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1.
Environ Sci Process Impacts ; 22(1): 197-206, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31841122

RESUMO

17ß-estradiol (E2) ubiquitously exists in various water bodies with long-term endocrine-disrupting and carcinogenic impacts on wildlife even at the trace level of ng L-1. However, it remains unclear how easy-to-degrade carbon sources alter E2 biodegradation patterns. In this study, E2 biodegradation by Sphingomonas sp. MCCC 1A06484 was investigated with regard to alternative carbon sources. Results showed that the bacterium preferentially utilized glucose, sodium succinate and sodium acetate over E2. Interestingly, the presence of these preferred nutrients increased the E2 removal efficiency by 20.1%. Furthermore, a positive relation (p < 0.05) between the utilization of total organic carbon (TOC) and E2 was found. Using intracellular metabolomics by UHPLC-QTOF-MS, 11 up-regulated and 35 down-regulated metabolites (variable importance > 1, p < 0.05) were identified in the bacterium when cultivated with E2 under various carbon and nitrogen backgrounds. The E2 exposure contributed to metabolism changes of lipid, nucleotide, carbohydrate, amino acid and membrane transport, which were considered to play roles in the E2 metabolism. The up-regulated phosphatidylcholine might act as an indicator during the bacterial degradation of E2. Generally, this study contributes to an in-depth understanding of E2 biodegradation in complex environments with multiple carbon and nitrogen sources.


Assuntos
Estradiol , Metabolômica , Sphingomonas , Poluentes Químicos da Água , Biodegradação Ambiental , Carbono , Estradiol/metabolismo , Sphingomonas/metabolismo , Poluentes Químicos da Água/metabolismo
2.
Environ Sci Pollut Res Int ; 26(30): 31392-31400, 2019 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31471855

RESUMO

Tetrabromobisphenol A (TBBPA) is an emerging contaminant and exists widely in river and lake systems due to its widespread use. In natural water-sediment systems, hydrodynamic disturbances always exist. However, few studies have investigated the mechanism of TBBPA biodegradation under the influence of water disturbances. In this paper, using a specialized type of racetrack-style flumes, the TBBPA biodegradation in water-sediment systems was studied under the influence of three typical hydrodynamic disturbances. The results of 5-week experiments showed that strong hydrodynamic disturbances greatly accelerate the TBBPA biodegradation rate of the water-sediment systems. The half-lives (T1/2) under static condition (SC) were approximately 40.2 days, and the T1/2 was reduced to 16.0 days under strong hydrodynamic condition (SHC). Furthermore, the physicochemical properties and corresponding bacterial communities under these conditions were investigated to help explain the TBBPA biodegradation mechanism. The results showed that strong currents could promote dissolved oxygen (DO) levels, increase nutrient concentrations, and reduce the bacterial diversity in the sediment. Meanwhile, due to the increase in DO and nutrient concentrations, the aerobic bacterial genera conducting TBBPA biodegradation showed rapid growth with strong water disturbances, while the growth of anaerobic bacterial genera was inhibited. Citrobacter, which was the most dominant degrading bacterial genus (0.6%-14.9% in water and 3.5%-17.4% in sediment), was closely related to water disturbances and may be linked to enhanced TBBPA biodegradation. Other minor degrading bacterial genera, such as Bacillus, Sphingomonas, Anaeromyxobacter, Geobacter, Clostridium, and Flavobacterium, were also found in these water-sediment systems. The findings from this study showed the importance of considering hydrodynamic disturbance in understanding TBBPA biodegradation in aquatic environments.


Assuntos
Biodegradação Ambiental , Bifenil Polibromatos/metabolismo , Poluentes Químicos da Água/metabolismo , Bacillus/metabolismo , Bactérias Aeróbias/metabolismo , Sedimentos Geológicos/química , Hidrodinâmica , Lagos/química , Rios/química , Sphingomonas/metabolismo , Água/análise , Poluentes Químicos da Água/análise
3.
J Biotechnol ; 302: 1-9, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31199955

