Inoculation methods using Rhodococcus erythropolis strain P30 affects bacterial assisted phytoextraction capacity of Nicotiana tabacum

• Published in: International Journal of Phytoremediation
• Main Authors: Alvarez-Lopez, Vanessa, Prieto-Fernández, A., Janssen, Jo, Herzig, R., Vangronsveld, Jaco, Kidd, P. S.
• Format: Article in Journal/Newspaper
• Language: English
• Published: TAYLOR & FRANCIS INC 2016
• Subjects: bioaugmentation; high biomass crops; inoculation protocols; plant growthpromoting rhizobacteria (PGPR); phytoremediation; trace metal-contaminated soil; plant growth-promoting rhizobacteria (PGPR); Greenland
• Online Access: http://hdl.handle.net/1942/21665; https://doi.org/10.1080/15226514.2015.1109600

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). This research was supported by the Spanish Ministerio de Economia y Competitividad (CTM2012-39904-C02-01) and FEDER, and by the 7th Framework Program of the European Commission (FP7-KBBE-266124, GREENLAND).]