**Genomic Analysis of** γ**-Hexachlorocyclohexane-Degrading** *Sphingopyxis lindanitolerans* **WS5A3p Strain in the Context of the Pangenome of** *Sphingopyxis*

#### **Michal A. Kaminski 1, Adam Sobczak 1,2, Andrzej Dziembowski 1,2 and Leszek Lipinski 1,2,\***


Received: 29 July 2019; Accepted: 2 September 2019; Published: 6 September 2019

**Abstract:** *Sphingopyxis* inhabit diverse environmental niches, including marine, freshwater, oceans, soil and anthropogenic sites. The genus includes 20 phylogenetically distinct, valid species, but only a few with a sequenced genome. In this work, we analyzed the nearly complete genome of the newly described species, *Sphingopyxis lindanitolerans*, and compared it to the other available *Sphingopyxis* genomes. The genome included 4.3 Mbp in total and consists of a circular chromosome, and two putative plasmids. Among the identified set of *lin* genes responsible for γ-hexachlorocyclohexane pesticide degradation, we discovered a gene coding for a new isoform of the LinA protein. The significant potential of this species in the remediation of contaminated soil is also correlated with the fact that its genome encodes a higher number of enzymes potentially involved in aromatic compound degradation than for most other *Sphingopyxis* strains. Additional analysis of 44 *Sphingopyxis* representatives provides insights into the pangenome of *Sphingopyxis* and revealed a core of 734 protein clusters and between four and 1667 unique proteins per genome.

**Keywords:** *Sphingopyxis lindanitolerans*; pesticide; complete genome sequence; pangenome; γ-HCH degradation; *lin* genes
