Population dynamics and antagonistic potential of enterococci colonizing the phyllosphere of grasses.
OBJECTIVE
To investigate the spatial and temporal dynamics of enterococci colonizing forage grass and their ability to produce bacteriocins.


RESULTS
Enterococci could be detected on above-ground plant parts throughout the growing season, with high continuity but low cell numbers (2.60 x 101-6.16 x 104 cfu g-1 fresh matter). A total of 750 strains were isolated and identified by their whole-cell protein patterns as Enterococcus faecalis (7.9%), Ent. mundtii (7.9%), Ent. casseliflavus (5.5%), Ent. faecium (5.2%) and Ent. sulfureus (0.1%). The vast majority of the strains (69.7%) formed a homogeneous 16S rDNA genotype that differed from those of known enterococci. A screening for antagonistic activity using an agar spot test revealed that 18.4% of all isolates were potential antagonists. Partially-purified proteins extracted from cell-free culture supernatant fluids of various species were characterized as pH- and heat-stable bacteriocins active against a wide range of lactic acid bacteria, clostridia and Listeria. The producing strains were antagonistically active even on 'phylloplane agar' at temperatures between 4 and 37 degrees C.


CONCLUSIONS
Enterococci are a common part of the epiphytic microflora of grasses, displaying probably some antagonistic activity.


CONCLUSIONS
The results provide new information on the distribution, species diversity and antagonistic potential of enterococci in the phyllosphere.
Ott
E M
EM
Department of Agricultural Ecology, University of Rostock, Justus-von-liebig-Weg 8, D-18059 Rostock, Germany. edda.ott@agrarfak.uni-rostock.de
Müller
T
T
Müller
M
M
Franz
C M
CM
Ulrich
A
A
Gabel
M
M
Seyfarth
W
W
D000898:Antibiosis / Q000502:physiology*; D001430:Bacteriocins / Q000378:metabolism*; D015169:Colony Count, Microbial; D016983:Enterococcus / Q000302:isolation & purification / Q000378:metabolism / Q000502:physiology*; D006109:Poaceae / Q000382:microbiology*; D011157:Population Dynamics
D001430:Bacteriocins