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1.
Environ Res ; 212(Pt A): 113176, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-35364039

RESUMO

Sulfide generally exists in wastewater, black and odor river, as well as aquaculture water, and give rise to adverse effect on ecological stability and biological safety, due to the toxicity, corrosivity and malodor of sulfide. In the present study, a chemolithotrophic sulfide-oxidizing bacteria (SOB) was isolated and identified as Marinobacter maroccanus strain SDSWS8. And it produced no hemolysin and was susceptible to most antibiotics. There were no accumulation of sulfide, sulfate and thiosulfate during the sulfide removal process. The optimum conditions of sulfide removal were temperature 15-40 °C, initial pH value 4.5-9.5, salinity 10-40‰, C/N ratio 0-20 and sulfide concentration 25-150 mg/L. The key genes of sulfide oxidation, Sox system (soxB, soxX, soxA, soxZ, soxY, soxD, soxC), dissimilatory sulfur oxidation (dsrA, aprA and sat) and sqr, were successfully amplified and expressed, indicating the three pathways coordinated to complete the sulfide oxidation. Besides, strain SDSWS8 had inhibitory effect on four pathogen Vibrio (V. harveyi, V. parahaemolyticus, V. anguillarum and V. splendidus). Furthermore, efficient removal of sulfide from real aquaculture water and sludge mixture could be accomplished by strain SDSWS8. This study may provide a promising candidate strain for sulfide-rich water treatment.


Assuntos
Marinobacter , Bactérias/metabolismo , Marinobacter/genética , Marinobacter/metabolismo , Oxirredução , Sulfetos/toxicidade , Enxofre/metabolismo
2.
PLoS One ; 17(2): e0263420, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35196352

RESUMO

Marine microbial communities play an important role in biodegradation of subsurface plumes of oil that form after oil is accidentally released from a seafloor wellhead. The response of these mesopelagic microbial communities to the application of chemical dispersants following oil spills remains a debated topic. While there is evidence that contrasting results in some previous work may be due to differences in dosage between studies, the impacts of these differences on mesopelagic microbial community composition remains unconstrained. To answer this open question, we exposed a mesopelagic microbial community from the Gulf of Mexico to oil alone, three concentrations of oil dispersed with Corexit 9500, and three concentrations of Corexit 9500 alone over long periods of time. We analyzed changes in hydrocarbon chemistry, cell abundance, and microbial community composition at zero, three and six weeks. The lowest concentration of dispersed oil yielded hydrocarbon concentrations lower than oil alone and microbial community composition more similar to control seawater than any other treatments with oil or dispersant. Higher concentrations of dispersed oil resulted in higher concentrations of microbe-oil microaggregates and similar microbial composition to the oil alone treatment. The genus Colwellia was more abundant when exposed to multiple concentrations of dispersed oil, but not when exposed to dispersant alone. Conversely, the most abundant Marinobacter amplicon sequence variant (ASV) was not influenced by dispersant when oil was present and showed an inverse relationship to the summed abundance of Alcanivorax ASVs. As a whole, the data presented here show that the concentration of oil strongly impacts microbial community response, more so than the presence of dispersant, confirming the importance of the concentrations of both oil and dispersant in considering the design and interpretation of results for oil spill simulation experiments.


Assuntos
Lipídeos/farmacologia , Microbiota/efeitos dos fármacos , Microbiota/genética , Poluição por Petróleo/efeitos adversos , Água do Mar/química , Água do Mar/microbiologia , Alcanivoraceae/genética , Alteromonadaceae/genética , Biodegradação Ambiental/efeitos dos fármacos , DNA Bacteriano/genética , DNA Bacteriano/isolamento & purificação , Golfo do México , Hidrocarbonetos/metabolismo , Marinobacter/genética , Petróleo/metabolismo , RNA Ribossômico 16S/genética , Poluentes Químicos da Água/análise
3.
Arch Microbiol ; 204(2): 155, 2022 Jan 30.
Artigo em Inglês | MEDLINE | ID: mdl-35094174

RESUMO

A Gram-negative, rod-shaped, motile bacterium, designated strain CAU 1620T, was isolated from a tidal flat sediment in Incheon, Republic of Korea. Strain CAU 1620T grew optimally at 30 °C and pH 8.0 in the presence of 6.0% (w/v) NaCl. The results of 16S rRNA gene sequence analysis revealed that strain CAU 1620T showed the highest similarity to Marinobacter adhaerens DSM 23420T (98.5%), followed by Marinobacter algicola DSM 16394T (98.3%) and Marinobacter maroccanus LMG 30465T (98.2%). The average nucleotide identity and digital DNA-DNA hybridisation values between strain CAU 1620T and related strains were estimated as 75.6-78.1% and 19.5-20.9%, respectively. The DNA G + C content based on the draft genome sequence was 59.2%, and the major respiratory quinone was ubiquinone-9. The predominant cellular fatty acids were C12:0, C16:0, C18:1 ω9c, and C12:0 3OH. The predominant polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, and phosphatidylglycerol. According to phenotypic, genotypic, and chemotaxonomic analyses, strain CAU 1620T represents a novel species of the genus Marinobacter, for which the name Marinobacter arenosus sp. nov. is proposed. The type strain is CAU 1620T (= KCTC 82431T = MCCC 1K06079T).


