TY - JOUR

T1 - Antibiotic and biosurfactant properties of cyclic lipopeptides produced by fluorescent Pseudomonas spp. from the sugar beet rhizosphere

AU - Nielsen, T H

AU - Sørensen, D

AU - Tobiasen, C

AU - Andersen, Jens Bo

AU - Christophersen, C

AU - Givskov, M

AU - Sørensen, J

PY - 2002

Y1 - 2002

N2 - Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600 fluorescent Pseudomonas spp. from two different agricultural soils by using three different growth media. CLP production was observed in a large proportion of the strains (approximately 60%) inhabiting the sandy soil, compared to a low proportion (approximately 6%) in the loamy soil. Chemical structure analysis revealed that all CLPs could be clustered into two major groups, each consisting of four subgroups. The two major groups varied primarily in the number of amino acids in the cyclic peptide moiety, while each of the subgroups could be differentiated by substitutions of specific amino acids in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties and that some also had antibiotic properties towards root-pathogenic microfungi. The CLP-producing P. fluorescens strains provide a useful resource for selection of biological control agents, whether a single strain or a consortium of strains was used to maximize the synergistic effect of multiple antagonistic traits in the inoculum.

AB - Cyclic lipopeptides (CLPs) with antibiotic and biosurfactant properties are produced by a number of soil bacteria, including fluorescent Pseudomonas spp. To provide new and efficient strains for the biological control of root-pathogenic fungi in agricultural crops, we isolated approximately 600 fluorescent Pseudomonas spp. from two different agricultural soils by using three different growth media. CLP production was observed in a large proportion of the strains (approximately 60%) inhabiting the sandy soil, compared to a low proportion (approximately 6%) in the loamy soil. Chemical structure analysis revealed that all CLPs could be clustered into two major groups, each consisting of four subgroups. The two major groups varied primarily in the number of amino acids in the cyclic peptide moiety, while each of the subgroups could be differentiated by substitutions of specific amino acids in the peptide moiety. Production of specific CLPs could be affiliated with Pseudomonas fluorescens strain groups belonging to biotype I, V, or VI. In vitro analysis using both purified CLPs and whole-cell P. fluorescens preparations demonstrated that all CLPs exhibited strong biosurfactant properties and that some also had antibiotic properties towards root-pathogenic microfungi. The CLP-producing P. fluorescens strains provide a useful resource for selection of biological control agents, whether a single strain or a consortium of strains was used to maximize the synergistic effect of multiple antagonistic traits in the inoculum.

KW - Agriculture

KW - Anti-Bacterial Agents

KW - Beta vulgaris

KW - Denmark

KW - Fluorescence

KW - Fungi

KW - Peptides, Cyclic

KW - Pseudomonas fluorescens

KW - Soil Microbiology

KW - Surface-Active Agents

M3 - Journal article

C2 - 12089023

VL - 68

SP - 3416

EP - 3423

JO - Applied and Environmental Microbiology

JF - Applied and Environmental Microbiology

SN - 0099-2240

IS - 7

ER -