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1.
Int J Mol Sci ; 25(12)2024 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-38928460

RESUMO

Osteoporosis, a prevalent chronic health issue among the elderly, is a global bone metabolic disease. Flavonoids, natural active compounds widely present in vegetables, fruits, beans, and cereals, have been reported for their anti-osteoporotic properties. Onion is a commonly consumed vegetable rich in flavonoids with diverse pharmacological activities. In this study, the trabecular structure was enhanced and bone mineral density (BMD) exhibited a twofold increase following oral administration of onion flavonoid extract (OFE). The levels of estradiol (E2), calcium (Ca), and phosphorus (P) in serum were significantly increased in ovariectomized (OVX) rats, with effects equal to alendronate sodium (ALN). Alkaline phosphatase (ALP) and tartrate-resistant acid phosphatase (TRAP) levels in rat serum were reduced by 35.7% and 36.9%, respectively, compared to the OVX group. In addition, the effects of OFE on bone health were assessed using human osteoblast-like cells MG-63 and osteoclast precursor RAW 264.7 cells in vitro as well. Proliferation and mineralization of MG-63 cells were promoted by OFE treatment, along with increased ALP activity and mRNA expression of osteoprotegerin (OPG)/receptor activator of nuclear factor-kappaB ligand (RANKL). Additionally, RANKL-induced osteoclastogenesis and osteoclast activity were inhibited by OFE treatment through decreased TRAP activity and down-regulation of mRNA expression-related enzymes in RAW 264.7 cells. Overall findings suggest that OFE holds promise as a natural functional component for alleviating osteoporosis.


Assuntos
Flavonoides , Cebolas , Osteoblastos , Osteogênese , Osteoporose , Extratos Vegetais , Animais , Feminino , Humanos , Camundongos , Ratos , Densidade Óssea/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Flavonoides/farmacologia , Cebolas/química , Osteoblastos/efeitos dos fármacos , Osteoblastos/metabolismo , Osteoclastos/efeitos dos fármacos , Osteoclastos/metabolismo , Osteogênese/efeitos dos fármacos , Osteoporose/tratamento farmacológico , Osteoporose/metabolismo , Osteoporose/patologia , Osteoprotegerina/metabolismo , Osteoprotegerina/genética , Ovariectomia , Extratos Vegetais/farmacologia , Extratos Vegetais/química , Ligante RANK/metabolismo , Ratos Sprague-Dawley , Células RAW 264.7
2.
Molecules ; 29(10)2024 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-38792167

RESUMO

Methylglyoxal-induced ROS elevation is the primary cause of neuronal damage. Metformin is a traditional hypoglycemic drug that has been reported to be beneficial to the nervous system. In this study, flavonoids were found to enhance the protective effect of metformin when added at a molar concentration of 0.5%. The structure-activity relationship (SAR) analysis indicated that ortho- substitution in the B ring, and the absence of double bonds between the 2 and 3 position combined with the gallate substitution with R configuration at the 3 position in the C ring played crucial roles in the synergistic effects, which could be beneficial for designing a combination of the compounds. Additionally, the mechanism study revealed that a typical flavonoid, EGCG, enhanced ROS scavenging and anti-apoptotic ability via the BCL2/Bax/Cyto C/Caspase-3 pathway, and synergistically inhibited the expression of GSK-3ß, BACE-1, and APP in PC-12 cells when used in combination with metformin. The dose of metformin used in the combination was only 1/4 of the conventional dose when used alone. These results suggested that ROS-mediated apoptosis and the pathways related to amyloid plaques (Aß) formation can be the targets for the synergistic neuroprotective effects of flavonoids and metformin.


