Species Of Williamsia Research Articles

Genome-based reclassification of Williamsia marianensis as a later heterotypic synonym of Williamsia muralis.

The present study used whole-genome data to clarify the taxonomic assignment of two closely related Williamsia species. Genomic information for 10 type strains was available at the time of conducting this analysis. One group of type strains was found to be conspecific, namely Williamsia muralis Kämpfer et al. 1999 and Williamsia marianensis Pathom-aree et al. 2006. The 16S rRNA gene sequences showed 99 % similarity between these type strains. Whole-genome-based comparisons showed that Williamsia muralis DSM 44343T and Williamsia marianensis DSM 44944T shared 98.07 % average nucleotide identity, 98.29 % average amino acid identity and 84.80 % digital DNA-DNA hybridization values. These values exceeded the threshold values for bacterial species delineation. Further, phylogenomic analysis based on the core genomes of the strains under study confirmed that Williamsia muralis DSM 44343T and Williamsia marianensis DSM 44944T formed a monophyletic clade. Based on this evidence, we propose the reclassification of Williamsia marianensis Pathom-aree et al. 2006 as a later heterotypic synonym of Williamsia muralis Kämpfer et al. 1999.

Application of Thin-Layer Chromatography-Flame Ionization Detection (TLC-FID) to Total Lipid Quantitation in Mycolic-Acid Synthesizing Rhodococcus and Williamsia Species.

In addition to cell membrane phospholipids, Actinobacteria in the order Corynebacteriales possess a waxy cell envelope containing mycolic acids (MA). In optimized culture condition, some species can also accumulate high concentrations of intracellular triacylglycerols (TAG), which are a potential source of biodiesel. Bacterial lipid classes and composition alter in response to environmental stresses, including nutrient availability, thus understanding carbon flow into different lipid classes is important when optimizing TAG synthesis. Quantitative and qualitative analysis of lipid classes normally requires combinations of different extraction, derivatization, chromatographic and detection methods. In this study, a single-step thin-layer chromatography-flame ionization detection (TLC-FID) technique was applied to quantify lipid classes in six sub-Antarctic Corynebacteriales strains identified as Rhodococcus and Williamsia species. A hexane:diethyl-ether:acetic acid solvent system separated the total cellular lipids extracted from cells lysed by bead beating, which released more bound and unbound MA than sonication. Typical profiles included a major broad non-polar lipid peak, TAG and phospholipids, although trehalose dimycolates, when present, co-eluted with phospholipids. Ultra-performance liquid chromatography-tandem mass-spectrometry and nuclear magnetic resonance spectroscopy detected MA signatures in the non-polar lipid peak and indicated that these lipids were likely bound, at least in part, to sugars from cell wall arabinogalactan. Waxy esters were not detected. The single-solvent TLC-FID procedure provides a useful platform for the quantitation and preliminary screening of cellular lipid classes when testing the impacts of growth conditions on TAG synthesis.

Toxic anterior segment syndrome caused by autoclave reservoir wall biofilms and their residual toxins

To identify etiology of toxic anterior segment syndrome (TASS) after uneventful phacoemulsification. EyeMD Laser and Surgery Center, Oakland, California. Retrospective case series. Patient charts with TASS were reviewed. Reservoirs of 2 autoclaves associated with these cases were cultured for bacterial contamination. Cultures were performed on 23 other autoclave reservoirs at surgery centers in the local area. The main outcome measures were the incidence of TASS and prevalence of bacterial biofilm contamination of autoclave reservoirs. From 2010 to 2013, 11 935 consecutive cataract surgeries were performed at 1 center by multiple surgeons with no reported TASS. Between January 1, 2014, and January 15, 2015, 10 cases of TASS occurred out of 3003 cataract surgeries; these patients' charts were reviewed. Cultures of 2 Statim autoclave reservoir walls grew Bacillus species, Williamsia species, Mycobacterium mucogenicum, and Candida parapsilosis. Scanning electron microscopy of reservoir wall sections showed prominent biofilm. The 2 autoclaves were replaced in January 2015. Subsequently, 2875 cataract surgeries were performed with no reported TASS (P<.001, χ2 test). Eighteen of 23 additional regional autoclaves were also contaminated with bacterial biofilms. Toxic anterior segment syndrome was strongly associated with bacterial biofilm contamination of autoclave reservoirs. An etiological mechanism might involve transport of heat-stable bacterial cell antigens in the steam with deposition on surgical instrumentation. Data suggest widespread prevalence of bacterial biofilms on fluid-reservoir walls, despite adherence to manufacturer guidelines for cleaning and maintenance. Prevention or elimination of autoclave fluid-reservoir biofilms might reduce the risk for postoperative TASS. None of the authors has a financial or proprietary interest in any material or method mentioned.