RESUMO

To elucidate the possible biosynthetic pathway of a precursor UDP-glucose of the sphingan WL gum produced by Sphingomonas sp. WG, two enzymes phosphoglucomutase (PGM) and UDP-glucose pyrophosphorylase (UGPase) were bioinformatically analysed, expressed in Escherichia coli BL21 (DE3) and characterized. PGM was in the phosphoglucomutase/phosphomannomutase subclass and UGPase was predicted to be a UDP-glucose pyrophosphatase in a tetrameric structure. Both enzymes were expressed in soluble form, purified to near homogeneity with high activity at 1159 and 796 U/mg, exhibited folding with reasonable secondary structures, and existed as monomer and tetramer, respectively. The optimal pH and temperature of PGM were 9.0 and 50 °C, respectively, and this protein was stable at pH 8.0 and at temperatures ranging from 40 to 50 °C. The optimal pH and temperature of UGPase were 9.0 and 45 °C, respectively, and the protein was stable at pH 8.0 and at temperatures ranging from 30 to 55 °C. A small-scale one-pot biosynthesis of UDP-glucose by combining PGM and UGPase using glucose-6-phosphate and UTP as substrates was also performed, and formation of UDP-glucose was observed by HPLC detection, which confirmed the biosynthetic pathway of UDP-glucose in vitro. PGM and UGPase will be ideal targets for the metabolic engineering to improve WL gum yields in industrial production.


Assuntos
Biotecnologia/métodos , Polissacarídeos Bacterianos/metabolismo , Sphingomonas/metabolismo , Uridina Difosfato Glucose/metabolismo , UTP-Glucose-1-Fosfato Uridililtransferase/metabolismo
4.
Carbohydr Polym ; 220: 236-246, 2019 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-31196546

RESUMO

In the present work, the biosynthesis of the gellan gum exopolysaccharide from Sphingomonas paucimobilis fermentation was improved to 24 g/L, by increasing the oxygen content (1:5). FTIR and NMR data indicated the following procedures to recover gellan from culture medium: filtration; washing with acetone and ether (200 mL each one); permeate dissolution with distilled water; precipitation with acetonitrile (1:3). Gellan microsphere formulation by water-in-oil emulsion was optimized through central composite design to minimize the diameter (≈ 300 µm), and reinforced with different counter-ions. The optimal point was reached with 1.27% gellan concentration, 750 rpm and 92.54 °C of oil temperature. Microspheres with nickel as counter-ion revealed the most satisfactory results from semi-optical microscopy, SEM and EDX analysis. The manipulation of ionic strength or pH on the binding and elution steps allowed capturing different model proteins, exploring electrostatic or affinity interactions with these microspheres.


Assuntos
Muramidase/química , Polissacarídeos Bacterianos , Soroalbumina Bovina/química , Sphingomonas/metabolismo , Meios de Cultura , Fermentação , Microesferas , Tamanho da Partícula , Polissacarídeos Bacterianos/biossíntese , Polissacarídeos Bacterianos/química , Polissacarídeos Bacterianos/isolamento & purificação , Ligação Proteica
5.
Chemosphere ; 234: 769-776, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31238273

RESUMO

Plant growth promoting bacteria (PGPB) have been reported to have the ability to promote plant growth, development and increase heavy metals (HMs) uptake. Therefore, PGPB inoculation as soil remediation agents into plants with larger biomass and potential of phytoextraction is of great importance to increase bioremediation efficiency. In this study, 12 PGPB strains isolated from a cadmium (Cd)/zinc hyperaccumulator Sedum alfredii Hance were inoculated into non-host plant Brassica juncea and their effects on plant growth and Cd uptake were determined. The results showed that inoculation of most PGPB strains promoted plant growth, boosted root development and improved chlorophyll content in the absence of Cd. Inoculation of PGPB strains promoted plant growth up to 111% in shoot and 358% in root when treated with 2 µM Cd. In addition, PGPB inoculation not only ameliorated plant root morphology including the total root length (RL), total surface area (SA), total root volume (RV) and number of root tips (RT), but also facilitated Cd uptake up to 126%. Furthermore, inoculation of PGPB strains promoted plant Cd accumulation up to 261% in shoot and up to 8.93-fold increase in root. Among all the 12 PGPB strains, Burkholdria SaMR10 and Sphingomonas SaMR12 were identified as the promising microbes for improving phytoremediation efficiency of Cd contaminated soils. These results not only provided useful findings for further investigation of interacting mechanisms between different bacterial strains and plants, but also facilitated the development of microbe-assisted phytoremediation application for HM contaminated soil.


