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1.
Artigo em Inglês | MEDLINE | ID: mdl-34435948

RESUMO

Strain S02T was isolated from a surface sediment sample collected from the Bering Sea (64.3361° N, 170.9541° W). The cells were Gram-stain-negative, motile and rod-shaped. The temperature range for growth was 4-25 °C and the pH for growth was 5.5-9.0, with optimum growth occurring at 20-25 °C and pH 7.0-8.0. Growth occurred in the presence of 0-7 % (w/v) NaCl (optimum, 2-5 %). Strain S02T had menaquinone-8 as the major respiratory quinone and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C16:0, C17 : 0 cyclo, summed feature 3 (C16 : 1 ω7c /C16 : 1 ω7c), C17 : 0 and C18 : 0 as major fatty acids. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and two glycolipids. The genomic DNA G+C content was approximately 63.8 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain S02T belonged to the genus Devosia. Strain S02T showed the highest sequence similarities to Devosia psychrophila Cr7-05T (97.5 %), Devosia naphthalenivorans CM5-1T (97.7 %), Devosia submarina KMM 9415T (97.4 %), Devosia epidermidihirudinis E84T (97.44 %), Devosia euplotis LIV5T (97.1 %) and Devosia limi DSM 17137T (96.7 %). On the basis of phylogenetic analyses and phenotypic characteristics, a novel species of the genus Devosia, Devosia beringensis sp. nov., is proposed, with the type strain S02T (=JCM 33772=CCTCC AB 2019343).


Assuntos
Hyphomicrobiaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hyphomicrobiaceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química
2.
Artigo em Inglês | MEDLINE | ID: mdl-34287119

RESUMO

A polyphasic taxonomic approach was used to characterize a Gram-stain-negative bacterium, designated strain CC-YST696T, harbouring antibiotic- and toxic compound-resistace genes, isolated from poultry manure in Taiwan. Cells of CC-YST696T were short rods, motile with polar flagella, catalase- and oxidase-positive. Optimal growth occurred at 30 °Ð¡, pH 9 and with 1 % NaCl. The results of phylogenetic analyses based on 16S rRNA genes revealed a distinct taxonomic position attained by CC-YST696T associated with Devosia chinhatensis (97.9 % sequence identity), Devosia riboflavina (97.3 %) and Devosia indica (97.2 %), and with lower sequence similarity values to other species. Average nucleotide identity (ANI) values were 72.8-80.0 % (n=17) compared within the type strains of species of of the genus Devosia. CC-YST696T contained C16:0, C18:0, C18:1ω7c 11-methyl and C18:1ω6c/ C18:1ω7c as the predominant fatty acids. The polar lipid profile consisted of phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids, three unidentified glycolipids, two unidentified phospholipids and three unidentified lipids. The DNA G+C content was 62.2 mol% and the predominant quinone was ubiquinone Q-10. On the basis of its distinct phylogenetic, phenotypic and chemotaxonomic traits together with results of comparative 16S rRNA gene sequence and ANI analyses, strain CC-YST696T is proposed to represent a novel species of the genus Devosia, for which the name Devosia faecipullorum sp. nov. (type strain CC-YST696T=BCRC 81284T=JCM 34167T) is proposed.


Assuntos
Hyphomicrobiaceae/classificação , Esterco/microbiologia , Filogenia , Aves Domésticas/microbiologia , Animais , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hyphomicrobiaceae/isolamento & purificação , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Taiwan , Ubiquinona/análogos & derivados , Ubiquinona/química
3.
Arch Microbiol ; 203(7): 4517-4523, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34146114

RESUMO

A novel Gram-negative, cream-colored, rod-shaped, aerobic, non-motile bacterium, designated MSA67T, was isolated from a subterranean sediment sample of the Mohe Basin in Northeast China. Strain MSA67T was detected to grow at 4-40 °C (optimum 28-30 °C), pH 5.0-10.0 (optimum, pH 7.0) and in 0.0-8.0% (w/v) NaCl (optimum 2.0-3.0%). Phylogenetic analysis based on 16S rRNA gene sequence revealed that strain MSA67T was a member of the genus Devosia, with the highest similarity with D. riboflavina IFO13584T (98.0%) and D. chinhatensis IPL18T (97.0%). The major cellular fatty acids are C16:0, C18:1ω7c 11-methyl and C18:1ω6c and/or C18:1ω7c. The major polar lipids are diphosphatidylglycerol, phosphatidylglycerol, glycolipids and three unidentified phospholipids. The major respiratory quinone is ubiquinone 10 (Q-10). The genomic size of strain MSA67T is 4.1 MB and DNA G + C content is 63.6%. Based on genotypic, phenotypic and phylogenetic results, strain MSA67T is concluded to represent a novel species of the genus Devosia, for which the name Devosia sediminis sp. nov. is proposed. The type strain is MSA67T (= CGMCC 1.18467T = KCTC 82192T).


