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1.
J Hazard Mater ; 422: 126914, 2022 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-34419851

RESUMO

Plasticizer phthalic acid esters (PAEs) are commonly found as contaminants in various soils. Previous studies indicated that their natural degradation can substantially differ among soil types; however, potential implications of the soil microbiome remained largely unexplored. Here, we have collected ten soil types from nine different geographical regions of China to investigate the degradation of DBP therein and role of bacteria in this process. Results showed that the degradation rate of DBP was lowest in nutrient-poor red soils from Jiangxi Province, while it was highest in fluvo-aquatic soil from Hebei Province. Bacterial community responses to DBP substantially differed in each of the analyzed soils. Arthrobacter is known for its broad-spectrum activity in terms of DBP degradation in soil and was therefore implemented as bioremediating inoculant in many polluted environments. In the present study, network analyses indicated that synergism between soil bacteria increased following exposure to DBP. Arthrobacter and Sphingomonas were found to expand their positive interactions with other members of the microbiome in DBP-contaminated soils. The overall findings of our study provide a basis for biomarker development for detection of DBP contaminations and an extended basis for future bioremediation approaches based on beneficial bacteria.


Assuntos
Arthrobacter , Ácidos Ftálicos , Poluentes do Solo , Biodegradação Ambiental , Dibutilftalato , Ésteres , Solo , Poluentes do Solo/análise
2.
J Hazard Mater ; 421: 126811, 2022 01 05.
Artigo em Inglês | MEDLINE | ID: mdl-34388933

RESUMO

There is an urgent requirement to treat cellulose present in papermaking black liquor since it induces severe economic wastes and causes environmental pollution. We characterized cellulase activity at different temperatures and pH to seek thermo-alkali-stable cellulase-producing bacteria, a natural consortium of Serratia sp. AXJ-M and Arthrobacter sp. AXJ-M1 was used to improve the degradation of cellulose. Notably, the enzyme activities and the degradation rate of cellulose were increased by 30%-70% and 30% after co-culture, respectively. In addition, the addition of cosubstrates increased the degradation rate of cellulose beyond 30%. The thermo-alkali-stable endoglucanase (bcsZ) gene was derived from the strain AXJ-M and was cloned and expressed. The purified bcsZ displayed the maximum activity at 70 °C and pH 9. Mn2+, Ca2+, Mg2+ and Tween-20 had beneficial effects on the enzyme activity. Structurally, bcsZ potentially catalyzed the degradation of cellulose. The co-culture with ligninolytic activities significantly decreased target the parameters (cellulose 45% and COD 95%) while using the immobilized fluidized bed reactors (FBRs). Finally, toxicological tests and antioxidant enzyme activities indicated that the co-culture had a detoxifying effect on black liquor. Our study showed that Serratia sp. AXJ-M acts synergistically with Arthrobacter sp. AXJ-M1 may be potentially useful for bioremediation for black liquor.


Assuntos
Arthrobacter , Celulase , Álcalis , Arthrobacter/genética , Celulase/genética , Celulose , Serratia/genética
3.
Int J Syst Evol Microbiol ; 71(12)2021 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34919039

RESUMO

Two Gram-stain-positive, aerobic, rod-shaped, pink and light pink colony-forming bacteria, designated as Hz2T and MDT2-14T, respectively, were isolated from glacier cryoconite samples. Comparisons based on 16S rRNA gene sequences showed that strains Hz2T and MDT2-14T take Arthrobacter bussei KR32T and Arthrobacter zhaoguopingii J391T as their closest neighbours, respectively. The average nucleotide identity values between the two novel strains and their closest relatives were 83.56 and 93.06 %, respectively. The two strains contain MK-9(H2) as their predominant menaquinone. The polar lipids of both strains were phosphatidylglycerol, diphosphatidylglycerol, phosphatidylinositol and an unidentified glycolipid. The major fatty acids of strain Hz2T were anteiso-C15 : 0, summed feature 3 (comprising C16 : 1 ω7c and/or C16 : 1 ω6c) and iso-C15 : 0, while the major fatty acids of strain MDT2-14T were anteiso-C15 : 0 and anteiso-C17 : 0. Based on these data, we propose two novel species, Arthrobacter cheniae sp. nov. (Hz2T = CGMCC 1.9262T=NBRC 113086T) and Arthrobacter frigidicola sp. nov. (MDT2-14T=CGMCC 1.9882T=NBRC 113089T).


