Yet More Evidence of Collusion: a New Viral Defense System Encoded by Gordonia Phage CarolAnn.

Temperate phages play important roles in the physiology of their bacterial hosts and establish a lysogenic relationship with the host through which prophage-expressed genes confer new phenotypes. A key phenotype is prophage-mediated defense against heterotypic viral attack, in which temperate phages collude with their bacterial host to prevent other phages from attacking, sometimes with exquisite specificity. Such defense systems have been described in Pseudomonas and Mycobacterium phages but are likely widespread throughout the microbial community. Here, we describe a novel prophage-mediated defense system encoded by Gordonia phage CarolAnn, which defends against infection by unrelated phages grouped in cluster CZ. CarolAnn genes 43 and 44 are coexpressed with the repressor and are necessary and sufficient to confer defense against phage Kita and its close relatives. Kita and these relatives are targeted through Kita gene 53, a gene that is of unknown function but which is the location of defense escape mutations that overcome CarolAnn defense. Expression of Kita gene 53 is toxic to Gordonia terrae in the presence of CarolAnn genes 43 and 44, suggesting that defense may be mediated by an abortive infection type of mechanism. CarolAnn genes 43 and 44 are distant relatives of mycobacteriophage Sbash genes 31 and 30, respectively, which also confer viral defense but use a different targeting system.IMPORTANCE Prophage-mediated viral defense systems play a key role in microbial dynamics, as lysogeny is established relatively efficiently, and prophage-expressed genes can strongly inhibit lytic infection of other, unrelated phages. Demonstrating such defense systems in Gordonia terrae suggests that these systems are widespread and that there are a multitude of different systems with different specificities for the attacking phages.

Characterization and genomic analysis of highly efficient thermotolerant oil-degrading bacterium Gordonia sp. 1D.

A thermotolerant bacterial strain 1D isolated from refinery oil-contaminated soil was identified as Gordonia sp. based on the analysis of 16S rRNA and gyrB gene sequences. The strain was found to utilize crude oil, diesel fuel, and a wide spectrum of alkanes at temperatures up to 50 °C. Strain 1D is the first representative of Gordonia amicalis capable of utilizing alkanes of chain length up to С36 at a temperature of 45-50 °C. The degree of crude oil degradation by Gordonia sp. 1D at 45 °C was 38% in liquid medium and 40% in soil (with regard to abiotic loss). There are no examples of so effective hydrocarbon-oxidizing thermotolerant Gordonia in the world literature. The 1D genome analysis revealed the presence of two alkane hydroxylase gene clusters, genes of dibenzothiophene cleavage, and the cleavage of salicylate and gentisate - naphthalene metabolism intermediates. The highly efficient thermotolerant strain Gordonia sp. 1D can be used in remediation of oil-contaminated soils in hot climates.

An insight into the ecology, diversity and adaptations of Gordonia species.

The bacterial genus Gordonia encompasses a variety of versatile species that have been isolated from a multitude of environments. Gordonia was described as a genus about 20 years ago, and to date, 39 different species have been identified. Gordonia is recognized for symbiotic associations with multiple hosts, including aquatic (marine and fresh water) biological forms and terrestrial invertebrates. Some Gordonia species isolated from clinical specimens are known to be opportunistic human pathogens causing secondary infections in immunocompromised and immunosuppressive individuals. They are also predominant in mangrove ecosystems and terrestrial sites. Members of the genus Gordonia are ecologically adaptable and show marked variations in their properties and products. They generate diverse bioactive compounds and produce a variety of extracellular enzymes. In addition, production of surface active compounds and carotenoid pigments allows this group of microorganisms to grow under different conditions. Several isolates from water and soil have been implicated in bioremediation of different environments and plant associated species have been explored for agricultural applications. This review highlights the prevalence of the members of this versatile genus in diverse environments, details its associations with living forms, summarizes the biotechnologically relevant products that can be obtained and discusses the salient genomic features that allow this Actinomycete to survive in different ecological niches.

Bacteriophages of wastewater foaming-associated filamentous Gordonia reduce host levels in raw activated sludge.

Filamentous bacteria are a normal and necessary component of the activated sludge wastewater treatment process, but the overgrowth of filamentous bacteria results in foaming and bulking associated disruptions. Bacteriophages, or phages, were investigated for their potential to reduce the titer of foaming bacteria in a mixed-microbial activated sludge matrix. Foaming-associated filamentous bacteria were isolated from activated sludge of a commercial wastewater treatment plan and identified as Gordonia species by 16S rDNA sequencing. Four representative phages were isolated that target G. malaquae and two un-named Gordonia species isolates. Electron microscopy revealed the phages to be siphophages with long tails. Three of the phages--GordTnk2, Gmala1, and GordDuk1--had very similar ~76 kb genomes, with >93% DNA identity. These genomes shared limited synteny with Rhodococcus equi phage ReqiDocB7 and Gordonia phage GTE7. In contrast, the genome of phage Gsput1 was smaller (43 kb) and was not similar enough to any known phage to be placed within an established phage type. Application of these four phages at MOIs of 5-15 significantly reduced Gordonia host levels in a wastewater sludge model by approximately 10-fold as compared to non-phage treated reactors. Phage control was observed for nine days after treatment.

Plastic Expander-Related Gordonia Sputi Infection: Case Report and Literature Review.

Gordonia sputi causes rare bacterial infections resulting from a contaminated indwelling medical device. We report the case of a postoperative plastic expander abscess in a woman, with G. sputi identification by 16S ribosomal RNA sequencing. This report indicates that Gordonia spp. should be included in the list of organisms causing plastic implant infections.

