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1.
Appl Microbiol Biotechnol ; 108(1): 33, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38175234

RESUMO

Due to the limited resources and environmental problems associated with fossil fuels, there is a growing interest in utilizing renewable resources for the production of biofuels through microbial fermentation. Isobutanol is a promising biofuel that could potentially replace gasoline. However, its production efficiency is currently limited by the use of naturally isolated microorganisms. These naturally isolated microorganisms often encounter problems such as a limited range of substrates, low tolerance to solvents or inhibitors, feedback inhibition, and an imbalanced redox state. This makes it difficult to improve their production efficiency through traditional process optimization methods. Fortunately, recent advancements in genetic engineering technologies have made it possible to enhance microbial hosts for the increased production of isobutanol from renewable resources. This review provides a summary of the strategies and synthetic biology approaches that have been employed in the past few years to improve naturally isolated or non-natural microbial hosts for the enhanced production of isobutanol by utilizing different renewable resources. Furthermore, it also discusses the challenges that are faced by engineered microbial hosts and presents future perspectives to enhancing isobutanol production. KEY POINTS: • Promising potential of isobutanol to replace gasoline • Engineering of native and non-native microbial host for isobutanol production • Challenges and opportunities for enhanced isobutanol production.


Assuntos
Biocombustíveis , Gasolina , Butanóis , Clonagem Molecular
2.
Int J Mol Sci ; 25(13)2024 Jun 29.
Artigo em Inglês | MEDLINE | ID: mdl-39000292

RESUMO

Latilactobacillus (L.) sakei is a species of lactic acid bacteria (LAB) mostly studied according to its application in food fermentation. Previously, L. sakei L3 was isolated by our laboratory and possessed the capability of high exopolysaccharide (EPS) yield during sucrose-added fermentation. However, the understanding of sucrose promoting EPS production is still limited. Here, we analyzed the growth characteristics of L. sakei L3 and alterations of its transcriptional profiles during sucrose-added fermentation. The results showed that L. sakei L3 could survive between pH 4.0 and pH 9.0, tolerant to NaCl (<10%, w/v) and urea (<6%, w/v). Meanwhile, transcriptomic analysis showed that a total of 426 differentially expressed genes and eight non-coding RNAs were identified. Genes associated with sucrose metabolism were significantly induced, so L. sakei L3 increased the utilization of sucrose to produce EPS, while genes related to uridine monophosphate (UMP), fatty acids and folate synthetic pathways were significantly inhibited, indicating that L. sakei L3 decreased self-growth, substance and energy metabolism to satisfy EPS production. Overall, transcriptome analysis provided valuable insights into the mechanisms by which L. sakei L3 utilizes sucrose for EPS biosynthesis. The study provided a theoretical foundation for the further application of functional EPS in the food industry.


Assuntos
Fermentação , Perfilação da Expressão Gênica , Regulação Bacteriana da Expressão Gênica , Latilactobacillus sakei , Polissacarídeos Bacterianos , Sacarose , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/metabolismo , Sacarose/metabolismo , Latilactobacillus sakei/metabolismo , Latilactobacillus sakei/genética , Transcriptoma , Concentração de Íons de Hidrogênio
3.
Molecules ; 29(2)2024 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-38257328

RESUMO

(R)-Benzylsuccinate is generated in anaerobic toluene degradation by the radical addition of toluene to fumarate and further degraded to benzoyl-CoA by a ß-oxidation pathway. Using metabolic modules for benzoate transport and activation to benzoyl-CoA and the enzymes of benzylsuccinate ß-oxidation, we established an artificial pathway for benzylsuccinate production in Escherichia coli, which is based on its degradation pathway running in reverse. Benzoate is supplied to the medium but needs to be converted to benzoyl-CoA by an uptake transporter and a benzoate-CoA ligase or CoA-transferase. In contrast, the second substrate succinate is endogenously produced from glucose under anaerobic conditions, and the constructed pathway includes a succinyl-CoA:benzylsuccinate CoA-transferase that activates it to the CoA-thioester. We present first evidence for the feasibility of this pathway and explore product yields under different growth conditions. Compared to aerobic cultures, the product yield increased more than 1000-fold in anaerobic glucose-fermenting cultures and showed further improvement under fumarate-respiring conditions. An important bottleneck to overcome appears to be product excretion, based on much higher recorded intracellular concentrations of benzylsuccinate, compared to those excreted. While no export system is known for benzylsuccinate, we observed an increased product yield after adding an unspecific mechanosensitive channel to the constructed pathway.