Assuntos
Sedimentos Geológicos , Hyphomicrobiaceae , China , Ácidos Graxos/análise , Sedimentos Geológicos/microbiologia , Hyphomicrobiaceae/química , Hyphomicrobiaceae/classificação , Hyphomicrobiaceae/genética , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Especificidade da Espécie , Ubiquinona
4.
Curr Microbiol ; 78(7): 2548-2555, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33963447

RESUMO

Strain H239T, a gram-negative, strictly aerobic, and oxidase-positive, and catalase-negative bacterium, was isolated from mountain soil in Gangwon-do of South Korea. Colonies were orange colored, and cells were motile rods with a single polar flagellum. Growth was observed between 25 and 30 °C (optimum, 30 °C), between pH 7.0 and pH 9.0 (optimum, pH 7.5), and in the presence of 0-1.5% (w/v) NaCl (optimum 0.5-1%). Ubiquinone-10 was detected as the sole respiratory quinone. The major fatty acids (>10%) of strain H239T were C18:1 ω7c, C18:0, and C16:0. The polar lipids detected from strain H239T consisted of two unidentified glycolipids, two unidentified phospholipids, and three unidentified polar lipids. The G+C content of strain H239T based on its genome sequence was 62.0 mol%. Comparative 16S rRNA gene sequence analysis indicated that strain H239T was most closely related to Devosia chinhatensis IPL18T (97.7%), Devosia submarina KMM 9415T (97.7%), and Devosia yakushimensis Yak96BT (97.3%). Phylogenetic analyses based on the 16S rRNA gene and whole-genome sequences revealed that strain H239T formed a distinct phyletic lineage as a new species within the genus Devosia. Based on its physiological, chemotaxonomic, and molecular properties, strain H239T represents a novel species of the genus Devosia, for which the name Devosia aurantiaca sp. nov. is proposed. The type strain is H239T (=KACC 21662T=JCM 33930T). In addition, because the prokaryotic genus name Geomonas Khan et al. 2020 is a later homonym of Geomonas Xu et al. 2020, the name is illegitimate (Principle 6 in the International Code of Nomenclature of Prokaryotes). Therefore, we propose to replace the problematic prokaryotic names Geomonas and Geomonas soli with Albitalea with Albitalea terrae, respectively.


Assuntos
Fosfolipídeos , Solo , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Hyphomicrobiaceae , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Ubiquinona
5.
Arch Microbiol ; 203(5): 2681-2687, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33715031

RESUMO

A Gram-staining negative, motile, non-spore-forming, rod-shaped bacterium, designated NAJP-14T, was isolated from the alkali-saline soil in Heilongjiang, Northeast China. Phylogenetic analysis based on 16S rRNA gene sequencing illustrated that strain NAJP-14T was a member of the genus Pelagibacterium, and shared 94.6-96.6% sequence identities to species from the genus Pelagibacterium. Strain NAJP-14T grew at 20-45 °C (optimum, 30 °C), pH 7.0-10.0 (optimum, pH 8.0) and in the presence of up to 5% w/v NaCl. The menaquinone was determined to be Q (10). The major fatty acids were identified as C18:1w6c (38.7%), C16:0 (16.2%) and C19:0 cyclo w8c (13.9%). The G + C content of the genomic DNA was 61.2%. Out of the 3442 predicted genes, 3391 were protein-coding genes and 51 were ncRNA. Digital DNA-DNA hybridization (dDDH) estimation and average nucleotide identity (ANI) of the strain NAJP-14T and the type strains of related species in the same family ranged between 17.9 and 21.8% and between 61.4 and 78.7%, respectively. Based on these data, it is concluded that strain NAJP-14T possesses sufficient characteristics to differentiate it from all recognized Pelagibacterium species, and should be considered as a novel species for which the name Pelagibacterium limicola sp. nov. is proposed. The type strain is NAJP-14T (= CGMCC 1.16631T, = JCM 33746T).