Assuntos
Arthrobacter , Arthrobacter/genética , Técnicas de Tipagem Bacteriana , Composição de Bases , DNA Bacteriano/genética , Ácidos Graxos/química , Camada de Gelo , Filogenia , RNA Ribossômico 16S/genética , Análise de Sequência de DNA
4.
Arch Microbiol ; 204(1): 70, 2021 Dec 24.
Artigo em Inglês | MEDLINE | ID: mdl-34951666

RESUMO

Carotenoids have several crucial biological functions and are part of the cold adaptation mechanism of some bacteria. Some pink-pigmented Arthrobacter species produce the rare C50 carotenoid bacterioruberin, whose function in these bacteria is unclear and is found mainly in halophilic archaea. Strains Arthrobacter agilis DSM 20550T and Arthrobacter bussei DSM 109896T show an increased bacterioruberin content if growth temperature is reduced from 30 down to 10 °C. In vivo anisotropy measurements with trimethylammonium-diphenylhexatriene showed increased membrane fluidity and a broadening phase transition with increased bacterioruberin content in the membrane at low-temperature growth. Suppression of bacterioruberin synthesis at 10 °C using sodium chloride confirmed the function of bacterioruberin in modulating membrane fluidity. Increased bacterioruberin content also correlated with increased cell resistance to freeze-thaw stress. These findings confirmed the adaptive function of bacterioruberin for growth at low temperatures for pink-pigmented Arthrobacter species.


Assuntos
Arthrobacter , Carotenoides , Fluidez de Membrana , Cloreto de Sódio
5.
J Agric Food Chem ; 69(43): 12773-12784, 2021 Nov 03.
Artigo em Inglês | MEDLINE | ID: mdl-34694802

RESUMO

Due to its superior Δ1-dehydrogenation ability, Arthrobacter simplex has been widely used for the biotransformation of cortisone acetate (CA) into prednisone acetate (PA) in the steroid industry. However, its molecular fundamentals are still unclear. Herein, the genome organization, gene regulation, and previously unreported genes involved in Δ1-dehydrogenation are revealed through genome and transcriptome analysis. A comparative study of transcriptomes of an industrial strain induced by CA or at different biotransformation periods was performed. By overexpression, the roles of six genes in CA conversion were confirmed, among which sufC and hsaA behaved better by reinforcing catalytic enzyme activity and substrate transmembrane transport. Additionally, GroEL endowed cells with the strongest stress tolerance by alleviating oxidative damage and enhancing energy levels. Finally, an optimal strain was created by coexpressing three genes, achieving 46.8 and 70.6% increase in PA amount and productivity compared to the initial values, respectively. Our study expanded the understanding of the Δ1-dehydrogenation mechanism and offered an effective approach for excellent steroid-transforming strains.


Assuntos
Actinobacteria , Arthrobacter , Cortisona , Arthrobacter/genética , Transcriptoma
6.
PLoS One ; 16(9): e0257449, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34529734