Assuntos
Coenzima A-Transferases , Escherichia coli , Escherichia coli/genética , Succinatos , Benzoatos , Fumaratos , Glucose , Tolueno
4.
Angew Chem Int Ed Engl ; : e202410381, 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39087309

RESUMO

For piezoelectric catalysis, the catalytic mechanism is a topic of great controversy, with debates centered around whether it belongs to the energy band theory of photocatalysis or the screening charge effect of electrochemical catalysis. Due to the formation of different intermediate active-species during two-electron oxygen reduction reaction (ORR) via electro- and photo-catalysis, the key to solving this problem is precisely monitoring the active species involved in ORR during electro-, photo-, and piezo-catalysis under identical condition. Here, a semiconductor material, BiOBr with abundant oxygen vacancies (BOB-OV) was found remarkable catalytic activity in H2O2 production by all three catalytic methods. By employing in-situ electron paramagnetic resonance (EPR) spectroscopy, the H2O2 evolution pathway through piezo-catalysis over BOB-OV was monitored, which showed a similar reaction pathway to that observed in photo-catalytic process. This finding represents solid evidence supporting the notion that piezo-catalytic mechanism of ORR is more inclined towards photo-catalysis rather than electro-catalysis. Significantly, this exploratory conclusion provides insight to deepen our understanding of piezo-catalysis.

5.
Crit Rev Biotechnol ; : 1-18, 2023 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-37380349

RESUMO

Recent studies are increasingly focusing on advanced biotechnological tools, self-adjusting smart microorganisms, and artificial intelligent networks, to engineer microorganisms with various functions. Microbial cell factories are a vital platform for improving the bioproduction of medicines, biofuels, and biomaterials from renewable carbon sources. However, these processes are significantly affected by cellular metabolism, and boosting the efficiency of microbial cell factories remains a challenge. In this review, we present a strategy for reprogramming cellular metabolism to enhance the efficiency of microbial cell factories for chemical biosynthesis, which improves our understanding of microbial physiology and metabolic control. Current methods are mainly focused on synthetic pathways, metabolic resources, and cell performance. This review highlights the potential biotechnological strategy to reprogram cellular metabolism and provide novel guidance for designing more intelligent industrial microbes with broader applications in this growing field.

6.
World J Microbiol Biotechnol ; 39(8): 224, 2023 Jun 09.
Artigo em Inglês | MEDLINE | ID: mdl-37291450

RESUMO

Menaquinone-7 (MK-7), a valuable member of the vitamin K2 series, is an essential nutrient for humans. It is used for treating coagulation disorders, and osteoporosis, promoting liver function recovery, and preventing cardiovascular diseases. In this study, to further improve the metabolic synthesis of MK-7 by the mutant strain, the effect of surfactants on the metabolic synthesis of MK-7 by the mutant strain Bacillus subtilis 168 KO-SinR (BS168 KO-SinR) was analyzed. The scanning electron microscopy and flow cytometry results showed that the addition of surfactants changed the permeability of the cell membrane of the mutant strain and the structural components of the biofilm. When 0.7% Tween-80 was added into the medium, the extracellular and intracellular synthesis of MK-7 reached 28.8 mg/L and 59.2 mg/L, respectively, increasing the total synthesis of MK-7 by 80.3%. Quantitative real-time PCR showed that the addition of surfactant significantly increased the expression level of MK-7 synthesis-related genes, and the electron microscopy results showed that the addition of surfactant changed the permeability of the cell membrane. The research results of this paper can serve as a reference for the industrial development of MK-7 prepared by fermentation.


