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1.
Immunity ; 53(2): 303-318.e5, 2020 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-32579887

RESUMO

Granulocyte-monocyte progenitors (GMPs) have been previously defined for their potential to generate various myeloid progenies such as neutrophils and monocytes. Although studies have proposed lineage heterogeneity within GMPs, it is unclear if committed progenitors already exist among these progenitors and how they may behave differently during inflammation. By combining single-cell transcriptomic and proteomic analyses, we identified the early committed progenitor within the GMPs responsible for the strict production of neutrophils, which we designate as proNeu1. Our dissection of the GMP hierarchy led us to further identify a previously unknown intermediate proNeu2 population. Similar populations could be detected in human samples. proNeu1s, but not proNeu2s, selectively expanded during the early phase of sepsis at the expense of monocytes. Collectively, our findings help shape the neutrophil maturation trajectory roadmap and challenge the current definition of GMPs.


Assuntos
Células Precursoras de Granulócitos/citologia , Monócitos/citologia , Mielopoese/fisiologia , Neutrófilos/citologia , Animais , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Análise de Célula Única
2.
Gastroenterology ; 165(6): 1404-1419, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37704113

RESUMO

BACKGROUND & AIMS: Pien Tze Huang (PZH) is a well-established traditional medicine with beneficial effects against inflammation and cancer. We aimed to explore the chemopreventive effect of PZH in colorectal cancer (CRC) through modulating gut microbiota. METHODS: CRC mouse models were established by azoxymethane plus dextran sulfate sodium treatment or in Apcmin/+ mice treated with or without PZH (270 mg/kg and 540 mg/kg). Gut barrier function was determined by means of intestinal permeability assays and transmission electron microscopy. Fecal microbiota and metabolites were analyzed by means of metagenomic sequencing and liquid chromatography mass spectrometry, respectively. Germ-free mice or antibiotic-treated mice were used as models of microbiota depletion. RESULTS: PZH inhibited colorectal tumorigenesis in azoxymethane plus dextran sulfate sodium-treated mice and in Apcmin/+ mice in a dose-dependent manner. PZH treatment altered the gut microbiota profile, with an increased abundance of probiotics Pseudobutyrivibrio xylanivorans and Eubacterium limosum, while pathogenic bacteria Aeromonas veronii, Campylobacter jejuni, Collinsella aerofaciens, and Peptoniphilus harei were depleted. In addition, PZH increased beneficial metabolites taurine and hypotaurine, bile acids, and unsaturated fatty acids, and significantly restored gut barrier function. Transcriptomic profiling revealed that PZH inhibited PI3K-Akt, interleukin-17, tumor necrosis factor, and cytokine-chemokine signaling. Notably, the chemopreventive effect of PZH involved both microbiota-dependent and -independent mechanisms. Fecal microbiota transplantation from PZH-treated mice to germ-free mice partly recapitulated the chemopreventive effects of PZH. PZH components ginsenoside-F2 and ginsenoside-Re demonstrated inhibitory effects on CRC cells and primary organoids, and PZH also inhibited tumorigenesis in azoxymethane plus dextran sulfate sodium-treated germ-free mice. CONCLUSIONS: PZH manipulated gut microbiota and metabolites toward a more favorable profile, improved gut barrier function, and suppressed oncogenic and pro-inflammatory pathways, thereby suppressing colorectal carcinogenesis.


Assuntos
Neoplasias Colorretais , Microbioma Gastrointestinal , Camundongos , Animais , Transdução de Sinais , Sulfato de Dextrana/toxicidade , Fosfatidilinositol 3-Quinases/metabolismo , Apoptose , Medicina Tradicional , Neoplasias Colorretais/induzido quimicamente , Neoplasias Colorretais/prevenção & controle , Neoplasias Colorretais/metabolismo , Carcinogênese , Azoximetano/toxicidade
3.
BMC Musculoskelet Disord ; 25(1): 82, 2024 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-38245762