RESUMO

Despite the formation of biofilms on catheters for extracorporeal membrane oxygenation (ECMO), some patients do not show bacteremia. To elucidate the specific linkage between biofilms and bacteremia in patients with ECMO, an improved understanding of the microbial community within catheter biofilms is necessary. Hence, we aimed to evaluate the biofilm microbiome of ECMO catheters from adults with (n = 6) and without (n = 15) bacteremia. The microbiomes of the catheter biofilms were evaluated by profiling the V3 and V4 regions of bacterial 16s rRNA genes using the Illumina MiSeq sequencing platform. In total, 2,548,172 reads, with an average of 121,341 reads per sample, were generated. Although alpha diversity was slightly higher in the non-bacteremic group, the difference was not statistically significant. In addition, there was no difference in beta diversity between the two groups. We found 367 different genera, of which 8 were present in all samples regardless of group; Limnohabitans, Flavobacterium, Delftia, Massilia, Bacillus, Candidatus, Xiphinematobacter, and CL0-1 showed an abundance of more than 1% in the sample. In particular, Arthrobacter, SMB53, Neisseria, Ortrobactrum, Candidatus Rhabdochlamydia, Deefgae, Dyella, Paracoccus, and Pedobacter were highly abundant in the bacteremic group. Network analysis indicated that the microbiome of the bacteremic group was more complex than that of the non-bacteremic group. Flavobacterium and CL0.1, which were abundant in the bacteremic group, were considered important genera because they connected different subnetworks. Biofilm characteristics in ECMO catheters varied according to the presence or absence of bacteremia. There were no significant differences in diversity between the two groups, but there were significant differences in the community composition of the biofilms. The biofilm-associated community was dynamic, with the bacteremic group showing very complex network connections within the microbiome.


Assuntos
Bacteriemia/microbiologia , Infecções Relacionadas a Cateter/microbiologia , Oxigenação por Membrana Extracorpórea/instrumentação , Microbiota , Arthrobacter/genética , Arthrobacter/isolamento & purificação , Arthrobacter/fisiologia , Bacteriemia/patologia , Bactérias/genética , Bactérias/isolamento & purificação , Biofilmes , Infecções Relacionadas a Cateter/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neisseria/genética , Neisseria/isolamento & purificação , Neisseria/fisiologia , RNA Ribossômico 16S/análise , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Estudos Retrospectivos
7.
Bioresour Technol ; 340: 125634, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34325393

RESUMO

The bacterial degradation of isoprene is important for maintaining its atmospheric concentration in unpolluted environment. It may be possible to use natural isoprene degrading bacteria in engineered systems to eliminate or limit isoprene emissions from various sources. Biodegradation of isoprene by Arthrobacter sp. strain BHU FT2 was investigated. The genome was found to contain 4151545 bp long chromosome having 3747 coding genes, and coded potential isoprene degrading enzymes. The molecular docking of monooxygenases with isoprene displayed a higher binding energy (-4.59 kcal/mol) for WP_015938387.1 monooxygenase. Analysis of the identified monooxygenases with the known isoprene monooxygenases revealed 67% sequence identity of WP_015938387.1 (Locus tag JHV56_10705) monooxygenase of the considered strain with the OPX16961.1 monooxygenase of Gordonia sp. i37 isoprene degrading starin. These results provided a strong evidence for the high isoprene degrading potential of the Arthrobacter sp. BHU FT2 which could be efficiently exploited for isoprene degradation in large scale bio-filtration units.


Assuntos
Arthrobacter , Arthrobacter/genética , Biodegradação Ambiental , Butadienos , Genômica , Hemiterpenos , Simulação de Acoplamento Molecular , Proteômica
8.
J Vet Diagn Invest ; 33(6): 1089-1095, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34293996

RESUMO

Avian influenza surveillance is a requirement for commercial trade in ostrich products, but influenza A viruses (IAVs) have proven difficult to isolate from ostrich tracheal swabs that test positive using molecular methods. We hypothesized that microbes unique to the ostrich trachea propagate in the transport medium after sampling and affect viral viability. We cultured tracheal swabs from 50 ostriches on 4 farms in South Africa, and recovered and identified 13 bacterial, 1 yeast, and 2 fungal species. Dietzia sp. had not been identified previously in the oropharyngeal tract of a bird, to our knowledge. The bacteria were tested for antimicrobial susceptibility, and most aerobic species, except for Streptococcus sp. and Pseudomonas sp., were sensitive to enrofloxacin; all were susceptible to sulfonamide. Virus inhibition experiments determined that ostrich-source Streptococcus sp., Pantoea sp., and Citrobacter freundii produced extracellular metabolites that caused a substantial reduction in the IAV titers of 99.9%. Streptomyces, Corynebacterium, Staphylococcus, Arthrobacter gandavensis, Pseudomonas putida, and Acinetobacter spp. similarly reduced the viability of IAV from 77.6% to 24.1%. Dietzia appeared to have no effect, but Rothia dentocariosa, Rhodotorula spp., and Clostridium spp. slightly increased the viability of IAV by 25.9, 34.9, and 58.5%, respectively.