Chemical constituents and chemotaxonomic study on the marine actinomycete Williamsia sp. MCCC 1A11233

The marine actinomycete Williamsia sp. MCCC 1A11233 was isolated from a deep sea sediment sample of the southwestern Indian Ocean. It was closely related to Williamsia limnetica L1505T with a 16S rRNA gene sequence similarity value of 99.2%. A systematic investigation on its chemical constituents was performed in this study, which led to the isolation of one new (1) and 23 known (2–24) secondary metabolites. By mainly detailed analysis of the 1D and 2D NMR spectroscopic data and comparisons with the published data, the chemical structure of 1 was determined to be 3-benzyl-3α,4β-dihydroxypentan-2-one. Noteworthily, the question on which family Williamsia species should belong to was left unsolved at the first beginning when it was found in 1999. Interestingly, the result of this investigation consolidated that Williamsia should be placed a chemotaxonomic position in Nocardiaceae Family. Furthermore, 2-aminobenzoic acid derivatives (8–10) could be taken as chemotaxonomic markers for the genus of Williamsia.

Identification of Microbial Populations Assimilating Nitrogen from RDX in Munitions Contaminated Military Training Range Soils by High Sensitivity Stable Isotope Probing

The leaching of RDX (hexahydro-1,3,5-trinitro-1,3,5-triazine) from particulates deposited in live-fire military training range soils contributes to significant pollution of groundwater. In situ microbial degradation has been proposed as a viable method for onsite containment of RDX. However, there is only a single report of RDX degradation in training range soils and the soil microbial communities involved in RDX degradation were not identified. Here we demonstrate aerobic RDX degradation in soils taken from a target area of an Eglin Air Force Base bombing range, C52N Cat's Eye, (Eglin, Florida U.S.A.). RDX-degradation activity was spatially heterogeneous (found in less than 30% of initial target area field samples) and dependent upon the addition of exogenous carbon sources to the soils. Therefore, biostimulation (with exogenous carbon sources) and bioaugmentation may be necessary to sustain timely and effective in situ microbial biodegradation of RDX. High sensitivity stable isotope probing analysis of extracted soils incubated with fully labeled (15)N-RDX revealed several organisms with (15)N-labeled DNA during RDX-degradation, including xplA-bearing organisms. Rhodococcus was the most prominent genus in the RDX-degrading soil slurries and was completely labeled with (15)N-nitrogen from the RDX. Rhodococcus and Williamsia species isolated from these soils were capable of using RDX as a sole nitrogen source and possessed the genes xplB and xplA associated with RDX-degradation, indicating these genes may be suitable genetic biomarkers for assessing RDX degradation potential in soils. Other highly labeled species were primarily Proteobacteria, including: Mesorhizobium sp., Variovorax sp., and Rhizobium sp.

Williamsia faeni sp. nov., an actinomycete isolated from a hay meadow

The taxonomic status of an actinomycete isolated from soil collected from a hay meadow was determined using a polyphasic approach. The strain, designated N1350(T), had morphological and chemotaxonomic properties consistent with its classification in the genus Williamsia and formed a distinct phyletic line within the clade comprising the type strains of species of the genus Williamsia in the 16S rRNA gene tree. Strain N1350(T) shared highest 16S rRNA gene sequence similarities with Williamsia marianensis MT8(T) (98.1 %) and Williamsia muralis MA140-96(T) (98.3 %). However, strain N1350(T) was readily distinguished from the type strains of Williamsia species using a combination of phenotypic properties. On the basis of these data, strain N1350(T) is considered to represent a novel species of the genus Williamsia. The name proposed for this taxon is Williamsia faeni sp. nov., with the type strain N1350(T) (=DSM 45372(T) =NCIMB 14575(T) =NRRL B-24794(T)).