Assuntos
Apoptose , Sinergismo Farmacológico , Flavonoides , Metformina , Aldeído Pirúvico , Espécies Reativas de Oxigênio , Metformina/farmacologia , Metformina/química , Ratos , Flavonoides/farmacologia , Flavonoides/química , Células PC12 , Animais , Relação Estrutura-Atividade , Apoptose/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Neuroblastoma/tratamento farmacológico , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/química , Transdução de Sinais/efeitos dos fármacos
3.
Molecules ; 28(4)2023 Feb 16.
Artigo em Inglês | MEDLINE | ID: mdl-36838890

RESUMO

Although black soldier fly larvae (BSFL) can convert food waste into insectile fatty acids (FAs), the chronological and diet-dependent transformation of larval FAs has yet to be determined. This study focused on the dynamics of larval FA profiles following food waste treatment and characterized factors that may drive FA composition and bioaccumulation. Larval FA matters peaked on Day 11 as 7.7 ± 0.7% of food waste dry matter, maintained stably from Day 11-19, and decreased slightly from Day 19-21. The BSFL primarily utilized waste carbohydrates for FA bioconversion (Day 0-11) and shifted to waste FAs (Day 7-17) when the carbohydrates were close to depletion. The optimal time window for larvae harvest was Days 17-19, which fulfilled both targets of waste oil removal and larval FA transformation. Larval FAs were dominated by C12:0, followed by C18:2, C18:1, and C16:0. The waste-reducing carbohydrate primarily accounted for larval FA bioaccumulation (r = -0.947, p < 0.001). The increase in diet carbohydrate ratio resulted in the elevation of larval C12:0 yield, which indicated that larval C12:0-FA was primarily biosynthesized from carbohydrates and further transformed from ≥C16 FAs. This study elucidates the bioaccumulation process of larval FAs for food waste treatment and highlights the importance of waste carbohydrates for both the composition and transformation of larval FAs.


Assuntos
Dípteros , Eliminação de Resíduos , Animais , Larva , Alimentos , Ácidos Graxos , Carboidratos
4.
Curr Microbiol ; 79(2): 54, 2022 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-34982238

RESUMO

Two-component signal system (TCS) is the predominant bacterial sense-and-response machinery. RpfC/RpfG TCS involved in quorum sensing molecule Diffuse Signal Factor (DSF) signal perception and transduction was well studied in many bacteria. However, whether other environmental factors participating in the signal perception and transduction of RpfC/RpfG was still unclear. Here, we showed that RpfC/RpfG could integrate temperature and DSF signal partially controlling the production of the temperature-dependent protease (SmtP) in S. maltophilia FF11, a strain isolated from frozen Antarctic krill, exhibited spoilage potential due to secret more protease at low temperatures involving in protein degradation. qRT-PCR analysis revealed rpf system mediating approximately 60% transcription activity of Clp, a critical transcription factor linking with LotS/LotR, consisting a signal network controlling completely the SmtP production in previous study. Protease production was partially reduced in rpfF (coding DSF synthetase) mutant strains at 15 °C or 25 °C, not be increased through addition DSF or overexpression RpfF in WT at 37 °C, indicating that DSF was effective for protease production only at low temperatures in S. maltophilia. Additionally, biochemical analysis revealed the enzymatic activity of RpfG from strain FF11 cultured at 37 °C or DSF-deficient strains grown at 25 °C was significantly reduced compared to that of RpfG from strain FF11 cultured at 25 °C. These findings outline an interplay mechanism that allows S. maltophilia to integrate quorum sensing and temperature cues controlling protease production, and imply a potential relationship between two distinct systems of RpfC/RpfG and LotS/LotR.


Assuntos
Stenotrophomonas maltophilia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Regulação Bacteriana da Expressão Gênica , Peptídeo Hidrolases/genética , Transdução de Sinais , Stenotrophomonas maltophilia/metabolismo , Temperatura
5.
Molecules ; 27(22)2022 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-36431904

RESUMO

Methylglyoxal-induced oxidative stress and cytotoxicity are the main factors causing neuronal death-related, diabetically induced memory impairment. Antioxidant and anti-apoptotic therapy are potential intervention strategies. In this study, 25 flavonoids with different substructures were assayed for protecting PC-12 cells from methylglyoxal-induced damage. A structure-activity relationship (SAR) analysis indicated that the absence of the double bond at C-2 and C-3, substitutions of the gallate group at the 3 position, the pyrogallol group at the B-ring, and the R configuration of the 3 position enhanced the protection of flavan-3-ols, and a hydroxyl substitution at the 4' and meta-positions were important for the protection of flavonol. These SARs were further confirmed by molecular docking using the active site of the Keap1-Nrf2 complex as the receptor. The mechanistic study demonstrated that EGCG with the lowest EC50 protected the PC-12 cells from methylglyoxal-induced damage by reducing oxidative stress via the Nrf2/Keap1/HO-1 and Bcl-2/Bax signaling pathways. These results suggested that flavan-3-ols might be a potential dietary supplement for protection against diabetic encephalopathy.


