One of the most important concerns associated with the
use of BCAs in plant production is the possible disruption
of microbial processes that are essential to general soil
ecosystem functioning. This includes e¡ects on microorganisms
and on carbon, nitrogen and phosphorus cycling,
as well as general impacts on soil ecosystem functioning.
E¡ects on non-target microorganisms (bacteria, fungi and
protozoa), and on the biochemical functions they catalyze,
are frequently studied in the rhizosphere where the BCA is
introduced. This has led us to review non-target e¡ects on
microbial abundance and community structure, enzyme
activities and available nutrients, microbial indicators,
and other trophic levels such as protozoa, nematodes
and plants.