Assuntos
Hyphomicrobiaceae/classificação , Hyphomicrobiaceae/isolamento & purificação , Microbiologia do Solo , Álcalis/análise , Técnicas de Tipagem Bacteriana , Composição de Bases/genética , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Hyphomicrobiaceae/genética , Hibridização de Ácido Nucleico , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Solo/química
6.
Microb Biotechnol ; 14(3): 1159-1170, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33683803

RESUMO

Marine photosynthetic microalgae are ubiquitously associated with bacteria in nature. However, the influence of these bacteria on algal cultures in bioreactors is still largely unknown. In this study, eighteen different bacterial strains were isolated from cultures of Nannochloropsis sp. CCAP211/78 in two outdoor pilot-scale tubular photobioreactors. The majority of isolates was affiliated with the classes Alphaproteobacteria and Flavobacteriia. To assess the impact of the eighteen strains on the growth of Nannochloropsis sp. CCAP211/78, 24-well plates coupled with custom-made LED boxes were used to simultaneously compare replicate axenic microalgal cultures with addition of individual bacterial isolates. Co-culturing of Nannochloropsis sp. CCAP211/78 with these strains demonstrated distinct responses, which shows that the technique we developed is an efficient method for screening the influence of harmful/beneficial bacteria. Two of the tested strains, namely a strain of Maritalea porphyrae (DMSP31) and a Labrenzia aggregata strain (YP26), significantly enhanced microalgal growth with a 14% and 12% increase of the chlorophyll concentration, respectively, whereas flavobacterial strain YP206 greatly inhibited the growth of the microalga with 28% reduction of the chlorophyll concentration. Our study suggests that algal production systems represent a 'natural' source to isolate and study microorganisms that can either benefit or harm algal cultures.


Assuntos
Microalgas , Estramenópilas , Biomassa , Hyphomicrobiaceae , Rhodobacteraceae
7.
Biochemistry (Mosc) ; 86(1): 1-7, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33705277

RESUMO

In this review, we discuss our studies conducted in 1985-1988 in collaboration with A. A. Konstantinov, one of the top scientists in the field of membrane bioenergetics. Studying fast kinetics of membrane potential generation in photosynthetic reaction centers (RCs) of purple bacteria in response to a laser flash has made it possible to examine in detail the mechanisms of electrogenic reactions at the donor and acceptor sides of RCs. Electrogenesis associated with the intraprotein electron transfer from the exogenous secondary donors, redox dyes, and soluble cytochrome (cyt) c to the photooxidized dimer of bacteriochlorophyll P870 was studied using proteoliposomes containing RCs from the non-sulfur purple bacterium Rhodospirillum rubrum. It was found that reduction of the secondary quinone electron acceptor QB accompanied by its protonation in the chromatophores from R. rubrum in response to every second light flash was electrogenic. Spectral characteristics and redox potentials of the four hemes in the tightly bound cyt c in the RC of Blastochloris viridis and electrogenic reactions associated with the electron transfer within the RC complex were identified. For the first time, relative amplitudes of the membrane potential generated in the course of individual electrogenic reactions were compared with the distances between the redox cofactors determined based on the three-dimensional structure of the Bl. viridis RC.


Assuntos
Bactérias/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Proteínas de Bactérias/metabolismo , Citocromos c/metabolismo , Transporte de Elétrons , História do Século XX , Hyphomicrobiaceae/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/história , Rhodospirillum rubrum/metabolismo
8.
Arch Microbiol ; 203(4): 1335-1343, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33386867

