TY - JOUR
T1 - Isolation and characterization of nitrogen fixing heterotrophic bacteria from the rhizosphere of pioneer plants growing on mine tailings
AU - Navarro-Noya, Yendi E.
AU - Hernández-Mendoza, Emma
AU - Morales-Jiménez, Jesús
AU - Jan-Roblero, Janet
AU - Martínez-Romero, Esperanza
AU - Hernández-Rodríguez, César
N1 - Funding Information:
To Michael Dunn for reviewing the ms. This work was supported by grants SIP 20100430 , 20111068 and 20121495 Instituto Politécnico Nacional (IPN) . Y. E. Navarro-Noya thanks the Consejo Nacional de Ciencia y Tecnología (CONACyT) and the Programa Institucional de Formación de Investigadores (PIFI), IPN, for scholarships. C. Hernández-Rodríguez and J. Jan-Roblero appreciate the COFAA, and EDI, IPN fellowships; and SNI, CONACyT.
PY - 2012/11
Y1 - 2012/11
N2 - Mine tailings are extreme environments containing high concentrations of heavy metals and deficient in nitrogen and organic matter. However, some plant species tolerant to heavy metals are capable of growing on mine tailings. In this environment, it is expected that biological nitrogen fixation is the major source of nitrogen available for plants. In this work, three different nitrogen-free culture media were used to isolate nitrogen-fixing bacteria associated with nine plant species growing on mine tailings in Zacatecas, Mexico. Acetylene reduction assays (ARA) with and without heavy metals were carried out, as were the determination of minimum inhibitory concentration (MIC) of Ni, Cu, Co, Cr and Zn, and plant growth promotion (PGP) activities of each bacterial isolate. The major nitrogen-fixing bacteria distributed among rhizospheres of Juniperus sp., Aster gymnocephalus, Gringelia sp., Lygodesmia sp., and Haplopappus sp. were members of the genus Paenibacillus. However, Azospirillum lipoferum and Bradyrhizobium japonicum were also isolated from the rhizosphere of Haplopappus sp., and Viguiera linearis. Functionally, Paenibacillus durus BR_30 had the highest ARA and PGP activities, but was highly sensitive to heavy metals. However, Paenibacillus graminis BR_35 and Paenibacillus borealis BR_32 maintained a significant ARA activity in the presence of relatively high concentrations of Ni and Zn. Also, B. japonicum KYR_C5 and A. lipoferum showed moderate ARA and PGP activities. The majority of the isolates grew in moderate concentrations of heavy metals but ARA activities were inhibited at low Co and Cr concentrations. The diversity of nitrogen-fixing bacteria in the rhizosphere of pioneer plants may contribute to their adaptation to toxic stress and nutrient-deficiency in environments such as mine tailings.
AB - Mine tailings are extreme environments containing high concentrations of heavy metals and deficient in nitrogen and organic matter. However, some plant species tolerant to heavy metals are capable of growing on mine tailings. In this environment, it is expected that biological nitrogen fixation is the major source of nitrogen available for plants. In this work, three different nitrogen-free culture media were used to isolate nitrogen-fixing bacteria associated with nine plant species growing on mine tailings in Zacatecas, Mexico. Acetylene reduction assays (ARA) with and without heavy metals were carried out, as were the determination of minimum inhibitory concentration (MIC) of Ni, Cu, Co, Cr and Zn, and plant growth promotion (PGP) activities of each bacterial isolate. The major nitrogen-fixing bacteria distributed among rhizospheres of Juniperus sp., Aster gymnocephalus, Gringelia sp., Lygodesmia sp., and Haplopappus sp. were members of the genus Paenibacillus. However, Azospirillum lipoferum and Bradyrhizobium japonicum were also isolated from the rhizosphere of Haplopappus sp., and Viguiera linearis. Functionally, Paenibacillus durus BR_30 had the highest ARA and PGP activities, but was highly sensitive to heavy metals. However, Paenibacillus graminis BR_35 and Paenibacillus borealis BR_32 maintained a significant ARA activity in the presence of relatively high concentrations of Ni and Zn. Also, B. japonicum KYR_C5 and A. lipoferum showed moderate ARA and PGP activities. The majority of the isolates grew in moderate concentrations of heavy metals but ARA activities were inhibited at low Co and Cr concentrations. The diversity of nitrogen-fixing bacteria in the rhizosphere of pioneer plants may contribute to their adaptation to toxic stress and nutrient-deficiency in environments such as mine tailings.
KW - Acetylene reduction assay
KW - Diazotrophs
KW - Heavy-metals
KW - Mine tailings
KW - Paenibacillus
UR - http://www.scopus.com/inward/record.url?scp=84868555771&partnerID=8YFLogxK
U2 - 10.1016/j.apsoil.2012.07.011
DO - 10.1016/j.apsoil.2012.07.011
M3 - Artículo
SN - 0929-1393
VL - 62
SP - 52
EP - 60
JO - Applied Soil Ecology
JF - Applied Soil Ecology
ER -