Open AccessThe putative phosphate transporter PitB (PP1373) is involved in tellurite uptake in Pseudomonas putida KT2440
Author(s) -
Rafael Montenegro,
Sofía Vieto,
Daniela Wicki Emmenegger,
Felipe Vásquez-Castro,
Carolina Ruiz,
Paola Fuentes-Schweizer,
Paula Calderón Mesén,
Reinaldo Pereira Reyes,
Max Chavarría
Publication year - 2021
Publication title -
microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.019
H-Index - 179
eISSN - 1465-2080
pISSN - 1350-0872
DOI - 10.1099/mic.0.001002
Subject(s) - pseudomonas putida , oxyanion , mutant , strain (injury) , phosphate , wild type , pseudomonas , bacteria , metalloid , chemistry , tellurium , transporter , microbiology and biotechnology , biochemistry , biology , gene , inorganic chemistry , genetics , metal , organic chemistry , anatomy , catalysis
Tellurium oxyanions are chemical species of great toxicity and their presence in the environment has increased because of mining industries and photovoltaic and electronic waste. Recovery strategies for this metalloid that are based on micro-organisms are of interest, but further studies of the transport systems and enzymes responsible for implementing tellurium transformations are required because many mechanisms remain unknown. Here, we investigated the involvement in tellurite uptake of the putative phosphate transporter PitB (PP1373) in soil bacterium Pseudomonas putida KT2440. For this purpose, through a method based on the CRISPR/Cas9 system, we generated a strain deficient in the pitB gene and characterized its phenotype on exposing it to varied concentrations of tellurite. Growth curves and transmission electronic microscopy experiments for the wild-type and Δ pitB strains showed that both were able to internalize tellurite into the cytoplasm and reduce the oxyanion to black nano-sized and rod-shaped tellurium particles, although the Δ pitB strain showed an increased resistance to the tellurite toxic effects. At a concentration of 100 μM tellurite, where the biomass formation of the wild-type strain decreased by half, we observed a greater ability of Δ pitB to reduce this oxyanion with respect to the wild-type strain (~38 vs ~16 %), which is related to the greater biomass production of Δ pitB and not to a greater consumption of tellurite per cell. The phenotype of the mutant was restored on over-expressing pitB in trans . In summary, our results indicate that PitB is one of several transporters responsible for tellurite uptake in P. putida KT2440.