Carbon cycling pathways in lacustrine systems are complex because there are often multiple sources of organic carbon available to the food webs. Among the techniques used to delineate carbon flows from organic matter to consumers, stable isotope analysis may be the most powerful one because isotope compositions of consumers reflect those of the dietary carbon assimilated and incorporated into t...

We compared the stable carbon isotopic composition (d13C) of crustacean zooplankton with that of potential carbon sources in 15 lakes in northern Sweden with different dissolved organic carbon (DOC) concentrations (2–9 mg L21) to test the hypothesis that zooplankton depended more on allochthonous carbon in humic lakes than in clear-water lakes. Based on d13C signature, we found that the pool of...

Paracoccus pantotrophus can express a periplasmic nitrate reductase (Nap) during aerobic growth. A proposed role for this enzyme is the dissipation of excess redox energy during oxidative metabolism of reduced carbon substrates. To investigate the regulation of nap expression, a transcriptional fusion between the nap promoter region of P. pantotrophus and the lacZ gene was constructed. When thi...

Glucose is the primary source of energy for the budding yeast Saccharomyces cerevisiae. Although yeast cells can utilize a wide range of carbon sources, presence of glucose suppresses molecular activities involved in the use of alternate carbon sources as well as it represses respiration and gluconeogenesis. This dominant effect of glucose on yeast carbon metabolism is coordinated by several si...

the aim of this study was to determine the feasibility of coupling an electrochemical process with a biological treatment in order to degrade phosmet, an organophosphorous pesticide. the absence of biodegradability of phosmet by pseudomonas fluorescens and activated sludge was verified in our operational conditions. so, a conventional biological treatment is not appropriate for phosmet polluted...

Pseudomonas putida has a variety of potential uses in bioremediation and biosynthesis of biodegradable plastics. P. putida is able to utilize a wide range of carbon sources. In this study, P. putida KT2440 was grown on glucose, glycerol, citrate, or fatty acid (lauric acid) as the sole carbon source. Differences in expression levels of genes involved in the Entner-Doudoroff pathway, glycerol me...

microbial cells are producers of natural polymers present in plant cells. production of pullulan (an extracellular microbial polysaccharide) by aureobasidium pullularia pullulans (p. pullulans) was studied under fermentation conditions, and kinetic parameters were determined. pullulan formation obeyed a growth and non-growth associated term. phb (polyhydroxybutyrates) an intracellular biopolyme...

Slime production by bacterium W3A1 was greatly enhanced during growth on methanol and, to a lesser extent, during growth on trimethylamine. Of the major dehydrogenases synthesized, trimethylamine and methylamine dehydrogenases were induced to different levels by certain carbon sources, while methanol dehydrogenase was expressed during growth on all carbon sources.

The major player for catabolite repression is the phosphotransferase systems (PTSs) and cAMP-Crp. Moreover, Cra controls the carbon flow in the metabolic network. In the present research, the effect of modulating cra gene (Δcra) on the consumption of multiple carbon sources such as glucose and fructose (as well as xylose) was investigated under both aerobic and anaerobic conditions. It was show...

Algae are sustainable sources of biomass for fuel, food, feed and essential for their growth are light, CO2, and inorganic nutrients like nitrogen and phosphorous. The aim of our study was to explore the effect of different carbon sources on biomass accumulation in microalgae Chlorella vulgaris and its ability to remove N and P compounds during its cultivation in aquaculture wastewater. Microal...