AIMS: To investigate the spatial and temporal dynamics of enterococci colonizing forage grass and their ability to produce bacteriocins. METHODS AND 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. CONCLUSION: Enterococci are a common part of the epiphytic microflora of grasses, displaying probably some antagonistic activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The results provide new information on the distribution, species diversity and antagonistic potential of enterococci in the phyllosphere.
AIMS: To investigate the spatial and temporal dynamics of enterococci colonizing forage grass and their ability to produce bacteriocins. METHODS AND 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. CONCLUSION: Enterococci are a common part of the epiphytic microflora of grasses, displaying probably some antagonistic activity. SIGNIFICANCE AND IMPACT OF THE STUDY: The results provide new information on the distribution, species diversity and antagonistic potential of enterococci in the phyllosphere.
Authors: Rachel T Noble; A Denene Blackwood; John F Griffith; Charles D McGee; Stephen B Weisberg Journal: Appl Environ Microbiol Date: 2010-09-24 Impact factor: 4.792
Authors: Yong-Jin Lee; Marirosa Molina; Jorge W Santo Domingo; Jonathan D Willis; Michael Cyterski; Dinku M Endale; Orin C Shanks Journal: Appl Environ Microbiol Date: 2008-09-19 Impact factor: 4.792
Authors: Qinghong Ran; Brian D Badgley; Nicholas Dillon; Gary M Dunny; Michael J Sadowsky Journal: Appl Environ Microbiol Date: 2013-03-01 Impact factor: 4.792