Assuntos
Marinobacter , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Marinobacter/genética , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Int J Syst Evol Microbiol ; 71(11)2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34762582

RESUMO

A novel marine bacterium, designated strain CHFG3-1-5T, was isolated from mangrove sediment sampled at Jiulong River estuary, Fujian, PR China. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CHFG3-1-5T belonged to the genus Marinobacter, with the highest sequence similarity to Marinobacter segnicrescens SS011B1-4T (97.6%), followed by Marinobacter nanhaiticus D15-8WT (97.5%), Marinobacter bohaiensis T17T (97.1%) and Marinobacter hydrocarbonoclasticus SP.17T (90.6%). The bacterium was Gram-stain-negative, facultative anaerobic, oxidase- and catalase-positive, rod-shaped and motile with a polar flagellum. Strain CHFG3-1-5T grew optimally at 32-37 °C, pH 6.0-8.0 and in the presence of 2.0-3.0% (w/v) NaCl. The G+C content of the chromosomal DNA was 61.1 mol%. The major respiratory quinone was determined to be Q-9. The principal fatty acids were C16 : 0, summed feature 3 (C16 : 1 ω7c/ω6c), C12 : 0, summed feature 9 (C17 : 1 iso ω9c and/or C16 : 0 10-methyl), C12 : 0 3-OH and summed feature 8 (C18 : 1 ω7c and/or C18 : 1 ω6c). The polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, three phospholipids, one glycolipid and two aminolipids. The average nucleotide identity and digital DNA-DNA hybridization values among the genomes of strain CHFG3-1-5T and the reference strains were 73.4-79.4 and 19.6-22.4%, respectively. Like many other species reported in the genus Marinobacter, strain CHFG3-1-5T was able to oxidise iron. The combined genotypic and phenotypic data showed that strain CHFG3-1-5T represents a novel species within the genus Marinobacter, for which the name Marinobacter mangrovi sp. nov. is proposed, with the type strain CHFG3-1-5T (=MCCC 1A18306T=KCTC 82398T).


Assuntos
Sedimentos Geológicos/microbiologia , Marinobacter , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , China , DNA Bacteriano/genética , Ácidos Graxos/química , Marinobacter/classificação , Marinobacter/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Vitamina K 2/análogos & derivados , Vitamina K 2/química , Áreas Alagadas
5.
Soft Matter ; 17(37): 8474-8482, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34586147

RESUMO

We identify factors leading to aggregation of bacteria in the presence of a surfactant using absorbance and microscopy. Two marine bacteria, Marinobacter hydrocarbonoclasticus SP17 and Halomonas titanicae Bead 10BA, formed aggregates of a broad size distribution in synthetic sea water in the presence of an anionic surfactant, dioctyl sodium sulfosuccinate (DOSS). Both DOSS at high concentrations and calcium ions were necessary for aggregate formation, but DOSS micelles were not required for aggregation. Addition of proteinase K but not DNase1 eliminated aggregate formation over two hours. Finally, swimming motility also enhanced aggregate formation.


Assuntos
Cálcio , Tensoativos , Bactérias , Halomonas , Íons , Marinobacter
6.
Appl Environ Microbiol ; 87(24): e0136721, 2021 11 24.
Artigo em Inglês | MEDLINE | ID: mdl-34586913