RESUMO

PURPOSE: The objective of this study was to investigate the correlation between lower limb alignment and patient outcomes after lateral unicompartmental knee arthroplasty (LUKA). METHODS: In this retrospective study, the information of 51 patients who underwent lateral UKA was collected after an average of 27months of follow-up (13 to 60 months). Evaluation indicators include the AKS and WOMAC score. The Kellgren-Lawrence grade is used to evaluate the severity of osteoarthritis, while the hip-knee-ankle (HKA) angle is utilized to measure the valgus angle of lower limb alignment. RESULT: Patients with postoperative valgus (≥ 3°) alignment had the best outcomes, while those with varus (≤-3°) alignment had the worst outcomes (p < 0.001). Furthermore, it was noted that patients with preoperative mild valgus (≤ 4°) alignment had worse postoperative outcomes than those with severe valgus (≥ 7°) alignment (p < 0.05). The study also revealed a positive correlation between postoperative valgus and WOMAC scores (p < 0.001), whereas a negative correlation was observed between the change in valgus angle and WOMAC scores (p = 0.005). CONCLUSION: During follow-ups, we found that lower limb alignment seems to be an independent predictor of postoperative outcomes. It is recommended that more than 3° of valgus alignment should be maintained after LUKA. Surgeons performing lateral UKA should be cautious of overcorrecting alignment, particularly in patients with preoperative mild valgus alignment.


Assuntos
Artroplastia do Joelho , Osteoartrite do Joelho , Humanos , Artroplastia do Joelho/efeitos adversos , Estudos Retrospectivos , Osteoartrite do Joelho/diagnóstico por imagem , Osteoartrite do Joelho/cirurgia , Articulação do Joelho/diagnóstico por imagem , Articulação do Joelho/cirurgia , Extremidade Inferior/cirurgia
4.
EMBO Rep ; 22(8): e52835, 2021 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-34196465

RESUMO

Tissue-resident macrophages in white adipose tissue (WAT) dynamically adapt to the metabolic changes of their microenvironment that are often induced by excess energy intake. Currently, the exact contribution of these macrophages in obesity-driven WAT remodeling remains controversial. Here, using a transgenic CD169-DTR mouse strain, we provide new insights into the interplay between CD169+ adipose tissue macrophages (ATMs) and their surrounding WAT microenvironment. Using targeted in vivo ATM ablation followed by transcriptional and metabolic WAT profiling, we found that ATMs protect WAT from the excessive pathological remodeling that occurs during obesity. As obesity progresses, ATMs control not only vascular integrity, adipocyte function, and lipid and metabolic derangements but also extracellular matrix accumulation and resultant fibrosis in the WAT. The protective role of ATMs during obesity-driven WAT dysfunction supports the notion that ATMs represent friends, rather than foes, as has previously assumed.


Assuntos
Tecido Adiposo , Macrófagos , Tecido Adiposo Branco , Animais , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos
5.
Plant Dis ; 107(6): 1839-1846, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-36444141

RESUMO

Watermelon diseases caused by pathogenic bacteria were endemic in Liaoning and Jilin Provinces from 2019 to 2020 in China, resulting in serious economic losses to the watermelon industry. This study characterized 56 strains isolated from symptomatic watermelon leaves collected from Liaoning and Jilin Provinces. Through morphological observation, 16S rRNA and gyrB sequence analysis, and BIOLOG profiles, the pathogen was identified as Pseudomonas syringae. In China, the watermelon disease caused by P. syringae was reported for the first time. The multilocus sequence analysis showed that the isolated strains belonged to three different clades within P. syringae phylogroup 2. Interestingly, most of them (79%) belonged to clade 2a, 14% were clade 2b, and 7% were clade 2d. This indicates that bacterial leaf spot outbreaks of watermelon in China were caused by multiple sources and mainly by P. syringae clade 2a.


Assuntos
Citrullus , Citrullus/genética , RNA Ribossômico 16S/genética , Doenças das Plantas/microbiologia , Filogenia , Pseudomonas syringae , China
6.
Metab Eng ; 70: 79-88, 2022 03.
Artigo em Inglês | MEDLINE | ID: mdl-35038553

RESUMO

Corynebacterium glutamicum is a versatile chassis which has been widely used to produce various amino acids and organic acids. In this study, we report the development of an efficient C. glutamicum strain to produce 1,3-propanediol (1,3-PDO) from glucose and xylose by systems metabolic engineering approaches, including (1) construction and optimization of two different glycerol synthesis modules; (2) combining glycerol and 1,3-PDO synthesis modules; (3) reducing 3-hydroxypropionate accumulation by clarifying a mechanism involving 1,3-PDO re-consumption; (4) reducing the accumulation of toxic 3-hydroxypropionaldehyde by pathway engineering; (5) engineering NADPH generation pathway and anaplerotic pathway. The final engineered strain can efficiently produce 1,3-PDO from glucose with a titer of 110.4 g/L, a yield of 0.42 g/g glucose, and a productivity of 2.30 g/L/h in fed-batch fermentation. By further introducing an optimized xylose metabolism module, the engineered strain can simultaneously utilize glucose and xylose to produce 1,3-PDO with a titer of 98.2 g/L and a yield of 0.38 g/g sugars. This result demonstrates that C. glutamicum is a potential chassis for the industrial production of 1,3-PDO from abundant lignocellulosic feedstocks.


