Bacterioplankton biomass, production, and growth rate were measured over a 2-yr period in Lake Dillon, a mesotrophic Colorado reservoir. In addition, a multivariate statistical analysis and nutrient addition experiments were used to analyze the regulation of bacterioplankton growth in situ. Biomass ranged between 170 (winter) and 2,200 mg C m-* (summer); production ranged from 10 (winter) to 62...

Microbial mats are characterized by high primary production but low growth rates, pointing to a limitation of growth by the lack of nutrients or substrates. We identified compounds that instantaneously stimulated photosynthesis rates and oxygen consumption rates in a hypersaline microbial mat by following the short-term response (c. 6 h) of these processes to addition of nutrients, organic and ...

Given recent focus on large rivers as conduits for excess nutrients to coastal zones, their role in processing and retaining nutrients has been overlooked and understudied. Empirical measurements of nutrient uptake in large rivers are lacking, despite a substantial body of knowledge on nutrient transport and removal in smaller streams. Researchers interested in nutrient transport by rivers (dis...

The use of pelletized poultry litter (PPL) as a substitute for inorganic fertilizers is increasingly being encouraged in states like Delaware which have a considerable surplus of poultry litter. However, we know very little about the impacts of PPL on runoff water quality and whether it is an environmentally-sound and sustainable alternative to inorganic fertilizer. To address these questions w...

Human milk is the main source of nutrients for a child during the first months of life. Alkaline phosphatase (EC 3.1.3.1) is a very important enzyme in clinical chemistry because of its activity in various tissues and biological fluids, being an indicator of physiological or diseased states. Milk contains several phosphatases, the principal ones being alkaline and acid phosphomonoesterases whic...

Poultry litter is composted to reduce odor and pathogens and to improve its quality as a soil amendment. Organic material, e.g., sawdust, is added to increase the C:N ratio to achieve optimum degradation of organic C and retention of N through microbial biomass formation. However, the relative biodegradabilities of the organic material in poultry litter and the amendment are usually not known. ...

BACKGROUND Vermicompost has been proposed as a valuable fertilizer for sustainable agriculture. The effects of vermicompost on yield and quality of sweet corn were evaluated in this study. In two field trials, sweet corn plants were grown under (i) a conventional fertilization regime with inorganic fertilizer, and integrated fertilization regimes in which 75% of the nutrients were supplied by t...

Natural floodplains play an essential role in the processing and decomposition of organic matter and in the self-purification ability of rivers, largely due to the activity of bacteria. Knowledge about the composition of bacterial communities and its impact on organic-matter cycling is crucial for the understanding of ecological processes in river-floodplain systems. Particle-associated and fre...

Background: As the decomposition of lignocellulosic compounds is a rate-limiting stage in the nutrient mineralization from organic matters, elucidation of the changes in soil enzyme activity can provide insight into the nutrient dynamics and ecosystem functioning. The current study aimed to assess the effect of thinning intensities on soil conditions. Un-thinned control, 20 % thinning, and 30 %...