Assuntos
Fator 2 Relacionado a NF-E2 , Neuroblastoma , Humanos , Proteína 1 Associada a ECH Semelhante a Kelch/metabolismo , Fator 2 Relacionado a NF-E2/metabolismo , Aldeído Pirúvico/toxicidade , Flavonoides/farmacologia , Simulação de Acoplamento Molecular , Estresse Oxidativo , Relação Estrutura-Atividade
6.
Biotechnol Bioeng ; 118(7): 2597-2608, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33829485

RESUMO

Bacillus coagulans, a thermophilic facultative anaerobe, is a favorable chassis strain for the biosynthesis of desired products. In this study, B. coagulans was converted into an efficient malic acid producer by metabolic engineering and promoter engineering. Promoter mapping revealed that the endogenous promoter Pldh was a tandem promoter. Accordingly, a promoter library was developed, covering a wide range of relative transcription efficiencies with small increments. A reductive tricarboxylic acid pathway was established in B. coagulans by introducing the genes encoding pyruvate carboxylase (pyc), malate dehydrogenase (mdh), and phosphoenolpyruvate carboxykinase (pckA). Five promoters of various strengths within the library were screened to fine-tune the expression of pyc to improve the biosynthesis of malic acid. In addition, genes involved in the competitive metabolic pathways were deleted to focus the substrate and energy flux toward malic acid. Dual-phase fed-batch fermentation was performed to increase the biomass of the strain, further improving the titer of malic acid to 25.5 g/L, with a conversion rate of 0.3 g/g glucose. Our study is a pioneer research using promoter engineering and genetically modified B. coagulans for the biosynthesis of malic acid, providing an effective approach for the industrialized production of desired products using B. coagulans.


Assuntos
Bacillus coagulans , Proteínas de Bactérias , Ciclo do Ácido Cítrico , Malatos/metabolismo , Engenharia Metabólica , Regiões Promotoras Genéticas , Bacillus coagulans/genética , Bacillus coagulans/metabolismo , Proteínas de Bactérias/biossíntese , Proteínas de Bactérias/genética
7.
Protein Expr Purif ; 178: 105768, 2021 02.
Artigo em Inglês | MEDLINE | ID: mdl-33035660

RESUMO

κ-Carrageenase (EC3.2.1.83) is a class of glycoside hydrolase, which can be used for hydrolysis of κ-carrageenan to κ-carrageenan oligosaccharides. In this study, a bacterium, identified as Pseudoalteromonas sp. ZDY3 isolated from rotten algae, was capable to degrade κ-carrageenan. The κ-carrageenase produced by Pseudoalteromonas sp. ZDY3 was purified to homogeneity and named as CgkZDY3. The accurate molecular mass of CgkZDY3 was determined through LC-HRMS, and a posttranslational removal of C-terminal end of the protein was discovered. CgkZDY3 had strict hydrolysis specificity to κ-carrageenan, the values of Km and kcat/Km of CgkZDY3 were 3.67 mg mL-1 and 53.0 mL mg-1 s-1, respectively. CgkZDY3 was a cold-adapted κ-carrageenase with excellent storage stability of both the temperature below 35 °C and a wide pH range, and was an endo-type κ-carrageenase with high hydrolysis rate, oligosaccharides with different degrees of polymerization can be obtained by controlling the hydrolysis time, and the final products were κ-neocarrabiose and κ-neocarratetraose. These properties are of great significance for production of κ-carrageenan oligosaccharides with different polymerization degrees under process control.


