title: Inoculation methods using Rhodococcus erythropolis strain P30 affects bacterial assisted phytoextraction capacity of Nicotiana tabacum.
abstract: In this study different bacterial inoculation methods were tested for tobacco plants growing in a mine-soil contaminated with Pb, Zn, and Cd. The inoculation methods evaluated were: seed inoculation, soil inoculation, dual soil inoculation event, and seed+soil inoculation. Each inoculum was added at two bacterial densities (10(6) CFUs mL(-1) and 10(8) CFUs mL(-1)). The objectives were to evaluate whether or not the mode of inoculation or the number of applied microorganisms influences plant response. The most pronounced bacterial-induced effect was found for biomass production, and the soil inoculation treatment (using 10(6) CFUs mL(-1)) led to the highest increase in shoot dry weight yield (up to 45%). Bacterial-induced effects on shoot metal concentrations were less pronounced; although a positive effect was found on shoot Pb concentration when using 10(8) CFUs mL(-1) in the soil inoculation (29% increase) and in the seed+soil inoculation (34% increase). Also shoot Zn concentration increased by 24% after seed inoculation with 10(6) CFUs mL(-1). The best effects on the total metal yield were not correlated with an increasing number of inoculated bacteria. In fact the best results were found after a single soil inoculation using the lower cellular density of 10(6) CFUs mL(-1).
authors.affiliation: a Instituto de Investigaciones Agrobiológicas de Galicia, CSIC , Santiago de Compostela , Spain.
authors.forename: V
authors.initials: V
authors.lastname: Álvarez-López
authors.affiliation: a Instituto de Investigaciones Agrobiológicas de Galicia, CSIC , Santiago de Compostela , Spain.
authors.forename: A
authors.initials: A
authors.lastname: Prieto-Fernández
authors.affiliation: b Hasselt University, Centre for Environmental Sciences , Diepenbeek , Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Janssen
authors.affiliation: c Phytotech Foundation and AGB , Bern , Switzerland.
authors.forename: R
authors.initials: R
authors.lastname: Herzig
authors.affiliation: b Hasselt University, Centre for Environmental Sciences , Diepenbeek , Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Vangronsveld
authors.affiliation: a Instituto de Investigaciones Agrobiológicas de Galicia, CSIC , Santiago de Compostela , Spain.
authors.forename: P S
authors.initials: PS
authors.lastname: Kidd
mesh_terms: D059827:Agricultural Inoculants / Q000254:growth & development / Q000502:physiology*; D001673:Biodegradation, Environmental; D002104:Cadmium / Q000032:analysis / Q000378:metabolism; D018520:Plant Shoots / Q000737:chemistry / Q000378:metabolism; D012240:Rhodococcus / Q000254:growth & development / Q000502:physiology*; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism*; D014026:Nicotiana / Q000737:chemistry / Q000254:growth & development / Q000378:metabolism* / Q000382:microbiology*
chemical_list: D012989:Soil Pollutants; D002104:Cadmium
keywords: bioaugmentation; high biomass crops; inoculation protocols; phytoremediation; plant growth-promoting rhizobacteria (PGPR); trace metal-contaminated soil