A basic criterion in the selection of microalgae suitable as source of oil for biodiesel should be their actual capacity to produce lipids or, more properly, the fatty acid yield. Performance assessment of 10 preselected microalgae under both batch and continuous culture points to the latter approach as the most adequate for evaluating fatty acid productivity. Differences were patent in continu...

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 ...

BACKGROUND Secretion of heterologous proteins depends both on biomass concentration and on the specific product secretion rate, which in turn is not constant at varying specific growth rates. As fed batch processes usually do not maintain a steady state throughout the feed phase, it is not trivial to model and optimize such a process by mathematical means. RESULTS We have developed a model fo...

In order to investigate the effect of fixation temperature on flow cytometric measurement of intracellular antibody content of hybridoma cells, cells in different growth stages during a batch culture were fixed and stored at 4 and -20 OC, respectively. Flow cytometric analysis indicates that both fixation temperatures can he used in monitoring the changes in intracellular antibody content of th...

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 ...

A kinetic model is presented giving a mathematical description of batch culture of Pseudomonas putida PGA1 grown using saponified palm kernel oil as carbon source and ammonium as the limiting nutrient. The growth of the micro-organism is well-described using Tessier-type model which takes into account the inhibitory effect of ammonium at high concentrations. The ammonium consumption rate by the...

The aims of this research were to determine the main limiting nutrient to bacterial growth in Imboassica lagoon, southeastern Brazil, to estimate the percentage of dissolved organic carbon (DOC) available for bacterial growth, and to determine the bacterial growth efficiency (BGE) of natural assemblages. Bacterial growth and DOC consumption were determined in batch culture experiments, in which...

A two-stage continuous cultivation experiment with Clostridium beijerinckii NRRL B592 is described. The experiment was designed to mimic the two phases of batch culture growth of the organism in a two-stage continuous process. Thus in the first stage turbidostat the organism was grown acidogenically as rapidly as possible, and transferred to the second stage at the 'acid break point'. The secon...