Assuntos
Aclimatação , Proteínas de Bactérias , Pseudoalteromonas/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/isolamento & purificação , Temperatura Baixa , Glicosídeo Hidrolases/química , Glicosídeo Hidrolases/isolamento & purificação
8.
Environ Res ; 194: 110498, 2021 03.
Artigo em Inglês | MEDLINE | ID: mdl-33220246

RESUMO

Fe(III) oxides have been investigated to accelerate anaerobic methanogenic degradation of complex organic compounds. However, the critical role linked to the characteristics of different types of Fe(III) oxides is still unclear. Study presented here performed a side-by-side comparison of four types of Fe(III) oxides including Fe(III)-citrate, ferrihydrite, hematite and magnetite to evaluate their effectiveness in methanogenic degradation of phenol. Results showed that, amorphous Fe(III)-citrate group showed the fastest phenol degradation and Fe2+ release among all the groups, followed by poorly crystalline ferrihydrite. Although Fe(III)-citrate group also showed the fastest methane production rate, the efficiency of electron recovery in methane production was only 58-78%, which was evidently lower than that in both crystalline hematite (86-89%) and magnetite (93-97%) groups. Methane production rate with non-conductive ferrihydrite was nearly same as that with conductive magnetite, both of which were significantly higher than that with semi-conductive hematite. X-ray Diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) analysis showed that sludge collected from hematite and magnetite group still respectively presented a relatively intact characteristic spectra involved in hematite and magnetite. Differently, the characteristic spectra involved in ferrihydrite was not evident in sludge collected from ferrihydrite group, whereas the characteristic spectra involved in magnetite was detected. Microbial community analysis showed that, both Fe(III)-citrate and ferrihydrite specially enriched Fe(III)-reducing bacteria capable of degrading phenol into fatty acids (Trichococcus and Caloramator) via dissimilatory Fe(III) reduction. Fe(III)-citrate also stimulated the growth of Syntrophus capable of degrading phenol/benzoate into acetate and proceeding direct interspecies electron transfer (DIET). In magnetite and hematite group, the abundance of Enterococcus species evidently increased, and they might proceed DIET with Methanothrix species in syntrophic conversion of fatty acids into methane.


Assuntos
Compostos Férricos , Óxidos , Anaerobiose , Óxido Ferroso-Férrico , Metano , Oxirredução
9.
Molecules ; 25(21)2020 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-33114310

RESUMO

Pleurotus ostreatus is one of the widely cultivated edible fungi across the world. Mycelial subculture is an indispensable part in the process of cultivation and production for all kinds of edible fungi. However, successive subcultures usually lead to strain degeneration. The degenerated strains usually have a decrease in stress resistance, yield, and an alteration in fruiting time, which will subsequently result in tremendous economic loss. Through proteomic analysis, we identified the differentially expressed proteins (DEPs) in the mycelium of Pleurotus ostreatus from different subcultured generations. We found that the DNA damage repair system, especially the double-strand breaks (DSBs), repairs via homologous recombination, was impaired in the subcultured mycelium, and gradual accumulation of the DSBs would lead to the strain degeneration after successive subculture. The TUNEL assay further confirmed our finding about the DNA breaks in the subcultured mycelium. Interestingly, the enzyme activity of laccase, carboxylic ester hydrolase, α-galactosidase, and catalase directly related to passage number could be used as the characteristic index for strain degeneration determination. Our results not only reveal for the first time at the molecular level that genomic instability is the cause of degeneration, but also provide an applicable approach for monitoring strain degeneration in process of edible fungi cultivation and production.


Assuntos
Extratos Celulares/química , Carpóforos/metabolismo , Proteínas Fúngicas/genética , Micélio/enzimologia , Pleurotus/química , Proteômica/métodos , Carboxilesterase/genética , Carboxilesterase/metabolismo , Catalase/genética , Catalase/metabolismo , Células Cultivadas , Estabilidade Enzimática , Indústria Alimentícia , Proteínas Fúngicas/metabolismo , Lacase/genética , Lacase/metabolismo , Espectrometria de Massas em Tandem , alfa-Galactosidase/genética , alfa-Galactosidase/metabolismo
10.
Pharmacol Res ; 147: 104387, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31408695

RESUMO

Topotecan (TPT), a semisynthetic derivative of camptothecin, has been used in cancer chemotherapy, but side effects and drug resistance limit its clinical application. Daidzein (DAI), a natural isoflavone and bioactive food component widely existing in fruits, nuts, soybeans and soy-based products, is a type of phytoestrogen. Combination treatment with DAI and TPT showed a strong synergistic effect on tumor cells, with a 0.10˜0.66 combined index, by increasing TPT inhibition on Topo Ⅰ, resulting in more cells arresting at the G2/M phase and inducing more cells to undergo apoptosis. In addition, the resistance of MCF7/ADR cells to TPT was reversed (the resistance index decreased from 7.17 to 0.77) by inhibiting the expression of ERα and BCRP to increase TPT accumulation intracellularly. Moreover, the combination of DAI and TPT showed a stronger inhibitory effect (P < 0.01) on tumor growth in both MCF7 and MCF7/ADR xenograft models than the 9 mg/kg TPT monotherapy group. Our results may provide a reasonable, new approach to develop safe and efficient nutrition components from foods for breast cancer combination treatment.


