title: Selective cultures for the isolation of biosurfactant producing bacteria: comparison of different combinations of environmental inocula and hydrophobic carbon sources.
abstract: The potential of estuarine microniches as reservoirs of biosurfactant-producing bacteria was evaluated by testing different combinations of inocula and hydrophobic carbon sources. Selective cultures using diesel, petroleum, or paraffin as hydrophobic carbon sources were prepared and inoculated with water from the surface microlayer, bulk sediments, and sediment of the rhizosphere of Halimione portulacoides. These inocula were compared regarding the frequency of biosurfactant-producing strains among selected isolates. The community structure of the selective cultures was profiled using denaturing gradient gel electrophoresis (DGGE) of the 16S rRNA gene fragments at the end of the incubation. The DGGE profiles corresponding to the communities established in selective cultures at the end of the incubation revealed that communities were different in terms of structural diversity. The highest diversity was observed in the selective cultures containing paraffin (H (') = 2.5). Isolates were obtained from the selective cultures (66) and tested for biosurfactant production by the atomized oil assay. Biosurfactant production was detected in 17 isolates identified as Microbacterium, Pseudomonas, Rhodococcus, and Serratia. The combination of estuarine surface microlayer (SML) water as inoculum and diesel as carbon source seems promising for the isolation of surfactant-producing bacteria. Supplemental materials are available for this article. Go to the publisher's online edition of Preparative Biochemistry and Biotechnology to view the supplemental file.
authors: Department of Biology and CESAM, University of Aveiro, Campus de Santiago, Aveiro, Portugal.
authors: Patrícia M
authors: PM
authors: Domingues
authors: António
authors: A
authors: Louvado
authors: Vanessa
authors: V
authors: Oliveira
authors: Francisco J C R
authors: FJ
authors: Coelho
authors: Adelaide
authors: A
authors: Almeida
authors: Newton C M
authors: NC
authors: Gomes
authors: Angela
authors: A
authors: Cunha
mesh_terms: D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism*; D002244:Carbon / Q000378:metabolism*; D003470:Culture Media; D005742:Gasoline; D019015:Geologic Sediments / Q000382:microbiology; D057927:Hydrophobic and Hydrophilic Interactions; D010578:Petroleum; D011174:Portugal; D011549:Pseudomonas / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents / Q000378:metabolism*; D014871:Water Microbiology; D014874:Water Pollutants, Chemical / Q000378:metabolism
chemical_list: D003470:Culture Media; D005742:Gasoline; D010578:Petroleum; D012336:RNA, Ribosomal, 16S; D013501:Surface-Active Agents; D014874:Water Pollutants, Chemical; D002244:Carbon