Williamsia serinedens sp. nov., isolated from an oil-contaminated soil

The taxonomic status of a bacterium designated strain IMMIB SR-4(T) isolated from an oil-contaminated soil sample was characterized by using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that on pyrolysis GC produce C(16 : 0) and C(18 : 0) fatty acids, and dihydrogenated menaquinone with nine isoprene units as the predominant menaquinone. The generic assignment was confirmed by 16S rRNA gene sequence analysis. Comparative analysis of the 16S rRNA gene sequence showed that strain IMMIB SR-4(T) formed a distinct phyletic line within the genus Williamsia, displaying sequence similarities of 95.5-98.1 % with the type strains of recognized Williamsia species. Strain IMMIB SR-4(T) was distinguished from the type strains of recognized species of the genus Williamsia based on a set of phenotypic features. The genotypic and phenotypic data indicated that strain IMMIB SR-4(T) represents a novel species of the genus Williamsia, for which the name Williamsia serinedens sp. nov. is proposed. The type strain is IMMIB SR-4(T) (=DSM 45037(T)=CCUG 53151(T)).

Williamsia marianensis sp. nov., a novel actinomycete isolated from the Mariana Trench

The taxonomic status of an actinomycete isolated from sediment collected from the Mariana Trench was established using a combination of genotypic and phenotypic data. Isolate MT8T had chemotaxonomic and morphological properties consistent with its classification in the genus Williamsia, and formed a distinct phyletic line in the 16S rRNA gene tree together with the type strain of Williamsia muralis. The isolate was readily distinguished from the latter, and from representatives of other Williamsia species, using DNA-DNA relatedness and phenotypic criteria. Predominant cellular fatty acids were oleic, palmitic and tuberculostearic acids and a hexadecenoic acid. The DNA G+C content was 65.2 mol%. It is apparent that the isolate belongs to a novel species of Williamsia. Strain MT8T (=DSM 44944T=NCIMB 14085T) was thus considered to be the type strain of a novel species in the genus Williamsia, for which the name Williamsia marianensis sp. nov. is proposed.

Williamsia deligens sp. nov., isolated from human blood

The taxonomic status of two bacterial strains isolated from human blood was characterized using a polyphasic approach. Chemotaxonomic investigations revealed the presence of cell-wall chemotype IV, short-chain mycolic acids that co-migrated with those extracted from members of the genus Williamsia and that produce C(16 : 0) and C(18 : 0) fatty acids on pyrolysis GC, and dihydrogenated menaquinone with nine isoprene units as the predominant isoprenologue. The generic assignment was confirmed by 16S rRNA gene sequencing. Comparative analysis of the 16S rRNA gene sequence showed that these isolates constitute a distinct phyletic line within the genus Williamsia, displaying 96.2 and 97.2 % sequence similarities to Williamsia muralis and Williamsia maris, respectively. The two isolates could be distinguished from the type strains of the latter species on the basis of several phenotypic traits. The genotypic and phenotypic data show that the strains merit classification as a novel species of Williamsia, for which the name Williamsia deligens sp. nov. is proposed, with type strain IMMIB RIV-956T (= DSM 44902T = CCUG 50873T).

Williamsia maris sp. nov., a novel actinomycete isolated from the Sea of Japan.

The taxonomic position of a marine actinomycete, strain SJS0289/JS1T, was determined using a polyphasic taxonomic approach. The organism, which had phenotypic properties consistent with its classification in the genus Williamsia, formed a distinct clade in the 16S rRNA gene tree together with the type strain of Williamsia muralis, but was readily distinguished from this species using DNA-DNA relatedness and phenotypic data. The genotypic and phenotypic data show that the organism merits recognition as a new species of Williamsia. The name proposed for the new species is Williamsia maris; the type strain is SJS0289/JS1T (=DSM 44693T=JCM 12070T=KCTC 9945T=NCIMB 13945T).