During succession, ecosystem development occurs; but in the long-term absence of catastrophic disturbance, a decline phase eventually follows. We studied six long-term chronosequences, in Australia, Sweden, Alaska, Hawaii, and New Zealand; for each, the decline phase was associated with a reduction in tree basal area and an increase in the substrate nitrogen-to-phosphorus ratio, indicating incr...

The effects of various concentrations of sulfate, organic sulfur, and organic carbon on sulfate uptake by aerobic bacteria were studied using pure cultures growing in a defined medium. Cultures of Pseudomonas fluorescens and Corynebacterium striatum took up sulfate faster when young, but sulfate uptake by Serratia marcescens was faster in older cultures. Organic sulfur was found to decrease sul...

The investigations were made in a loop bioreactor, where biomass was immobilized in the ceramic carrier. The influence of the internal circulation rate on the biodegradation efficiency of brewery wastes by immobilized biomass and on production of surplus sludge was examined. The rates of the internal circulation were 12, 38, 50 dm·h. The experiments were performed at constant loading rate of th...

BACKGROUND Loss of biodiversity and increased nutrient inputs are two of the most crucial anthropogenic factors driving ecosystem change. Although both received considerable attention in previous studies, information on their interactive effects on ecosystem functioning is scarce. In particular, little is known on how soil biota and their functions are affected by combined changes in plant dive...

The effects of various concentrations of sulfate, organic sulfur, and organic carbon on sulfate uptake by aerobic bacteria were studied using pure cultures growing in a defined medium. Cultures of Pseudomonas fluorescens and Corynebacterium striatum took up sulfate faster when young, but sulfate uptake by Serratia marcescens was faster in older cultures. Organic sulfur was found to decrease sul...

An indigenous microalga was isolated from the springs in Cuatro Ciénegas, México. It was morphologically identified as Scenedesmus obtusiusculus and cultivated in bubble-column photobioreactors in batch operation mode. This microalga grows at 10% of carbon dioxide (CO(2)) showing a maximum CO(2) fixation rate of 970gm(-3)d(-1). The microalga, without any nutrient limitation, contained 20% of no...

Drought stress (DS) is an important limiting factor for crop growth and production in some regions of the world. Limitation in water availability precludes optimal irrigation in some production regions. Therefore, investigations on the interaction of other factors to mitigate the DS to varying degree are important. Two field experiments were conducted in the experimental farm of the National Re...

Improved production costs will accelerate commercialization of polyhydroxyalkanoate (PHA) polymer and PHA-based products. Plant oils are considered favorable feedstocks, due to their high carbon content and relatively low price compared to sugars and other refined carbon feedstocks. Different PHA production strategies were compared using a recombinant strain of Ralstonia eutropha that produces ...

Some major latitudinal trends in the physiology, population dynamics and ecology of flatfish are illustrated, and related to their ultimate cause: temperature-mediated difference of metabolic rate. The niche of tropical flatfish is then defined with some emphasis on Psettodes erumei in the Gulf of Thailand, and a hypothesis is derived to explain the generally low observed biomass-and hence recr...

Slow rates of plant production and decomposition in ombrotrophic bogs are believed to be partially the result of low nutrient availability. To test the effect of nutrient availability on decomposition, carbon dioxide (CO2) flux dynamics, microbial biomass, and nutrients, we added nitrogen (N) with phosphorus (P) and potassium (K), to prevent limitation of the latter 2 nutrients, over 2 growing ...