title: Mechanisms of pollution induced community tolerance in a soil microbial community exposed to Cu.
abstract: Pollution induced community tolerance (PICT) to Cu(2+), and co-tolerance to nanoparticulate Cu, ionic silver (Ag(+)), and vancomycin were measured in field soils treated with Cu(2+) 15 years previously. EC50 values were determined using substrate induced respiration and correlations made against soil physicochemical properties, microbial community structure, physiological status (qCO2; metabolic quotient), and abundances of genes associated with metal and antibiotic resistance. Previous level of exposure to copper was directly (P < 0.05) associated with tolerance to addition of new Cu(2+), and also of nanoparticle Cu. However, Cu-exposed communities had no co-tolerance to Ag(+) and had increased susceptibly to vancomycin. Increased tolerance to both Cu correlated (P < 0.05) with increased metabolic quotient, potentially indicating that the community directed more energy towards cellular maintenance rather than biomass production. Neither bacterial or fungal community composition nor changes in the abundance of genes involved with metal resistance were related to PICT or co-tolerance mechanisms.
authors.affiliation: AgResearch Ltd, Lincoln Science Centre, Private Bag 4749, Christchurch, New Zealand. Electronic address: steve.wakelin@agresearch.co.nz.
authors.forename: Steven
authors.initials: S
authors.lastname: Wakelin
authors.affiliation: AgResearch Ltd, Lincoln Science Centre, Private Bag 4749, Christchurch, New Zealand.
authors.forename: Emily
authors.initials: E
authors.lastname: Gerard
authors.affiliation: Bio-Protection Research Centre, P.O. Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand; Faculty of Agriculture and Life Sciences, PO Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand.
authors.forename: Amanda
authors.initials: A
authors.lastname: Black
authors.affiliation: Faculty of Agriculture and Life Sciences, PO Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand; CSIRO Plant Industry, Canberra ACT 2601, Australia.
authors.forename: Kelly
authors.initials: K
authors.lastname: Hamonts
authors.affiliation: Faculty of Agriculture and Life Sciences, PO Box 85084, Lincoln University, Lincoln 7647, Christchurch, New Zealand.
authors.forename: Leo
authors.initials: L
authors.lastname: Condron
authors.affiliation: Institute for Environmental Genomics, University of Oklahoma, 101 David L Boren Blvd, OK 73019, USA.
authors.forename: Tong
authors.initials: T
authors.lastname: Yuan
authors.affiliation: Institute for Environmental Genomics, University of Oklahoma, 101 David L Boren Blvd, OK 73019, USA.
authors.forename: Joy
authors.initials: J
authors.lastname: van Nostrand
authors.affiliation: Institute for Environmental Genomics, University of Oklahoma, 101 David L Boren Blvd, OK 73019, USA.
authors.forename: Jizhong
authors.initials: J
authors.lastname: Zhou
authors.affiliation: AgResearch Ltd, Lincoln Science Centre, Private Bag 4749, Christchurch, New Zealand.
authors.forename: Maureen
authors.initials: M
authors.lastname: O'Callaghan
mesh_terms: D000222:Adaptation, Physiological; D018533:Biomass; D003300:Copper / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*; D012987:Soil / Q000737:chemistry; D012988:Soil Microbiology; D012989:Soil Pollutants / Q000032:analysis / Q000378:metabolism / Q000633:toxicity*
chemical_list: D012987:Soil; D012989:Soil Pollutants; D003300:Copper
keywords: Co-tolerance; PICT; Pollution induced community tolerance; Soil ecotoxicology