This justifies the interpretation of cArct_4215 as (potentially circular) selleck chemical chromosome and of the other scaffolds as (potentially circular) extrachromosomal elements [36,37]. Nitrogen metabolism Although it was reported that strain 20188T did not reduce nitrate [1], the enzymes required for nitrate reduction and metabolism of other nitrogen oxides are encoded in the genome of DSM 23566T. The presence of nitrate reductase (narGHIJ, Phaar_00816 – Phaar_00819; nasA, Phaar_03836) and nitrite reductase (NAD(P)H) (nirBD; Phaar_03837, Phaar_03838) suggests the capacity for assimilatory nitrate reduction, i.e. reduction of nitrate via nitrite to ammonium [38]. Interestingly, only a copper-type nitrite reductase gene, analogous to nirK in P. gallaeciensis [39], is missing to complete the pathway for potential denitrification from nitrate to nitrogen.

In addition to the above mentioned nitrate reductase genes, nitric oxide reductase (norBCDQ; Phaar_00646 – Phaar_00649) and, in contrast to P. gallaeciensis, even nitrous oxide reductase genes (nosDZ; Phaar_02837, Phaar_02838) are present, indicating the potential to reduce nitric oxide via nitrous oxide to nitrogen [40]. Small methylated amines are also considered as potential nitrogen source for many members of the marine Roseobacter clade [41]. In contrast to L. nanhaiensis DSM 24252T (IMG object ID 2521172577), no methylamine-utilizing genes could be detected in P. arcticus strain DSM 23566T, nor in P. gallaeciensis.

When using the suggested protein sequences for trimethylamine monooxygenase (Tmm, “type”:”entrez-protein”,”attrs”:”text”:”ACK52489″,”term_id”:”217505080″,”term_text”:”ACK52489″ACK52489) and GMA synthetase (GmaS, “type”:”entrez-protein”,”attrs”:”text”:”BAF99006″,”term_id”:”165932237″,”term_text”:”BAF99006″BAF99006) [41] as query in the BLAST in the IMG database [42,43] no hits (��e-80 [44],) were found. Lower e-value cutoffs (> e-30) yielded some hits but in contrast to methylamine-utilizing genes [41], these hits were not clustered together. Although the strain did not grow with serine, L-glutamate or leucine as single substrate [1], L-serine dehydratase (EC:4.3.1.17, Phaar_02408) and threonine dehydratase (EC:4.3.1.19, Phaar_00247, _03532, _03664) genes, which catalyze the conversion of serine to pyruvate are found. The glutamate dehydrogenase (NAD(P)+) (EC:1.4.1.

3, Phaar_00693) gene degrading L-glutamate to 2-oxoglutarate is also present in the genome sequence. However, we cannot exclude a putative lack of respective transport systems. For leucine degradation, all but one gene is present; dihydrolipoamide transacylase Carfilzomib (EC:2.3.1.168). When using the respective protein sequence from the leucine utilizer Paracoccus denitrificans PD1222 as query through BLASTP, no hits were found in strain DSM 23566T. Interestingly, in P. daeponensis (IMG object ID 2521172619) which is known to grow with leucine, but also in P.