RESUMO

Autotrophic bacteria utilizing Fe(II) as their energy and electron sources for growth affect multiple biogeochemical cycles. Some chemoheterotrophic bacteria have also been considered to exhibit an Fe(II) oxidation phenotype. For example, several Marinobacter strains have been reported to oxidize Fe(II) based on formation of oxidized iron bands in semi-solid gradient tubes that produce opposing concentration gradients of Fe(II) and oxygen. While gradient tubes are a simple and visually compelling method to test for Fe(II) oxidation, this method alone cannot confirm if, and to what extent, Fe(II) oxidation is linked to metabolism in chemoheterotrophic bacteria. Here we probe the possibility of protein-mediated and metabolic by-product-mediated Fe(II) oxidation in Marinobacter subterrani JG233, a chemoheterotroph previously proposed to oxidize Fe(II). Results from conditional and mutant studies, along with measurements of Fe(II) oxidation rates, suggest M. subterrani is unlikely to facilitate Fe(II) oxidation under microaerobic conditions. We conclude that the Fe(II) oxidation phenotype observed in gradient tubes inoculated with M. subterrani JG233 is a result of oligo-heterotrophic activity, shifting the location where oxygen dependent chemical Fe(II) oxidation occurs, rather than a biologically mediated process. IMPORTANCE Gradient tubes are the most commonly used method to isolate and identify neutrophilic Fe(II)-oxidizing bacteria. The formation of oxidized iron bands in gradient tubes provides a compelling assay to ascribe the ability to oxidize Fe(II) to autotrophic bacteria whose growth is dependent on Fe(II) oxidation. However, the physiological significance of Fe(II) oxidation in chemoheterotrophic bacteria is less well understood. Our work suggests that oligo-heterotrophic activity of certain bacteria may create a false-positive phenotype in gradient tubes by altering the location of the abiotic, oxygen-mediated oxidized iron band. Based on the results and analysis presented here, we caution against utilizing gradient tubes as the sole evidence for the capability of a strain to oxidize Fe(II) and that additional experiments are necessary to ascribe this phenotype to new isolates.


Assuntos
Compostos Ferrosos/metabolismo , Marinobacter , Marinobacter/metabolismo , Oxirredução , Fenótipo
7.
J Microbiol Methods ; 187: 106277, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34237402

RESUMO

Recently, studies have begun to identify oil-degrading bacteria and host-taxon specific bacterial assemblages associated with the coral holobiont, including deep-sea cold-water corals, which are thought to provide metabolic functions and additional carbon sources to their coral hosts. Here, we describe the identification of Marinobacter on the soft tissue of Lophelia pertusa coral polyps by Catalyzed Reporter Deposition Fluorescence in situ Hybridization (CARD-FISH). L. pertusa samples from three reef sites in the northeast Atlantic (Logachev, Mingulay and Pisces) were collected at depth by vacuum seal to eliminate contamination issues. After decalcification, histological processing and sagittal sectioning of the soft coral polyp tissues, the 16S rRNA-targeted oligonucleotide HRP-labelled probe Mrb-0625-a, and Cyanine 3 (Cy3)-labelled tyramides, were used to identify members of the hydrocarbon-degrading genus Marinobacter. Mrb-0625-a-hybridized bacterial cell signals were detected in different anatomical sites of all polyps collected from each of the three reef sites, suggesting a close, possibly intimate, association between them, but the purpose of which remains unknown. We posit that Marinobacter, and possibly other hydrocarbon-degrading bacteria associated with Lophelia, may confer the coral with the ability to cope with toxic levels of hydrocarbons in regions of natural oil seepage and where there is an active oil and gas industry presence.


Assuntos
Antozoários/microbiologia , Recifes de Corais , Hidrocarbonetos/metabolismo , Marinobacter/isolamento & purificação , Marinobacter/metabolismo , Animais , Oceano Atlântico , Biodegradação Ambiental , Catálise , Hibridização in Situ Fluorescente , Simbiose
8.
Molecules ; 26(11)2021 May 24.
Artigo em Inglês | MEDLINE | ID: mdl-34073991

RESUMO

Although axenic microbial cultures form the basis of many large successful industrial biotechnologies, the production of single commercial microbial strains for use in large environmental biotechnologies such as wastewater treatment has proved less successful. This study aimed to evaluate the potential of the co-culture of two halophilic bacteria, Marinirhabdus sp. and Marinobacter hydrocarbonoclasticus for enhanced protease activity. The co-culture was significantly more productive than monoculture (1.6-2.0 times more growth), with Marinobacter hydrocarbonoclasticus being predominant (64%). In terms of protease activity, enhanced total activity (1.8-2.4 times) was observed in the co-culture. Importantly, protease activity in the co-culture was found to remain active over a much broader range of environmental conditions (temperature 25 °C to 60 °C, pH 4-12, and 10-30% salinity, respectively). This study confirms that the co-culturing of halophilic bacteria represents an economical approach as it resulted in both increased biomass and protease production, the latter which showed activity over arange of environmental conditions.


