title: Interactions between hyphosphere-associated bacteria and the fungus Cladosporium herbarum on aquatic leaf litter.
abstract: We investigated microbial interactions of aquatic bacteria associated with hyphae (the hyphosphere) of freshwater fungi on leaf litter. Bacteria were isolated directly from the hyphae of fungi from sedimented leaves of a small stream in the National Park "Lower Oder," Germany. To investigate interactions, bacteria and fungi were pairwise co-cultivated on leaf-extract medium and in microcosms loaded with leaves. The performance of fungi and bacteria was monitored by measuring growth, enzyme production, and respiration of mono- and co-cultures. Growth inhibition of the fungus Cladosporium herbarum by Ralstonia pickettii was detected on leaf extract agar plates. In microcosms, the presence of Chryseobacterium sp. lowered the exocellulase, endocellulase, and cellobiase activity of the fungus. Additionally, the conversion of leaf material into microbial biomass was retarded in co-cultures. The respiration of the fungus was uninfluenced by the presence of the bacterium.
authors.affiliation: Department of Environmental Microbiology, Technische Universität Berlin, Franklinstrasse 29, 10587 Berlin, Germany. christiane.baschien@tu-berlin.de
authors.forename: Christiane
authors.initials: C
authors.lastname: Baschien
authors.forename: Georg
authors.initials: G
authors.lastname: Rode
authors.forename: Uta
authors.initials: U
authors.lastname: Böckelmann
authors.forename: Peter
authors.initials: P
authors.lastname: Götz
authors.forename: Ulrich
authors.initials: U
authors.lastname: Szewzyk
mesh_terms: D000898:Antibiosis; D001673:Biodegradation, Environmental; D002244:Carbon / Q000032:analysis; D044602:Cellulases / Q000378:metabolism; D045247:Chryseobacterium / Q000254:growth & development / Q000302:isolation & purification / Q000378:metabolism; D002963:Cladosporium / Q000201:enzymology / Q000254:growth & development* / Q000302:isolation & purification; D018920:Coculture Techniques; D025301:Hyphae; D009584:Nitrogen / Q000032:analysis; D018515:Plant Leaves / Q000382:microbiology*; D049920:Ralstonia pickettii / Q000254:growth & development* / Q000302:isolation & purification; D045483:Rivers / Q000382:microbiology; D014871:Water Microbiology; D001617:beta-Glucosidase / Q000378:metabolism
chemical_list: D002244:Carbon; D044602:Cellulases; D001617:beta-Glucosidase; D009584:Nitrogen