Assuntos
Antineoplásicos/uso terapêutico , Neoplasias da Mama/tratamento farmacológico , Isoflavonas/uso terapêutico , Topotecan/uso terapêutico , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/genética , Membro 2 da Subfamília G de Transportadores de Cassetes de Ligação de ATP/metabolismo , Animais , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Sinergismo Farmacológico , Receptor alfa de Estrogênio/genética , Receptor alfa de Estrogênio/metabolismo , Feminino , Humanos , Isoflavonas/farmacologia , Células MCF-7 , Camundongos Nus , Proteínas de Neoplasias/genética , Proteínas de Neoplasias/metabolismo , Topotecan/farmacologia , Carga Tumoral/efeitos dos fármacos
11.
Nano Lett ; 18(10): 6150-6156, 2018 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-30132675

RESUMO

Synthetic membranes usually suffer from a ubiquitous trade-off between permeability and selectivity. Carbon nanotube (CNT)-based hybrid materials have shown attractive properties in high-performance membrane preparation; however, the aggregation of random CNTs in polymer remains a great challenge. Herein, the aligned and open-ended CNT/(polydimethylsiloxane) PDMS membranes are controllably fabricated to form a hamburger-like structure that possesses nanochannels (∼10 nm) in the intermediate layer as well as angstrom cavities in the embedded PDMS. These aligned CNT membranes surpass the filling content limitation of the nonaligned CNT/PDMS membrane (37.4 wt % versus ∼10 wt %), leading to excellent mechanical properties and a multiplying performance increase of mass flux and selectivity for the separation of alcohols. The membranes break the permeability-selectivity trade-off with both parameters remarkably increasing (maximum 9 times) for bioalcohol separation. The established pervaporative-ultrafiltration mechanism indicates that the penetrant molecules preferentially pass through CNT internal nanochannels with increasing membrane permeability, thereby paving a way to nanoscale design of highly efficient channeled membranes for separation application.

12.
Int J Mol Sci ; 20(24)2019 Dec 14.
Artigo em Inglês | MEDLINE | ID: mdl-31847351

RESUMO

Pleurotus ostreatus is a widely cultivated edible fungus around the world. At present, studies on the developmental process of the fruiting body are limited. In our study, we compared the differentially expressed proteins (DEPs) in the stipe and cap of the fruiting body by high-throughput proteomics. GO and pathway analysis revealed the great differences in the metabolic levels, including sucrose and starch metabolism, and sphingolipid signaling and metabolism, and the differences of 16 important DEPs were validated further by qPCR analysis in expression level. In order to control the cap and stipe development, several chemical inducers were applied to the primordium of the fruiting body according to the pathway enrichment results. We found that CaCl2 can affect the primordium differentiation through inhibiting the stipe development. EGTA (ethyleneglycol bis (ß-aminoethyl ether)-N,N,N',N'-tetraacetic acid) treatment confirmed the inhibitory role of Ca2+ in the stipe development. Our study not only shows great metabolic differences during the cap and stipe development but also reveals the underlying mechanism directing the primordium differentiation in the early development of the fruiting body for the first time. Most importantly, we provide a reliable application strategy for the cultivation and improvement of the Pleurotus ostreatus, which can be an example and reference for a more edible fungus.


