The Complete Genome Sequence of the Nicotine-Degrading Bacterium Shinella sp. HZN7

Nicotine is a natural alkaloid that is very toxic to humans. To eliminate the harmful effects of nicotine in the environment, biological methods employing microbes to degrade nicotine are required (Brandsch, 2006; Liu et al., 2015). Shinella sp. HZN7 can degrade nicotine efficiently via the variant of a pyridine and pyrrolidine pathways (VPP; Ma et al., 2013; Qiu et al., 2014, 2015). The main intermediates in this pathway include 6-hydroxy-nicotine, 6-hydroxy-N-methylmyosmine, 6-hydroxypseudooxynicotine, 6-hydroxy-3-succinoyl-pyridine, and 2,5-dihydroxypyridine. This strain is the first nicotine-degrading bacterium to be isolated from the genus Shinella. The genus Shinella was established in 2006 within the “Rhizobiaceae group” of the Alphaproteobacteria (An et al., 2006). Six species were assigned to this genus namely S. daejeonensis, S. fusca, S. granuli, S. kummerowiae, S. yambaruensis, S. zoogloeoides. However, most strains in this genus have not been identified at the species level. Shinella spp. have been isolated from various environmental samples, such as active sludge, zooplankton gut, soils, and water. They also exhibit a range of functional diversity, such as nitrogen fixation (Lin et al., 2008), assimilation of phosphite (Poehlein et al., 2016), and degradation of the toxic pollutants, 4-aminobenzenesulfonate (Biala et al., 2014), chlorothalonil (Liang et al., 2011), and pyridine (Bai et al., 2009). Until now, only three Shinella draft genomes have been deposited in GenBank (http://www.ncbi.nlm.nih.gov/genome/ genomes/32494). To further understand the molecular mechanism of nicotine degradation and advance the potential biotechnological applications of Shinella strains, we present the first complete genome sequence of Shinella sp. HZN7 and its features.