Assuntos
Arthrobacter , Vírus da Influenza A , Influenza Aviária , Struthioniformes , Animais , Fazendas , Micrococcaceae
9.
J Basic Microbiol ; 61(8): 745-756, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-34228381

RESUMO

Antagonistic bacteria can act as biocontrol agents against various phytopathogens. Recently, Arthrobacter spp. demonstrated antifungal activity, but were not further characterized. In this study, the antimicrobial activity of Arthrobacter humicola strains M9-1A, M9-2, and M9-8, and Arthrobacter psychrophenolicus strain M9-17 were evaluated against nine plant pathogens in vitro, and their cell-free filtrates were additionally assessed for inhibition of Alternaria alternata and suppression of black mold disease on tomato fruit. Results indicated that A. humicola M9-1A and A. psychrophenolicus M9-17 were the most inhibitory, reducing growth of seven of the pathogens studied. Cell-free filtrates of A. psychrophenolicus M9-17 reduced the growth of most pathogens. All cell-free bacterial filtrates, except those from A. humicola M9-2, suppressed black mold on tomato fruit. Disk diffusion assays with ethyl acetate soluble culture filtrate extracts of all bacteria reduced the mycelial growth of A. alternata. Clear inhibition zones were observed for A. psychrophenolicus M9-17 extracts using drop bioassays. The antifungal compound N-acetyltryptamine was purified and characterized from the A. psychrophenolicus M9-17 cell-free ethyl acetate soluble extract. This study suggests that antibiosis may play a key role in the antimicrobial activity of Arthrobacter spp.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/farmacologia , Arthrobacter/isolamento & purificação , Arthrobacter/metabolismo , Compostagem , Alternaria/efeitos dos fármacos , Antibiose/efeitos dos fármacos , Antifúngicos/química , Antifúngicos/farmacologia , Frutas/microbiologia , Lycopersicon esculentum/microbiologia , Micrococcaceae , Doenças das Plantas/microbiologia
10.
J Environ Manage ; 293: 112911, 2021 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-34087648

RESUMO

The hydrocarbons in petroleum sludge are environmental pollutants. It is crucial to eliminate this type of pollution. In this study, a comprehensive and operational study has been conducted on the total petroleum hydrocarbons (TPH) biodegradation in oily sludge. The experiments were performed in a semi-solid phase by two degrader bacterium, Arthrobacter citreus and Rhodococcus jostii, and they were compared with the slurry phase. Solid samples were prepared in three mixing modes of oily sludge with clay. Experiments were conducted by semi-solid bioreactors and other methods on samples contaminated with petroleum hydrocarbons. The performance of the semi-solid bioreactor for the removal of clay-free oily sludge samples showed the best results, in which biodegradation of TPH was 90.33%. GC analyses were conducted on samples before and after biodegradation. It was observed that the contaminants were decomposed uniformly by the microorganisms, except for a combination with a large peak in 12 min. For the best case, the GC-MS test was performed before and after biodegradation. Compounds with a high concentration in the sludge were significantly reduced. Only one heavy aromatic compound was detected in 51.628 min, which decomposed quite slowly and produced a large peak. It was found that 78.2% of the compounds were removed completely.


