The Relationship between Microbial Community Structure and Functional Stability, Tested Experimentally in an Upland Pasture Soil

• Published in: Microbial ecology Vol. 47; no. 1; pp. 104 - 113
• Main Authors: Griffiths, B. S., Kuan, H. L., Ritz, K., Glover, L. A., McCaig, A. E., Fenwick, C.
• Format: Journal Article
• Language: English
• Published: New York, NY Springer-Verlag New York Inc 01.01.2004; Springer; Springer Nature B.V
• Subjects: Agricultural soils; Analysis of Variance; Bacteria - genetics; Bacteria - growth & development; Bacterial Physiological Phenomena - drug effects; Bacterial Physiological Phenomena - radiation effects; Bacteriology; Biodiversity; Biological and medical sciences; Carbon Dioxide - metabolism; Chloroform; Chloroform - toxicity; Community structure; Copper; Copper - toxicity; Decomposition; Ecosystem; Forest soils; Fumigation; Fundamental and applied biological sciences. Psychology; Gamma Rays; Grassland soils; Hot Temperature; Irradiation; Microbiology; Miscellaneous; Nitrates - analysis; Pasture; Principal Component Analysis; Quaternary Ammonium Compounds - analysis; Reverse Transcriptase Polymerase Chain Reaction; Scotland; Soil biochemistry; Soil ecology; Soil Microbiology; Soil microorganisms; Soil pollution; Soils; Scotland; Volatile compound; Chloroform; Microbiology; Ecology; Microbial biomass; Infection; Amplification; Polymerase chain reaction; Resistance; Soils; Organochlorine compounds; Bacteriosis; Bacteria; Detection; Reverse transcription polymerase chain reaction; Microbial community
• ISSN: 0095-3628; 1432-184X
• DOI: 10.1007/s00248-002-2043-7

Soil collected from an upland pasture was manipulated experimentally in ways shown previously to alter microbial community structure. One set of soil was subjected to chloroform fumigation for 0, 0.5, 2, or 24 h and the other was sterilised by gamma-irradiation and inoculated with a 10⁻², 10⁻⁴, 10⁻⁶, or 10⁻⁸ dilution of a soil suspension prepared from unsterilized soil. Following incubation for 8 months, to allow for the stabilization of microbial biomass and activity, the resulting microbial community structure (determined by PCR-DGGE of bacterial specific amplification products of total soil DNA) was assessed. In addition, the functional stability (defined here as the resistance and resilience of short-term decomposition of plant residues to a transient heat or a persistent copper perturbation) was determined. Changes in the active bacterial population following perturbation (determined by RT-PCR-DGGE of total soil RNA) were also monitored. The manipulations resulted in distinct shifts in microbial community structure as shown by PCR-DGGE profiles, but no significant decreases in the number of bands. These shifts in microbial community structure were associated with a reduction in functional stability. The clear correlation between altered microbial community structure and functional stability observed in this upland pasture soil was not evident when the same protocols were applied to soils in other studies. RT-PCR-DGGE profiles only detected a shift in the active bacterial population following heat, but not copper, perturbation. We conclude that the functional stability of decomposition is related to specific components of the microbial community.