Assuntos
Bacillus subtilis , Tensoativos , Humanos , Vitamina K 2/metabolismo , Fermentação , Bacillus subtilis/metabolismo , Tensoativos/metabolismo , Biofilmes
7.
Zhongguo Zhong Yao Za Zhi ; 48(12): 3132-3139, 2023 Jun.
Artigo em Zh | MEDLINE | ID: mdl-37381995

RESUMO

Strigolactones(SLs) are a class of sesquiterpenoids derived from the carotenoid biosynthesis pathway with the core carbon skeleton consisting of tricyclic lactone(ABC tricyclic ring) and α,ß-unsaturated furan ring(D ring). SLs are widely distributed in higher plants and are symbiotic signals between plants and Arbuscular mycorrhiza(AM), which play key roles in the evolution of plant colonizing terrestrial habitats. As a new type of plant hormone, SLs possess such important biological functions as inhibiting shoot branching(tillers), regulating root architecture, promoting secondary growth, and improving plant stress resistance. Therefore, SLs have attracted wide attention. The biological functions of SLs are not only closely related to the formation of "excellent shape and quality" of Chinese medicinal materials but also have important practical significance for the production of high-quality medicinal materials. However, SLs have been currently widely studied in model plants and crops such as Oryza sativa and Arabidopsis thaliana, and few related studies have been reported on SLs in medicinal plants, which need to be strengthened. This review focused on the latest research progress in the isolation and identification, biological and artificial synthesis pathways, biosynthesis sites and transport modes, signal transduction pathways and mechanisms, and biological functions of SLs, and prospected the research on the regulation mechanism of SLs in the growth and development of medicinal plants and their related application on targeted regulation of Chinese herbal medicine production, which is expected to provide some references for the in-depth research on SLs in the field of Chinese medicinal resources.


Assuntos
Arabidopsis , Plantas Medicinais , Lactonas
8.
Med Chem Res ; 31(2): 232-243, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35002192

RESUMO

During the COVID-19 pandemic, various drug candidates have been developed, molnupiravir (MK-4482 and EIDD-2801), which is a new orally anti-viral agent under development for the treatment of COVID-19, is under study in the final stage of the clinical trial. Molnupiravir enhances the replication of viral RNA mutations in animals and humans. Due to the high demand for the synthesis of this drug, it was essential to develop an efficient and suitable synthetic pathway from raw material. In this study, molecular docking analysis on molnupiravir is examined also, the mechanism of action (MOA) and the recent synthetic pathway is reported. This review will be helpful to different disciplines such as medicinal chemistry, organic chemistry, biochemistry, and pharmacology.

9.
Cell Mol Biol (Noisy-le-grand) ; 66(3): 8-16, 2020 Jun 05.
Artigo em Inglês | MEDLINE | ID: mdl-32538741

RESUMO

In order to explore the pathway of non-structural carbohydrate synthesis, an analysis of the pathway of non-structural carbohydrate synthesis under the network security model was proposed. Taking non-structural carbohydrates as the research object, the experimental materials and equipment were selected under the network security model. Through the establishment of detection methods, the preparation of freeze-dried carbohydrates, the influence of synthesis pathway-specific inhibitors on the synthesis of non-structural carbohydrates, the influence of precursors and intermediates in the pathway on the synthesis of non-structural carbohydrates, the effect of multiple factors on the synthesis of non-structural carbohydrates, the influence of polysaccharide synthesis, the treatment of reaction solution for detection, the preparation of detection sample, the detection conditions of a liquid phase, the detection conditions of LC-MS and the determination of carbohydrate biomass were studied. The results showed that the synthesis of nonstructural carbohydrates requires the participation of the glycolysis, shikimic acid and phenylpropane pathways, but not the polyketone pathway.


