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1.
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.2.
Korey J. Brownstein Mahmoud Gargouri William R. Folk David R. Gang 《Metabolomics : Official journal of the Metabolomic Society》2017,13(11):133
Introduction
Botanicals containing iridoid and phenylethanoid/phenylpropanoid glycosides are used worldwide for the treatment of inflammatory musculoskeletal conditions that are primary causes of human years lived with disability, such as arthritis and lower back pain.Objectives
We report the analysis of candidate anti-inflammatory metabolites of several endemic Scrophularia species and Verbascum thapsus used medicinally by peoples of North America.Methods
Leaves, stems, and roots were analyzed by ultra-performance liquid chromatography-mass spectrometry (UPLC-MS) and partial least squares-discriminant analysis (PLS-DA) was performed in MetaboAnalyst 3.0 after processing the datasets in Progenesis QI.Results
Comparison of the datasets revealed significant and differential accumulation of iridoid and phenylethanoid/phenylpropanoid glycosides in the tissues of the endemic Scrophularia species and Verbascum thapsus.Conclusions
Our investigation identified several species of pharmacological interest as good sources for harpagoside and other important anti-inflammatory metabolites.3.
4.
Introduction
Cellulose microfibril is a major cell wall polymer that plays an important role in the growth and development of plants. The gene cellulose synthase A (CesA), encoding cellulose synthases, is involved in the synthesis of cellulose microfibrils. However, the regulatory mechanism of CesA gene expression is not well understood, especially during the early developmental stages.Objective
To identify factor(s) that regulate the expression of CesA genes and ultimately control seedling growth and development.Methods
The presence of cis-elements in the promoter region of the eight CesA genes identified in flax (Linum usitatissimum L. ‘Nike’) seedlings was verified, and three kinds of ethylene-responsive cis-elements were identified in the promoters. Therefore, the effect of ethylene on the expression of four selected CesA genes classified into Clades 1 and 6 after treatment with 10?4 and 10?3 M 1-aminocyclopropane-1-carboxylic acid (ACC) was examined in the hypocotyl of 4–6-day-old flax seedlings.Results
ACC-induced ethylene either up- or down-regulated the expression of the CesA genes depending on the clade to which these genes belonged, age of seedlings, part of the hypocotyl, and concentration of ACC.Conclusion
Ethylene might be one of the factors regulating the expression of CesA genes in flax seedlings.5.
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.6.
Thijs Welle Anna T. Hoekstra Ineke A. J. J. M. Daemen Celia R. Berkers Matheus O. Costa 《Metabolomics : Official journal of the Metabolomic Society》2017,13(7):83
Introduction
Swine dysentery caused by Brachyspira hyodysenteriae is a production limiting disease in pig farming. Currently antimicrobial therapy is the only treatment and control method available.Objective
The aim of this study was to characterize the metabolic response of porcine colon explants to infection by B. hyodysenteriae.Methods
Porcine colon explants exposed to B. hyodysenteriae were analyzed for histopathological, metabolic and pro-inflammatory gene expression changes.Results
Significant epithelial necrosis, increased levels of l-citrulline and IL-1α were observed on explants infected with B. hyodysenteriae.Conclusions
The spirochete induces necrosis in vitro likely through an inflammatory process mediated by IL-1α and NO.7.
Mehran Kausar Saima Siddiqi Muhammad Yaqoob Sajid Mansoor Outi Makitie Asif Mir Chiea Chuen Khor Jia Nee Foo Mariam Anees 《Journal of biomedical science》2018,25(1):82
Introduction
Osteogenesis imperfecta (OI) is a clinically and genetically heterogeneous disease with skeletal fragility and variable extra-skeletal manifestations. To date several point mutations in 18 different genes causing different types of OI have been identified. Mutations in WNT1 compromise activity of the osteoblasts leading to disturbed bone mass accrual, fragility fractures and progressive skeletal abnormalities. The present study was conducted to determine the underlying genetic cause of an autosomal recessive skeletal dysplasia in a large consanguineous family from Chinute, Pakistan.Materials and methods
Blood was collected from 24 individuals of affected family along with clinical data. Homozygosity mapping was performed to confirm consanguinity. SNPs were identified, followed by whole exome and Sanger sequencing. In silico characterization of WNT1 mutation was performed using multiple platforms.Results
Nine affected family members exhibited severe bone deformities, recurrent fractures, short stature and low bone mineral density. SNP array data revealed homozygous segments >?1 Mb in length accounting for 2.1–12.7% of the genome in affected individuals and their siblings and a single 6,344,821 bp homozygous region in all affected individuals on chromosome 12q12-q13. This region includes two potential OI candidate genes WNT1 and VDR. We did whole-exome sequencing for both genes in two patients and identified a novel damaging missense mutation in exon 4 of WNT1: c.1168G?>?T (NM_005430) resulting in p.G324C. Sanger sequencing confirmed segregation of mutation with the disease in family.Conclusion
We report a novel mutation responsible for OI and our investigation expands the spectrum of disease-causing WNT1 mutations and the resulting OI phenotypes.8.