Assuntos
Inoculantes Agrícolas , Bactérias/isolamento & purificação , Biodegradação Ambiental , Cádmio/farmacocinética , Poluentes do Solo/metabolismo , Bactérias/metabolismo , Burkholderia/metabolismo , Metais Pesados/farmacocinética , Mostardeira/crescimento & desenvolvimento , Mostardeira/microbiologia , Desenvolvimento Vegetal/efeitos dos fármacos , Sedum/microbiologia , Poluentes do Solo/análise , Sphingomonas/metabolismo
6.
Arch Microbiol ; 201(7): 907-918, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30997539

RESUMO

The environmental fate of the extensively used chloroacetanilide herbicides (CH) has been a cause of increasing concern in the past decade because of their carcinogenic properties. Although microbes play important roles in CH degradation, Sphingomonas wittichii DC-6 was the first reported CH-mineralizing bacterium. In this study, the complete genome of strain DC-6 was sequenced and comparative genomic analysis was performed using strain DC-6 and other three partial CH-degrading bacteria, Sphingobium quisquiliarum DC-2, Sphingobium baderi DE-13, and Sphingobium sp. MEA3-1. 16S rDNA phylogenetic analysis indicated that strain DC-2, MEA3-1, and DE-13 are closely related and DC-6 has relatively distant genetic relationship with the other three strains. The identified CH degradation genes responsible for the upstream and downstream pathway, including cndA, cmeH, meaXY, and meaAB, were all located in conserved DNA fragments (or genetic islands) in the vicinity of mobile element proteins. Protein BLAST in the NCBI database showed that cndA and cmeH were present in the genomes of other sequenced strains isolated from various habitats; however, the gene compositions in these host strains were completely different from those of other sphingomonads, and codon usage of genes for upstream pathway were also different from that of downstream pathway. These results showed that the upstream and downstream pathways of CH degradation in strain DC-6 have evolved by horizontal gene transfer and gene combination. In addition, the genes of the ring-cleavage pathway were not conserved and may have evolved directly from bacterial degradation of hydroxyquinol. The present study provides insights into the evolutionary strategy and microbial catabolic pathway of CH mineralization.


Assuntos
Acetamidas/metabolismo , Genoma Bacteriano , Sphingomonas/genética , Sphingomonas/metabolismo , Sequência de Bases , Biodegradação Ambiental , Evolução Biológica , DNA Ribossômico/genética , Filogenia , Sphingomonadaceae/classificação
7.
Environ Pollut ; 250: 284-291, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30999205

RESUMO

Tributyl phosphate (TBP) is recognised as a global environmental contaminant because of its wide use in floatation reagents, nuclear fuel reprocessing and plasticisers. This contaminant is hardly degraded by hydrolysis in the environment due to its special physicochemical properties. In this study, one TBP-degrading strain was isolated from TBP-contaminated abandoned mine tailings, and 16S rRNA identification revealed that the strain belonged to the genus Sphingomonas. Results validated that the strain could utilise TBP as the sole carbon source, and vitamin was not the essential factor for its growth. Liquid chromatography time-of-flight mass spectrometry analysis identified di-n-butyl phosphate (DnBP) and mono-n-butyl phosphate (MnBP) as the intermediate metabolites for TBP biodegradation. No obvious change in carbon and hydrogen isotope composition was observed in biodegradation processes (cell suspension and crude extract degradation), which indicated that the first irreversible bond cleavage did not involve carbon or hydrogen. Hence, the TBP degradation scheme by Sphingomonas sp. proposed that the first irreversible step of TBP transferred to DnBP would lead to PO bond cleavage. This study combined the identification of products and isotope fractionation in substrates to investigate the transformation mechanism, thereby providing an eco-friendly and cost-effective way for the in situ bioremediation of TBP-contaminated sites by the isolated TBP degradation strain.


Assuntos
Mineração , Organofosfatos/metabolismo , Microbiologia do Solo , Poluentes do Solo/metabolismo , Sphingomonas/metabolismo , Biodegradação Ambiental , Fosfatos/metabolismo , RNA Ribossômico 16S/genética , Sphingomonas/química , Sphingomonas/classificação , Sphingomonas/genética
8.
Arch Microbiol ; 201(5): 591-601, 2019 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-30714085

RESUMO

Plant endophytes play vital role in plant growth promotion as well as in abiotic and biotic stress tolerance. They also mediate biotransformation of complex organic materials to simpler and useful by-product. Therefore, the role of plant endophyte in plant growth promotion and stress tolerance has gained considerable attention in recent days. Sphingomonas sp. LK11 is an important plant endophyte that actively regulates plant growth. However, the biotransformation and stress tolerance potential of Sphingomonas sp. LK11 was yet to be elucidated. Therefore, we studied the biotransformation of benzoin by Sphingomonas sp. LK11. We found that, Sphingomonans sp. LK11 biotransformed benzoin to benzamide. Further application of benzamide to Cucumis sativus led to decrease in agronomic potential of C. sativus as benzamide acts as an abiotic stress agent. However, the application of Sphingomonas sp. LK11 inoculums with benzamide reverted back the agronomic trait of the plants, suggesting the role of Sphingomonas sp. LK11 in biotransformation and abiotic stress tolerance in plants.