Assuntos
Carboidratos/química , Modelos Biológicos , Vias Biossintéticas/efeitos dos fármacos , Carboidratos/síntese química , Iodoacetamida/farmacologia , Policetídeos/química , Policetídeos/metabolismo
10.
Molecules ; 25(23)2020 Nov 28.
Artigo em Inglês | MEDLINE | ID: mdl-33260656

RESUMO

Pulcherriminic acid is a cyclic dipeptide found mainly in Bacillus and yeast. Due to the ability of pulcherriminic acid to chelate Fe3+ to produce reddish brown pulcherrimin, microorganisms capable of synthesizing pulcherriminic acid compete with other microorganisms for environmental iron ions to achieve bacteriostatic effects. Therefore, studying the biosynthetic pathway and their enzymatic catalysis, gene regulation in the process of synthesis of pulcherriminic acid in Bacillus can facilitate the industrial production, and promote the wide application in food, agriculture and medicine industries. After initially discussing, this review summarizes current research on the synthesis of pulcherriminic acid by Bacillus, which includes the crystallization of key enzymes, molecular catalytic mechanisms, regulation of synthetic pathways, and methods to improve efficiency in synthesizing pulcherriminic acid and its precursors. Finally, possible applications of pulcherriminic acid in the fermented food, such as Chinese Baijiu, applying combinatorial biosynthesis will be summarized.


Assuntos
Antibacterianos/biossíntese , Bacillus/metabolismo , Vias Biossintéticas/efeitos dos fármacos , Pirazinas/metabolismo , Bacillus/crescimento & desenvolvimento , Pirazinas/isolamento & purificação
11.
Biochem Biophys Res Commun ; 520(3): 538-543, 2019 12 10.
Artigo em Inglês | MEDLINE | ID: mdl-31615653

RESUMO

The BioH carboxylesterase which is a typical α/ß-hydrolase enzyme involved in biotin synthetic pathway in most bacteria. BioH acts as a gatekeeper and blocks the further elongation of its substrate. In the pathogen Klebsiella pneumoniae, BioH plays a critical role in the biosynthesis of biotin. To better understand the molecular function of BioH, we determined the crystal structure of BioH from K. pneumoniae at 2.26 Šresolution using X-ray crystallography. The structure of KpBioH consists of an α-ß-α sandwich domain and a cap domain. B-factor analysis revealed that the α-ß-α sandwich domain is a rigid structure, while the loops in the cap domain shows the structural flexibility. The active site of KpBioH contains the catalytic triad (Ser82-Asp207-His235) on the interface of the α-ß-α sandwich domain, which is surrounded by the cap domain. Size exclusion chromatography shows that KpBioH prefers the monomeric state in solution, whereas two-fold symmetric dimeric formation of KpBioH was observed in the asymmetric unit, the conserved Cys31-based disulfide bonds can maintain the irreversible dimeric formation of KpBioH. Our study provides important structural insight for understanding the molecular mechanisms of KpBioH and its homologous proteins.


Assuntos
Proteínas de Bactérias/química , Carboxilesterase/química , Klebsiella pneumoniae/enzimologia , Proteína de Transporte de Acila/metabolismo , Sequência de Aminoácidos , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Vias Biossintéticas , Biotina/biossíntese , Carboxilesterase/genética , Carboxilesterase/metabolismo , Domínio Catalítico , Cristalografia por Raios X , Klebsiella pneumoniae/genética , Klebsiella pneumoniae/metabolismo , Modelos Moleculares , Conformação Proteica , Estrutura Quaternária de Proteína , Especificidade por Substrato
12.
Appl Environ Microbiol ; 85(14)2019 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-31053589

