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Journal of Biochemistry Jul 2019Cytochrome P450 monooxygenases (P450s) play crucial roles in the cell metabolism and provide an unsurpassed diversity of catalysed reactions. Here, we report the...
Cytochrome P450 monooxygenases (P450s) play crucial roles in the cell metabolism and provide an unsurpassed diversity of catalysed reactions. Here, we report the identification and biochemical characterization of two P450s from Arthrobacter sp., a Gram-positive organism known to degrade the opium alkaloid papaverine. Combining phylogenetic and genomic analysis suggested physiological roles for P450s in metabolism and revealed potential gene clusters with redox partners facilitating the reconstitution of the P450 activities in vitro. CYP1232F1 catalyses the para demethylation of 3,4-dimethoxyphenylacetic acid to homovanillic acid while CYP1232A24 continues demethylation to 3,4-dihydroxyphenylacetic acid. Interestingly, the latter enzyme is also able to perform both demethylation steps with preference for the meta position. The crystal structure of CYP1232A24, which shares only 29% identity to previous published structures of P450s helped to rationalize the preferred demethylation specificity for the meta position and also the broader substrate specificity profile. In addition to the detailed characterization of the two P450s using their physiological redox partners, we report the construction of a highly active whole-cell Escherichia coli biocatalyst expressing CYP1232A24, which formed up to 1.77 g l-1 3,4-dihydroxyphenylacetic acid. Our results revealed the P450s' role in the metabolic pathway of papaverine enabling further investigation and application of these biocatalysts.
Topics: Arthrobacter; Biocatalysis; Cytochrome P-450 Enzyme System; Molecular Structure; Oxidation-Reduction; Papaverine
PubMed: 30759214
DOI: 10.1093/jb/mvz010 -
Applied and Environmental Microbiology Mar 2020The Gram-positive soil bacterium sp. strain TS-15 (DSM 32400), which is capable of metabolizing ephedrine as a sole source of carbon and energy, was isolated. According...
The Gram-positive soil bacterium sp. strain TS-15 (DSM 32400), which is capable of metabolizing ephedrine as a sole source of carbon and energy, was isolated. According to 16S rRNA gene sequences and comparative genomic analysis, sp. TS-15 is closely related to Distinct from all known physiological paths, ephedrine metabolism by sp. TS-15 is initiated by the selective oxidation of the hydroxyl function at the α-C atom, yielding methcathinone as the primary degradation product. Rational genome mining revealed a gene cluster potentially encoding the novel pathway. Two genes from the cluster, which encoded putative short-chain dehydrogenases, were cloned and expressed in The obtained enzymes were strictly NAD dependent and catalyzed the oxidation of ephedrine to methcathinone. Pseudoephedrine dehydrogenase (PseDH) selectively converted ()-(+)-pseudoephedrine and ()-(+)-ephedrine to ()- and ()-methcathinone, respectively. Ephedrine dehydrogenase (EDH) exhibited strict selectivity for the oxidation of the diastereomers (,)-(-)-ephedrine and (,)-(-)-pseudoephedrine. sp. TS-15 is a newly isolated bacterium with the unique ability to degrade ephedrine isomers. The initiating steps of the novel metabolic pathway are described. sp. TS-15 and its isolated ephedrine-oxidizing enzymes have potential for use in decontamination and synthetic applications.
Topics: Arthrobacter; Biodegradation, Environmental; Ephedrine; Escherichia coli; Gene Expression Regulation, Bacterial; Genes, Bacterial; Micrococcaceae; Microorganisms, Genetically-Modified; Multigene Family; Pseudoephedrine; Stereoisomerism
PubMed: 31900306
DOI: 10.1128/AEM.02487-19 -
Microbiological Research Dec 2017Phenolic acids can enhance the mycotoxin production and activities of hydrolytic enzymes related to pathogenicity of soilborne fungus Fusarium oxysporum. However,...
