Bacterial and fungal community composition and community-level physiological profiles in forest soils.

We characterized the potential functioning and composition of the bacterial and fungal communities in the O and A horizons of forest soils using community-level physiological profile (CLPP) based on BIOLOG analysis, and polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) analysis of 16S and 18S rDNA fragments, respectively. In addition, relationships between the potential functioning and the community composition in each horizon, and between the O and A horizons, were assessed using Procrustes analysis. For the bacterial and fungal communities, the CLPP and DGGE profile were clearly separated between the O and A horizons in a principal coordinate analysis except for the fungal CLPP.

Evaluating the Effects of Metals on Microorganisms in Flooded Paddy Soils Using the SEM/AVS-Based Approach and Measurements of Exchangeable Metal Concentrations.

We examined possible adverse effects of heavy metals on microbial activity, biomass, and community composition using the simultaneously extracted metals (SEM)/acid-volatile sulfide (AVS)-based approach and measurements of exchangeable metal concentrations in three paddy soils (wastewater-contaminated soil, mine-contaminated soil, and noncontaminated soil) incubated for 60 days under flooded conditions. Incubation under flooding increased pH and decreased Eh in all samples. AVS increased when Eh decreased to approximately -200 mV for the mine-contaminated and noncontaminated soils, while the wastewater-contaminated soil originally had a high concentration of AVS despite its air-dried condition.