RESUMO

Candida albicans and Cryptococcus neoformans, human-pathogenic fungi found worldwide, are receiving increasing attention due to high morbidity and mortality in immunocompromised patients. In the present work, 110 fungus pairs were constructed by coculturing 16 wood-decaying basidiomycetes, among which coculture of Trametes robiniophila Murr and Pleurotus ostreatus was found to strongly inhibit pathogenic fungi through bioactivity-guided assays. A combination of metabolomics and molecular network analysis revealed that 44 features were either newly synthesized or produced at high levels in this coculture system and that 6 of the features that belonged to a family of novel and unusual linear sesterterpenes contributed to high activity with MICs of 1 to 32 µg/ml against pathogenic fungi. Furthermore, dynamic 13C-labeling analysis revealed an association between induced features and the corresponding fungi. Unusual sesterterpenes were 13C labeled only in P. ostreatus in a time course after stimulation by the coculture, suggesting that these sesterterpenes were synthesized by P. ostreatus instead of T. robiniophila Murr. Sesterterpene compounds 1 to 3 were renamed postrediene A to C. Real-time reverse transcription-quantitative PCR (RT-qPCR) analysis revealed that transcriptional levels of three genes encoding terpene synthase, farnesyl-diphosphate farnesyltransferase, and oxidase were found to be 8.2-fold, 88.7-fold, and 21.6-fold higher, respectively, in the coculture than in the monoculture, indicating that biosynthetic gene cluster 10 was most likely responsible for the synthesis of these sesterterpenes. A putative biosynthetic pathway of postrediene A to postrediene C was then proposed based on structures of sesterterpenes and molecular network analysis.IMPORTANCE A number of gene clusters involved in biosynthesis of secondary metabolites are presumably silent or expressed at low levels under conditions of standard laboratory cultivation, resulting in a large gap between the pool of discovered metabolites and genome capability. This work mimicked naturally occurring competition by construction of an artificial coculture of basidiomycete fungi for the identification of secondary metabolites with novel scaffolds and excellent bioactivity. Unusual linear sesterterpenes of postrediene A to C synthesized by P. ostreatus not only were promising lead drugs against human-pathogenic fungi but also highlighted a distinct pathway for sesterterpene biosynthesis in basidiomycetes. The current work provides an important basis for uncovering novel gene functions involved in sesterterpene synthesis and for gaining insights into the mechanism of silent gene activation in fungal defense.


Assuntos
Antifúngicos/farmacologia , Pleurotus/metabolismo , Sesterterpenos/metabolismo , Trametes/metabolismo , Candida albicans/efeitos dos fármacos , Técnicas de Cocultura , Cryptococcus neoformans/efeitos dos fármacos , Sesterterpenos/farmacologia
13.
Biotechnol Bioeng ; 116(11): 3072-3083, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31317529

RESUMO

Cinnabarinic acid is a valuable phenoxazinone that has broad applications in the pharmaceutical, chemical, and dyeing industries. However, few studies have investigated the production of cinnabarinic acid or its derivatives using genetically engineered microorganisms. Herein, an efficient synthetic pathway of cinnabarinic acid was designed and constructed in Pseudomonas chlororaphis GP72 for the first tim, which was more straightforward and robust than the known eukaryotic biosynthetic pathways. First, we screened and identified trans-2,3-dihydro-3-hydroxyanthranilic acid (DHHA) dehydrogenases from Escherichia coli MG1655 (encoded by entA), Streptomyces sp. NRRL12068 (encoded by bomO) and Streptomyces chartreusis NRRL3882 (encoded by calB3 ) based on the structural similarity of the substrate and product, and the DHHA dehydrogenase encoded by calB3 was selected for the synthesis of cinnabarinic acid due to its high DHHA conversion rate. Subsequently, cinnabarinic acid was synthesized by the expression of the DHHA dehydrogenase CalB3 and the phenoxazinone synthase CotA in the DHHA-producing strain P. chlororaphis GP72, resulting in a cinnabarinic acid titer of 20.3 mg/L at 48 hr. Further fermentation optimization by the addition of Cu2+ , H2 O2 , and with adding glycerol increased cinnabarinic acid titer to 136.2 mg/L in shake flasks. The results indicate that P. chlororaphis GP72 may be engineered as a microbial cell factory to produce cinnabarinic acid or its derivatives from renewable bioresources.