Assuntos
Cálcio/metabolismo , Carpóforos/metabolismo , Pleurotus/crescimento & desenvolvimento , Pleurotus/metabolismo , Cloreto de Cálcio/metabolismo , Diferenciação Celular/efeitos dos fármacos , Diferenciação Celular/fisiologia , Ácido Egtázico/farmacologia , Carpóforos/crescimento & desenvolvimento , Proteínas Fúngicas/metabolismo , Perfilação da Expressão Gênica/métodos , Regulação Fúngica da Expressão Gênica/efeitos dos fármacos , Regulação Fúngica da Expressão Gênica/fisiologia , Pleurotus/efeitos dos fármacos , Proteômica/métodos , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Esfingolipídeos/metabolismo
13.
Extremophiles ; 22(2): 287-300, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29332142

RESUMO

By screening 25 different psychrophilic strains isolated from the Arctic habitat, we isolated a strain capable of producing lipase. We identified this strain as Psychrobacter sp. ZY124 based on the amplified 16S rDNA sequence. The lipase, named as Lipase ZC12, produced from the supernatant of Psychrobacter sp. ZY124 cultured at 15 °C was purified to homogeneity by ammonium sulfate precipitation followed by Phenyl Sepharose FF gel hydrophobic chromatography. Based on the obtained amino acid sequence, Lipase ZC12 is classified as a member of the Proteus/psychrophilic subfamily of lipase family I.1; it has a molecular weight of 37.9 kDa. We also determined that the apparent optimum temperature for Lipase ZC12 activity is 40 °C. Lipase ZC12 shows remarkable organic solvent tolerance by remaining more 50% after incubated with 10-90% different organic solvents. In addition, acyl chain esters with C12 or longer were confirmed to be preferable substrates for Lipase ZC12. Lipase ZC12 also shows better stereoselectivity for (R, S)-1-phenylethanol chiral resolution in n-hexane solvent with (S)-1-phenylethanol (eep 92%) and conversion rate (39%) by transesterification reactions. These properties may provide potential applications in biocatalysis and biotransformation in non-aqueous media, such as in detergent, transesterification or esterification and chiral resolution.


Assuntos
Proteínas de Bactérias/metabolismo , Lipase/metabolismo , Psychrobacter/enzimologia , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Estabilidade Enzimática , Hexanos/química , Lipase/química , Lipase/genética , Psychrobacter/genética , Solventes/química , Especificidade por Substrato
14.
Appl Microbiol Biotechnol ; 102(15): 6479-6491, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-29796971

RESUMO

Acetoin is an important physiological metabolite excreted by microbes. Its functions include avoiding acidification, participating in regulation of the NAD+/NADH ratio, and storing carbon. Acetolactate decarboxylase is a well-characterized anabolic enzyme involved with 3-hydroxy butanone (acetoin). It catalyzes conversion of the (R)- and (S)-enantiomers of acetolactate to generate the single product, (R)-acetoin. In addition to the X-ray crystal structure of acetolactate decarboxylase from Bacillus brevis, although the enzyme is widely present in microorganisms, very few atomic structures of acetolactate decarboxylase are reported. In this paper, we solved and reported a 1.5 Å resolution crystal structure of acetolactate decarboxylase from Bacillus subtilis. Dimeric assembly is observed in the solved structure, which is consistent with the elution profile conducted by molecular filtration. A zinc ion is coordinated by highly conserved histidines (191, 193, and 204) and conserved glutamates (62 and 251). We performed kinetic studies on acetolactate decarboxylase from Bacillus subtilis using circular dichroism, allowing the conversion of acetolactate to chiral acetoin for real-time tracking, yielding a Km value of 21 mM and a kcat value of 2.2 s-1. Using the two enantiomers of acetolactate as substrates, we further investigated the substrate preference of acetolactate decarboxylase from Bacillus subtilis by means of molecular docking and dynamic simulation in silico. The binding free energy of (S)-acetolactate was found to be ~ 30 kcal/mol greater than that of (R)-acetolactate, indicating a more stable binding for (S)-acetolactate.


Assuntos
Bacillus subtilis/enzimologia , Carboxiliases/química , Carboxiliases/metabolismo , Modelos Moleculares , Acetoína/metabolismo , Bacillus subtilis/genética , Cinética , Simulação de Acoplamento Molecular , Estrutura Terciária de Proteína
15.
Int J Mol Sci ; 19(1)2017 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-29271931

