The Role of Hydrophobicity and Surface Receptors at Hyphae ofLyophyllumsp. Strain Karsten in the Interaction withBurkholderia terraeBS001 - Implications for Interactions in Soil.
The soil bacteriumBurkholderia terraestrain BS001 can interact with varying soil fungi, using mechanisms that range from the utilization of carbon/energy sources such as glycerol to the ability to reach novel territories in soil via co-migration with growing fungal mycelia. Here, we investigate the intrinsic properties of theB. terraeBS001 interaction with the basidiomycetous soil fungusLyophyllumsp. strain Karsten. In some experiments, the ascomycetousTrichoderma asperellum302 was also used. The hyphae ofLyophyllumsp. strain Karsten were largely hydrophilic on water-containing media versus hydrophobic when aerial, as evidenced by contact angle analyses (CA). Co-migration ofB. terraestrain BS001 cells with the hyphae of the two fungi occurred preferentially along the - presumably hydrophilic - soil-dwelling hyphae, whereas aerial hyphae did not allow efficient migration, due to reduced thickness of their surrounding mucous films. Moreover, the cell numbers over the length of the hyphae in soil showed an uneven distribution, i.e., the CFU numbers increased from minima at the inoculation point to maximal numbers in the middle of the extended hyphae, then decreasing toward the terminal side. Microscopic analyses of the strain BS001 associations with theLyophyllumsp. strain Karsten hyphae in the microcosms confirmed the presence ofB. terraeBS001 cells on the mucous matter that was present at the hyphal surfaces of the fungi used. Cell agglomerates were found to accumulate at defined sites on the hyphal surfaces, which were coined 'fungal-interactive' hot spots. Evidence was further obtained for the contention that receptors for a physical bacterium-fungus interaction occur at theLyophyllumsp. strain Karsten hyphal surface, in which the specific glycosphingolipid ceramide monohexoside (CMH) plays an important role. Thus, bacterial adherence may be mediated by heterogeneously distributed fungal-specific receptors, implying the CMH moieties. This study sheds light on the physical aspects of theB. terraeBS001 -Lyophyllumsp. strain Karsten interaction, highlighting heterogeneity along the hyphae with respect to hydrophobicity and the presence of potential anchoring sites.
Laboratório de Biologia Celular de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
Taissa
T
Vila
Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of GroningenGroningen, Netherlands; Department of Environmental Sciences, COMSATS Institute of Information TechnologyAbbottabad, Pakistan.
Rashid
R
Nazir
Laboratório de Biologia Celular de Fungos, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
Sonia
S
Rozental
Laboratório de Química Biológica de Microrganismos, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
Giulia M P
GM
Dos Santos
Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of GroningenGroningen, Netherlands; Laboratório de Química Biológica de Microrganismos, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de JaneiroRio de Janeiro, Brazil.
Renata O R
RO
Calixto
Laboratório de Química Biológica de Microrganismos, Instituto de Microbiologia Paulo de Goes, Universidade Federal do Rio de Janeiro Rio de Janeiro, Brazil.
Eliana
E
Barreto-Bergter
Department of Environmental Microbiology, UFZ - Helmholtz Centre for Environmental Research Leipzig, Germany.
Lukas Y
LY
Wick
Department of Microbial Ecology, Groningen Institute for Evolutionary Life Sciences, University of Groningen Groningen, Netherlands.
Jan Dirk
JD
van Elsas
Burkholderia terrae; CMH; Lyophyllum sp. Karsten; cerebroside; fungal-bacterial association; soil fungi