Assuntos
Flavobacteriaceae/enzimologia , Marinobacter/enzimologia , Peptídeo Hidrolases/biossíntese , Técnicas de Cocultura , Flavobacteriaceae/crescimento & desenvolvimento , Concentração de Íons de Hidrogênio , Marinobacter/crescimento & desenvolvimento , Salinidade , Temperatura
9.
J Mol Biol ; 433(15): 167092, 2021 07 23.
Artigo em Inglês | MEDLINE | ID: mdl-34116122

RESUMO

Protein dynamics play a major role for the catalytic function of enzymes, the interaction of protein complexes or signal integration in regulatory proteins. In the context of multi-domain proteins involved in light-regulation of enzymatic effectors, the central role of conformational dynamics is well established. Light activation of sensory modules is followed by long-range signal transduction to different effectors; rather than domino-style structural rearrangements, a complex interplay of functional elements is required to maintain functionality. One family of such sensor-effector systems are red-light-regulated phytochromes that control diguanylate cyclases involved in cyclic-dimeric-GMP formation. Based on structural and functional studies of one prototypic family member, the central role of the coiled-coil sensor-effector linker was established. Interestingly, subfamilies with different linker lengths feature strongly varying biochemical characteristics. The dynamic interplay of the domains involved, however, is presently not understood. Here we show that the PHY domain dimer interface plays an essential role in signal integration, and that a functional coupling with the coiled-coil linker element is crucial. Chimaeras of two biochemically different family members highlight the phytochrome-spanning helical spine as an essential structural element involved in light-dependent upregulation of enzymatic turnover. However, isolated structural elements can frequently not be assigned to individual characteristics, which further emphasises the importance of global conformational dynamics. Our results provide insights into the intricate processes at play during light signal integration and transduction in these photosensory systems and thus provide additional guidelines for a more directed design of novel sensor-effector combinations with potential applications as optogenetic tools.


Assuntos
Marinobacter/metabolismo , Fitocromo/química , Fitocromo/metabolismo , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Cristalografia por Raios X , Proteínas de Escherichia coli/metabolismo , Regulação Bacteriana da Expressão Gênica , Marinobacter/química , Modelos Moleculares , Fósforo-Oxigênio Liases/metabolismo , Conformação Proteica , Domínios Proteicos
10.
Eur Biophys J ; 50(3-4): 561-570, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-34009405

RESUMO

Iron-sulfur centers are widespread in living organisms, mostly performing electron transfer functions, either in electron transfer chains or as part of multi-enzymatic complexes, while being also present in enzyme active sites, handling substrate catalysis. Rubredoxin is the simplest iron-sulfur containing protein constituted by a single polypeptide chain of 50 to 60 amino acids, of which four cysteine residues are responsible for metal binding in a tetrahedral coordination sphere. In this manuscript we explore the structure and stability of both apo- and holo-forms of a Rubredoxin from Marinobacter hydrocarbonoclasticus using Synchrotron Radiation Circular Dichroism (SRCD) in combination with other biochemical and spectroscopic techniques. The results are consistent with a holo-protein form containing a monomeric iron center with UV-visible maxima at 760, 578, 494, 386, 356 and 279 nm, an intense EPR resonance with a g value around 4.3 and Mössbauer spectroscopy parameters of δ equal to 0.69 mm/s and ΔEQ equal to 3.25 mm/s, for the ferrous reconstituted state. SRCD data, obtained for the first time for the apo-form, show a quite defined structure with ∆ε maximum at 191 nm and minima at 203 and 231 nm. Most significantly, the presence of isosbestic points at 189 and 228 nm made the interconversion between the two stable apo- and holo-form solution structures clear. SRCD temperature dependence data shows that for both forms the denaturation process proceeds through an intermediate species.


Assuntos
Proteínas Ferro-Enxofre/química , Dicroísmo Circular , Espectroscopia de Ressonância de Spin Eletrônica , Ferro/metabolismo , Marinobacter , Rubredoxinas , Enxofre
11.
J Environ Manage ; 291: 112658, 2021 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-33934020