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.9.
Chelladurai Rathnasingh Jong Myoung Park Duk-ki Kim Hyohak Song Yong Keun Chang 《Biotechnology letters》2016,38(6):975-982
Objectives
To improve the production of 2,3-butanediol (2,3-BD) in Klebsiella pneumoniae, the genes related to the formation of lactic acid, ethanol, and acetic acid were eliminated.Results
Although the cell growth and 2,3-BD production rates of the K. pneumoniae ΔldhA ΔadhE Δpta-ackA strain were lower than those of the wild-type strain, the mutant produced a higher titer of 2,3-BD and a higher yield in batch fermentation: 91 g 2,3-BD/l with a yield of 0.45 g per g glucose and a productivity of 1.62 g/l.h in fed-batch fermentation. The metabolic characteristics of the mutants were consistent with the results of in silico simulation.Conclusions
K. pneumoniae knockout mutants developed with an aid of in silico investigation could produce higher amounts of 2,3-BD with increased titer, yield, and productivity.10.
11.
Jiwei Mao Quanli Liu Xiaofei Song Hesuiyuan Wang Hui Feng Haijin Xu Mingqiang Qiao 《Biotechnology letters》2017,39(7):977-982
Objective
To identify new enzymatic bottlenecks of l-tyrosine pathway for further improving the production of l-tyrosine and its derivatives.Result
When ARO4 and ARO7 were deregulated by their feedback resistant derivatives in the host strains, the ARO2 and TYR1 genes, coding for chorismate synthase and prephenate dehydrogenase were further identified as new important rate-limiting steps. The yield of p-coumaric acid in the feedback-resistant strain overexpressing ARO2 or TYR1, was significantly increased from 6.4 to 16.2 and 15.3 mg l?1, respectively. Subsequently, we improved the strain by combinatorial engineering of pathway genes increasing the yield of p-coumaric acid by 12.5-fold (from 1.7 to 21.3 mg l?1) compared with the wild-type strain. Batch cultivations revealed that p-coumaric acid production was correlated with cell growth, and the formation of by-product acetate of the best producer NK-M6 increased to 31.1 mM whereas only 19.1 mM acetate was accumulated by the wild-type strain.Conclusion
Combinatorial metabolic engineering provides a new strategy for further improvement of l-tyrosine or other metabolic biosynthesis pathways in S. cerevisiae.12.
P. J. P. M. Cuijpers G. Bookelman W. Kicken W. de Vries A. P. M. Gorgels 《Netherlands heart journal》2016,24(7-8):456-461
Background
Integrating cardiopulmonary resuscitation (CPR) training in secondary schools will increase the number of potential CPR providers. However, currently too few certified instructors are available for this purpose. Training medical students and physical education student teachers to become CPR instructors could decrease this shortage.Aim
Examine whether medical students and physical education student teachers can provide CPR training for secondary school pupils as well as (i.?e., non-inferior to) registered nurses.Methods
A total of 144 secondary school pupils were randomly assigned to CPR training by a registered nurse (n = 12), a medical student (n = 17) or a physical education student teacher (n = 15). CPR performance was assessed after training and after eight weeks in a simulated cardiac arrest scenario on a resuscitation manikin, using manikin software and video recordings.Results
No significant differences were found between the groups on the overall Cardiff Test scores and the correctness of the CPR techniques during the post-training and retention test. All pupils showed sufficient CPR competence, even after eight weeks.Conclusion
Training by medical students or physical education student teachers is non-inferior to training by a registered nurse, suggesting that school teachers, student teachers and medical students can be recruited for CPR training in secondary schools.13.
Objectives
To enhance the yield of 9α-hydroxy-4-androstene-3,17-dione (9-OHAD) from phytosterols, a phytosterol transport system was constructed in Mycobacterium sp. strain MS136.Results
9-OHAD can be produced via the controlled degradation of phytosterols by mycobacteria. This involves an active transport process that requires trans-membrane proteins and ATP. A phytosterol transport system from Mycobacterium tuberculosis H37Rv was constructed in Mycobacterium sp. strain MS136 by co-expression of an energy-related gene, mceG, and two integrated membrane protein genes, yrbE4A and yrbE4B. The resultant of the Mycobacterium sp. strain MS136-GAB gave 5.7 g 9-OHAD l?1, which was a 20% increase over 4.7 g l?1 by the wild-type strain. The yield of 9-OHAD was increased to 6.0 g l?1 by optimization of fermentation conditions, when 13 g phytosterols l?1 were fermented for 84 h in 30 ml biotransformation medium in shake flasks.Conclusions
Phytosterol transport system plays an active role in the uptake and transport of sterols, cloning of the system improved the mass transfer of phytosterols and increased the production of 9-OHAD.14.