Assuntos
Petróleo , Poluentes do Solo , Arthrobacter , Biodegradação Ambiental , Ingestão de Líquidos , Hidrocarbonetos , Petróleo/análise , Rhodococcus , Esgotos
11.
BMC Genomics ; 22(1): 403, 2021 Jun 02.
Artigo em Inglês | MEDLINE | ID: mdl-34078272

RESUMO

BACKGROUND: The Arthrobacter group is a known set of bacteria from cold regions, the species of which are highly likely to play diverse roles at low temperatures. However, their survival mechanisms in cold regions such as Antarctica are not yet fully understood. In this study, we compared the genomes of 16 strains within the Arthrobacter group, including strain PAMC25564, to identify genomic features that help it to survive in the cold environment. RESULTS: Using 16 S rRNA sequence analysis, we found and identified a species of Arthrobacter isolated from cryoconite. We designated it as strain PAMC25564 and elucidated its complete genome sequence. The genome of PAMC25564 is composed of a circular chromosome of 4,170,970 bp with a GC content of 66.74 % and is predicted to include 3,829 genes of which 3,613 are protein coding, 147 are pseudogenes, 15 are rRNA coding, and 51 are tRNA coding. In addition, we provide insight into the redundancy of the genes using comparative genomics and suggest that PAMC25564 has glycogen and trehalose metabolism pathways (biosynthesis and degradation) associated with carbohydrate active enzyme (CAZymes). We also explain how the PAMC26654 produces energy in an extreme environment, wherein it utilizes polysaccharide or carbohydrate degradation as a source of energy. The genetic pattern analysis of CAZymes in cold-adapted bacteria can help to determine how they adapt and survive in such environments. CONCLUSIONS: We have characterized the complete Arthrobacter sp. PAMC25564 genome and used comparative analysis to provide insight into the redundancy of its CAZymes for potential cold adaptation. This provides a foundation to understanding how the Arthrobacter strain produces energy in an extreme environment, which is by way of CAZymes, consistent with reports on the use of these specialized enzymes in cold environments. Knowledge of glycogen metabolism and cold adaptation mechanisms in Arthrobacter species may promote in-depth research and subsequent application in low-temperature biotechnology.


Assuntos
Arthrobacter , Regiões Antárticas , Arthrobacter/genética , Composição de Bases , Hibridização Genômica Comparativa , Genoma Bacteriano
12.
Microbiome ; 9(1): 136, 2021 06 12.
Artigo em Inglês | MEDLINE | ID: mdl-34118971

RESUMO

BACKGROUND: Microorganisms drive critical global biogeochemical cycles and dominate the biomass in Earth's expansive cold biosphere. Determining the genomic traits that enable psychrophiles to grow in cold environments informs about their physiology and adaptive responses. However, defining important genomic traits of psychrophiles has proven difficult, with the ability to extrapolate genomic knowledge to environmental relevance proving even more difficult. RESULTS: Here we examined the bacterial genus Arthrobacter and, assisted by genome sequences of new Tibetan Plateau isolates, defined a new clade, Group C, that represents isolates from polar and alpine environments. Group C had a superior ability to grow at -1°C and possessed genome G+C content, amino acid composition, predicted protein stability, and functional capacities (e.g., sulfur metabolism and mycothiol biosynthesis) that distinguished it from non-polar or alpine Group A Arthrobacter. Interrogation of nearly 1000 metagenomes identified an over-representation of Group C in Canadian permafrost communities from a simulated spring-thaw experiment, indicative of niche adaptation, and an under-representation of Group A in all polar and alpine samples, indicative of a general response to environmental temperature. CONCLUSION: The findings illustrate a capacity to define genomic markers of specific taxa that potentially have value for environmental monitoring of cold environments, including environmental change arising from anthropogenic impact. More broadly, the study illustrates the challenges involved in extrapolating from genomic and physiological data to an environmental setting. Video Abstract.


