title: The contribution of endophytic bacteria to Albizia lebbeck-mediated phytoremediation of tannery effluent contaminated soil.
abstract: Toxicity of chromium often impairs the remediation capacity of plants used in phytoremediation of polluted soils. In this study, we have identified Albizia lebbeck as a prospective chromium hyperaccumulator and examined cultivable diversity of endophytes present in chromium-treated and control saplings. High numbers (22-100%) of endophytic bacteria, isolated from root, stem, and leaf tissues, could tolerate elevated (1-3 mM) concentrations of K2CrO7. 16S rRNA gene sequence-based phylogenetic analysis showed that the 118 isolates obtained comprised of 17 operational taxonomic units affiliated with the proteobacterial genera Rhizobium (18%), Marinomonas (1%), Pseudomonas (16%), and Xanthomonas (7%) but also with members of Firmicutes genera, such as Bacillus (35%) and Salinococcus (3%). The novel isolates belonging to Salinococcus and Bacillus could tolerate high K2CrO7 concentrations (3 mM) and also showed elevated activity of chromate reductase. In addition, majority (%) of the endophytic isolates also showed production of indole-3-acetic acid. Taken together, our results indicate that the innate endophytic bacterial community assists plants in reducing heavy metal toxicity.
authors.affiliation: a Department of Bioresource and Food Science , Konkuk University , Seoul , Korea.
authors.forename: Muthu
authors.initials: M
authors.lastname: Manikandan
authors.affiliation: b Center for Advanced Studies in Botany , University of Madras Guindy Campus , Chennai , India.
authors.forename: Vijayaraghavan
authors.initials: V
authors.lastname: Kannan
authors.affiliation: c Department of Botany , Stella Maris College , Chennai , India.
authors.forename: Ordetta Hannah
authors.initials: OH
authors.lastname: Mendoza
authors.affiliation: b Center for Advanced Studies in Botany , University of Madras Guindy Campus , Chennai , India.
authors.forename: Mahalingam
authors.initials: M
authors.lastname: Kanimozhi
authors.affiliation: a Department of Bioresource and Food Science , Konkuk University , Seoul , Korea.
authors.forename: Sechul
authors.initials: S
authors.lastname: Chun
authors.affiliation: d Department of Biology , Biotechnical Faculty, University of Ljubljana , Ljubljana , Slovenia.
authors.forename: Lejla
authors.initials: L
authors.lastname: Pašić
mesh_terms: D031289:Albizzia / Q000378:metabolism*; D001419:Bacteria / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D031723:Bambusa / Q000378:metabolism; D001673:Biodegradation, Environmental; D002857:Chromium / Q000378:metabolism*; D004269:DNA, Bacterial / Q000235:genetics / Q000378:metabolism; D060026:Endophytes / Q000145:classification / Q000235:genetics / Q000378:metabolism*; D007887:Fabaceae / Q000378:metabolism; D007220:Industrial Waste / Q000032:analysis; D008969:Molecular Sequence Data; D010802:Phylogeny; D012336:RNA, Ribosomal, 16S / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D012989:Soil Pollutants / Q000378:metabolism*; D013633:Tanning
chemical_list: D004269:DNA, Bacterial; D007220:Industrial Waste; D012336:RNA, Ribosomal, 16S; D012989:Soil Pollutants; D002857:Chromium; C074702:chromium hexavalent ion
keywords: chromate reductase; chromium remediation; endophytic bacteria; phytoremediation; tannery effluent