Assuntos
Benzamidas/metabolismo , Benzoína/metabolismo , Cucumis sativus/crescimento & desenvolvimento , Sphingomonas/metabolismo , Estresse Fisiológico/fisiologia , Biotransformação/fisiologia , Endófitos/metabolismo , Desenvolvimento Vegetal , Reguladores de Crescimento de Planta/metabolismo
9.
Biosci Biotechnol Biochem ; 83(5): 794-802, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30744540

RESUMO

Alginate is an acidic heteropolysaccharide produced by brown seaweed and certain kinds of bacteria. The cells of Sphingomonas sp. strain A1, a gram-negative bacterium, have several alginate-degrading enzymes in their cytoplasm and efficiently utilize this polymer for their growth. Sphingomonas sp. strain A1 cells can directly incorporate alginate into their cytoplasm through a transport system consisting of a "pit" on their cell surface, substrate-binding proteins in their periplasm, and an ATP-binding cassette transporter in their inner membrane. This review deals with the structural and functional aspects of bacterial systems necessary for the recognition and uptake of alginate.


Assuntos
Alginatos/metabolismo , Proteínas de Bactérias/metabolismo , Sphingomonas/metabolismo , Transportadores de Cassetes de Ligação de ATP/metabolismo , Alginatos/química , Sequência de Aminoácidos , Proteínas de Bactérias/química , Transporte Biológico , Cristalografia por Raios X , Citoplasma/enzimologia , Metais/metabolismo , Periplasma/metabolismo , Ligação Proteica , Conformação Proteica , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Homologia de Sequência de Aminoácidos , Sphingomonas/enzimologia
10.
Microbiome ; 7(1): 16, 2019 02 06.
Artigo em Inglês | MEDLINE | ID: mdl-30728080

RESUMO

BACKGROUND: Understanding microbial interactions in engineering bioprocesses is important to enhance and optimize performance outcomes and requires dissection of the multi-layer complexities of microbial communities. However, unraveling microbial interactions as well as substrates involved in complex microbial communities is a challenging task. Here, we demonstrate an integrated approach of metagenomics, metatranscriptomics, and targeted metabolite analysis to identify the substrates involved in interspecies interactions from a potential cross-feeding model community-bisphenol A (BPA)-biodegrading community, aiming to establish an identification method of microbial interactions in engineering or environmental bioprocesses. RESULTS: The community-level BPA-metabolic pathway was constructed using integrated metagenomics and targeted metabolite analyses. The dynamics of active functions and metabolism of major community members were identified using metagenomic and metatranscriptomic analyses in concert. Correlating the community BPA biodegradation performance to the individual bacterial activities enabled the discovery of substrates involved in a synergistic interaction of cross-feeding between BPA-degrading Sphingonomas species and intermediate users, Pseudomonas sp. and Pusillimonas sp. This proposed synergistic interaction was confirmed by the co-culture of a Sphingonomas sp. and Pseudomonas sp. isolates, which demonstrated enhanced BPA biodegradation compared to the isolate of Sphingonomas sp. alone. CONCLUSION: The three types of integrated meta-omics analyses effectively revealed the metabolic capability at both community-wide and individual bacterial levels. The correlation between these two levels revealed the hidden connection between apparent overall community performance and the contributions of individual community members and their interactions in a BPA-degrading microbial community. In addition, we demonstrated that using integrated multi-omics in conjunction with culture-based confirmation approach is effective to elucidate the microbial interactions affecting the performance outcome. We foresee this approach would contribute the future application and operation of environmental bioprocesses on a knowledge-based control.