Assuntos
Corynebacterium glutamicum , Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Fermentação , Glucose/metabolismo , Engenharia Metabólica , Propilenoglicóis , Xilose/metabolismo
7.
Metab Eng ; 74: 168-177, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-36328298

RESUMO

1,5-Pentanediol (1,5-PDO) is a high value-added chemical which is widely used as a monomer in the polymer industry. There are no natural organisms that could directly produce 1,5-PDO from renewable carbon sources. In this study, we report metabolic engineering of Escherichia coli for high-level production of 1,5-PDO from glucose via a cadaverine-derived pathway. In the newly proposed pathway, cadaverine can be converted to 1,5-PDO via 5-hydroxyvalerate (5-HV) by introducing only one heterologous enzyme in E. coli. Different endogenous genes of E. coli were screened and heterologous carboxylic acid reductase genes were tested to build a functional pathway. Compared to the previously reported pathways, the engineered cadaverine-based pathway has a higher theoretical yield (0.70 mol/mol glucose) and higher catalytic efficiency. By further combining strategies of pathway engineering and process engineering, we constructed an engineered E. coli strain that could produce 2.62 g/L 1,5-PDO in shake-flask and 9.25 g/L 1,5-PDO with a yield of 0.28 mol/mol glucose in fed-batch fermentation. The proposed new pathway and engineering strategies reported here should be useful for developing biological routes to produce 1,5-PDO for real application.


Assuntos
Escherichia coli , Engenharia Metabólica , Cadaverina/metabolismo , Escherichia coli/genética , Escherichia coli/metabolismo , Fermentação , Glucose/genética , Glucose/metabolismo
8.
BMC Microbiol ; 22(1): 184, 2022 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-35870901

RESUMO

BACKGROUND: Gastric microbial dysbiosis were reported to be associated with gastric cancer (GC). This study aimed to explore the variation, diversity, and composition patterns of gastric bacteria in stages of gastric carcinogenesis based on the published datasets. METHODS: We conducted a gastric microbial analysis using 10 public datasets based on 16S rRNA sequencing, including 1270 gastric biopsies of 109 health control, 183 superficial gastritis (SG), 135 atrophic gastritis (AG), 124 intestinal metaplasia (IM), 94 intraepithelial neoplasia (IN), 344 GC, and 281 adjacent normal tissues. And QIIME2-pipeline, DESeq2, NetMoss2, vegan, igraph, and RandomForest were used for the data processing and analysis. RESULTS: We identified three gastric microbial communities among all the gastric tissues. The first community (designate as GT-H) was featured by the high abundance of Helicobacter. The other two microbial communities, namely GT-F, and GT-P, were featured by the enrichment of phylum Firmicutes and Proteobacteria, respectively. The distribution of GC-associated bacteria, such as Fusobacterium, Peptostreptococcus, Streptococcus, and Veillonella were enriched in tumor tissues, and mainly distributed in GT-F type microbial communities. Compared with SG, AG, and IM, the bacterial diversity in GC was significantly reduced. And the strength of microbial interaction networks was initially increased in IM but gradually decreased from IN to GC. In addition, Randomforest models constructed in in GT-H and GT-F microbial communities showed excellent performance in distinguishing GC from SG and precancerous stages, with varied donated bacteria. CONCLUSIONS: This study identified three types of gastric microbiome with different patterns of composition which helps to clarify the potential key bacteria in the development of gastric carcinogenesis.