Assuntos
Proteínas de Bactérias , Vias Biossintéticas , Regulação Bacteriana da Expressão Gênica , Engenharia Metabólica , Oxazinas/metabolismo , Pseudomonas chlororaphis , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética , Pseudomonas chlororaphis/genética , Pseudomonas chlororaphis/metabolismo
14.
Metab Eng ; 39: 228-236, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-28013086

RESUMO

Natural products (NPs) and their derivatives are widely used as frontline treatments for many diseases. Actinobacteria spp. are used to produce most of NP antibiotics and have also been intensively investigated for NP production, derivatization, and discovery. However, due to the complicated transcriptional and metabolic regulation of NP biosynthesis in Actinobacteria, especially in the cases of genome mining and heterologous expression, it is often difficult to rationally and systematically engineer synthetic pathways to maximize biosynthetic efficiency. With the emergence of new tools and methods in metabolic engineering, the synthetic pathways of many chemicals, such as fatty acids and biofuels, in model organisms (e.g. Escherichia coli ), have been refactored to realize precise and flexible control of production. These studies also offer a promising approach for synthetic pathway refactoring in Actinobacteria. In this review, the great potential of Actinobacteria as a microbial cell factory for biosynthesis of NPs is discussed. To this end, recent progress in metabolic engineering of NP synthetic pathways in Actinobacteria are summarized and strategies and perspectives to rationally and systematically refactor synthetic pathways in Actinobacteria are highlighted.


Assuntos
Actinobacteria/fisiologia , Proteínas de Bactérias/metabolismo , Produtos Biológicos/metabolismo , Vias Biossintéticas/fisiologia , Melhoramento Genético/métodos , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/fisiologia , Proteínas de Bactérias/genética , Produtos Biológicos/isolamento & purificação , Análise do Fluxo Metabólico/métodos , Modelos Biológicos
15.
Appl Microbiol Biotechnol ; 100(6): 2651-62, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26585444

RESUMO

Ansamitocin P-3 (AP-3), an amacrocyclic lactam compound, is produced by Actinosynnema pretiosum. As a group of maytansinoid antibiotics, ansamitocins have an extraordinary antitumor activity by blocking the assembly of tubulin forming into functional microtubules. The biosynthesis of ansamitocins is initialized by the formation of UDP-glucose (UDPG) which is converted from glucose-1-phosphate (G1P). In this study, we focused on the influence of enhancement of UDPG biosynthesis on the production of ansamitocins in A. pretiosum. The homologous overexpressions of phosphoglucomutase, starch phosphorylase, and UTP-G1P uridylyltransferase, respectively, could largely increase the pool sizes of G1P and UDPG and result in improved AP-3 production. The elevated intracellular glucose-6-phosphate (G6P) level provided by the enhanced glyconeogenesis had, however, no significant effects on the biosynthesis of AP-3. The G6P-G1P-UDPG pathway was therefore systematically engineered by multiple genetic modifications, and a significant increase in AP-3 production was achieved (168 mg/L of AP-3 in flask culture, 40 % higher than the control strain). We also found that the enhancement of starch assimilation pathway could also improve the assembly of AP-3 to some extent. In addition, heterologous gene overexpression from Actinosynnema mirum could result in more AP-3 biosynthesis in comparison to the corresponding homologous overexpression, suggesting an alternative and promising avenue of metabolic engineering strategy for improving AP-3 production.