Assuntos
Alcaligenaceae/metabolismo , Compostos Benzidrílicos/metabolismo , Biodegradação Ambiental , Fenóis/metabolismo , Pseudomonas/metabolismo , Sphingomonas/metabolismo , Alcaligenaceae/genética , Alcaligenaceae/isolamento & purificação , Metagenômica , Interações Microbianas/fisiologia , Microbiota/fisiologia , Pseudomonas/genética , Pseudomonas/isolamento & purificação , RNA Ribossômico 16S/genética , Sphingomonas/genética , Sphingomonas/isolamento & purificação
11.
Curr Microbiol ; 76(5): 536-544, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30796475

RESUMO

Electronic waste (E-Waste) is consumed at high speed in the world. These residues contain metals that increase their price each year, generating new research on the ability of microorganisms to recover the metals from these wastes. Therefore, this work evaluated the biologic lixiviation of Cu, Ag and Au from printed circuit boards (PCB) of mobile phones by three strains of Aspergillus niger, Candida orthopsilosis, Sphingomonas sp. and their respective consortia, in addition to leaching with citric acid. The microorganisms were cultured in mineral media with 0.5 g of PCB, and the treatments with 1M citric acid were added the same amount of PCB. All treatments were incubated for 35 days at room temperature. The results showed that Sphingomonas sp. MXB8 and the consortium of C. orthopsilosis MXL20 and A. niger MXPE6 can increase their dry biomass by 147% and 126%, respectively, in the presence of PCB. In the bioleaching of metals, the inoculation of A. niger MXPE6, the consortium of Sphingomonas sp. MXB8/C. orthopsilosis MXL20 and Sphingomonas sp. MXB8 leached 54%, 44.2% and 35.8% of Ag. The consortium of A. niger MX5 and A. niger MXPE6 showed a leaching of 0.53% of Au. A. niger MX5 leaching 2.8% Cu. Citric acid increased Cu leaching by 280% compared to treatments inoculated with microorganisms. Although further research is required, A. niger MXPE6 and the consortium of Sphingomonas sp. MXB8/C. orthopsilosis MXL20 could be an alternative to recover Ag from PCB of mobile phones.


Assuntos
Telefone Celular , Cobre/metabolismo , Resíduo Eletrônico , Ouro/metabolismo , Consórcios Microbianos , Prata/metabolismo , Aspergillus niger/metabolismo , Candida/metabolismo , Ácido Cítrico/química , Reciclagem/métodos , Sphingomonas/metabolismo
12.
Biotechnol Lett ; 41(3): 379-389, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30689146

RESUMO

OBJECTIVES: To investigate the biosynthesis of silver nanoparticles (AgNPs) using extracts of some bacterial isolates Bacillus pumilus, Bacillus paralicheniformis and Sphingomonas paucimobilis. The formation of AgNPs was detected by the change in color into yellow and confirmed by the UV-Vis spectroscopy. The nanoparticles were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM) and Fourier transform infrared spectroscopy (FTIR). RESULTS: The obtained AgNPs were spherical to oval in shape with particle size ranged from 4 to 20 nm and surface area 118 m2/g. The AgNPs have been used as nanocatalyst for the removal of malachite green dye (MG) from aqueous solution. The dye was chosen as a model dye released in wastewater. The AgNPs showed excellent nanocatalyst for the removal of MG. The dye removal process was observed by the continuous decrease in dye absorbance at 617 nm until it vanished over 160 min. The removal kinetics followed closely the pseudo-first-order kinetic model. CONCLUSION: The B. paralicheniformis strain KJ-16 was the most effective isolated bacteria to give extract for biosynthesis of AgNPs and dye removal. This method may be considered easy and eco-friendly, and could be applicable for large-scale decontamination of wastewater from harmful dyes.


Assuntos
Bacillus/metabolismo , Corantes/isolamento & purificação , Misturas Complexas/metabolismo , Nanopartículas Metálicas , Prata/metabolismo , Sphingomonas/metabolismo , Poluentes da Água/isolamento & purificação , Microscopia Eletrônica de Transmissão , Corantes de Rosanilina/isolamento & purificação , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Águas Residuárias/química , Difração de Raios X
13.
Bioprocess Biosyst Eng ; 42(5): 897-900, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-30671627

RESUMO

2-Deoxy-D-glucose (2-DG) is a non-metabolizable glucose analogue and competitive inhibitor of glycolysis. Effect of 2-DG on gellan gum biosynthesis by Sphingomonas paucimobilis ATCC31461 were studied in this research. The concentration and the addition time of 2-DG significantly affected the biomass and gellan gum accumulation. The maximum gellan gum yield of 20.78 g/L was obtained with the addition of 50 µg/L of 2-DG at 24 h. The mechanism of 2-DG addition favoring to gellan production was revealed by determining the activities of key enzymes. Results indicated that 2-DG addition increased the activities of glucosyltransferase and inhibited UDP-glucose pyrophosphorylase activity. The result indicated that 2-DG inhibited glycolysis and changed metabolic driving force to activate gellan gum biosynthesis metabolism pathways.