RESUMO

A Gram stain-negative bacterial strain, designated SY4-7T, was isolated from rhizosphere mudflat of a halophyte (Zoysia sinica) collected around Seonyu Island, Republic of Korea. Cells of the organism were strictly aerobic, non-sporulating, non-motile rods and grew at 20-42 °C, pH 6-8 and 1-6% (w/v) NaCl. The 16S rRNA gene-based phylogenetic analyses revealed that strain SY4-7T formed an independent cluster separated from the recognized genera of the family Stappiaceae, which was also supported by phylogenomic analysis-based 92-core gene sequences. The type stains of the phylogenetically closest relatives were Stappia indica (95.6% sequence similarity), Stappia stellulata (95.1%) and Roseibium hamelinense (95.1%). The isoprenoid quinone was Q-10. The polar lipids consisted of phosphatidylcholine, phosphatidylethanolamine, phosphatidylglycerol, three unidentified aminophospholipids, an unidentified phosphoglycolipid, an unidentified aminolipid, two unidentified phospholipids and an unidentified lipid. The major cellular fatty acids are C18:1ω7c and C19:1 cyclo ω8c. The G + C content of the genomic DNA is 60.7%. Discrimination of the organism from all the recognized genera of the family Stappiaceae was apparent by the chemotaxonomic and phylogenetic features. Based on the results presented here, strain SY4-7T (= KCTC 72226T = NBRC 113902T) represents a novel species of a new genus in the family Stappiaceae, for which the name Hongsoonwoonella zoysiae sp. nov. is proposed.


Assuntos
Hyphomicrobiaceae/classificação , Hyphomicrobiaceae/fisiologia , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Genoma Bacteriano/genética , Hyphomicrobiaceae/química , Ilhas , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , República da Coreia , Rizosfera , Plantas Tolerantes a Sal/microbiologia , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/análise
9.
Nature ; 589(7841): 310-314, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33268896

RESUMO

Photosynthetic reaction centres harvest the energy content of sunlight by transporting electrons across an energy-transducing biological membrane. Here we use time-resolved serial femtosecond crystallography1 using an X-ray free-electron laser2 to observe light-induced structural changes in the photosynthetic reaction centre of Blastochloris viridis on a timescale of picoseconds. Structural perturbations first occur at the special pair of chlorophyll molecules of the photosynthetic reaction centre that are photo-oxidized by light. Electron transfer to the menaquinone acceptor on the opposite side of the membrane induces a movement of this cofactor together with lower amplitude protein rearrangements. These observations reveal how proteins use conformational dynamics to stabilize the charge-separation steps of electron-transfer reactions.


Assuntos
Complexo de Proteínas do Centro de Reação Fotossintética/química , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Bacterioclorofilas/metabolismo , Sítios de Ligação/efeitos dos fármacos , Clorofila/metabolismo , Clorofila/efeitos da radiação , Cristalografia , Citoplasma/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Elétrons , Hyphomicrobiaceae/enzimologia , Hyphomicrobiaceae/metabolismo , Lasers , Modelos Moleculares , Oxirredução/efeitos da radiação , Feofitinas/metabolismo , Complexo de Proteínas do Centro de Reação Fotossintética/efeitos da radiação , Prótons , Ubiquinona/análogos & derivados , Ubiquinona/metabolismo , Vitamina K 2/metabolismo
10.
Biochemistry ; 59(25): 2351-2358, 2020 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-32515940

RESUMO

Blastochloris tepida is a newly described thermophilic purple bacterium containing bacteriochlorophyll b. Using purified light-harvesting 1 reaction center (LH1-RC) core complexes from Blc. tepida, we compared the biochemical, spectroscopic, and thermal denaturation properties of these complexes with those of its mesophilic counterpart, Blc. viridis. Besides their growth temperature optima, a striking difference between the two species was seen in the carotenoid composition of their LH1-RC complexes. The more thermostable Blc. tepida complex contained more carotenoids with longer conjugation lengths (n > 9), such as lycopenes (n = 11), and had a total carotenoid content significantly higher than that of the Blc. viridis complex, irrespective of the light intensity used for growth. The thermostability of LH1-RCs from both Blc. tepida and Blc. viridis decreased significantly in cells grown in the presence of diphenylamine, a compound that inhibits the formation of highly conjugated carotenoids. In contrast to the thermophilic purple bacterium Thermochromatium tepidum, where Ca2+ is essential for LH1-RC thermostability, Ca2+ neither was present in nor had any effect on the thermostability of the Blc. tepida LH1-RC. These results point to a mechanism that carotenoids with elongated conjugations enhance hydrophobic interactions with proteins in the Blc. tepida LH1-RC, thereby allowing the complexes to withstand thermal denaturation. This conclusion is bolstered by a structural model of the Blc. tepida LH1-RC and is the first example of photocomplex thermostability being linked to a carotenoid-based mechanism.