Assuntos
Arthrobacter , Arthrobacter/genética , Canadá , Genômica , Metagenoma , Metagenômica
13.
Environ Pollut ; 285: 117394, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-34051563

RESUMO

Current study was carried out with an objective to remediate highly contaminated sludge with HMX and RDX obtained from an explosive manufacturing facility in North India employing indigenous microbes, Arthrobacter subterraneus (isolate no. S2-TSB-17) and Bacillus sonorensis (isolate no. S8-TSB-4) which were isolated from the same contaminated site. In-vessel composting of the explosive contaminated sludge was performed in 12 different bioreactors using cow manure and garden waste as bulking agents. 78.5% degradation of HMX was observed in reactor no. 2 with Bacillus sonorensis having combination of 10% sludge, 70% cow manure and 20% garden waste on 80th day. Two secondary metabolites Bis(hydroxymethyl)nitramine and methylene dinitramine were identified while studying the degradation pathway. Similarly, degradation of 91.2% was observed for RDX in reactor no. 11 with consortia of Arthrobacter subterraneus and Bacillus sonorensis on 80th day. During the study, release of significant nitrate and nitrite ions were observed. It has already been established that RDX and HMX degradation leads to release of nitrite/nitrate ions. The highest nitrite (reactor no. 11) and nitrate (reactor no. 2) release observed were 24.02 ± 0.05 mg/kg and 30.65 ± 0.99 mg/kg on 50th and 70th day, respectively. Scanning electron microscopic studies confirmed the attachment and presence of microbes with solid surface and no deformation in structure was observed in the microbial cells due to contamination stress. Findings of the study concluded that in-vessel composting assisted with native bacterial species can be a potential technology for the treatment of explosive contaminated sludge at the contaminated sites.


Assuntos
Compostagem , Esgotos , Arthrobacter , Azocinas , Bacillus , Biodegradação Ambiental , Triazinas/análise
14.
Curr Microbiol ; 78(7): 2577-2588, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33983483

RESUMO

For decades, bacterial natural products have served as valuable resources for developing novel drugs to treat several human diseases. Recent advancements in the integrative approach of using genomic and functional tools have proved beneficial in obtaining a comprehensive understanding of these biomolecules. This study presents an in-depth characterization of the anti-diabetic activity exhibited by a bacterial isolate SW1, isolated from an effluent treatment plant. As a primary screening, we assessed the isolate for its potential to inhibit alpha-amylase and alpha-glucosidase enzymes. Upon confirmation, we further utilized LC-MS, ESI-MS/MS, and NMR spectroscopy to identify and characterize the biomolecule. These efforts were coupled with the genomic assessment of the biosynthetic gene cluster involved in the anti-diabetic compound production. Our investigation discovered that the isolate SW1 inhibited both α-amylase and α-glucosidase activity. The chemical analysis suggested the production of acarbose, an anti-diabetic biomolecule, which was further confirmed by the presence of biosynthetic gene cluster "acb" in the genome. Our in-depth chemical characterization and genome mining approach revealed the potential of bacteria from an unconventional niche, an effluent treatment plant. To the best of our knowledge, it is one of the first few reports of acarbose production from the genus Arthrobacter.


Assuntos
Arthrobacter , Acarbose , Arthrobacter/genética , Genômica , Inibidores de Glicosídeo Hidrolases , Humanos , Espectrometria de Massas em Tandem , alfa-Glucosidases/genética
15.
mBio ; 12(3): e0084621, 2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34044592

RESUMO

Plant roots constitute the primary interface between plants and soilborne microorganisms and harbor microbial communities called the root microbiota. Recent studies have demonstrated a significant contribution of plant specialized metabolites (PSMs) to the assembly of root microbiota. However, the mechanistic and evolutionary details underlying the PSM-mediated microbiota assembly and its contribution to host specificity remain elusive. Here, we show that the bacterial genus Arthrobacter is predominant specifically in the tobacco endosphere and that its enrichment in the tobacco endosphere is partially mediated by a combination of two unrelated classes of tobacco-specific PSMs, santhopine and nicotine. We isolated and sequenced Arthrobacter strains from tobacco roots as well as soils treated with these PSMs and identified genomic features, including but not limited to genes for santhopine and nicotine catabolism, that are associated with the ability to colonize tobacco roots. Phylogenomic and comparative analyses suggest that these genes were gained in multiple independent acquisition events, each of which was possibly triggered by adaptation to particular soil environments. Taken together, our findings illustrate a cooperative role of a combination of PSMs in mediating plant species-specific root bacterial microbiota assembly and suggest that the observed interaction between tobacco and Arthrobacter may be a consequence of an ecological fitting process. IMPORTANCE Host secondary metabolites have a crucial effect on the taxonomic composition of its associated microbiota. It is estimated that a single plant species produces hundreds of secondary metabolites; however, whether different classes of metabolites have distinctive or common roles in the microbiota assembly remains unclear. Here, we show that two unrelated classes of secondary metabolites in tobacco play a cooperative role in the formation of tobacco-specific compositions of the root bacterial microbiota, which has been established as a consequence of independent evolutionary events in plants and bacteria triggered by different ecological effects. Our findings illustrate mechanistic and evolutionary aspects of the microbiota assembly that are mediated by an arsenal of plant secondary metabolites.