RESUMO

Wastewaters generated by fish processing are characterised by salt concentrations similar to or greater than that of seawater together with high nutrient concentrations (e.g. organic carbon and total nitrogen) due to the presence of blood, oil, and fish tissues. Fish processing wastewater entering rivers and oceans have become a key factor leading to the pollution of receiving waters; the adequate treatment of this wastewater is, therefore, crucial to a sustainable fish industry. The present study aimed to determine whether augmentation of fish wastewater with either Marinirhabdus sp., Marinobacter hydrocarbonoclasticus or a consortium of the two halobacteria, could successfully enhance the removal of both chemical oxygen demand (COD) and total nitrogen (TN) from fish wastewater. Following 9 days of incubation, the bioaugmentation treatment resulted in a significant reduction in COD, 88%, 91%, and 92% in fish wastewater augmented with either Marinirhabdus sp., Marinobacter hydrocarbonoclasticus respectively, or a consortium of the two halobacteria compared with the control (non-bioaugmented) treatment (77% removal). In tall bioaugmentation treatments (79-88%) TN removal was also significantly greater than the control treatment (57%). After 9 days of incubation, the COD and TN in bioaugmentation reached the European Union's (EU) wastewater discharge standard (Level B, COD < 120 mg L-1, TN < 70 mg L-1). The addition of monoculture was effective in enhancing the removal of COD, while co-culture significantly improved TN removal. Results of 16S rDNA sequence analysis investigating the survival of these introduced bacteria showed that only Marinobacter hydrocarbonoclasticus was detected at the end of the treatment, constituting 36% of the total bacterial population when added alone to the wastewater. This study confirms the effectiveness of bioaugmentation in removing COD and TN in saline fish wastewater. The ability of Marinobacter hydrocarbonclasticus to enhance the treatment and dominate the bacterial community suggests the commercial potential of this organism for bioaugmentation of aquaculture wastewater without the need for further bioaugmentation.


Assuntos
Marinobacter , Águas Residuárias , Análise da Demanda Biológica de Oxigênio , Reatores Biológicos , Marinobacter/genética , Nitrogênio , Eliminação de Resíduos Líquidos
12.
Eur Biophys J ; 50(3-4): 513-521, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33900431

RESUMO

DNA-binding proteins from starved cells (Dps) are members of the ferritin family of proteins found in prokaryotes, with hollow rounded cube-like structures, composed of 12 equal subunits. These protein nanocages are bifunctional enzymes that protect the cell from the harmful reaction of iron and peroxide (Fenton reaction), thus preventing DNA damage by oxidative stress. Ferrous ions are oxidized at specific iron-binding sites in the presence of the oxidant and stored in its cavity that can accommodate up to ca. 500 iron atoms. DNA-binding properties of Dps are associated with the N-terminal, positive charge rich, extensions that can promote DNA binding and condensation, apparently by a cooperative binding mechanism. Here, we describe the binding and protection activities of Marinobacter hydrocarbonoclasticus Dps using Electrophoretic Mobility Shift Essays (EMSA), and synchrotron radiation circular dichroism (SRCD) spectroscopy. While no DNA condensation was observed in the tested conditions, it was possible to determine a Dps-DNA complex formation with an apparent dissociation constant of 6.0 ± 1.0 µM and a Hill coefficient of 1.2 ± 0.1. This interaction is suppressed by the inclusion of a single negative charge in the N-terminal region by point mutation. In Dps proteins containing a ferric mineral core (above 96 Fe/protein), DNA binding was impaired. SRCD data clearly showed that no significant modification existed either in secondary structure or protein stability of WT, Q14E variant and core containing proteins. It was, however, interesting to note that, in our experimental conditions, thermal denaturation induced protein aggregation that caused artifacts in thermal denaturation curves, which were dependent on radiation flux and vertical arrangement of the CD cell.


Assuntos
Marinobacter , Proteínas de Bactérias/genética , DNA , Ferro , Modelos Moleculares
13.
Antonie Van Leeuwenhoek ; 114(6): 709-718, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33751267

RESUMO

The marine phycosphere harbors unique cross-kingdom associations with ecological relevance. During investigating the diversity of phycosphere microbiota of marine harmful algal blooms dinoflagellates, a faint yellow-pigmented bacterium, designated as strain LZ-8, was isolated from paralytic shellfish poisoning toxin-producing dinoflagellate Alexandrium catenella LZT09. The new isolate appeared to have growth-promoting potential toward its algal host. Molecular analysis using 16S rRNA gene, housekeeping rpoD gene and whole-genome sequence comparison indicated that strain LZ-8T was a novel gammaproteobacterium of the family Alteromonadaceae. The major fatty acids of strain LZ-8T were C16:0, C18:1 ω9c, C12:0 3-OH, summed feature 3, C16:1 ω9c, C12:0 and summed feature 9. The major isoprenoid quinone was Q-9. Polar lipids were diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, unidentified phospholipid, two unidentified aminolipids and six unidentified polar lipids. The genomic DNA G+C content was 57.36 mol%. Based on genome sequencing, several biosynthetic gene clusters responsible for bacterial biosynthesis of carotenoids and siderophores that may involve in algae-bacterial interactions were identified in the genome of strain LZ-8T. The polyphasic characterization indicated that strain LZ-8T represents a novel Marinobacter species. The name Marinobacter alexandrii sp. nov., type strain LZ-8T (= CCTCC AB 2018386T = KCTC 72198T) is proposed.


