title: Comparison between cultivated and total bacterial communities associated with Cucurbita pepo using cultivation-dependent techniques and 454 pyrosequencing.
abstract: Endophytic bacteria often have beneficial effects on their host plants that can be exploited for bioremediation applications but, according to the literature, only 0.001-1% of all endophytic microbes should be cultivable. This study compared the cultivated endophytic communities of the roots and shoots of Cucurbita pepo with the total endophytic communities as determined by cultivation-dependent techniques and 454 pyrosequencing. The ten most abundant taxa of the total communities aligned well with the cultivated taxa; however, the abundance of these taxa in the two communities differed greatly. Enterobacter showed very low presence in the total communities, whereas they were dominantly present in the cultivated communities. Although Rhizobium dominated in total root and shoot communities, it was poorly cultivable and even then only in growth media containing plant extract. Since endophytes likely contribute to plant-growth promotion, cultivated bacterial strains were tested for their plant-growth promoting capabilities, and the results were correlated with their abundance in the total community. Bacillus and Pseudomonas showed promising results when considering cultivability, abundance in the total community and plant-growth promoting capability. This study demonstrated that, although a limited number of bacterial genera were cultivable, current cultivation-dependent techniques may be sufficient for further isolation and inoculation experiments that aim to improve phytoremediation efficiency.
authors.affiliation: Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Eevers
authors.affiliation: Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Beckers
authors.affiliation: Microbial Ecology Group, Department of Biology, Lund University, Ecology Building, SE-22 362 Lund, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Op de Beeck
authors.affiliation: Connecticut Agricultural Experiment Station, Department of Analytical Chemistry, 123 Huntington Street, New Haven, CT 06511, USA.
authors.forename: J C
authors.initials: JC
authors.lastname: White
authors.affiliation: Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek, Belgium. Electronic address: jaco.vangronsveld@uhasselt.be.
authors.forename: J
authors.initials: J
authors.lastname: Vangronsveld
authors.affiliation: Hasselt University, Centre for Environmental Sciences, Agoralaan Building D, 3590 Diepenbeek, Belgium.
authors.forename: N
authors.initials: N
authors.lastname: Weyens
mesh_terms: D001407:Bacillus / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D044822:Biodiversity; D028464:Cucurbita / Q000382:microbiology*; D004269:DNA, Bacterial / Q000235:genetics; D060026:Endophytes / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D004754:Enterobacter / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D058889:Molecular Typing; D018517:Plant Roots / Q000382:microbiology*; D018520:Plant Shoots / Q000382:microbiology*; D011549:Pseudomonas / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification; D012336:RNA, Ribosomal, 16S; D012231:Rhizobium / Q000235:genetics / Q000254:growth & development* / Q000302:isolation & purification
chemical_list: D004269:DNA, Bacterial; D012336:RNA, Ribosomal, 16S
keywords: Cucurbita pepo; Cultivable bacterial community; Total bacterial community