title: Characterization of plant-growth-promoting traits of Acinetobacter species isolated from rhizosphere of Pennisetum glaucum.
abstract: A total of 31 Acinetobacter isolates were obtained from the rhizosphere of Pennisetum glaucum and evaluated for their plant-growth-promoting traits. Two isolates, namely Acinetobacter sp. PUCM1007 and A. baumannii PUCM1029, produced indole acetic acid (10-13 microgram/ml). A total of 26 and 27 isolates solubilized phosphates and zinc oxide, respectively. Among the mineral-solubilizing strains, A. calcoaceticus PUCM1006 solubilized phosphate most efficiently (84 mg/ml), whereas zinc oxide was solubilized by A. calcoaceticus PUCM1025 at the highest solubilization efficiency of 918%. All the Acinetobacter isolates, except PUCM1010, produced siderophores. The highest siderophore production (85.0 siderophore units) was exhibited by A. calcoaceticus PUCM1016. Strains PUCM1001 and PUCM1019 (both A. calcoaceticus) and PUCM1022 (Acinetobacter sp.) produced both hydroxamate- and catechol-type siderophores, whereas all the other strains only produced catechol-type siderophores. In vitro inhibition of Fusarium oxysporum under iron-limited conditions was demonstrated by the siderophore-producing Acinetobacter strains, where PUCM1018 was the most potent inhibitor of the fungal phytopathogen. Acinetobacter sp. PUCM1022 significantly enhanced the shoot height, root length, and root dry weights of pearl millet seedlings in pot experiments when compared with controls, underscoring the plant-growth-promoting potential of these isolates.
authors.affiliation: Department of Microbiology, University of Pune, Maharashtra, India.
authors.forename: Farokh
authors.initials: F
authors.lastname: Rokhbakhsh-Zamin
authors.forename: Dhara
authors.initials: D
authors.lastname: Sachdev
authors.forename: Nadia
authors.initials: N
authors.lastname: Kazemi-Pour
authors.forename: Anupama
authors.initials: A
authors.lastname: Engineer
authors.forename: Karishma R
authors.initials: KR
authors.lastname: Pardesi
authors.forename: Smita
authors.initials: S
authors.lastname: Zinjarde
authors.forename: Prashant K
authors.initials: PK
authors.lastname: Dhakephalkar
authors.forename: Balu A
authors.initials: BA
authors.lastname: Chopade
mesh_terms: D000150:Acinetobacter / Q000145:classification / Q000235:genetics / Q000254:growth & development / Q000302:isolation & purification*; D015373:Bacterial Typing Techniques; D004269:DNA, Bacterial / Q000032:analysis / Q000235:genetics; D004275:DNA, Ribosomal / Q000032:analysis; D020459:Genes, rRNA; D007210:Indoleacetic Acids / Q000378:metabolism; D008969:Molecular Sequence Data; D031782:Pennisetum / Q000254:growth & development* / Q000382:microbiology*; D010802:Phylogeny; D010937:Plant Growth Regulators / Q000378:metabolism; D018517:Plant Roots / Q000382:microbiology*; D012336:RNA, Ribosomal, 16S / Q000235:genetics; D058441:Rhizosphere; D017422:Sequence Analysis, DNA; D017262:Siderophores / Q000378:metabolism; D012988:Soil Microbiology; D013045:Species Specificity
chemical_list: D004269:DNA, Bacterial; D004275:DNA, Ribosomal; D007210:Indoleacetic Acids; D010937:Plant Growth Regulators; D012336:RNA, Ribosomal, 16S; D017262:Siderophores; C030737:indoleacetic acid