Assuntos
Gastrite Atrófica , Gastrite , Microbioma Gastrointestinal , Infecções por Helicobacter , Helicobacter pylori , Microbiota , Neoplasias Gástricas , Bactérias/genética , Carcinogênese/patologia , Mucosa Gástrica/microbiologia , Gastrite/complicações , Gastrite/microbiologia , Gastrite/patologia , Gastrite Atrófica/complicações , Gastrite Atrófica/patologia , Microbioma Gastrointestinal/genética , Infecções por Helicobacter/microbiologia , Helicobacter pylori/genética , Humanos , Metaplasia , RNA Ribossômico 16S/genética
9.
Metab Eng ; 65: 52-65, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33722653

RESUMO

The economic viability of current bio-production systems is often limited by its low productivity due to slow cell growth and low substrate uptake rate. The fastest-growing bacterium Vibrio natriegens is a highly promising next-generation workhorse of the biotechnology industry which can utilize various industrially relevant carbon sources with high substrate uptake rates. Here, we demonstrate the first systematic engineering example of V. natriegens for the heterologous production of 1,3-propanediol (1,3-PDO) from glycerol. Systems metabolic engineering strategies have been applied in this study to develop a superior 1,3-PDO producer, including: (1) heterologous pathway construction and optimization; (2) engineering cellular transcriptional regulators and global transcriptomic analysis; (3) enhancing intracellular reducing power by cofactor engineering; (4) reducing the accumulation of toxic intermediate by pathway engineering; (5) systematic engineering of glycerol oxidation pathway to eliminate byproduct formation. A final engineered strain can efficiently produce 1,3-PDO with a titer of 56.2 g/L, a yield of 0.61 mol/mol, and an average productivity of 2.36 g/L/h. The strategies described in this study would be useful for engineering V. natriegens as a potential chassis for the production of other useful chemicals and biofuels.


Assuntos
Engenharia Metabólica , Vibrio , Glicerol , Propilenoglicóis , Vibrio/genética
10.
Molecules ; 26(8)2021 Apr 12.
Artigo em Inglês | MEDLINE | ID: mdl-33921241

RESUMO

Furfural is one of the most promising precursor chemicals with an extended range of downstream derivatives. In this work, conversion of xylose to produce furfural was performed by employing p-toluenesulfonic acid (pTSA) as a catalyst in DMSO medium at moderate temperature and atmospheric pressure. The production process was optimized based on kinetic modeling of xylose conversion to furfural alongwith simultaneous formation of humin from xylose and furfural. The synergetic effects of organic acids and Lewis acids were investigated. Results showed that the catalyst pTSA-CrCl3·6H2O was a promising combined catalyst due to the high furfural yield (53.10%) at a moderate temperature of 120 °C. Observed kinetic modeling illustrated that the condensation of furfural in the DMSO solvent medium actually could be neglected. The established model was found to be satisfactory and could be well applied for process simulation and optimization with adequate accuracy. The estimated values of activation energies for xylose dehydration, condensation of xylose, and furfural to humin were 81.80, 66.50, and 93.02 kJ/mol, respectively.

11.
Metab Eng ; 52: 77-86, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30458240

RESUMO

Increasing the availability of NADPH is commonly used to improve lysine production by Corynebacterium glutamicum since 4 mol of NADPH are required for the synthesis of 1 mol of lysine. Alternatively, engineering of enzymes in lysine synthesis pathway to utilize NADH directly can also be explored for cofactor balance during lysine overproduction. To achieve such a goal, enzyme mining was used in this study to quickly identify a full set of NADH-utilizing dehydrogenases, namely aspartate dehydrogenase from Pseudomonas aeruginosa (PaASPDH), aspartate-semialdehyde dehydrogenase from Tistrella mobilis (TmASADH), dihydrodipicolinate reductase from Escherichia coli (EcDHDPR), and diaminopimelate dehydrogenase from Pseudothermotoga thermarum (PtDAPDH). This allowed us to systematically perturb cofactor utilization of lysine synthesis pathway of C. glutamicum for the first time. Individual overexpression of PaASPDH, TmASADH, EcDHDPR, and PtDAPDH in C. glutamicum LC298, a basic lysine producer, increased the production of lysine by 30.7%, 32.4%, 17.4%, and 36.8%, respectively. Combinatorial replacement of NADPH-dependent dehydrogenases in C. glutamicum ATCC 21543, a lysine hyperproducer, also resulted in significantly improved lysine production. The highest increase of lysine production (30.7%) was observed for a triple-mutant strain (27.7 g/L, 0.35 g/g glucose) expressing PaASPDH, TmASADH, and EcDHDPR. A quadruple-mutant strain expressing all of the four NADH-utilizing enzymes allowed high lysine production (24.1 g/L, 0.30 g/g glucose) almost independent of the oxidative pentose phosphate pathway. Collectively, our results demonstrated that a combination of enzyme mining and cofactor engineering was a highly efficient approach to improve lysine production. Similar strategies can be applied for the production of other amino acids or their derivatives.