Assuntos
Desoxiglucose/farmacologia , Glicólise/efeitos dos fármacos , Polissacarídeos Bacterianos/biossíntese , Sphingomonas/metabolismo
14.
Appl Environ Microbiol ; 85(3)2019 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-30446556

RESUMO

Various bacteria, mainly actinobacteria and proteobacteria, are capable of aerobic estrogen degradation. In a previous study, we used the obligate aerobic alphaproteobacterium Sphingomonas sp. strain KC8 as a model microorganism to identify the initial metabolites involved in the oxygenolytic cleavage of the estrogen A ring: 4-hydroxyestrone, a meta-cleavage product, and a dead-end product pyridinestrone acid. In this study, we identified the downstream metabolites of this aerobic degradation pathway using ultraperformance liquid chromatography-high-resolution mass spectrometry (UPLC-HRMS). 4-Norestrogen-5(10)-en-3-oyl-coenzyme A and its closely related deconjugated (non-coenzyme A [non-CoA]) structure, 4-norestrogenic acid, were detected in the estrone-grown strain KC8 cultures. The structure of 4-norestrogenic acid was elucidated using nuclear magnetic resonance (NMR) spectroscopy. The extracellular distribution and the accumulation of 4-norestrogenic acid in the bacterial cultures indicate that the estrogen-degrading bacteria cannot degrade this deconjugated product. We also observed temporal accumulation and subsequent consumption of a common steroid metabolite, 3aα-H-4α(3'-propanoate)-7aß-methylhexahydro-1,5-indanedione (HIP), in the bacterial cultures. The metabolite profile and genomic analyses shed light on the biochemical mechanisms involved in the degradation of the A and B rings of natural estrogens. In this proposed aerobic pathway, C-4 of the meta-cleavage product is removed by a 2-oxoacid oxidoreductase through oxidative decarboxylation to produce the 4-norestrogen-5(10)-en-3-oyl-CoA. Subsequently, the B ring is cleaved by hydrolysis. The resulting A/B-ring-cleaved product is transformed into a common steroid metabolite HIP through ß-oxidation reactions. Accordingly, the A and B rings of different steroids are degraded through at least three peripheral pathways, which converge at HIP, and HIP is then degraded through a common central pathway.IMPORTANCE Estrogens, often detected in surface waters worldwide, have been classified as endocrine disrupting chemicals and carcinogens. Bacterial degradation is crucial for removing natural estrogens from natural and engineered ecosystems; however, current knowledge regarding the biochemical mechanisms and catabolic enzymes involved in estrogen biodegradation is very limited. Our estrogen metabolite profile and genomic analyses on estrone-degrading bacteria enabled us to characterize the aerobic estrogen degradation pathway. The results greatly expand our understanding of microbial steroid degradation. In addition, the characteristic metabolites, dead-end products, and degradation genes can be used as biomarkers to investigate the fate and biodegradation potential of estrogens in the environment.


Assuntos
Estrogênios/química , Estrogênios/metabolismo , Sphingomonas/metabolismo , Aerobiose , Biodegradação Ambiental , Estrutura Molecular , Oxirredução , Sphingomonas/genética
15.
Int J Biol Macromol ; 126: 118-122, 2019 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-30583004

RESUMO

A variety of physiological functions such as exopolysaccharide synthesis, antibiotic production, and primary metabolism are tightly controlled by quorum sensing in microorganisms. In this study, a marine-derived bacterium Sphingomonas sp. WG was found to possess a cyclo(L-Pro-L-Phe)-mediated quorum sensing mechanism. The cyclo(L-Pro-L-Phe) produced by Sphingomonas sp. WG functions as a signalling molecule in this quorum sensing system. It is the first attempt to characterize cyclic dipeptides as quorum sensing signalling molecules in Sphingomonas sp. and the results effectively make the classical quorum sensing theory more perfect. Furthermore, the supplementation with isolated cyclo(L-Pro-L-Phe) resulted in a 15% increase in the production of welan gum secreted by Sphingomonas sp. WG in the submerged fermentation. The data presented in this study will provide evidences for exploring the role of cyclic dipeptides in regulating the production of welan gum.