RESUMO

Leaf spot disease caused by the fungus Fusarium proliferatum (Matsushima) Nirenberg is a destructive disease of tomato plants in China. Typical symptoms of infected tomato plants are softened and wilted stems and leaves, leading to the eventual death of the entire plant. In this study, we resorted to transcriptional profile analysis to gain insight into the repertoire of effectors involved in F. proliferatum-tomato interactions. A total of 61,544,598 clean reads were de novo assembled to provide a F. proliferatum reference transcriptome. From these, 75,044 unigenes were obtained, with 19.46% of the unigenes being assigned to 276 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, with 22.3% having a homology with genes from F. fujikuroi. A total of 18,075 differentially expressed genes (DEGs) were identified, 720 of which were found to code for secreted proteins. Of these, 184 were identified as candidate effectors, while 79.89% had an upregulated expression. Moreover, 17 genes that were differentially expressed in RNA-seq studies were randomly selected for validation by quantitative real-time polymerase chain reaction (qRT-PCR). The study demonstrates that transcriptome analysis could be an effective method for identifying the repertoire of candidate effectors and may provide an invaluable resource for future functional analyses of F. proliferatum pathogenicity in F. proliferatum and tomato plant-host interactions.


Assuntos
Fusarium/genética , Doenças das Plantas/microbiologia , Solanum lycopersicum/microbiologia , Transcriptoma , Fusarium/patogenicidade , Perfilação da Expressão Gênica , Regulação Fúngica da Expressão Gênica , Genes Fúngicos , Folhas de Planta/microbiologia , Reação em Cadeia da Polimerase em Tempo Real
16.
J Ind Microbiol Biotechnol ; 43(6): 829-40, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27001262

RESUMO

Seafood is sometimes wasted due to the growth of psychrotolerant microbes which secrete proteases and break down proteins. Stenotrophomonas maltophilia FF11, isolated from frozen Antarctic krill, grows at a wide range of temperatures and secretes more proteases at low temperatures. According to zymogram analysis, two kinds of proteases were produced from this strain. A major protease was produced largely at 15 °C, but not at 37 °C. The temperature-dependent secreted protease was purified to homogeneity. Its molecular mass was determined at 37.4 kDa and its amino acid sequence was also obtained. This protease is a member of the subtilase group according to the NCBI blast analysis. The enzyme was highly stable at high salt concentration (4 M). Interestingly, its activity increased about 1.6-fold under high salt condition. The enzyme remains active and stable in different organic solvents (50 %, v/v) such as dimethylsulfoxide, dimethyl formamide, dioxane and acetone. These properties may provide potential applications in quality control for sea foods, in protein degradation at high salt concentration, in biocatalysis and biotransformation within non-aqueous media, such as detergent and transesterification.


Assuntos
Euphausiacea/microbiologia , Genes Bacterianos , Peptídeo Hidrolases/metabolismo , Cloreto de Sódio/química , Stenotrophomonas maltophilia/enzimologia , Sequência de Aminoácidos , Animais , Clonagem Molecular , Temperatura Baixa , Concentração de Íons de Hidrogênio , Peso Molecular , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Stenotrophomonas maltophilia/classificação , Stenotrophomonas maltophilia/isolamento & purificação
17.
J Ind Microbiol Biotechnol ; 40(5): 427-36, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23471779

RESUMO

Progenin III, one of the most active spirostanol saponins, is a potential candidate for anti-cancer therapy due to its strong antitumor activity and low hemolytic activity. However, the concentration of progenin III is extremely low in natural Dioscorea plants. In this paper, the progenin III production from total steroidal saponins of Dioscorea nipponica Makino was studied using the crude enzyme from Aspergillus oryzae DLFCC-38. The crude enzyme converting total steroidal saponins into progenin III was obtained from the A. oryzae DLFCC-38 culture. For enzyme production, the strain was cultured for 72 h at 30 °C with shaking at 150 rpm in 5 % (w/v) malt extract medium containing 2 % (v/v) extract of D. nipponica as the enzyme inducer. The crude enzyme converted total steroidal saponins into major progenin III with a high yield when the reaction was carried out for 9 h at 50 °C and pH 5.0 with the 20 mg/ml of substrate. In the preparation of progenin III, 117 g of crude progenin III was obtained from 160 g of substrate, and the crude product was purified with silica gel column to obtain 60.3 g progenin III of 93.4 % purity.