Assuntos
Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Lisina/biossíntese , Engenharia Metabólica/métodos , NAD/biossíntese , Meios de Cultura , Redes e Vias Metabólicas/genética , Modelos Moleculares , Mutação/genética , NADH Desidrogenase/metabolismo , NADPH Desidrogenase/genética , NADPH Desidrogenase/metabolismo , Via de Pentose Fosfato , Plasmídeos/genética
12.
Retrovirology ; 15(1): 27, 2018 04 02.
Artigo em Inglês | MEDLINE | ID: mdl-29609648

RESUMO

BACKGROUND: The native pre-fusion structure of gp120/gp41 complex of human immunodeficiency virus type 1 was recently revealed. In the model, the helices of gp41 (α6, α7, α8, and α9) form a four-helix collar underneath trimeric gp120. Gp41 is a class I fusion protein and mediates membrane fusion by forming a post-fusion structure called the six-helix bundle (6HB). The comparison of the pre- and post-fusion structures revealed the large conformational changes in gp41 during the antiparallel packing of the N- and C-terminal heptad repeats (NHRs and CHRs) in membrane fusion. Several mutagenesis studies of gp41 performed in the past were interpreted based on 6HB, the only available structure at that time. To obtain an insight about the current pre-fusion structural model and conformational changes during membrane fusion, alanine insertion mutagenesis of the NHR, CHR and connecting loop regions of HXB2 gp41 was performed. The effects of mutations on biosynthesis and membrane fusion were analyzed by immunoblotting and fusion assays, respectively. The extent of membrane fusion was evaluated by split luciferase-based pore formation and syncytia formation assays, respectively. RESULTS: Consistent with the current structural model, drastic negative effects of mutations on biosynthesis and membrane fusion were observed for NHR, loop, and proximal regions of CHR (up to amino acid position 643). The insertions in α9 after it leaves the four-helix collar were tolerable for biosynthesis. These CHR mutants showed varying effects on membrane fusion. Insertion at position 644 or 645 resulted in poor pore and syncytia formation. Efficient pore and syncytia formation almost similar to that of the wild type was observed for insertion at position 647, 648 or 649. However, recovery of virus infectivity was only observed for the insertions beyond position 648. CONCLUSIONS: The mutagenesis data for HXB2 gp41 is in agreement with the recent pre-fusion structure model. The virus infection data suggested that fusion pores sufficiently large enough for the release of the virus genome complex are formed after the completion of 6HB beyond position 648.


Assuntos
Proteína gp41 do Envelope de HIV/química , Proteína gp41 do Envelope de HIV/metabolismo , Infecções por HIV/virologia , HIV-1/fisiologia , Domínios e Motivos de Interação entre Proteínas , Sequências Repetitivas de Ácido Nucleico , Alanina/genética , Sequência de Aminoácidos , Proteína gp41 do Envelope de HIV/genética , Humanos , Modelos Biológicos , Modelos Moleculares , Mutagênese Insercional , Biossíntese de Proteínas , Conformação Proteica , Internalização do Vírus , Replicação Viral
13.
Molecules ; 23(11)2018 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-30373169

RESUMO

Allergic asthma is a highly prevalent airway inflammatory disease, which involves the interaction between the immune system, environmental and genetic factors. Co-relation between allergic asthma and gut microbiota upon the change of diet have been widely reported, implicating that oral intake of alternative medicines possess a potential in the management of allergic asthma. Previous clinical, in vivo, and in vitro studies have shown that the Pentaherbs formula (PHF) comprising five traditional Chinese herbal medicines Lonicerae Flos, Menthae Herba, Phellodendri Cortex, Moutan Cortex, and Atractylodis Rhizoma possesses an anti-allergic and anti-inflammatory potential through suppressing various immune effector cells. In the present study, to further investigate the anti-inflammatory activities of PHF in allergic asthma, intragastrical administration of PHF was found to reduce airway hyperresponsiveness, airway wall remodeling and goblet cells hyperplasia in an ovalbumin (OVA)-induced allergic asthma mice model. PHF also significantly suppressed pulmonary eosinophilia and asthma-related cytokines IL-4 and IL-33 in bronchoalveolar lavage (BAL) fluid. In addition, PHF modulated the splenic regulatory T cells population, up-regulated regulatory interleukin (IL)-10 in serum, altered the microbial community structure and the short chain fatty acids content in the gut of the asthmatic mice. This study sheds light on the anti-inflammatory activities of PHF on allergic asthma. It also provides novel in vivo evidence that herbal medicines can ameliorate symptoms of allergic diseases may potentially prevent the development of subsequent atopic disorder such as allergic asthma through the influence of the gut microbiota.