Assuntos
Dipeptídeos/metabolismo , Peptídeos Cíclicos/metabolismo , Polissacarídeos Bacterianos/biossíntese , Percepção de Quorum , Sphingomonas/metabolismo , Técnicas Biossensoriais , Dipeptídeos/química , Dipeptídeos/isolamento & purificação , Luminescência , Peptídeos Cíclicos/química , Peptídeos Cíclicos/isolamento & purificação , Transdução de Sinais
16.
Sci Rep ; 8(1): 14756, 2018 10 03.
Artigo em Inglês | MEDLINE | ID: mdl-30283150

RESUMO

The present study aimed to develop a plate-screening method, based on the specific color development of complexes formed between chlorogenic acid, a valuable plant-derived compound, and aluminum (III), to detect chlorogenic acid-producing microbial strains. Modified media with 0.75 mM aluminum chloride were developed to identify CGA-producing bacteria (based on beef extract agar medium) or fungi (based on the potato dextrose agar medium). Compared with conventional screening, the modified media let to 3.3 times more CGA producers from plants, at 90.9% selective accuracy. Novel chlorogenic acid-biosynthesizing strains included Brevibacillus borstelensis B14, Bacillus amyloliquefaciens B17, Bacillus badius B19, Sphingomonas yabuuchiae N21, Enterobacter tabaci N22, and Lodderomyces elongisporus S216 and P212. Strain S216 produced the highest chlorogenic acid yield (23.39 mg L-1). This study provides a highly efficient and low-cost tool for quick detection and subsequent identification of several newly isolated strains with chlorogenic acid-producing potential.


Assuntos
Bacillus amyloliquefaciens/metabolismo , Bacillus/metabolismo , Brevibacillus/metabolismo , Ácido Clorogênico/isolamento & purificação , Enterobacter/metabolismo , Ensaios de Triagem em Larga Escala , Sphingomonas/metabolismo , Cloreto de Alumínio/química , Bacillus/química , Bacillus amyloliquefaciens/química , Brevibacillus/química , Ácido Clorogênico/metabolismo , Complexos de Coordenação/análise , Meios de Cultura/química , Enterobacter/química , Concentração de Íons de Hidrogênio , Folhas de Planta/microbiologia , Plantas/microbiologia , Sphingomonas/química
17.
Ecotoxicol Environ Saf ; 164: 648-658, 2018 Nov 30.
Artigo em Inglês | MEDLINE | ID: mdl-30170313

RESUMO

Chromium Cr(VI) is highly toxic and leads to impaired phenotypic plasticity of economically important crops. The current study assessed an endophytic-bacteria assisted metal bio-remediation strategy to understand stress-alleviating mechanisms in Glycine max L (soybean) plants inoculated with Sphingomonas sp. LK11 under severe Cr(VI) toxicity. The screening analysis showed that high Cr concentrations (5.0 mM) slightly suppressed LK11 growth and metal uptake by LK11 cells, while significantly enhancing indole-3-acetic acid (IAA) production. Endophytic LK11 significantly upregulated its antioxidant system compared to control by enhancing reduced glutathione (GSH), catalase (CAT), peroxidase (POD), and superoxide dismutase (SOD) activities to counteract Cr-induced oxidative stress. Cr toxicity induced cell morphological alteration, as shown by SEM-EDX analysis and triggered significant lipid peroxidation. The interaction between LK11 and soybean in Cr-contaminated soil significantly increased plant growth attributes and down-regulated the synthesis of endogenous defense-related phytohormones, salicylic acid and abscisic acid, by 20% and 37%, respectively, and reduced Cr translocation to the roots, shoot, and leaves. Additionally, Cr-induced oxidative stress was significantly reduced in LK11-inoculated soybean, regulating metal responsive reduced GSH and enzymatic antioxidant CAT. Current findings indicate that LK11 may be a suitable candidate for the bioremediation of Cr-contaminated soil and stimulation of host physiological homeostasis.


Assuntos
Cromo/toxicidade , Soja/efeitos dos fármacos , Sphingomonas/metabolismo , Ácido Abscísico/metabolismo , Catalase/metabolismo , Produtos Agrícolas/efeitos dos fármacos , Produtos Agrícolas/metabolismo , Produtos Agrícolas/microbiologia , Glutationa/metabolismo , Ácidos Indolacéticos/metabolismo , Peroxidação de Lipídeos/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Peroxidase/metabolismo , Desenvolvimento Vegetal/efeitos dos fármacos , Reguladores de Crescimento de Planta/metabolismo , Folhas de Planta/efeitos dos fármacos , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Raízes de Plantas/efeitos dos fármacos , Raízes de Plantas/metabolismo , Raízes de Plantas/microbiologia , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/metabolismo , Brotos de Planta/microbiologia , Ácido Salicílico/metabolismo , Poluentes do Solo/toxicidade , Soja/metabolismo , Soja/microbiologia , Superóxido Dismutase/metabolismo , Regulação para Cima
18.
Appl Microbiol Biotechnol ; 102(23): 10171-10181, 2018 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-30229322

