TY - JOUR
T1 - Growth advantage in stationary-phase (GASP) phenotype in long-term survival strains of Geobacter sulfurreducens
AU - Helmus, Ruth A.
AU - Liermann, Laura J.
AU - Brantley, Susan L.
AU - Tien, Ming
N1 - Copyright:
Copyright 2012 Elsevier B.V., All rights reserved.
PY - 2012/1
Y1 - 2012/1
N2 - Geobacter sulfurreducens exists in the subsurface and has been identified in sites contaminated with radioactive metals, consistent with its ability to reduce metals under anaerobic conditions. The natural state of organisms in the environment is one that lacks access to high concentrations of nutrients, namely electron donors and terminal electron acceptors (TEAs). Most studies have investigated G. sulfurreducens under high-nutrient conditions or have enriched for it in environmental systems via acetate amendments. We replicated the starvation state through long-term batch culture of G. sulfurreducens, where both electron donor and TEA were scarce. The growth curve revealed lag, log, stationary, death, and survival phases using acetate as electron donor and either fumarate or iron(III) citrate as TEA. In survival phase, G. sulfurreducens persisted at a constant cell count for as long as 23 months without replenishment of growth medium. Geobacter sulfurreducens demonstrated an ability to acquire a growth advantage in stationary-phase phenotype (GASP), with strains derived from subpopulations from death- or survival phase being able to out-compete mid-log-phase populations when co-cultured. The molecular basis for GASP was not because of any detectable mutation in the rpoS gene (GSU1525) nor because of a mutation in a putative homolog to Escherichia coli lrp, GSU3370.
AB - Geobacter sulfurreducens exists in the subsurface and has been identified in sites contaminated with radioactive metals, consistent with its ability to reduce metals under anaerobic conditions. The natural state of organisms in the environment is one that lacks access to high concentrations of nutrients, namely electron donors and terminal electron acceptors (TEAs). Most studies have investigated G. sulfurreducens under high-nutrient conditions or have enriched for it in environmental systems via acetate amendments. We replicated the starvation state through long-term batch culture of G. sulfurreducens, where both electron donor and TEA were scarce. The growth curve revealed lag, log, stationary, death, and survival phases using acetate as electron donor and either fumarate or iron(III) citrate as TEA. In survival phase, G. sulfurreducens persisted at a constant cell count for as long as 23 months without replenishment of growth medium. Geobacter sulfurreducens demonstrated an ability to acquire a growth advantage in stationary-phase phenotype (GASP), with strains derived from subpopulations from death- or survival phase being able to out-compete mid-log-phase populations when co-cultured. The molecular basis for GASP was not because of any detectable mutation in the rpoS gene (GSU1525) nor because of a mutation in a putative homolog to Escherichia coli lrp, GSU3370.
UR - http://www.scopus.com/inward/record.url?scp=83555165053&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=83555165053&partnerID=8YFLogxK
U2 - 10.1111/j.1574-6941.2011.01211.x
DO - 10.1111/j.1574-6941.2011.01211.x
M3 - Article
C2 - 22029575
AN - SCOPUS:83555165053
SN - 0168-6496
VL - 79
SP - 218
EP - 228
JO - FEMS microbiology ecology
JF - FEMS microbiology ecology
IS - 1
ER -