Assuntos
Anti-Inflamatórios/uso terapêutico , Asma/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Microbioma Gastrointestinal/efeitos dos fármacos , Remodelação das Vias Aéreas , Animais , Anti-Inflamatórios/farmacologia , Asma/imunologia , Asma/metabolismo , Asma/patologia , Biodiversidade , Citocinas/metabolismo , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Eosinófilos/imunologia , Eosinófilos/metabolismo , Ácidos Graxos Voláteis/metabolismo , Imunoglobulina E/imunologia , Masculino , Camundongos , Ovalbumina/imunologia , Hipersensibilidade Respiratória/imunologia , Baço/imunologia , Baço/metabolismo , Linfócitos T Reguladores/imunologia , Linfócitos T Reguladores/metabolismo
14.
Metab Eng ; 39: 151-158, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27918882

RESUMO

3-Hydroxypropionic acid (3-HP) is a promising platform chemical which can be used for the production of various value-added chemicals. In this study,Corynebacterium glutamicum was metabolically engineered to efficiently produce 3-HP from glucose and xylose via the glycerol pathway. A functional 3-HP synthesis pathway was engineered through a combination of genes involved in glycerol synthesis (fusion of gpd and gpp from Saccharomyces cerevisiae) and 3-HP production (pduCDEGH from Klebsiella pneumoniae and aldehyde dehydrogenases from various resources). High 3-HP yield was achieved by screening of active aldehyde dehydrogenases and by minimizing byproduct synthesis (gapAA1GΔldhAΔpta-ackAΔpoxBΔglpK). Substitution of phosphoenolpyruvate-dependent glucose uptake system (PTS) by inositol permeases (iolT1) and glucokinase (glk) further increased 3-HP production to 38.6g/L, with the yield of 0.48g/g glucose. To broaden its substrate spectrum, the engineered strain was modified to incorporate the pentose transport gene araE and xylose catabolic gene xylAB, allowing for the simultaneous utilization of glucose and xylose. Combination of these genetic manipulations resulted in an engineered C. glutamicum strain capable of producing 62.6g/L 3-HP at a yield of 0.51g/g glucose in fed-batch fermentation. To the best of our knowledge, this is the highest titer and yield of 3-HP from sugar. This is also the first report for the production of 3-HP from xylose, opening the way toward 3-HP production from abundant lignocellulosic feedstocks.


Assuntos
Proteínas de Bactérias/genética , Vias Biossintéticas/fisiologia , Corynebacterium glutamicum/fisiologia , Glucose/metabolismo , Ácido Láctico/análogos & derivados , Engenharia Metabólica/métodos , Xilose/metabolismo , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica/genética , Melhoramento Genético/métodos , Glicerol/metabolismo , Ácido Láctico/biossíntese , Ácido Láctico/isolamento & purificação , Redes e Vias Metabólicas/fisiologia
15.
World J Microbiol Biotechnol ; 33(3): 54, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28220353

RESUMO

Oleaginous microorganisms are receiving significant attention worldwide for their utility in biodiesel production and the potentiality to produce some specialty-type lipids. There is an increasing interest in isolation/adaption of robust microbe strains and design of innovative fermentation processes to make microbial lipid production a more efficient and economically feasible bio-process. Currently, the genus Rhodosporidium has been considered an important candidate, for the reason that several strains belonging to this genus have shown excellent capabilities of lipid accumulation, broad adaptabilities to various substrates, and co-production of some carotenoids. This paper reviews the current trends in the exploitation of Rhodosporidium species for microbial lipid production, including the utilization of various (single or mixed, pure or waste-derived) substrates, progress of genetic modification and metabolic engineering, innovations in fermentation mode, lipid characterizations and their potential applications. Finally, the constraints and perspectives of cultivating Rhodosporidium species for lipid production are also discussed.


