title: Poly-β-hydroxybutyrate accumulation in bacterial consortia from different environments.
abstract: The aim of the present study was to examine soil samples from various vegetation zones in terms of physicochemical properties, microbial communities, and isolation and identification (by polymerase chain reaction and transmission electron microscopy) of bacteria producing poly-β-hydroxybutyrates (PHBs). Soil samples were analysed originating from zones with heterogeneous environmental conditions from the Romanian Carpathian Mountains (mountain zone with alpine meadow, karstic zone with limestone meadow, hill zone with xerophilous meadow, and flood plain zone with hygrophilic meadow). Different bacterial groups involved in the nitrogen cycle (aerobic mesophilic heterotrophs, ammonifiers, denitrifiers, nitrifiers, and free nitrogen-fixing bacteria from  Azotobacter  genus) were analysed. Soil biological quality was assessed by the bacterial indicator of soil quality, which varied between 4.3 and 4.7. A colony polymerase chain reaction technique was used for screening PHB producers. With different primers, specific bands were obtained in all the soil samples. Some wild types of Azotobacter species were isolated from the 4 studied sites. Biodegradable polymers of PHB were assessed by negative staining in transmission electron microscopy. The maximum PHB granules density was obtained in the strains isolated from the xerophilous meadow (10-18 granules/cell), which was the most stressful environment from all the studied sites, as the physicochemical and microbiological tests proved.
authors.affiliation: Babeş Bolyai University, Faculty of Biology and Geology, Department of Experimental Biology, Institute of Technology, 1 M.Kogalniceanu Str, Cluj-Napoca, 400084, Romania. k_hella@yahoo.com
authors.forename: Rahela
authors.initials: R
authors.lastname: Carpa
authors.forename: Anca
authors.initials: A
authors.lastname: Butiuc-Keul
authors.forename: Iulia
authors.initials: I
authors.lastname: Lupan
authors.forename: Lucian
authors.initials: L
authors.lastname: Barbu-Tudoran
authors.forename: Vasile
authors.initials: V
authors.lastname: Muntean
authors.forename: Cristina
authors.initials: C
authors.lastname: Dobrotă
mesh_terms: D001395:Azotobacter / Q000302:isolation & purification / Q000378:metabolism* / Q000648:ultrastructure; D001419:Bacteria / Q000302:isolation & purification / Q000378:metabolism; D004777:Environment; D006885:Hydroxybutyrates / Q000378:metabolism*; D046529:Microscopy, Electron, Transmission; D009586:Nitrogen Fixation; D011091:Polyesters / Q000378:metabolism*; D016133:Polymerase Chain Reaction; D012383:Romania; D012987:Soil / Q000737:chemistry*; D012988:Soil Microbiology; D000094122:Polyhydroxybutyrates
chemical_list: D006885:Hydroxybutyrates; D011091:Polyesters; D012987:Soil; C003182:poly-beta-hydroxybutyrate; D000094122:Polyhydroxybutyrates