Assuntos
Proteínas de Bactérias/química , Complexos de Proteínas Captadores de Luz/química , Licopeno/análogos & derivados , Complexo de Proteína do Fotossistema I/química , Sequência de Aminoácidos , Difenilamina/farmacologia , Hyphomicrobiaceae/química , Hyphomicrobiaceae/efeitos dos fármacos , Estabilidade Proteica , Alinhamento de Sequência , Temperatura
11.
Int J Syst Evol Microbiol ; 70(5): 3062-3068, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32375940

RESUMO

A Gram-stain-negative, aerobic, rod-shaped and motile bacterial strain, designated L53-10-65T, was isolated from deep seawater of the South China Sea. Strain L53-10-65T was found to grow at 4-41 °C (optimum, 28 °C), at pH 5.0-9.0 (pH 7.0-8.0) and in 0-7 % (w/v) NaCl (2 %). Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain L53-10-65T fell within the genus Devosia, with the highest similarity to Devosia indica IO390501T (98.4 %), followed by 'Devosia lucknowensis' L15T (97.7 %) and Devosia riboflavina IFO 13584T (96.8 %). The digital DNA-DNA hybridization (dDDH) values between strain L53-10-65T and the three relatives above were 43.7, 21.5 and 20.9 %, respectively; the average nucleotide identity (ANI) values were 91.3, 78.4 and 76.8 %, respectively. These values were below the 70 % dDDH and 95-96 % ANI thresholds for bacterial species delineation. The major cellular fatty acids of strain L53-10-65T were summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c), C18 : 1 ω7c 11-methyl and C16 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and glycolipids. The respiratory quinone was identified as Q-10. The DNA G+C content of strain L53-10-65T was 61.3 mol%. Based on the results of phylogenetic analysis and distinctive phenotypic characteristics, strain L53-10-65T is concluded to represent a novel species of the genus Devosia, for which the name Devosia marina sp. nov. is proposed. The type strain of the species is L53-10-65T (=MCCC 1A05139T=KCTC 72888T). Moreover, we propose that Devosia subaequoris is a later heterotypic synonym of Devosia soli based on the present results.


Assuntos
Hyphomicrobiaceae/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hyphomicrobiaceae/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
12.
Int J Syst Evol Microbiol ; 70(3): 1489-1495, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-32228770

RESUMO

A Gram-stain-negative, strictly aerobic, motile, ivory-coloured and rod-shaped bacterium (designated Gsoil 520T) isolated from ginseng cultivation soil was characterized by using a polyphasic approach to clarify its taxonomic position. Strain Gsoil 520T was observed to grow optimally at 30 °C and pH 7.0 on Reasoner's 2A agar medium. The results of phylogenetic analysis, based on 16S rRNA gene sequence similarities, indicated that Gsoil 520T belongs to the genus Devosia of the family Hyphomicrobiaceae and was most closely related to Devosia epidermidihirudinis E84T (98.0 %), Devosia yakushimensis Yak96BT (97.7 %), Devosia neptuniae J1T (97.7 %) and Devosia chinhatensis IPL18T (96.8 %). The complete genome of strain Gsoil 520T is a presumptive circular chromosome of 4 480 314 base pairs having G+C content of 63.7 mol%. A total of 4 354 genes, 4 303 CDS and 43 rRNA genes were assigned a putative function. The major isoprenoid quinone was Q-10. The main polar lipids were phosphatidylglycerol, diphosphatidylglycerol and two unidentified aminolipids (AL1 and AL3). The predominant fatty acids of strain Gsoil 520T were C18 : 1ω7c 11-methyl, C16 : 0 and C18 : 1ω7c/C18 : 1ω6c (summed feature 8) supporting the affiliation of strain Gsoil 520T to the genus Devosia. The low values of DNA-DNA hybridization distinguished strain Gsoil 520T from the recognized species of the genus Devosia. Thus, the novel isolate represents a novel species of the genus Devosia, for which the name Devosia ginsengisoli sp. nov. is proposed, with the type strain Gsoil 520T (=KACC 19440T=LMG 30329T).