Assuntos
Actinobacteria/genética , Actinobacteria/metabolismo , Vias Biossintéticas/genética , Maitansina/análogos & derivados , Engenharia Metabólica/métodos , Moduladores de Tubulina/metabolismo , Uridina Difosfato Glucose/biossíntese , Gluconeogênese , Maitansina/metabolismo , Amido/metabolismo
16.
Proc Natl Acad Sci U S A ; 110(29): 12108-13, 2013 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-23812755

RESUMO

Cytochrome P450 enzymes (CYPs) play major roles in generating highly functionalized terpenoids, but identifying the exact biotransformation step(s) catalyzed by plant CYP in terpenoid biosynthesis is extremely challenging. Tanshinones are abietane-type norditerpenoid naphthoquinones that are the main lipophilic bioactive components of the Chinese medicinal herb danshen (Salvia miltiorrhiza). Whereas the diterpene synthases responsible for the conversion of (E,E,E)-geranylgeranyl diphosphate into the abietane miltiradiene, a potential precursor to tanshinones, have been recently described, molecular characterization of further transformation of miltiradiene remains unavailable. Here we report stable-isotope labeling results that demonstrate the intermediacy of miltiradiene in tanshinone biosynthesis. We further use a next-generation sequencing approach to identify six candidate CYP genes being coregulated with the diterpene synthase genes in both the rhizome and danshen hairy roots, and demonstrate that one of these, CYP76AH1, catalyzes a unique four-electron oxidation cascade on miltiradiene to produce ferruginol both in vitro and in vivo. We then build upon the previous establishment of miltiradiene production in Saccharomyces cerevisiae, with incorporation of CYP76AH1 and phyto-CYP reductase genes leading to heterologous production of ferruginol at 10.5 mg/L. As ferruginol has been found in many plants including danshen, the results and the approaches that were described here provide a solid foundation to further elucidate the biosynthesis of tanshinones and related diterpenoids. Moreover, these results should facilitate the construction of microbial cell factories for the production of phytoterpenoids.


Assuntos
Abietanos/biossíntese , Sistema Enzimático do Citocromo P-450/metabolismo , Diterpenos/metabolismo , Engenharia Metabólica/métodos , Salvia miltiorrhiza/química , Abietanos/química , Abietanos/isolamento & purificação , Sequência de Bases , Sistema Enzimático do Citocromo P-450/genética , Primers do DNA/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Marcação por Isótopo , Cinética , Espectrometria de Massas , Dados de Sequência Molecular , Estrutura Molecular , Reação em Cadeia da Polimerase em Tempo Real , Saccharomyces cerevisiae
17.
Fungal Genet Biol ; 85: 14-24, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26519220

RESUMO

Fungal endophytes belonging to the genus Epichloë form associations with temperate grasses belonging to the sub-family Poöideae that range from mutualistic through to pathogenic. We previously identified a novel endophyte gene (designated gigA for grass induced gene) that is one of the most abundantly expressed fungal transcripts in endophyte-infected grasses and which is distributed and highly expressed in a wide range of Epichloë grass associations. Molecular and biochemical analyses indicate that gigA encodes a small secreted protein containing an imperfect 27 amino acid repeat that includes a kexin protease cleavage site. Kexin processing of GigA liberates within the plant multiple related products, named here as epichloëcyclins, which we have demonstrated by MS/MS to be cyclic peptidic in nature. Gene deletion of gigA leads to the elimination of all epichloëcyclins with no conspicuous phenotypic impact on the host grass, suggesting a possible bioactive role. This is a further example of a ribosomal peptide synthetic (RiPS) pathway operating within the Ascomycetes, and is the first description of such a pathway from a mutualistic symbiotic fungus from this Phylum.


Assuntos
Endófitos/genética , Epichloe/genética , Proteínas Fúngicas/genética , Poaceae/microbiologia , Endófitos/fisiologia , Epichloe/fisiologia , Proteínas Fúngicas/química , Proteínas Fúngicas/metabolismo , Oligopeptídeos/genética , Oligopeptídeos/metabolismo , Peptídeos Cíclicos/genética , Peptídeos Cíclicos/metabolismo , Biossíntese de Proteínas , Proteínas Ribossômicas/química , Proteínas Ribossômicas/metabolismo , Simbiose , Espectrometria de Massas em Tandem
18.
Biotechnol Bioeng ; 112(1): 120-8, 2015 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24981220