Assuntos
Marinobacter , Microbiota , Técnicas de Tipagem Bacteriana , DNA Bacteriano/genética , Ácidos Graxos/análise , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
14.
Antonie Van Leeuwenhoek ; 114(6): 765-775, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33751321

RESUMO

A facultatively anaerobic bacterium, strain W62T, was isolated from the marine solar saltern in Weihai, China. Cells of the novel strain were Gram-stain negative, non-flagellated, non-gliding, rod-shaped and around 0.3-0.5 × 2.5-3.9 µm in size. Optimum growth occurred at 33-37 °C, with 3-5% (w/v) NaCl and at pH 7.0-7.5. On the basis of phylogenetic analysis of the 16S rRNA gene sequence, strain W62T had close relationship with Marinobacter vulgaris F01T (98.6%), Marinobacter confluentis KCTC 42705T (98.4%) and Marinobacter halotolerans NBRC 110910T (97.7%). Genome sequencing revealed a genome size of 4,050,555 bp, a G+C content of 57.3% and a complete sox system related to thiosulfate oxidization. Strain W62T had ubiquinone-9 as the sole respiratory quinone and possessed Summed Features 3 (C16:1 ω7c/C16:1 ω6c), C16:0 and C18:1 ω9c as the major fatty acids. The major polar lipids of strain W62T were identified as aminophospholipid, phosphatidylglycerol and phosphatidylethanolamine. According to the results of the phenotypic, chemotaxonomic characterization, phylogenetic properties and genome analysis, strain W62T should represent a novel specie of the genus Marinobacter, for which the name Marinobacter orientalis sp. nov. is proposed. The type strain is W62T (= MCCC 1H00317T = KCTC 62593T).


Assuntos
Marinobacter , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/análise , Marinobacter/genética , Oxirredução , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Água do Mar , Análise de Sequência de DNA , Tiossulfatos
15.
Curr Microbiol ; 78(4): 1648-1655, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33651189

RESUMO

Phycosphere hosts the boundary of unique holobionts harboring dynamic algae-bacteria interactions. During our investigating the microbial consortia composition of phycosphere microbiota (PM) derived from diverse harmful algal blooms (HAB) dinoflagellates, a novel rod-shaped, motile and faint yellow-pigmented bacterium, designated as strain LZ-6 T, was isolated from HAB Alexandrium catenella LZT09 which produces high levels paralytic shellfish poisoning toxins. Phylogenetic analysis based on 16S rRNA gene and two housekeeping genes, rpoA and pheS sequences showed that the novel isolate shared the highest gene similarity with Marinobacter shengliensis CGMCC 1.12758 T (99.6%) with the similarity values of 99.6%, 99.9% and 98.5%, respectively. Further phylogenomic calculations of average nucleotide identity (ANI), average amino acid identity (AAI) and digital DNA-DNA hybridization (dDDH) values between strains LZ-6 T and the type strain of M. shengliensis were 95.9%, 96.4% and 68.5%, respectively. However, combined phenotypic and chemotaxonomic characterizations revealed that the new isolate was obviously different from the type strain of M. shengliensis. The obtained taxonomic evidences supported that strain LZ-6 T represents a novel subspecies of M. shengliensis, for which the name is proposed, Marinobacter shengliensis subsp. alexandrii subsp. nov. with the type strain LZ-6 T (= CCTCC AB 2018388TT = KCTC 72197 T). This proposal automatically creates Marinobacter shengliensis subsp. shengliensis for which the type strain is SL013A34A2T (= LMG 27740 T = CGMCC 1.12758 T).


Assuntos
Dinoflagelados , Microbiota , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Dinoflagelados/genética , Ácidos Graxos/análise , Marinobacter , Hibridização de Ácido Nucleico , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
16.
Curr Microbiol ; 78(3): 1045-1052, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33590298

