TY - JOUR
T1 - Simultaneous degradation of atrazine and simazine by a binary culture of Stenotrophomonas maltophilia and Arthrobacter sp. in a two-stage biofilm reactor
AU - Galíndez-Nájera, Silvia Patricia
AU - Ramos-Monroy, Oswaldo
AU - Ruiz-Ordaz, Nora
AU - Salmerón-Alcocer, Angélica
AU - Juárez-Ramírez, Cleotilde
AU - Ahuatzi-Chacón, Deifilia
AU - Curiel-Quesada, Everardo
AU - Galíndez-Mayer, Juvencio
PY - 2011/4
Y1 - 2011/4
N2 - BACKGROUND: The impact of mixtures of chloro-triazinic herbicides, such as atrazine and simazine, on aquatic ecosystems is of environmental concern. To study their biodegradation under various operational conditions, a binary community comprising Stenotrophomonas maltophilia and Arthrobacter sp. attached to the porous support of a packed bed reactor, was evaluated. RESULTS: The genetic analysis of the two atrazine-degrading strains revealed that genes atzA, atzB, atzC are present in both bacteria, but only S. maltophilia possess atzD. Thus, by cultivating Arthrobacter sp. on these herbicides, cyanuric acid accumulation was observed. When the binary community was cultivated in the biofilm reactor, at all the loading rates probed, both herbicides were entirely removed. However, complete biodegradation of cyanuric acid was not achieved. CONCLUSIONS: Even with a two-stage reactor, cyanuric acid was only partially removed. This fact could be attributed to the absence, in the second stage, of an easily degradable energy source, required by S. maltophilia for the uptake and cometabolic degradation of the recalcitrant heterocyclic ring. Responding to differences in nutritional conditions prevailing at each reactor stage, local differences in species' predominance were clearly detected by microbiological and molecular biology methods.
AB - BACKGROUND: The impact of mixtures of chloro-triazinic herbicides, such as atrazine and simazine, on aquatic ecosystems is of environmental concern. To study their biodegradation under various operational conditions, a binary community comprising Stenotrophomonas maltophilia and Arthrobacter sp. attached to the porous support of a packed bed reactor, was evaluated. RESULTS: The genetic analysis of the two atrazine-degrading strains revealed that genes atzA, atzB, atzC are present in both bacteria, but only S. maltophilia possess atzD. Thus, by cultivating Arthrobacter sp. on these herbicides, cyanuric acid accumulation was observed. When the binary community was cultivated in the biofilm reactor, at all the loading rates probed, both herbicides were entirely removed. However, complete biodegradation of cyanuric acid was not achieved. CONCLUSIONS: Even with a two-stage reactor, cyanuric acid was only partially removed. This fact could be attributed to the absence, in the second stage, of an easily degradable energy source, required by S. maltophilia for the uptake and cometabolic degradation of the recalcitrant heterocyclic ring. Responding to differences in nutritional conditions prevailing at each reactor stage, local differences in species' predominance were clearly detected by microbiological and molecular biology methods.
KW - Arthrobacter
KW - Atrazine
KW - Biodegradation
KW - Biofilm reactor
KW - Cyanuric acid
KW - Simazine
KW - Stenotrophomonas
UR - http://www.scopus.com/inward/record.url?scp=79952579506&partnerID=8YFLogxK
U2 - 10.1002/jctb.2550
DO - 10.1002/jctb.2550
M3 - Artículo
SN - 0268-2575
VL - 86
SP - 554
EP - 561
JO - Journal of Chemical Technology and Biotechnology
JF - Journal of Chemical Technology and Biotechnology
IS - 4
ER -