Assuntos
Hyphomicrobiaceae/classificação , Panax/microbiologia , Filogenia , Microbiologia do Solo , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Hyphomicrobiaceae/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
13.
Food Chem ; 321: 126703, 2020 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-32247890

RESUMO

The Fusarium mycotoxin deoxynivalenol (DON) is typically controlled by fungicides. Here, we report DON detoxification using enzymes from the highly active Devosia strain D6-9 which degraded DON at 2.5 µg/min/108 cells. Strain D6-9 catabolized DON to 3-keto-DON and 3-epi-DON, completely removing DON in wheat. Genome analysis of three Devosia strains (D6-9, D17, and D13584), with strain D6-9 transcriptomes, identified three genes responsible for DON epimerization. One gene encodes a quinone-dependent DON dehydrogenase QDDH which oxidized DON into 3-keto-DON. Two genes encode the NADPH-dependent aldo/keto reductases AKR13B2 and AKR6D1 that convert 3-keto-DON into 3-epi-DON. Recombinant proteins expressed in Escherichia coli efficiently degraded DON in wheat grains. Molecular docking and site-directed mutagenesis revealed that residues S497, E499, and E535 function in QDDH's DON-oxidizing activity. These results advance potential microbial and enzymatic elimination of DON in agricultural samples and lend insight into the underlying mechanisms and molecular evolution of DON detoxification.


Assuntos
Aldo-Ceto Redutases/metabolismo , Hyphomicrobiaceae/enzimologia , Tricotecenos/metabolismo , Triticum/enzimologia , Fusarium/metabolismo , Simulação de Acoplamento Molecular , NADP/metabolismo , Oxirredução , Quinona Redutases/metabolismo
14.
Biochim Biophys Acta Bioenerg ; 1861(8): 148204, 2020 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-32305414

RESUMO

Precise folding of photosynthetic proteins and organization of multicomponent assemblies to form functional entities are fundamental to efficient photosynthetic electron transfer. The bacteriochlorophyll b-producing purple bacterium Blastochloris viridis possesses a simplified photosynthetic apparatus. The light-harvesting (LH) antenna complex surrounds the photosynthetic reaction center (RC) to form the RC-LH1 complex. A non-membranous tetraheme cytochrome (4Hcyt) subunit is anchored at the periplasmic surface of the RC, functioning as the electron donor to transfer electrons from mobile electron carriers to the RC. Here, we use atomic force microscopy (AFM) and single-molecule force spectroscopy (SMFS) to probe the long-range organization of the photosynthetic apparatus from Blc. viridis and the unfolding pathway of the 4Hcyt subunit in its native supramolecular assembly with its functional partners. AFM images reveal that the RC-LH1 complexes are densely organized in the photosynthetic membranes, with restricted lateral protein diffusion. Unfolding of the 4Hcyt subunit represents a multi-step process and the unfolding forces of the 4Hcyt α-helices are approximately 121 picoNewtons. Pulling of 4Hcyt could also result in the unfolding of the RC L subunit that binds with the N-terminus of 4Hcyt, suggesting strong interactions between RC subunits. This study provides new insights into the protein folding and interactions of photosynthetic multicomponent complexes, which are essential for their structural and functional integrity to conduct photosynthetic electron flow.


Assuntos
Citocromos/química , Hyphomicrobiaceae/enzimologia , Complexo de Proteínas do Centro de Reação Fotossintética/química , Subunidades Proteicas/química , Desdobramento de Proteína , Fenômenos Biomecânicos , Modelos Moleculares , Complexo de Proteínas do Centro de Reação Fotossintética/metabolismo , Conformação Proteica
15.
Food Chem Toxicol ; 140: 111276, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32199966

RESUMO

Deoxynivalenol (DON), a toxic secondary metabolite produced by Fusarium species that mainly infests cereals such as wheat and corn, threatens human and livestock health. The present study describes the characterization of a novel bacterial strain, Pelagibacterium halotolerans ANSP101 which is capable of transforming DON to less-toxic product 3-keto-deoxynivalenol by the oxidation of the C3 hydroxyl group. Strain ANSP101 was isolated from a seawater sample from a depth of 55 m in Chinese Bohai sea. The strain was identified as Pelagibacterium halotolerans by morphology characterization and 16S rDNA gene sequencing. The DON degrading activity of strain ANSP101 was predominantly attributed to the bacterial cell lysate. Besides, the cell lysate was sensitive to sodium dodecyl sulfate, heat, and proteinase K treatment, indicating that the intracellular proteins or enzymes are responsible for the DON degradation. The optimal temperature and pH for the maximal degradation of DON were 40 °C and pH 8.0 by the cell lysate. These results provide the potential use of P. halotolerans ANSP101 as a detoxification agent for DON decontamination in cereals and feed.