RESUMO

A Gram-stain-negative, motile, aerobic, rod-shaped bacterium with flagella, designated M3-13T, was isolated from a saline soil in Zhoushan, China. According to phylogenetic analysis based on 16S rRNA gene sequences, strain M3-13T was assigned to the genus Marinobacter with highest 16S rRNA gene sequence similarity of 97.7% to Marinobacter maroccanus LMG 30466T, followed by Marinobacter sediminum R65 T (97.5%) and M. salsuginis SD-14BT (97.2%). Digital DNA-DNA hybridization (DDH) and average nucleotide identity (ANI) were determined to evaluate the genomic relationship between strain M3-13T and M. maroccanus LMG 30466T. Digital DDH estimation (19.8%) as well as ANI (72.98%) proved the dissimilarity of strain M3-13T. Optimal growth of the strain M3-13T was at 28-30 °C and at pH 8.0-8.5, in the presence of 3-6% (w/v) NaCl. The major fatty acids detected in strain M3-13T were C16:1 ω7c/C16:1 ω6c, C16:0, C18:1ω7c/C18:1 ω6c and C12:03-OH, and the predominant respiratory quinone was ubiquinone-9. The major polar lipids included diphosphatidyglycerol, phosphatidylglycerol, phosphatidylethanolamine, one unidentified aminophosphoglycolipid and one unidentified phosphoglycolipid. The DNA G+C content was 56.6%. A phylogenetic analysis based on 16S rRNA gene sequences showed that strain M3-13T belongs to the genus Marinobacter. Based on the polyphasic taxonomic characterization, strain M3-13T is considered to represent a novel species of the genus Marinobacter, for which the name Marinobacter caseinlyticus sp. nov. is proposed (type strain M3-13T = MCCC 1K04560T = KCTC 72043T).


Assuntos
Marinobacter , Técnicas de Tipagem Bacteriana , China , DNA Bacteriano/genética , Ácidos Graxos/análise , Marinobacter/genética , Fosfolipídeos/análise , Filogenia , RNA Ribossômico 16S/genética , Água do Mar , Análise de Sequência de DNA , Solo
17.
Bioprocess Biosyst Eng ; 44(2): 355-368, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32959147

RESUMO

This study aimed to characterize the biofilm microbial community that causes corrosion of API 5LX carbon steel. API 5LX carbon steel coupons were incubated with raw produced water collected from two oil reservoir stations or filter-sterilized produced water. Biofilm 16S rRNA amplicon sequencing revealed that the bacterial community present in the biofilm was dominated by Proteobacteria, including Marinobacter hydrocarbonoclaustics and Marinobacter alkaliphilus. Electrochemical analysis such as impedance and polarization results indicated that Proteobacteria biofilm accelerated corrosion by ~ twofold (2.1 ± 0.61 mm/years) or ~ fourfold (~ 3.7 ± 0.42 mm/years) when compared to the control treatment (0.95 ± 0.1 mm/years). Scanning electron and atomic force microscopy revealed the presence of a thick biofilm and pitting corrosion. X-ray diffraction revealed higher amounts of the corrosion products Fe2O3, γ-FeOOH, and α-FeOOH, and confirmed that the microbial biofilm strongly oxidized the iron and contributed to the acceleration of corrosion of carbon metal API 5LX.


Assuntos
Biofilmes/crescimento & desenvolvimento , Marinobacter/fisiologia , Consórcios Microbianos/fisiologia , Óleo Mineral , Aço
18.
Bioelectrochemistry ; 137: 107644, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-32971484

RESUMO

Bacterial extracellular electron transfer (EET) is envisioned for use in applied biotechnologies, necessitating electrochemical characterization of natural and engineered electroactive biofilms under conditions similar to the target application, including small-scale biosensing or biosynthesis platforms, which is often distinct from standard 100 mL-scale stirred-batch bioelectrochemical test platforms used in the laboratory. Here, we adapted an eight chamber, nanoliter volume (500 nL) electrochemical flow cell to grow biofilms of both natural (Biocathode MCL community, Marinobacter atlanticus, and Shewanella oneidensis MR1) or genetically modified (S. oneidensis ΔMtr and S. oneidensis ΔMtr + pLB2) electroactive bacteria on electrodes held at a constant potential. Maximum current density achieved by unmodified strains was similar between the nano- and milliliter-scale reactors. However, S. oneidensis biofilms engineered to activate EET upon exposure to 2,4-diacetylphloroglucinol (DAPG) produced current at wild-type levels in the stirred-batch reactor, but not in the nanoliter flow cell. We hypothesize this was due to differences in mass transport of DAPG, naturally-produced soluble redox mediators, and oxygen between the two reactor types. Results presented here demonstrate, for the first time, nanoliter scale chronoamperometry and cyclic voltammetry of a range of electroactive bacteria in a three-electrode reactor system towards development of miniaturized, and potentially high throughput, bioelectrochemical platforms.