RESUMO

Sphingomonas melonis TY utilizes nicotine as a sole source of carbon, nitrogen, and energy to grow. One of the genes in its ndp catabolic cluster, ndpT, encodes a hypothetical transporter. Since no transporter for nicotine has been identified in microorganisms, we investigated whether NdpT is responsible for nicotine transport. ndpT was induced by nicotine, and gene knockout and complementation studies clearly indicated that ndpT is essential for the catabolism of nicotine in strain TY. NdpT-GFP was located at the periphery of the cells, suggesting that NdpT is a membrane protein. Uptake assays with L-[14C] nicotine illustrated that nicotine uptake in strain TY is mediated by a constitutively synthesized permease with a Km of 0.362 ± 0.07 µM and a Vmax of 0.762 ± 0.068 µmol min-1 (mg cell dry weight)-1 and that ndpT may play a role in nicotine exclusion. Hence, we consider NdpT a nicotine catabolism-related protein.


Assuntos
Proteínas de Bactérias/genética , Proteínas de Membrana Transportadoras/genética , Nicotina/metabolismo , Sphingomonas/genética , Sphingomonas/metabolismo , Proteínas de Bactérias/metabolismo , Biotransformação , Carbono/metabolismo , Técnicas de Inativação de Genes , Concentração de Íons de Hidrogênio , Proteínas de Membrana Transportadoras/metabolismo , Nitrogênio/metabolismo
19.
J Ind Microbiol Biotechnol ; 45(11): 983-992, 2018 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-30191430

RESUMO

A shuttle vector pHSG396Sp was constructed to perform gene expression using Sphingomonas subterranea as a host. A new lasso peptide biosynthetic gene cluster, derived from Brevundimonas diminuta, was amplified by PCR and integrated to afford a expression vector pHSG396Sp-12697L. The new lasso peptide brevunsin was successfully produced by S. subterranea, harboring the expression vector, with a high production yield (10.2 mg from 1 L culture). The chemical structure of brevunsin was established by NMR and MS/MS experiments. Based on the information obtained from the NOE experiment, the three-dimensional structure of brevunsin was determined, which indicated that brevunsin possessed a typical lasso structure. This expression vector system provides a new heterologous production method for unexplored lasso peptides that are encoded by bacterial genomes.


Assuntos
Caulobacteraceae/metabolismo , Genoma Bacteriano , Família Multigênica , Peptídeos/metabolismo , Sphingomonas/metabolismo , Anti-Infecciosos/química , Brometo de Cianogênio/química , Espectroscopia de Ressonância Magnética , Biossíntese Peptídica , Sphingomonas/genética , Espectrometria de Massas em Tandem
20.
Methods Mol Biol ; 1852: 171-192, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30109631

RESUMO

The red diketocarotenoid, astaxanthin, exhibits extraordinary health-promoting activities such as antioxidant, anti-inflammatory, antitumor, and immune booster, which may potentially protect against many degenerative diseases such as cancers, heart diseases, and exercise-induced fatigue. These numerous health benefits and consumer interest in natural products have therefore increased the market demand of astaxanthin as a nutraceutical and medicinal ingredient in food, aquaculture feed, and pharmaceutical industries. Consequently, many research efforts have been made to discover novel microbial sources with effective biotechnological production of astaxanthin. Using a rapid screening method based on 16S rRNA gene, and effective HPLC-Diode array-MS methods for carotenoids analysis, we isolated a novel astaxanthin-producing bacterium (strain TDMA-17T) that belongs to the family Sphingomonadaceae (Asker et al., FEMS Microbiol Lett 273:140-148, 2007).In this chapter, we provide a comprehensive description of the methods used for the analysis and identification of carotenoids produced by strain TDMA-17T. We will also describe the methods of isolation and identification for a novel bacterial carotenoid (an astaxanthin derivative), a major carotenoid that is produced by the novel strain. Finally, the identification methods of the novel strain will be summarized.


Assuntos
Sphingomonas/metabolismo , Sphingomonas/efeitos da radiação , Antioxidantes/química , Antioxidantes/isolamento & purificação , Antioxidantes/metabolismo , Cromatografia Líquida de Alta Pressão , Estrutura Molecular , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Análise Espectral , Sphingomonas/química , Sphingomonas/ultraestrutura , Xantofilas/biossíntese , Xantofilas/química , Xantofilas/isolamento & purificação
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