Assuntos
Biodegradação Ambiental , Enzimas/metabolismo , Hyphomicrobiaceae/metabolismo , Tricotecenos/metabolismo , DNA Ribossômico/genética , Contaminação de Alimentos/análise , Concentração de Íons de Hidrogênio , Hyphomicrobiaceae/enzimologia , Hyphomicrobiaceae/genética , RNA Ribossômico 16S/genética , Temperatura
16.
Sci Rep ; 10(1): 1151, 2020 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-31980727

RESUMO

Devosia are well known for their dominance in soil habitats contaminated with various toxins and are best characterized for their bioremediation potential. In this study, we compared the genomes of 27 strains of Devosia with aim to understand their metabolic abilities. The analysis revealed their adaptive gene repertoire which was bared from 52% unique pan-gene content. A striking feature of all genomes was the abundance of oligo- and di-peptide permeases (oppABCDF and dppABCDF) with each genome harboring an average of 60.7 ± 19.1 and 36.5 ± 10.6 operon associated genes respectively. Apart from their primary role in nutrition, these permeases may help Devosia to sense environmental signals and in chemotaxis at stressed habitats. Through sequence similarity network analyses, we identified 29 Opp and 19 Dpp sequences that shared very little homology with any other sequence suggesting an expansive short peptidic transport system within Devosia. The substrate determining components of these permeases viz. OppA and DppA further displayed a large diversity that separated into 12 and 9 homologous clusters respectively in addition to large number of isolated nodes. We also dissected the genome scale positive evolution and found genes associated with growth (exopolyphosphatase, HesB_IscA_SufA family protein), detoxification (moeB, nifU-like domain protein, alpha/beta hydrolase), chemotaxis (cheB, luxR) and stress response (phoQ, uspA, luxR, sufE) were positively selected. The study highlights the genomic plasticity of the Devosia spp. for conferring adaptation, bioremediation and the potential to utilize a wide range of substrates. The widespread toxin-antitoxin loci and 'open' state of the pangenome provided evidence of plastic genomes and a much larger genetic repertoire of the genus which is yet uncovered.


Assuntos
Proteínas de Bactérias/genética , Genes Bacterianos , Hyphomicrobiaceae/genética , Proteínas de Membrana Transportadoras/genética , Adaptação Fisiológica , Composição de Bases , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Meio Ambiente , Ontologia Genética , Genoma Bacteriano , Hyphomicrobiaceae/classificação , Hyphomicrobiaceae/metabolismo , Redes e Vias Metabólicas/genética , Nutrientes/metabolismo , Fases de Leitura Aberta , Óperon , Peptídeos/metabolismo , Filogenia , Seleção Genética , Alinhamento de Sequência , Microbiologia do Solo , Poluentes do Solo , Especificidade da Espécie
17.
J Comput Chem ; 41(11): 1105-1115, 2020 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31981372

RESUMO

We introduce a combination of Monte Carlo simulation and thermodynamic integration methods to address a model problem in free energy computations, electron transfer in proteins. The feasibility of this approach is tested using the ferredoxin protein from Clostridium acidurici. The results are compared to numerical solutions of the Poisson-Boltzmann equation and data from recent molecular dynamics simulations on charge transfer in a protein complex, the NrfHA nitrite reductase of Desulfovibrio vulgaris. Despite the conceptual and computational simplicity of the Monte Carlo approach, the data agree well with those obtained by other methods. A link to experiments is established via the cytochrome subunit of the bacterial photosynthetic reaction center of Rhodopseudomonas viridis.


Assuntos
Ferredoxinas/química , Complexo de Proteínas do Centro de Reação Fotossintética/química , Citocromos/química , Transporte de Elétrons , Firmicutes/química , Hyphomicrobiaceae/química , Simulação de Dinâmica Molecular , Método de Monte Carlo , Nitrito Redutases/química , Termodinâmica
18.
Int J Syst Evol Microbiol ; 70(1): 340-345, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31596199

