Soil on imported shipping containers provides a source of new Pseudomonad biodiversity into New Zealand

Exotic soil attached to shipping containers imported to New Zealand was assessed for new species of Pseudomonas (sensu stricto) bacteria to determine whether this soil facilitated the introduction of new biodiversity. Pseudomonads were isolated from exotic soil originating from 19 different countries (termed container isolates (CIs)), and from soils in eight geographically distinct locations throughout New Zealand (termed New Zealand isolates (NZIs)). Partial 16S rRNA gene nucleotide sequences were determined from 40 selected CIs and 38 NZIs. Relationships between CIs, NZIs, and a further 25 typed Pseudomonad species were inferred by 16S rRNA phylogenetic analyses. CIs showed relatedness to a broad range of Pseudomonad species and many CIs grouped with NZIs suggesting they are closely related to Pseudomonads currently in New Zealand. However, unique phylogenetic branchings of CIs also indicate that soils attached to shipping containers may provide a source of new Pseudomonad biodiversity to New Zealand.