Sphingomonads gained particular attention for their ability to degrade a variety of compounds. MCT13 strain was isolated from a water sample collected in September 2007 at the artificial pond within the Laboratory of Experimental Ecology and Acquaculture (University of Tor Vergata, Rome, Italy). The isolate has been assigned to the Sphingomonas genus with the 16S rDNA sequencing. The morphological, biochemical and chemotaxonomic analyses revealed that MCT13 strain represents a novel species in the genus Sphingomonas, for which the name Sphingomonas turrisvirgatae sp. nov. was proposed. This isolate was able to produce evident pitting on Zobell agar plates, suggesting its ability to produce agarases, as was also confirmed by the analysis of MCT13 draft genome, deposited at DDBJ/EMBL/GenBank databases and announced on Frontiers in Environmental Science (2017). Up to now, agarolytic activity has been more often found in marine-bacteria and has not been observed in any of the characterized or validly published Sphingomonas species. The results of preliminary bioinformatic analyses suggest the presence of genes which could be potentially used either in bioremediation or in industrial applications, when the degradation complex carbohydrates is necessary.

A specific bacteriophage belonging to the Siphoviridae family was also isolated and identified for this new Sphingomonas species, named vB_StuS_MMDA13.

 

Marmo P., Thaller M.C., Di Lallo G., Henrici De Angelis L., Poerio N., De Santis F., Fraziano M., Migliore L., D’Andrea M.M. (2020). Characterization of vB_StuS_MMDA13, a newly discovered bacteriophage infecting the agar-degrading species Sphingomonas turrisvirgatae. Viruses, 12(8): 894. DOI: 10.3390/v12080894

 Members of Sphingomonas genus have gained a notable interest for their use in a wide range of biotechnological applications, ranging from bioremediation to the production of valuable compounds of industrial interest. To date, knowledge on phages targeting Sphingomonas spp. are still scarce. Here, we describe and characterize a lytic bacteriophage, named vB_StuS_MMDA13, able to infect the Sphingomonas turrisvirgatae MCT13 type strain. Physiological characterization demonstrated that vB_StuS_MMDA13 has a narrow host range, a long latency period, a low burst size, and it is overall stable to both temperature and pH variations. The phage has a double-stranded DNA genome of 63,743 bp, with 89 open reading frames arranged in two opposite arms separated by a 1186 bp non-coding region and shows a very low global similarity to any other known phages. Interestingly, vB_StuS_MMDA13 is endowed with an original nucleotide modification biosynthetic gene cluster, which greatly differs from those of its most closely related phages of the Nipunavirus genus. vB_StuS_MMDA13 is the first characterized lytic bacteriophage of the Siphoviridae family infecting members of the Sphingomonas genus.

 

Thaller M.C., D’Andrea M.M., Marmo P., Civitareale C., Casu F., Migliore L. (2018) - SPHINGOMONAS TURRISVIRGATAE SP. NOV., AN AGAR-DEGRADING SPECIES ISOLATED FROM FRESHWATER. International Journal of Systematic and Evolutionary Microbiology, 68(9): 2794-2799. DOI: 10.1099/ijsem.0.002896

 A yellow pigmented and agar-pitting colony was isolated from the water of a drainage ditch within a disused system of constructed wetlands. The strain was purified and named MCT13^T. This rod-shaped, Gram-negative, oxidase- and catalase-positive, aerobic, non-spore-forming and non-motile strain formed round colonies and grew optimally at pH 7.0±0.2, at 28–30 °C on LB agar, with 0-0.5% NaCl. The 16S rRNA gene sequence analysis placed the MCT13^T isolate within the Sphingomonas (sensu stricto) cluster. The DNA G+C content was 65.3%. The only observed ubiquinone was Q10. The major fatty acids included C17 : 1ω6c and summed feature 8. The major polar lipids were sphingoglycolipid, diphosphatidylglycerol, phosphatidylethanolamine and phosphatidylglycerol. The major polyamine was spermidine. The 16S rRNA phylogenetic analysis showed the closest relative of MCT13^T to be Sphingomonas koreensis (98.48%); however, there are several genotypical and phenotypical differences between the novel isolate and the type strain JSS26^T of S. koreeensis. On the basis of these results, the MCT13^T strain represents a novel species in the genus Sphingomonas, for which the name Sphingomonas turrisvirgatae sp. nov. is proposed. The type strain is MCT13^T (=DSMZ105457^T =BAC RE RSCIC7^T).

 

D'Andrea M., Ciacci N., Di Pilato V., Rossolini G.M., Thaller M.C. (2017). DRAFT GENOME SEQUENCE OF THE AGARASE-PRODUCING SPHINGOMONAS SP. MCT13. Frontiers in Environmental Science 5:9. DOI: 10.3389/fenvs.2017.00009