title: Bacterial growth and community composition in fractions of dissolved organic carbon of different molar mass from interstitial water.
abstract: The ability of different molar-mass fractions of interstitial dissolved organic carbon (DOC) from a small stream to stimulate bacterial growth was determined. Growth was the greatest in the low-molar mass (<1 kDa) (LMM) fraction and the least in the high-molar mass (>10 kDa) (HMM) one. The LMM fraction consistently had a higher ratio of carbon to organic nitrogen than other fractions. The fluorescence in situ hybridization analysis revealed that bacterial populations in interstitial water were dominated by beta-Proteobacteria. gamma-Proteobacteria together with the Cytophaga-Flavobacteria cluster dominated in LMM DOC (66.3%) while the proportions of bacterial groups in HMM and medium-molar mass (MMM) fractions were more equal. The fact that gamma-Proteobacteria strongly dominates in LMM DOC fraction refutes the idea that LMM DOC is readily utilized by all heterotrophic bacteria.
authors.affiliation: Department of Ecology and Environmental Sciences, Division of Ecological Laboratories, Faculty of Science, Palacký University, 783 71 Olomouc, Czechia.
authors.forename: S
authors.initials: S
authors.lastname: Axmanová
authors.forename: J
authors.initials: J
authors.lastname: Koutný
authors.forename: J
authors.initials: J
authors.lastname: Cupalová
authors.forename: M
authors.initials: M
authors.lastname: Rulík
mesh_terms: D020562:Betaproteobacteria / Q000254:growth & development / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D003589:Cytophaga / Q000378:metabolism*; D017753:Ecosystem; D041965:Flavobacteriaceae / Q000378:metabolism*; D005618:Fresh Water / Q000737:chemistry / Q000382:microbiology*; D020563:Gammaproteobacteria / Q000254:growth & development / Q000378:metabolism*; D017404:In Situ Hybridization, Fluorescence
chemical_list: D002244:Carbon