Linking Toluene Degradation with Specific Microbial Populations in Soil

Abstract

Phospholipid fatty acid (PLFA) analysis of a soil microbial community was coupled with 13C isotope tracer analysis to measure the community’s response to addition of 35 μg of [13C]toluene ml of soil solution−1. After 119 h of incubation with toluene, 96% of the incorporated13C was detected in only 16 of the total 59 PLFAs (27%) extracted from the soil. Of the total 13C-enriched PLFAs, 85% were identical to the PLFAs contained in a toluene-metabolizing bacterium isolated from the same soil. In contrast, the majority of the soil PLFAs (91%) became labeled when the same soil was incubated with [13C]glucose. Our study showed that coupling13C tracer analysis with PLFA analysis is an effective technique for distinguishing a specific microbial population involved in metabolism of a labeled substrate in complex environments such as soil.

Impact of plant species and atmospheric CO2 concentration on rhizodeposition and soil microbial activity and community composition

“…In total, 15 PLFA compounds were consistently detected above thresholds for accurate quantification and were used to assess microbial community structure and to quantify incorporation of root‐derived C. PLFAs were assigned into indicator groups as follows: fungi 18:2ω6, 9, 18:1ω9 ( Klamer and Bååth , ); actinobacteria 10Me‐16:0, 10Me‐17:0, 10Me‐18:0 ( Hanson et al, ; Zelles , ); G‐positive (G + ) bacteria i15:0, a15:0, i16:0, i17:0, a17:0 ( Hanson et al, ; Butler et al, ); G‐negative (G − ) bacteria 16:1ω7, 18:1ω7, cy17:0, cy19:0 ( Hanson et al, ; Zelles , ). Other PLFA compounds, not attributable to specific groups, were included for multivariate analyses of microbial community structure and fate of root‐derived C within soil PLFA profiles.…”

Population dynamics of type I and II methanotrophic bacteria in rice soils

“…PLFA analyses were conducted as previously described (Hanson et al, 1999;Macalady et al, 2000). Briefly, 1-5 g soil samples were extracted with a chloroform-methanolwater extractant, fractionated according to polarity by silica gel column chromatography, and derivatized by mild alkaline methanolysis to form polar lipid-derived fatty acid methyl esters (FAMEs).…”

Field-scale 13C-labeling of phospholipid fatty acids (PLFA) and dissolved inorganic carbon: tracing acetate assimilation and mineralization in a petroleum hydrocarbon-contaminated aquifer

“…PLFA, amino acids, nucleic acids), thus providing direct evidence of utilization of a speci¢c substrate. This approach has been successfully applied for linking speci¢c populations within complex microbial communities with substrate usage through 13 C-enrichment of PLFA biomarkers in soil, sediment, and aquifer microcosm experiments [4,5,27,28]. Recently, C assimilation and C £ux within di¡erent trophic levels of the food web were analyzed in situ in the intertidal zone using 13 C-labeled carbonate [29] (for further information on 13 C-labeling of biomarkers in microbial ecology see the review by Boschker and Middelburg [30]).…”