Tokusei Tanahashi Keisuke Kawai Keita Tatsushima Chihiro Saeki Kunie Wakabayashi Naho Tamura Tetsuya Ando Toshio Ishikawa 《BioPsychoSocial medicine》2017,11(1):22
Background
We examined how purging behaviors relate to subjective sleep quality and sleep patterns and how symptoms of disordered eating behaviors relate to global sleep quality in female patients with anorexia nervosa (AN).Methods
Participants were new consecutive female inpatients with a primary diagnosis of AN admitted to the Department of Psychosomatic Medicine at Kohnodai Hospital between June 26 and December 25, 2015. We recorded patients’ habitual eating behaviors, laxative overuse, or uretic misuse, and administered the Japanese versions of the Pittsburgh Sleep Quality Index (PSQI-J) and Center for Epidemiologic Studies Depression Scale. Raw PSQI-J data were used to determine sleep patterns (sleep-onset time, wake-up time, and sleep duration). To examine how purging behaviors related to sleep quality, we compared variables between AN restricting type (ANr) and AN binge-eating/purging type (ANbp). Spearman’s rank correlation analysis was used to examine which potential factors influence global PSQI-J score.Results
Participants were 20 patients, of whom 12 had ANbp. Two ANr patients (25%) had global PSQI-J scores greater than 5, compared to 9 ANbp patients (75%; P < 0.05). Circadian rhythm disruption and abnormal sleep duration were significantly greater in ANbp patients than in ANr patients (P < 0.05). Global PSQI-J was significantly correlated with a diagnosis of ANbp (ρ = 0.525; P < 0.05), vomiting (ρ = 0.561; P < 0.05), and duration of illness (ρ = 0.536; P < 0.05).Conclusions
ANbp patients had worse global sleep quality and greater disrupted sleep than did ANr patients. This suggests that treatments focusing on sleep would be useful, especially for ANbp patients. Furthermore, vomiting and duration of illness should be considered essential factors related to impaired global sleep quality.Trial registration
Not applicable.15.
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.16.
Chih-Yueh Liu Chang-Ching Weng Chih-Hsiang Lin Chiou-Ying Yang Kwok-Kong Tony Mong Yaw-Kuen Li 《Biotechnology letters》2017,39(3):407-413
Objectives
A Neissaria bacterial pilus sugar, bacillosamine, was synthesized and, for the first time, used as a probe to screen a single-chain variable fragment (scFv).Results
Four Neisseria, Neisseria gonorrhoeae, Neisseria meningitidis, Neisseria sicca and Neisseria subflava, and two negative controls, Streptococcus pneumoniae and Escherichia coli, were tested through ELISA, immunostaining and gold nanoparticle immunological assay. All results indicated that the selected scFv is feasible for the specific detection of Neisseria species via the recognition of bacillosamine.Conclusions
The recombinant scFv could detect Neisseria strains at 106 CFU/ml.17.
Anne Caroline Wiik Ernst-Otto Ropstad Ellen Bjerkås Frode Lingaas 《BMC veterinary research》2008,4(1):23
Background
A genetic study was performed to identify candidate genes associated with day blindness in the standard wire haired dachshund. Based on a literature review of diseases in dogs and human with phenotypes similar to day blindness, ten genes were selected and evaluated as potential candidate genes associated with day blindness in the breed.Results
Three of the genes, CNGB3, CNGA3 and GNAT2, involved in cone degeneration and seven genes and loci, ABCA4, RDH5, CORD8, CORD9, RPGRIP1, GUCY2D and CRX, reported to be involved in cone-rod dystrophies were studied. Polymorphic markers at each of the candidate loci were studied in a family with 36 informative offspring. The study revealed a high frequency of recombinations between the candidate marker alleles and the disease.Conclusion
Since all of the markers were at the exact position of the candidate loci, and several recombinations were detected for each of the loci, all ten genes were excluded as causal for this canine, early onset cone-rod dystrophy. The described markers may, however, be useful to screen other canine resource families segregating eye diseases for association to the ten genes.18.
19.
Objectives
To characterize the genes responsible for ethanol utilization in Pichia pastoris.Results
ADH3 (XM_002491337) and ADH (FN392323) genes were disrupted in P. pastoris. The ADH3 mutant strain, MK115 (Δadh3), lost its ability to grow on minimal ethanol media but produced ethanol in minimal glucose medium. ADH3p was responsible for 92 % of total Adh enzyme activity in glucose media. The double knockout strain MK117 (Δadh3Δadh) also produced ethanol. The Adh activities of X33 and MK116 (Δadh) strains were not different. Thus, the ADH gene does not play a role in ethanol metabolism.Conclusion
The PpADH3 is the only gene responsible for consumption of ethanol in P. pastoris.20.
Matthias Hirth Silvia Liverani Sebastian Mahlow François-Yves Bouget Georg Pohnert Severin Sasso 《Metabolomics : Official journal of the Metabolomic Society》2017,13(6):68