RESUMO

A Gram-stain-negative bacterium, designated IO390501T, was isolated from a sea water sample from the Indian Ocean and taxonomically characterized using a polyphasic approach. The strain is phylogenetically close to 'Devosia lucknowensis' L15 and Devosia chinhatensis IPL18T, with 16S rRNA gene sequence similarity of 97.7 and 97.4 %, respectively. The genome of IO390501T has a DNA G+C content of 61.9 mol% for the 3.9 Mb chromosome. Genome-based phylogenetic trees indicated that IO390501T clusters as an independent lineage with 'D. lucknowensis' L15. Genomic relatedness of in silico DNA-DNA hybridization between IO390501T and phylogenetic neighbours ranged from 18.8 to 21.5 %, below the cutoff of 70 %, and corresponding average nucleotide identity values were between 71.4 and 79.0 %, lower than the 95.0 % threshold. The predominant cellular fatty acids of IO390501T are summed feature 8 (C18 : 1ω7c/C18  : 1ω6c) and C16  :  0. IO390501T contains ubiquinone-10 as the sole respiratory quinone, and phosphatidylglycerol and glycolipids as the major polar lipids. On the basis of the results of phenotypic, chemotaxonomic and genetic analyses, strain IO390501T represents a novel species of the genus Devosia for which the name Devosia indica sp. nov. is proposed. The type strain is IO390501T.


Assuntos
Hyphomicrobiaceae/classificação , Filogenia , Água do Mar/microbiologia , Microbiologia da Água , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Glicolipídeos/química , Hyphomicrobiaceae/isolamento & purificação , Oceano Índico , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Ubiquinona/análogos & derivados , Ubiquinona/química
19.
Environ Microbiol ; 22(5): 1748-1763, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-31840364

RESUMO

Members of the SAR11 clade, despite their high abundance, are often poorly represented by metagenome-assembled genomes. This fact has hampered our knowledge about their ecology and genetic diversity. Here we examined 175 SAR11 genomes, including 47 new single-amplified genomes. The presence of the first genomes associated with subclade IV suggests that, in the same way as subclade V, they might be outside the proposed Pelagibacterales order. An expanded phylogenomic classification together with patterns of metagenomic recruitment at a global scale have allowed us to define new ecogenomic units of classification (genomospecies), appearing at different, and sometimes restricted, metagenomic data sets. We detected greater microdiversity across the water column at a single location than in samples collected from similar depth across the global ocean, suggesting little influence of biogeography. In addition, pangenome analysis revealed that the flexible genome was essential to shape genomospecies distribution. In one genomospecies preferentially found within the Mediterranean, a set of genes involved in phosphonate utilization was detected. While another, with a more cosmopolitan distribution, was unique in having an aerobic purine degradation pathway. Together, these results provide a glimpse of the enormous genomic diversity within this clade at a finer resolution than the currently defined clades.


Assuntos
Genoma Bacteriano/genética , Hyphomicrobiaceae/genética , Genômica , Hyphomicrobiaceae/classificação , Região do Mediterrâneo , Metagenoma/genética , Metagenômica , Oceanos e Mares , Organofosfonatos/metabolismo , Filogenia , Purinas/metabolismo , Água do Mar/microbiologia , Microbiologia da Água
20.
Acta Crystallogr D Struct Biol ; 75(Pt 10): 937-946, 2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31588925

RESUMO

Serial crystallography is having an increasing impact on structural biology. This emerging technique opens up new possibilities for studying protein structures at room temperature and investigating structural dynamics using time-resolved X-ray diffraction. A limitation of the method is the intrinsic need for large quantities of well ordered micrometre-sized crystals. Here, a method is presented to screen for conditions that produce microcrystals of membrane proteins in the lipidic cubic phase using a well-based crystallization approach. A key advantage over earlier approaches is that the progress of crystal formation can be easily monitored without interrupting the crystallization process. In addition, the protocol can be scaled up to efficiently produce large quantities of crystals for serial crystallography experiments. Using the well-based crystallization methodology, novel conditions for the growth of showers of microcrystals of three different membrane proteins have been developed. Diffraction data are also presented from the first user serial crystallography experiment performed at MAX IV Laboratory.


Assuntos
Complexo IV da Cadeia de Transporte de Elétrons/química , Halorrodopsinas/química , Lipídeos/química , Proteínas de Membrana/química , Complexo de Proteínas do Centro de Reação Fotossintética/química , Rodopsinas Sensoriais/química , Proteínas de Bactérias/química , Cristalização/métodos , Cristalografia por Raios X/métodos , Halobacteriaceae/enzimologia , Hyphomicrobiaceae/enzimologia , Thermus thermophilus/enzimologia
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