Phenolic acids can enhance the mycotoxin production and activities of hydrolytic enzymes related to pathogenicity of soilborne fungus Fusarium oxysporum. However, characteristics of phenolic acid-degrading bacteria have not been investigated. The objectives of this study were to isolate and characterize bacteria capable of growth on benzoic and vanillic acids as the sole carbon source in the peanut rhizosphere. Twenty-four bacteria were isolated, and the identification based on 16S rRNA gene sequencing revealed that pre-exposure to phenolic acids before sowing shifted the dominant culturable bacterial degraders from Arthrobacter to Burkholderia stabilis-like isolates. Both Arthrobacter and B. stabilis-like isolates catalysed the aromatic ring cleavage via the ortho pathway, and Arthrobacter isolates did not exhibit higher C12O enzyme activity than B. stabilis-like isolates. The culture filtrate of Fusarium sp. ACCC36194 caused a strong inhibition of Arthrobacter growth but not B. stabilis-like isolates. Additionally, Arthrobacter isolates responded differently to the culture filtrates of B. stabilis-like isolates. The Arthrobacter isolates produced higher indole acetic acid (IAA) levels than B. stabilis-like isolates, but B. stabilis-like isolates were also able to produce siderophores, solubilize mineral phosphate, and exert an antagonistic activity against peanut root rot pathogen Fusarium sp. ACCC36194. Results indicate that phenolic acids can shift their dominant culturable bacterial degraders from Arthrobacter to Burkholderia species in the peanut rhizosphere, and microbial interactions might lead to the reduction of culturable Arthrobacter. Furthermore, increasing bacterial populations metabolizing phenolic acids in monoculture fields might be a control strategy for soilborne diseases caused by Fusarium spp.
Topics: Antibiosis; Arachis; Arthrobacter; Bacteria; Benzoic Acid; Biological Control Agents; Burkholderia; Catechol 1,2-Dioxygenase; Catechol 2,3-Dioxygenase; Fusarium; Hydroxybenzoates; Indoleacetic Acids; Phosphates; Plant Diseases; Plant Roots; RNA, Ribosomal, 16S; Rhizosphere; Siderophores; Soil; Soil Microbiology; Vanillic Acid
PubMed: 28942837
DOI: 10.1016/j.micres.2017.09.005 -
Applied Microbiology and Biotechnology Feb 2018Chlorophenols are widespread and of environmental concern due to their toxic and carcinogenic properties. Development of less costly and less technically challenging...
Chlorophenols are widespread and of environmental concern due to their toxic and carcinogenic properties. Development of less costly and less technically challenging remediation methods are needed; therefore, we developed a formulation based on micronized vermiculite that, when air-dried, resulted in a granular product containing the 4-chlorophenol (4-CP)-degrading Gram-positive bacterium Arthrobacter chlorophenolicus A6. This formulation and stabilization method yielded survival rates of about 60% that remained stable in storage for at least 3 months at 4 °C. The 4-CP degradation by the formulated and desiccated A. chlorophenolicus A6 cells was compared to that of freshly grown cells in controlled-environment soil microcosms. The stabilized cells degraded 4-CP equally efficient as freshly grown cells in two different set-ups using both hygienized and non-treated soils. The desiccated microbial product was successfully employed in an outdoor pot trial showing its effectiveness under more realistic environmental conditions. No significant phytoremediation effects on 4-CP degradation were observed in the outdoor pot experiment. The 4-CP degradation kinetics from both the microcosms and the outdoor pot trial were used to generate a predictive model of 4-CP biodegradation potentially useful for larger-scale operations, enabling better bioremediation set-ups and saving of resources. This study also opens up the possibility of formulating and stabilizing also other Arthrobacter strains possessing different desirable pollutant-degrading capabilities.
Topics: Anti-Infective Agents, Local; Arthrobacter; Biodegradation, Environmental; Chlorophenols; Desiccation; Environmental Pollutants; Microbial Viability; Temperature; Time Factors
PubMed: 29349491
DOI: 10.1007/s00253-017-8706-6 -
PloS One 2022Bacteriophages exhibit a vast spectrum of relatedness and there is increasing evidence of close genomic relationships independent of host genus. The variability in phage...