Assuntos
Arthrobacter/genética , Arthrobacter/metabolismo , Genoma Bacteriano , Interações entre Hospedeiro e Microrganismos/genética , Raízes de Plantas/microbiologia , Tabaco/microbiologia , Endófitos/genética , Endófitos/metabolismo , Interações entre Hospedeiro e Microrganismos/fisiologia , Filogenia , Raízes de Plantas/metabolismo , RNA Ribossômico 16S/genética , Rizosfera , Metabolismo Secundário , Análise de Sequência de DNA , Microbiologia do Solo , Tabaco/metabolismo
16.
Enzyme Microb Technol ; 146: 109777, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33812565

RESUMO

The Δ1-dehydrogenation of 3-ketosteroid substrates is a crucial reaction in the production of steroids. Although 3-ketosteroid Δ1-dehydrogenase (KsdD) catalyzes this reaction with high efficiency and selectivity, the low stability and high cost of the purified enzyme catalyst have limited its industrial application. In this study, an epoxy support was used to evaluate the covalent immobilization of KsdD from Pimelobacter simplex, and the best androsta-1,4-diene-317-dione (ADD) production was achieved after optimized immobilization of KsdD enzyme in 1.5 M NaH2PO4- Na2HPO4 buffer (pH 6.5) for 12 h at 25 °C. The immobilized KsdD exhibited higher tolerance toward 20 % methanol. The dehydrogenation reaction reached a conversion efficiency of up to 90.0 % in 2 h when using 0.6 mg/mL of 4-androstene-317-dione (AD). The W299A and W299 G mutants of KsdD were also immobilized, and both showed the better catalytic performance with higher kcat/KM values compared with the wild type (WT). The immobilized W299A, W299 G and WT KsdD respectively maintained 70.5, 65.7 and 38.7 % of their initial activity at the end of 15 reaction cycles. Furthermore, the W299A retained 66.3 % of the initial activity after 30 days of incubation at 4 °C, and was more stable than free KsdD, Thus, the immobilized W299A is a promising biocatalyst for steroid dehydrogenation. In this study, we investigated the application of immobilized enzymes for the dehydrogenation of steroids, which will be of great importance for improving the development of green technology and sustainable use of biocatalysts in the steroid manufacturing industry.


Assuntos
Arthrobacter , Oxirredutases , Actinobacteria , Catálise , Estabilidade Enzimática , Enzimas Imobilizadas , Concentração de Íons de Hidrogênio , Oxirredutases/metabolismo , Esteroides
17.
Ecotoxicol Environ Saf ; 217: 112206, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33866286

RESUMO

1,4-Dioxane (dioxane), an emerging groundwater contaminant, is frequently detected in landfill leachates with its structural analog, tetrahydrofuran (THF). Along with undesirable leakage of landfill leachates, dioxane and THF inevitably percolate into groundwater leading to a broader region of contamination. Cometabolic bioremediation is an effective approach to manage commingled THF and dioxane pollution. In this study, a newly isolated bacterium Arthrobacter sp. WN18 is able to co-oxidize dioxane with THF as the primary substrate. Meanwhile, the THF-induced thmADBC gene cluster was responsible for the dioxane degradation rate indicating THF monooxygenase is the essential enzyme that initializing α-hydroxylation of THF and dioxane. Further, γ-butyrolactone and HEAA were characterized as the key metabolites of THF and dioxane, respectively. In addition, WN18 can tolerate the inhibition of trichloroethylene (5.0 mg/L) as a representative of co-existing leachate constituent, and sustain its activity at various pH (5-11), temperatures (15-42 °C), and salinities (up to 4%, as NaCl wt). Like other Arthrobacter species, WN18 also exhibited the capability of fixing nitrogen. All this evidence indicates the feasibility and advantage of WN18 as a thmADBC-catalyzed inoculator to bioremediate co-contamination of THF and dioxane.