Assuntos
Fontes de Energia Bioelétrica/microbiologia , Técnicas Eletroquímicas/métodos , Marinobacter/metabolismo , Nanotecnologia/instrumentação , Shewanella/metabolismo , Sequência de Bases , Biofilmes/crescimento & desenvolvimento , Reatores Biológicos , Eletrodos , Transporte de Elétrons , Genes Bacterianos , Limite de Detecção , Marinobacter/genética , Marinobacter/crescimento & desenvolvimento , Shewanella/genética , Shewanella/crescimento & desenvolvimento
19.
World J Microbiol Biotechnol ; 36(12): 181, 2020 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-33164140

RESUMO

Although the use of degrading-bacteria is one of the most efficient methods for the bioremediation of polluted sites, detection, selection and proliferation of the most efficient and competing bacteria is still a challenge. The objective of this multi-stage research was to investigate the effects of the selected bacterial strains on the degradation of anthracene, florentine, naphthalene, and oil, determined by biochemical tests. In the first stage, using the following tests: (a) biosurfactant production (emulsification, oil spreading, number of drops, drop collapse, and surface tension), (b) biofilm production, (c) activity of laccase enzyme, and (d) exopolysaccaride production, the three bacterial strains with the highest degrading potential including Bacillus pumilus, B. aerophilus, and Marinobacter hydrocarbonoclasticus were chosen. In the second stage using the following tests: (a) bacterial growth, (b) laccase enzyme activity, and (c) biosurfactant production (emulsification, oil spreading, and collapse of droplet) the degrading ability of the three selected bacterial strains plus Escherichia coli were compared. Different bacterial strains were able to degrade anthracene, florentine, naphthalene, and oil by the highest rate, three days after inoculation (DAI). However, M. hydrocarbonoclasticus showed the highest rate of florentine degradation. Although with increasing pollutant concentration the degrading potential of the bacterial strains significantly decreased, M. hydrocarbonoclasticus was determined as the most efficient bacterial strain.


Assuntos
Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Poluentes Ambientais/química , Hidrocarbonetos Policíclicos Aromáticos/química , Antracenos/química , Bacillus/crescimento & desenvolvimento , Bacillus/metabolismo , Bacillus pumilus/crescimento & desenvolvimento , Bacillus pumilus/metabolismo , Bactérias/isolamento & purificação , Biodegradação Ambiental , Biofilmes , Biocombustíveis/análise , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Lacase/metabolismo , Marinobacter/crescimento & desenvolvimento , Marinobacter/metabolismo , Naftalenos/química , Polissacarídeos Bacterianos/metabolismo , Tensoativos/metabolismo
20.
Int J Syst Evol Microbiol ; 70(12): 6294-6300, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-33079031

RESUMO

A Gram-staining-negative, aerobic, cream-coloured, marine bacterium, with rod-shaped cells, designated strain YJ-S3-2T, was isolated from salt flat sediment of Yongyu-do, Republic of Korea. YJ-S3-2T grew at pH 5.0-9.0 (optimum pH 7.0), 4-45 °C (optimum 30 °C) and with 1-18 % (w/v) NaCl (optimum 6 %). The results of 16S rRNA gene sequence analysis indicated that YJ-S3-2T was closely related to Marinobacter segnicrescens SS011B1-4T (97.0 %) followed by, 'Marinobacter nanhaiticus' D15-8W (96.7 %), Marinobacter bryozoorum 50-11T (96.7 %), Marinobacter koreensis DSMZ 179240T T (96.5 %) and Marinobacter bohaiensis T17T (96.5 %). The average nucleotide identity (ANI) and the genome to genome distance calculator (GGDC) estimate values between YJ-S3-2T and related type strains were 73.7-79.8 and 19.9-22.5 %, and also 73.5 and 20.7 % with Marinobacter hydrocarbonoclasticus. YJ-S3-2T was characterized as having Q-9 as the predominant respiratory quinone and the principal fatty acids (>10 %) were C16 : 0 (22.3 %), summed feature 9 (C17 : 1iso ω9c/C16 : 0 10-methyl, 13.8 %) and 3 (C16 : 1ω7c/C16 : 1ω6c, 11.9 %). The polar lipids consisted of diphosphatidylglycerol, phosphatidylethanolamine, phosphatidylglycerol, two unidentified aminolipids and two unidentified phospholipids. The DNA G+C content of YJ-S3-2T is 60.9 mol%. On the basis of the polyphasic taxonomic evidence presented in this study, YJ-S3-2T should be classified as representing a novel species within the genus Marinobacter, for which name Marinobacter halodurans sp. nov. is proposed, with the type strain YJ-S3-2T (=KACC 19883T=KCTC 62937T=JCM 33109T).


Assuntos
Sedimentos Geológicos , Marinobacter/classificação , Filogenia , Água do Mar/microbiologia , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Marinobacter/isolamento & purificação , Hibridização de Ácido Nucleico , Fosfolipídeos/química , RNA Ribossômico 16S/genética , República da Coreia , Análise de Sequência de DNA , Ubiquinona/química
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