Bacteriophages exhibit a vast spectrum of relatedness and there is increasing evidence of close genomic relationships independent of host genus. The variability in phage similarity at the nucleotide, amino acid, and gene content levels confounds attempts at quantifying phage relatedness, especially as more novel phages are isolated. This study describes three highly similar novel Arthrobacter globiformis phages-Powerpuff, Lego, and YesChef-which were assigned to Cluster AZ using a nucleotide-based clustering parameter. Phages in Cluster AZ, Microbacterium Cluster EH, and the former Microbacterium singleton Zeta1847 exhibited low nucleotide similarity. However, their gene content similarity was in excess of the recently adopted Microbacterium clustering parameter, which ultimately resulted in the reassignment of Zeta1847 to Cluster EH. This finding further highlights the importance of using multiple metrics to capture phage relatedness. Additionally, Clusters AZ and EH phages encode a shared integrase indicative of a lysogenic life cycle. In the first experimental verification of a Cluster AZ phage's life cycle, we show that phage Powerpuff is a true temperate phage. It forms stable lysogens that exhibit immunity to superinfection by related phages, despite lacking identifiable repressors typically required for lysogenic maintenance and superinfection immunity. The ability of phage Powerpuff to undergo and maintain lysogeny suggests that other closely related phages may be temperate as well. Our findings provide additional evidence of significant shared phage genomic content spanning multiple actinobacterial host genera and demonstrate the continued need for verification and characterization of life cycles in newly isolated phages.
Topics: Arthrobacter; Bacteriophages; Cluster Analysis; Genetic Variation; Genome, Viral; Genomics; Microbacterium; Phylogeny
PubMed: 35025964
DOI: 10.1371/journal.pone.0262556 -
Applied and Environmental Microbiology Nov 2009Of 31 freshwater bacterial isolates screened using the Biolog MT2 assay to determine their metabolism of the microcystin LR, 10 were positive. Phylogenetic analysis (16S...
Of 31 freshwater bacterial isolates screened using the Biolog MT2 assay to determine their metabolism of the microcystin LR, 10 were positive. Phylogenetic analysis (16S rRNA) identified them as Arthrobacter spp., Brevibacterium sp., and Rhodococcus sp. This is the first report of microcystin degraders that do not belong to the Proteobacteria.
Topics: Arthrobacter; Brevibacterium; Cluster Analysis; DNA, Bacterial; DNA, Ribosomal; Fresh Water; Microcystins; Molecular Sequence Data; Phylogeny; RNA, Ribosomal, 16S; Rhodococcus; Sequence Analysis, DNA
PubMed: 19734339
DOI: 10.1128/AEM.01928-09 -
Scientific Reports Jan 2021Pyrene and chromium (Cr(VI)) are persistent pollutants and cause serious environmental problems because they are toxic to organisms and difficult to remediate. The...
Pyrene and chromium (Cr(VI)) are persistent pollutants and cause serious environmental problems because they are toxic to organisms and difficult to remediate. The toxicity of pyrene and Cr(VI) to three crops (cotton, soybean and maize) was confirmed by the significant decrease in root and shoot biomass during growth in pyrene/Cr(VI) contaminated hydroponic solution. Two bacterial strains capable of simultaneous pyrene biodegradation and Cr(VI) reduction were isolated and identified as Serratia sp. and Arthrobacter sp. A mixture of the isolated strains at a ratio of 1:1 was more efficient for biotreatment of pyrene and Cr(VI) than either strain alone; the mixture effectively carried out bioremediation of contaminated water in a hydroponic system mainly through pyrene biodegradation and Cr(VI) reduction. Application of these isolates shows potential for practical microbial remediation of pyrene and Cr(VI) combined water pollution.
Topics: Arthrobacter; Biodegradation, Environmental; Chromium; Coculture Techniques; Pyrenes; Serratia; Water Pollutants, Chemical; Water Purification
PubMed: 33420172
DOI: 10.1038/s41598-020-80053-2 -
Scientific Reports Jan 2018Arthrobacter sp. CGMCC 3584 is able to produce high yields of extracellular cyclic adenosine monophosphate (cAMP), which plays a vital role in the field of treatment of...