Assuntos
Arthrobacter/metabolismo , Biodegradação Ambiental , Dioxanos/metabolismo , Furanos/metabolismo , Proteínas de Bactérias , Água Subterrânea , Oxigenases de Função Mista , Família Multigênica , Oxirredução , Tricloroetileno , Poluentes Químicos da Água
18.
PLoS One ; 16(3): e0248418, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33711060

RESUMO

Bacteriophages (phages) exhibit high genetic diversity, and the mosaic nature of the shared genetic pool makes quantifying phage relatedness a shifting target. Early parameters for clustering of related Mycobacteria and Arthrobacter phage genomes relied on nucleotide identity thresholds but, more recently, clustering of Gordonia and Microbacterium phages has been performed according to shared gene content. Singleton phages lack the nucleotide identity and/or shared gene content required for clustering newly sequenced genomes with known phages. Whole genome metrics of novel Arthrobacter phage BlueFeather, originally designated a putative singleton, showed low nucleotide identity but high amino acid and gene content similarity with Arthrobacter phages originally assigned to Clusters FE and FI. Gene content similarity revealed that BlueFeather shared genes with these phages in excess of the parameter for clustering Gordonia and Microbacterium phages. Single gene analyses revealed evidence of horizontal gene transfer between BlueFeather and phages in unique clusters that infect a variety of bacterial hosts. Our findings highlight the advantage of using shared gene content to study seemingly genetically isolated phages and have resulted in the reclustering of BlueFeather, a putative singleton, as well as former Cluster FI phages, into a newly expanded Cluster FE.


Assuntos
Arthrobacter/virologia , Bacteriófagos/genética , Transferência Genética Horizontal , Genes Virais , Variação Genética , Filogenia , Análise de Sequência de DNA , Arthrobacter/genética
19.
Chirality ; 33(5): 209-225, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33675087

RESUMO

Over the last few years, there has been a dramatic increase in the number of reports related to Arthrobacter sp. lipase (ABL:MTCC No. 5125) catalyzed kinetic resolution performed in biphasic media. A strain displaying esterase/lipase activity and designated as ABL was isolated, during the course of a screening program at Indian Institute of Integrative Medicine, Jammu. Considerable research has shown that reactions catalyzed by ABL are more selective than many commercial lipases. Since new applications of this lipase are emerging, there is a great need to provide all the relevant information exclusively. This review article is an attempt to cover all the relevant reports based on isolation, purification, immobilization, and application of ABL in the biopharmaceutical sector.


Assuntos
Arthrobacter/enzimologia , Lipase/metabolismo , Biocatálise , Enzimas Imobilizadas/metabolismo , Cinética , Estereoisomerismo
20.
Eur J Clin Microbiol Infect Dis ; 40(6): 1329-1331, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33432493

RESUMO

Corynebacteria are rare causative agents of infective endocarditis. This is a reported case of a destructive aorto-mitral infective endocarditis caused by Arthrobacter woluwensis. Microbial identification was achieved by 16S rRNA polymerase chain reaction on valve tissue samples. Outcome was favorable after surgical valve replacement and 4-week antibiotic treatment.


Assuntos
Arthrobacter/isolamento & purificação , Endocardite Bacteriana/microbiologia , Antibacterianos/uso terapêutico , Arthrobacter/efeitos dos fármacos , Arthrobacter/genética , Endocardite Bacteriana/diagnóstico , Endocardite Bacteriana/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade
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