpoints and the following variables were analyzed: ejection fraction (EF), pulmonary artery systolic pressure (PASP), NYHA class, renal function, Doppler cardiac output (CO), and LVOT VTI.Results
Study cohort consisted of 100 patients. At the 12-month follow up period, 30 events (28 deaths, 2 LVADs) were identified. Occurrence of death and LVAD implantation was statistically associated with a lower LVOT VTI (p = 0.039) but not EF (p = 0.169) or CO (p = 0.217). In multivariate analysis, LVOT VTI (p = 0.003) remained statistically significant, other significant variables were age (p = 0.033) and PASP (p = 0.022). Survival analysis by LVOT VTI tertile demonstrated an unadjusted hazard ratio of 4.755 (CI 1.576-14.348, p = 0.006) for combined LVAD and mortality at one year.Conclusions
Extremely low LVOT VTI strongly predicts adverse outcomes and identifies patients who may benefit most from advanced heart failure therapies.18.
Objectives
To establish a method for microbial transglutaminase (mTG)-mediated PEGylation of proteins at the level of lysine (Lys) residues.Results
Carboxybenzyl-glutaminyl–glycinyl-methoxypolyethylene glycol (CBZ-QG-mPEG) was prepared by introducing carboxybenzyl-glutaminyl-glycine (CBZ-QG) to mPEG amine. The analysis by Fourier transform infrared spectroscopy and SDS-PAGE showed that CBZ-QG-mPEG was successfully synthesized and can be recognized by mTG as an acyl donor to modify therapeutic protein, cytochrome c (cyt c). Finally, under an optimized condition (cyt c 0.5 mg/ml, CBZ-QG-mPEG 11.25 mg/ml, mTG 0.5 mg/ml, 37 °C, 2 h), the PEGylation yield reached 76.5 %.Conclusions
This is the first study regarding the PEGylation of protein at the level of Lys residues catalyzed by mTG. The novel method could be employed to immobilize active proteins and modify therapeutic proteins.19.
Aims
Forests induce a mechanical reinforcement of soil, generally quantified in terms of additional root cohesion (c r ), which decreases due to root decay after felling. The aim of this work is providing new field data on soil reinforcement by roots after trees cutting.Methods
The present work investigated c r decay in a mixed Silver Fir-Norway Spruce (Abies alba Mill. Picea abies (L.) Karst.) stand in the Italian Alps over a period of 3 years after felling by monitoring the two c r driving variables: root tensile resistance and root density.Results
Results showed that a significant difference in root resistance occurred only 3 years after felling, whereas the decrease in the number of roots was significant in the second year. The degradation process was more rapid in shallower layers and for thinner roots, as a consequence of the pattern of biological activity rate. The reduction of c r after felling was, for a reference profile depth of 70 cm, 55 % in the first 2 years and another 16 % in the third year.Conclusions
The findings of this study, providing new data on the decrease of c r after felling, can be introduced into geotechnical models allowing a better estimation of the stability of forest hillslopes.20.
Tokusei Tanahashi Keisuke Kawai Keita Tatsushima Chihiro Saeki Kunie Wakabayashi Naho Tamura Tetsuya Ando Toshio Ishikawa 《BioPsychoSocial medicine》2017,11(1):22