The chemical composition and quantity of plant inputs to soil are primary factors controlling the size and structure of the soil microbial community. Little is known about how changes in the composition of the soil microbial community affect decomposition rates and other ecosystem functions. This study examined the degradation of universally C-labeled glucose, glutamate, oxalate, and phenol in ...

Hawaiian volcanic deposits offer ideal opportunities to assess methanotrophic bacterial colonization of new substrates, and to determine the relative significance of methanotrophy during ecosystem succession. Activity and molecular ecological surveys indicated that significant methanotrophic activity was restricted to vegetated ecosystems characterized by closed-canopy forests and significant s...

Forensic crime scene sample analysis, by its nature, often deals with samples in which there are low amounts of nucleic acids, on substrates that often lead to inhibition of subsequent enzymatic reactions such as PCR amplification for STR profiling. Common substrates include denim from blue jeans, which yields indigo dye as a PCR inhibitor, and soil, which yields humic substances as inhibitors....

Mineral forms in rhizosphere and bulk substrate were examined for selected plant species (Cardaminopsis arenosa, Calamagrostis epigeios, Deschampsia caespitosa, Festuca ovina, Silene vulgaris, Viola tricolor) growing spontaneously in the close vicinity of a tailings pond and in a zone of eolian transmission of waste particles. Samples of substrates and plant roots were taken from sites in the B...

With global change expected to alter aspects of the carbon (C) cycle, empirical data describing how microorganisms function in different environmental conditions are needed to increase predictive capabilities of microbially-driven decomposition models. Given the importance of accelerated C fluxes during early decay in C cycling, we characterized how varying litter qualities (maple vs. oak) and ...

The kinetics of mineralization of carbonaceous substrates has been explained by a deterministic model which is applicable to either growth or nongrowth conditions in soil. The mixed-order nature of the model does not require a priori decisions about reaction order, discontinuity period of lag or stationary phase, or correction for endogenous mineralization rates. The integrated equation is simp...

All processes and functions taking place in the rhizosphere are dominated by the activities of plant roots, rhizosphere microorganisms and root-microorganism interactions, and enzymes are recognized as main actors of all activities occurring in rhizosphere environments. Rhizosphere enzymes have, in general, a higher activity than those operating in bulk soil, as the rhizosphere soil is richer i...

Understanding the temperature sensitivity (Q 10) of soil organic matter (SOM) decomposition is important for predicting soil carbon (C) sequestration in terrestrial ecosystems under warming scenarios. Whether Q 10 varies predictably with ecosystem succession and the ways in which the stoichiometry of input SOM influences Q 10 remain largely unknown. We investigate these issues using a grassland...

Aerobic mineralization of PCBs, which are toxic and persistent organic pollutants, involves the upper (biphenyl, BP) and lower (benzoate, BZ) degradation pathways. The activity of different members of the soil microbial community in performing one or both pathways, and their synergistic interactions during PCB biodegradation, are not well understood. This study investigates BP and BZ biodegrada...

Arbuscular mycorrhizal fungi (AMF) proliferate in soil pores, on the surface of soil particles and affect soil structure. Although modifications in substrate moisture retention depend on structure and could influence plant water extraction, mycorrhizal impacts on water retention and hydraulic conductivity were rarely quantified. Hence, we asked whether inoculation with AMF affects substrate wat...