(2007) [7]. These genes are present in the genomes selleck chem ARQ197 of strains DSM 17395 and DSM 24588, too (PGA1_c04930 and PGA1_c05350, _c13760, _c28490; PGA2_c05370 and PGA2_c04910, _c13660, _71p110). The genes Inhi_3983 of P. inhibens strain T5T and PGA2_71p110 of P. inhibens strain DSM 24588 are located on the 69 kb plasmid (Fig. 3) and 71 kb plasmid, respectively. In contrast, the homologous gene (PGA1_c28490) of P. inhibens strain DSM 17395 is located on the chromosome. For the P. inhibens strains DSM 17395 and DSM 24588 a surface-attached lifestyle was inferred from the genome analysis [3]. Even though strain T5T was isolated from a water sample, it exhibits the same genes associated with the biosynthesis and transport of polysaccharides as strains DSM 17395 and DSM 24588.
This includes genes described as unique for the strains DSM 17395 and DSM 24588, i.e. a gene coding for a glycosyltransferase-like protein (Inhi_3961) and two ORFs (Inhi_3954 and Inhi_3955) related to a type I secretion system and used for the transport of exopolysaccharides. Production of extracellular polysaccharides is a major factor contributing to surface attachment [77,78]. Thus it appears likely that T5T is also well-adapted to a surface attached lifestyle. P. inhibens was described as a strictly aerobic bacterium [1]. However, we found genes involved in the dissimilatory nitrate reduction pathway to nitrogen, including the gene coding for a copper containing nitrite reductase (Inhi_3645) and a nitric oxide reductase cluster (Inhi_3648 – Inhi_3654), both located on the replicon pInhi_A227.
These genes are also present and located on the largest plasmids of P. inhibens DSM 17395 (PGA1_262p) and P. inhibens DSM 24588 (PGA2_239p) (Figure 3). In addition, P. inhibens strain T5T possesses a gene cluster coding for a nitrous oxide reductase (Inhi_3786 �C Inhi_3792) located on the replicon pInhi_B88, which is absent in the strains DSM 17395 and DSM 24588 (Figure 3). Neither strain T5T nor DSM 17395 and DSM 24588 have genes coding for a nitrate reductase. The findings suggest that P. inhibens T5T has a complete dissimilatory nitrite reduction pathway, but is not able to reduce Carfilzomib nitrate, as previously described by Martens et al. (2006) [1]. To confirm the results we tested strain T5T for its capability to grow anaerobically with nitrite. Anaerobic marine basal medium was prepared according to Cypionka and Pfennig (1986) [79] and supplemented with nitrite and glucose, both in a final concentration of 5 mM. After two weeks a decrease of nitrite was determined by photometric analysis at 545 nm by using the Griess reaction [80] and an increase of the turbidity was detected (results not shown). Thus it became clear that P.