Arthrobacter sp. CGMCC 3584 is able to produce high yields of extracellular cyclic adenosine monophosphate (cAMP), which plays a vital role in the field of treatment of disease and animal food, during aerobic fermentation. However, the molecular basis of cAMP production in Arthrobacter species is rarely explored. Here, for the first time, we report the comparative transcriptomic and proteomic study of Arthrobacter cells to elucidate the higher productivity of cAMP under high oxygen supply. We finally obtained 14.1% and 19.3% of the Arthrobacter genome genes which were up-regulated and down-regulated notably, respectively, with high oxygen supply, and identified 54 differently expressed proteins. Our results revealed that high oxygen supply had two major effects on metabolism: inhibition of glycolysis, pyruvate metabolism, nitrogen metabolism, and amino acid metabolism (histidine, branched-chain amino acids and glutamate metabolism); enhancement of the tricarboxylic acid cycle and purine metabolism. We also found that regulation of adenylate cyclase and phosphodiesterase was not significant under high oxygen supply, suggesting efficient cAMP export might be important in cAMP production. These findings may contribute to further understanding of capacities of Arthrobacter species and would be highly useful in genetic regulation for desirable production.
Topics: Arthrobacter; Cyclic AMP; Oxygen; Proteome; Transcriptome
PubMed: 29352122
DOI: 10.1038/s41598-017-18889-4 -
Journal of Clinical Microbiology Oct 1996Arthrobacter spp. are very widely distributed in the environment (e.g., soil) but have not been described as causing disease in humans. Over a 6-year period, two...
Arthrobacter spp. are very widely distributed in the environment (e.g., soil) but have not been described as causing disease in humans. Over a 6-year period, two reference laboratories isolated or received 11 strains which were eventually identified as belonging to the genus Arthrobacter. These strains had been initially identified as Centers for Disease Control and Prevention coryneform group B-1 and B-3 bacteria (whitishgrayish colonies of 2 mm or greater in diameter after 24 h of incubation, respiratory metabolism, absent or weak acid production from sugars, and hydrolysis of gelatin). However, chemotaxonomic investigations revealed lysine as the diamino acid of the cell wall and the presence of branched cellular fatty acids (with anteiso-pentadecanoic acid predominating) which was compatible with an assignment of the 11 isolates to the genus Arthrobacter only. Peptidoglycan and 16S rRNA gene sequence analyses demonstrated that three of the strains studied were representatives of a new Arthrobacter species for which the name Arthrobacter cumminsii sp. nov. is proposed and that one other strain represented a second new Arthrobacter species for which the name Arthrobacter woluwensis sp. nov. is proposed. This report is the first on the isolation of Arthrobacter spp. from clinical specimens.
Topics: Arthrobacter; Bacterial Typing Techniques; Molecular Sequence Data; RNA, Bacterial; RNA, Ribosomal, 16S; Sequence Analysis
PubMed: 8880479
DOI: 10.1128/jcm.34.10.2356-2363.1996 -
Archives of Microbiology Feb 2022Sulfoglycolysis pathways enable the breakdown of the sulfosugar sulfoquinovose and environmental recycling of its carbon and sulfur content. The prototypical...
Sulfoglycolysis pathways enable the breakdown of the sulfosugar sulfoquinovose and environmental recycling of its carbon and sulfur content. The prototypical sulfoglycolytic pathway is a variant of the classical Embden-Meyerhof-Parnas (EMP) pathway that results in formation of 2,3-dihydroxypropanesulfonate and was first described in gram-negative Escherichia coli. We used enrichment cultures to discover new sulfoglycolytic bacteria from Australian soil samples. Two gram-positive Arthrobacter spp. were isolated that produced sulfolactate as the metabolic end-product. Genome sequences identified a modified sulfoglycolytic EMP gene cluster, conserved across a range of other Actinobacteria, that retained the core sulfoglycolysis genes encoding metabolic enzymes but featured the replacement of the gene encoding sulfolactaldehyde (SLA) reductase with SLA dehydrogenase, and the absence of sulfoquinovosidase and sulfoquinovose mutarotase genes. Excretion of sulfolactate by these Arthrobacter spp. is consistent with an aerobic saprophytic lifestyle. This work broadens our knowledge of the sulfo-EMP pathway to include soil bacteria.
Topics: Arthrobacter; Australia; Glycolysis; Multigene Family; Sulfur
PubMed: 35201431
DOI: 10.1007/s00203-022-02803-2