S. maltophilia has wide environmental distribution and is
readily isolated from water, soil and sewage. However, little is
known about its abundance within these environments. In the
present work, we enumerated S. maltophilia within the bulk
soil of agricultural sites that are physically, chemically and
geographically different from each other, and we determined
whether soil characteristics influenced its distribution. Whatever
their characteristics, most soil samples from France
(Feucherolles, Pierrelaye, and Burgundy) and Tunisia led to
the detection of S. maltophilia, confirming its widespread
presence and as the fact that this species is a natural inhabitant
of soil. This result was expected, since soil is considered to be
a reservoir of S. maltophilia [41]. S. maltophilia showed a high
frequency of occurrence in the rhizosphere [21] and a recent
report on its presence as a rice endophyte led the authors to
conclude that this species is highly adapted to the plant niche
[42]. Our data evidenced that S. maltophilia can also survive in
bulk soil far from the influence of plant roots. Furthermore,
several of our samples were collected whereas the soil was not
planted, or else long after crop harvest. Nevertheless, we
showed that the success of isolation and the abundance of S.
maltophilia differed both within and between sites. Sites from
Burgundy showed the lowest abundance of S. maltophilia and
the site of Feucherolles the highest. At the latter, S. maltophilia
represented up to 1.2% of total heterotrophic microflora.