Assuntos
Basidiomycota/metabolismo , Lipídeos/biossíntese , Basidiomycota/enzimologia , Basidiomycota/genética , Biocombustíveis , Ácidos Graxos/metabolismo , Fermentação , Microbiologia Industrial/métodos , Metabolismo dos Lipídeos , Lipídeos/economia , Engenharia Metabólica
16.
Metab Eng ; 33: 12-18, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26556130

RESUMO

Development of sustainable biological process for the production of bulk chemicals from renewable feedstock is an important goal of white biotechnology. Ethylene glycol (EG) is a large-volume commodity chemical with an annual production of over 20 million tons, and it is currently produced exclusively by petrochemical route. Herein, we report a novel biosynthetic route to produce EG from glucose by the extension of serine synthesis pathway of Corynebacterium glutamicum. The EG synthesis is achieved by the reduction of glycoaldehyde derived from serine. The transformation of serine to glycoaldehyde is catalyzed either by the sequential enzymatic deamination and decarboxylation or by the enzymatic decarboxylation and oxidation. We screened the corresponding enzymes and optimized the production strain by combinatorial optimization and metabolic engineering. The best engineered C. glutamicum strain is able to accumulate 3.5 g/L of EG with the yield of 0.25 mol/mol glucose in batch cultivation. This study lays the basis for developing an efficient biological process for EG production.


Assuntos
Corynebacterium glutamicum/genética , Corynebacterium glutamicum/metabolismo , Etilenoglicol/metabolismo , Glucose/metabolismo , Engenharia Metabólica/métodos , Serina/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Etilenoglicol/isolamento & purificação , Transdução de Sinais/fisiologia
17.
World J Microbiol Biotechnol ; 32(7): 107, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27263002

RESUMO

Microbial oil is drawing increasing interest worldwide as an alternative non-food oil feedstock for biodiesel industry. Nowadays researchers have been increasingly focused on the improvement of microbial oil production process. Oleaginous yeast Rhodosporidium toruloides (R. toruloides) is considered an important candidate due to its excellent capabilities of lipid accumulation, broad adaptabilities to various carbon substrates, and the potential of co-production of some pigments. In present work, the individual effects of non-ionic, cationic, and anionic surfactant on cell growth and lipid accumulation of R. toruloides were investigated for the first time. Interesting results were noticed when some anionic surfactants were supplemented. The most significant effect was observed with addition of 0.2 % (w/v) sodium lignosulfonate, that biomass concentration, lipid concentration, and lipid yield was increased by 25.1, 44.9, and 15.7 %, respectively. The fatty acid compositions of R. toruloides lipids remained unchanged, which is similar to that of vegetable oils, and is considered potential feedstock for biodiesel preparation.


Assuntos
Basidiomycota/efeitos dos fármacos , Basidiomycota/metabolismo , Lipídeos/biossíntese , Tensoativos/farmacologia , Basidiomycota/crescimento & desenvolvimento , Biomassa , Carbono/metabolismo , Ácidos Graxos/metabolismo , Fermentação , Lignina/análogos & derivados , Lignina/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Pigmentos Biológicos/biossíntese , Tensoativos/química
18.
Guang Pu Xue Yu Guang Pu Fen Xi ; 35(11): 3167-71, 2015 Nov.
Artigo em Zh | MEDLINE | ID: mdl-26978929

RESUMO

Hyperspectral imaging technology covered the range of 380-1000 nm was employed to detect defects (bruise and insect damage) of hawthorn fruit. A total of 134 samples were collected, which included damage fruit of 46, pest fruit of 30, injure and pest fruit of 10 and intact fruit of 48. Because calyx · s⁻¹ tem-end and bruise/insect damage regions offered a similar appearance characteristic in RGB images, which could produce easily confusion between them. Hence, five types of defects including bruise, insect damage, sound, calyx, and stem-end were collected from 230 hawthorn fruits. After acquiring hyperspectral images of hawthorn fruits, the spectral data were extracted from region of interest (ROI). Then, several pretreatment methods of standard normalized variate (SNV), savitzky golay (SG), median filter (MF) and multiplicative scatter correction (MSC) were used and partial least squares method(PLS) model was carried out to obtain the better performance. Accordingly to their results, SNV pretreatment methods assessed by PLS was viewed as best pretreatment method. Lastly, SNV was chosen as the pretreatment method. Spectral features of five different regions were combined with Regression coefficients(RCs) of partial least squares-discriminant analysis (PLS-DA) model was used to identify the important wavelengths and ten wavebands at 483, 563, 645, 671, 686, 722, 777, 819, 837 and 942 nm were selected from all of the wavebands. Using Kennard-Stone algorithm, all kinds of samples were randomly divided into training set (173) and test set (57) according to the proportion of 3:1. And then, least squares-support vector machine (LS-SVM) discriminate model was established by using the selected wavebands. The results showed that the discriminate accuracy of the method was 91.23%. In the other hand, images at ten important wavebands were executed to Principal component analysis (PCA). Using "Sobel" operator and region growing algrorithm "Regiongrow", the edge and defect feature of 86 Hawthorn could be recognized. Lastly, the detect precision of bruised, insect damage and two-defect samples is 95.65%, 86.67% and 100%, respectively. This investigation demonstrated that hyperspectral imaging technology could detect the defects of bruise, insect damage, calyx, and stem-end in hawthorn fruit in qualitative analysis and feature detection which provided a theoretical reference for the defects nondestructive detection of hawthorn fruit.