Assuntos
Aspergillus oryzae/enzimologia , Dioscorea/química , Saponinas/isolamento & purificação , Saponinas/metabolismo , Biotecnologia , Biotransformação , Enzimas/isolamento & purificação , Enzimas/metabolismo , Saponinas/química
18.
Eng Life Sci ; 23(6): e2200125, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-37275213

RESUMO

Traditional technology of cell disruption has become one of the bottlenecks restricting the industrialization of genetic engineering products due to its high cost and low efficiency. In this study, a novel bioprocess of phage lysis coupled with salting-out extraction (SOE) was evaluated. The lysis effect of T7 phage on genetically engineered Escherichia coli expressing κ-carrageenase was investigated at different multiplicity of infection (MOI), meanwhile the phage and enzyme released into the lysate were separated by SOE. It was found that T7 phage could lyse 99.9% of host cells at MOI = 1 and release more than 90.0% of enzyme within 90 min. After phage lysis, 87.1% of T7 phage and 71.2% of κ-carrageenase could be distributed at the middle phase and the bottom phase, respectively, in the SOE system composed of 16% ammonium sulfate and 20% ethyl acetate (w/w). Furthermore, κ-carrageenase in the bottom phase could be salted out by ammonium sulfate with a yield of 40.1%. Phage lysis exhibits some advantages, such as mild operation conditions and low cost. While SOE can efficiently separate phage and intracellular products. Therefore, phage lysis coupled with SOE is expected to become a viable alternative to the classical cell disruption and intracellular product recovery.

19.
Food Chem ; 412: 135581, 2023 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-36731239

RESUMO

Nelumbo nucifera Gaertn, commonly known as lotus, is a genus comprising perennial and rhizomatous aquatic plants, found throughout Asia and Australia. This review aimed to cover the biosynthesis of flavonoids, alkaloids, and lipids in plants and their types in different parts of lotus. This review also examined the physiological functions of bioactive compounds in lotus and the extracts from different organs of the lotus plant. The structures and identities of flavonoids, alkaloids, and lipids in different parts of lotus as well as their biosynthesis were illustrated and updated. In the traditional medicine systems and previous scientific studies, bioactive compounds and the extracts of lotus have been applied for treating inflammation, cancer, liver disease, Alzheimer's disease, etc. We suggest future studies to be focused on standardization of the extract of lotus, and their pharmacological mechanisms as drugs or functional foods. This review is important for the lotus-based food processing and application.


Assuntos
Alcaloides , Lotus , Nelumbo , Nelumbo/química , Alcaloides/química , Extratos Vegetais/química , Flavonoides , Lipídeos
20.
Nanoscale ; 15(24): 10412-10422, 2023 Jun 23.
Artigo em Inglês | MEDLINE | ID: mdl-37305976

RESUMO

Aligned carbon nanotube (CNT) arrays have been widely used in the preparation of polymer composites. CNT arrays are commonly prepared by chemical vapor deposition (CVD) in a high temperature tubular furnace, and the areas of the aligned CNT/polymer membranes prepared are relatively small (<30 cm2) due to the limitation of the inner diameter of the furnace, which limits its practical application in the field of membrane separation. Herein, the vertically aligned CNT arrays/polydimethylsiloxane (PDMS) membrane with large and expandable area was prepared by a modular splicing method for the first time, with a maximum area of 144 cm2. The addition of CNT arrays with openings at both ends significantly improved the pervaporation performance of the PDMS membrane for ethanol recovery. At 80 °C, the flux (671.6 g m-2 h-1) and separation factor (9.0) of CNT arrays/PDMS membrane were increased by 435.12% and 58.52%, respectively, compared with those of the PDMS membrane. Furthermore, the expandable area enabled the CNT arrays/PDMS membrane to couple with fed-batch fermentation for pervaporation for the first time, which increased the ethanol yield (0.47 g g-1) and productivity (2.34 g L-1 h-1) by 9.3% and 4.9% respectively compared with batch fermentation. Besides, the flux (135.47-166.79 g m-2 h-1) and separation factor (8.83-9.21) of CNT arrays/PDMS membrane remained stable in this process, indicating that this membrane has the potential to be applied in industrial bioethanol production. This work provides a new idea for the preparation of large-area aligned CNT/polymer membranes, and also opens up a new direction for the application of large-area aligned CNT/polymer membranes.


Assuntos
Nanotubos de Carbono , Etanol , Fermentação , Membranas Artificiais , Dimetilpolisiloxanos , Polímeros
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