Neuroactive diol and acyloin metabolites from cone snail-associated bacteria.

The bacterium Gordonia sp. 647W.R.1a.05 was cultivated from the venom duct of the cone snail, Conus circumcisus. The Gordonia sp. organic extract modulated the action potential of mouse dorsal root ganglion neurons. Assay-guided fractionation led to the identification of the new compound circumcin A (1) and 11 known analogs (2-12). Two of these compounds, kurasoin B (7) and soraphinol A (8), were active in a human norepinephrine transporter assay with Ki values of 2575 and 867 nM, respectively. No neuroactivity had previously been reported for compounds in this structural class. Gordonia species have been reproducibly isolated from four different cone snail species, indicating a consistent association between these organisms.

Gordonia cholesterolivorans sp. nov., a cholesterol-degrading actinomycete isolated from sewage sludge.

The taxonomic position of the cholesterol-degrading strain Chol-3(T), isolated from a sewage sludge sample, was clarified using a polyphasic taxonomic approach. Phylogenetic analysis of its 16S rRNA gene sequence, whole-cell fatty acid profile and mycolic acid composition revealed that this isolate is a member of the genus Gordonia with the species Gordonia sihwensis, G. hydrophobica and G. shandongensis being the nearest phylogenetic neighbours. The results of DNA-DNA hybridization against its phylogenetically closest neighbours as well as the results of physiological and biochemical tests allowed genotypic and phenotypic differentiation of strain Chol-3(T) from the other Gordonia species with validly published names. Strain Chol-3(T) therefore merits recognition as a member of a novel species within the genus Gordonia, for which the name Gordonia cholesterolivorans sp. nov. is proposed. The type strain is Chol-3(T) (=CECT 7408(T) =DSM 45229(T)).

Surface-active compounds and their role in the access to hydrocarbons in Gordonia strains.

Three new bacterial strains (M22, BS25 and BS29) belonging to the Gordonia genus were isolated from a site chronically contaminated by diesel. Those Gordonia strains were able to grow using a wide range of straight and branched aliphatic hydrocarbons as carbon and energy sources and to produce at least two classes of surface-active compounds. Emulsifying agents were released in the culture medium when bacteria grew both on hydrocarbons and water-soluble substrates. Cell-bound biosurfactants, which reduce the surface tension, were produced on hydrocarbons; however, their production was significantly lower on water soluble substrates. The relationship of growth phase, surface-active compound production and cell-surface properties was analyzed in kinetic experiments on hydrocarbons. Gordonia sp. BS29 synthesized, and released extracellularly, bioemulsans during the exponential phase with n-hexadecane as carbon and energy source. The production of biosurfactants started in the exponential phase and their concentration increased during the following linear growth. Furthermore, the adhesion of bacterial cells to hydrocarbons decreased during growth. Our results led us to hypothesize a change in the mode by which Gordonia cells access the substrate during growth on hydrocarbons.

Gordonia soli sp. nov., a novel actinomycete isolated from soil.

A soil isolate, strain CC-AB07T, was characterized using a polyphasic approach. This organism had chemotaxonomic and morphological properties consistent with its classification in the genus Gordonia. 16S rRNA gene sequence analysis showed that the novel strain formed a monophyletic branch at the periphery of the evolutionary radiation occupied by the genus Gordonia, its closest neighbours being the type strains of Gordonia alkanivorans, Gordonia amicalis, Gordonia bronchialis, Gordonia desulfuricans, Gordonia polyisoprenivorans and Gordonia rhizosphera. The novel isolate was distinguished from all of these type strains using a range of phenotypic properties and by gyrB gene sequence analysis. It was evident from the genotypic and phenotypic data that strain CC-AB07T should be classified as representing a novel species in the genus Gordonia, for which the name Gordonia soli sp. nov. is proposed. The type strain is CC-AB07T (=BCRC 16810T=DSM 44995T).

Pathways in the degradation of hydrolyzed alcohols of butyl benzyl phthalate in metabolically diverse Gordonia sp. strain MTCC 4818.

In the present study, the metabolic pathways involved in the degradation of benzyl alcohol and 1-butanol, the hydrolyzed products of butyl benzyl phthalate, were investigated by the Gordonia sp. strain MTCC 4818. The strain can utilize both benzyl alcohol and 1-butanol individually as sole carbon sources, where benzyl alcohol was found to be metabolized via benzaldehyde, benzoic acid and catechol, which was further degraded by ortho-cleavage dioxygenase to cis,cis-muconic acid and subsequently to muconolactone leading to tricarboxylic acid cycle. On the other hand, 1-butanol was metabolized via butyraldehyde and butyric acid, which was channeled into the tricarboxylic acid cycle via the beta-oxidation pathway. Numbers of dehydrogenases, both NAD+-dependent and NAD+-independent, were found to be involved in the degradation of benzyl alcohol and 1-butanol, where several dehydrogenases exhibited relaxed substrate specificity. Both 2,3- and 3,4-dihydroxybenzoic acids were utilized by the test organism for growth and metabolized by the ortho-cleavage pathway by the cell-free extract of benzoate-grown cells, similar to catechol, suggesting possible broad substrate specificity of the ring cleavage dioxygenase. Moreover, the test organism can utilize various primary and secondary alcohols, aliphatic aldehydes and acids in the C2-C5 range besides n-hexadecane, 1,4-butanediol and cyclohexanol individually as the sole carbon sources indicating metabolic diversity in the Gordonia sp. strain MTCC 4818.