RESUMO

Several synthetic metabolic pathways for butanol synthesis have been reported in Escherichia coli by modification of the native CoA-dependent pathway from selected Clostridium species. These pathways are all dependent on the O2 -sensitive AdhE2 enzyme from Clostridium acetobutylicum that catalyzes the sequential reduction of both butyryl-CoA and butyraldehyde. We constructed an O2 -tolerant butanol pathway based on the activities of an ACP-thioesterase, acting on butyryl-ACP in the native fatty acid biosynthesis pathway, and a promiscuous carboxylic acid reductase. The pathway was genetically optimized by screening a series of bacterial acyl-ACP thioesterases and also by modification of the physical growth parameters. In order to evaluate the potential of the pathway for butanol production, the ACP-dependent butanol pathway was compared with a previously established CoA-dependent pathway. The effect of (1) O2 -availability, (2) media, and (3) co-expression of aldehyde reductases was evaluated systematically demonstrating varying and contrasting functionality between the ACP- and CoA-dependent pathways. The yield of butanol from the ACP-dependent pathway was stimulated by enhanced O2 -availability, in contrast to the CoA-dependent pathway, which did not function well under aerobic conditions. Similarly, whilst the CoA-dependent pathway only performed well in complex media, the ACP-dependent pathway was not influenced by the choice of media except in the absence of O2 . A combination of a thioesterase from Bacteroides fragilis and the aldehyde reductase, ahr, from E. coli resulted in the greatest yield of butanol. A product titer of ~300 mg/L was obtained in 24 h under optimal batch growth conditions, in most cases exceeding the performance of the reference CoA-pathway when evaluated under equivalent conditions.


Assuntos
Butanóis/metabolismo , Escherichia coli/metabolismo , Ácidos Graxos/biossíntese , Engenharia Metabólica/métodos , Redes e Vias Metabólicas/genética , Biocombustíveis , Escherichia coli/genética
19.
Metab Eng ; 23: 175-84, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24576819

RESUMO

Overexpression of genes in production pathways and permanent knockout of genes in competing pathways are often employed to improve production titer and yield in metabolic engineering. However, the deletion of a pathway responsible for growth and cell maintenance has not previously been employed, even if its competition with the production pathway is obvious. In order to optimize intracellular metabolism at each fermentation phase for bacterial growth and production, a methodology employing conditional knockout is required. We constructed a metabolic toggle switch in Escherichia coli as a novel conditional knockout approach and applied it to isopropanol production. The resulting redirection of excess carbon flux caused by interruption of the TCA cycle via switching gltA OFF improved isopropanol production titer and yield up to 3.7 and 3.1 times, respectively. This approach is a useful tool to redirect carbon flux responsible for bacterial growth and/or cell maintenance toward a synthetic production pathway.


Assuntos
2-Propanol/metabolismo , Ciclo do Ácido Cítrico , Escherichia coli , Engenharia Metabólica/métodos , Escherichia coli/genética , Escherichia coli/metabolismo , Técnicas de Silenciamento de Genes
20.
Food Chem ; 460(Pt 1): 140459, 2024 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-39059325

RESUMO

Lignanamides are a class of compounds containing amide functional groups in lignans. These compounds have excellent anti-inflammatory and neuroprotective, which have shown great potential in terms of food additives, medicine and health supplement. We summarized the recent progress of lignanamides, including chemical constituents, extraction methods, biological activities, and synthetic pathways. The structures were classified according to an updated nomenclature system, can be classified into sixteen types and have certain roles in many respects such as anti-inflammatory, anti-cancer, and antioxidative, which may be important source of materials for functional food. The potential and limitations of different extraction method, chromatographic packing, and synthetic pathway are analyzed. Notably, this review provides an overview of synthesis pathways and applications of lignanamides, further research is needed to improve extraction efficiency and synthesis method, especially in a greener way for better application.

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