The three most abundant bacterial classes in the tomato fruit surface environments compared in this study were Gamma, Alpha and Betaproteobacteria. These were also found in higher abundance in the phyllosphere

of other plant species, although the relative abundances for these classes vary [16–18, 27]. Genera here found in high abundance in the tomato fruit surface, such as Pantoea and Enterobacter, are buy MM-102 also abundant in the phyllosphere of certain Atlantic Pictilisib molecular weight rainforest tree species and cottonwood, indicating a wide distribution across different plant species [16, 18]. Bacterial genera found in our 2009 fruit surface samples were also identified among the culturable bacteria on leaves of field-grown tomatoes, including Pseudomonas, Pantoea, Sphingomonas, Massilia, Xhantomonas and Curtobacterium [32]. Two additional genera, Burkholderia and Leuconostoc, showed high abundance in our study. Burkholderia was the most abundant genus in our groundwater samples, representing 75% of the sequences, and might have been introduced in the environment through groundwater applications. Leuconostoc has been previously described as the predominant lactic acid bacteria on tomato fruit buy LY2874455 surfaces [33]. Similar bacterial classes and genera were found in high abundance in samples collected in 2008 and 2009, with the largest differences corresponding

to the unclassified sequences. Several different reasons could account for this variation, including differences in DNA extraction, sequencing sample preparation and primers used in both years, as well as potential growing season effects. Of special interest is the high proportion of sequences identified Tideglusib as Enterobacteriaceae, given that this family includes important human pathogenic bacteria like Salmonella and E. coli. Similar representation of this family was obtained in the phyllosphere of Trichilia spp. and Pinus ponderosa, but not in that of Campomanesia xanthocarpa [16, 27]. The high adaptability of this family to

the tomato fruit surface environment might be associated to the higher risk of disease outbreaks associated with this crop. Differences between fruit surface environments do not appear to be linked to the water applications, indicating that plant conditions allow for only some of the bacterial groups present in water to establish themselves. Similar results were obtained when the fruit surface communities living on apple trees under conventional and organic management were compared, where only low abundance groups differed between the two environments [17]. Similarly, no effect on the levels of fecal and total coliforms was observed when reclaimed water with higher coliform counts, and well water were sprayed on six horticultural crops [14].