Assuntos
Crataegus , Frutas , Animais , Medicamentos de Ervas Chinesas/análise , Insetos , Análise Espectral
19.
Biotechnol Bioeng ; 111(4): 639-53, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24284881

RESUMO

Biodiesel is an environment-friendly and renewable fuel produced by transesterification of various feedstocks. Although the lipase-catalyzed biodiesel production has many advantages over the conventional alkali catalyzed process, its industrial applications have been limited by high-cost and low-stability of lipase enzymes. This review provides a general overview of the recent advances in lipase engineering, including both protein modification and production. Recent advances in biotechnology such as in protein engineering, recombinant methods and metabolic engineering have been employed but are yet to impact lipase engineering for cost-effective production of biodiesel. A summary of the current challenges and perspectives for potential solutions are also provided.


Assuntos
Biocombustíveis , Biotecnologia , Enzimas Imobilizadas , Lipase , Engenharia de Proteínas , Proteínas de Bactérias , Estabilidade Enzimática , Esterificação , Proteínas Fúngicas , Engenharia Metabólica
20.
BMC Neurol ; 14: 188, 2014 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-25300531

RESUMO

BACKGROUND: Intracranial aneurysms are pathological dilatations of the cerebral artery, while rupture of intracranial aneurysms causes life-threatening subarachnoid hemorrhage. The molecular mechanisms of pathogenesis of intracranial aneurysms are poorly understood. MicroRNAs have fundamental roles in modulating vascular biology and disease. In the present study, we carried out a genome-wide characterization on expressions of microRNAs, and performed integrative analyses in conjunction with changes of the transcriptome in human intracranial aneurysms. METHODS: Genome-wide microRNA screening was performed in 6 intracranial aneurysmal samples and 6 normal superficial temporal arteries. Each case and control pair was individually matched with gender, age (±5 years), and high blood pressure history. Microarray analysis was performed using Agilent Human miRNA arrays. RESULTS: As compared to normal arteries, we identified 157 microRNAs that were differentially expressed in the aneurysmal tissue (P < 0.05 and fold change ≥ 2), including 72 upregulated and 85 downregulated. The changed microRNAs included endothelium-enriched microRNAs such as members of the let-7 family, miR-17, miR-23b, miR-126, hsa-miR-24-1 and miR-222, and vascular smooth muscle-enriched miRNAs such as miR-143 and miR-145. Moreover, miR-1, miR-10a, miR-125b, and miR-26a, which were implicated in modulating vascular smooth muscle cell functions such as proliferation, apoptosis and shift of phenotype, were also changed. In contrast, microRNAs involved in monocyte and macrophage functions, such as miR-155, miR-146a, miR-223, and miR-124a, were not significantly changed. Bioinformatic analysis revealed that the changed microRNAs were associated with several biological processes related to aneurysm formation, including inflammation, dysregulation of extracellular matrix, smooth muscle cell proliferation, programmed cell death, and response to oxidative stress. Interestingly, we found that a subset of the potential microRNA target genes belonged to the protein translation machinery, including various eukaryotic translation initiation factors and ribosomal proteins, and this finding was highly correlated with our previous transcriptome data showing that multiple genes of the ribosomal proteins and translation initiation and elongation factors were significantly downregulated in human intracranial aneurysms. CONCLUSIONS: Our results support that dysregulated microRNAs may have a pathogenic role in intracranial aneurysms. Disruption of the protein translation process may have a pathogenic role in the development of intracranial aneurysms.


Assuntos
Estudo de Associação Genômica Ampla , Aneurisma Intracraniano/metabolismo , MicroRNAs/metabolismo , Feminino , Expressão Gênica , Humanos , Masculino , Análise em Microsséries , Pessoa de Meia-Idade , Transcriptoma
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