Publications by authors named "Vivien Biro"
Article Synopsis
- - The study investigates how low concentrations of manganese(II) ions affect gene expression in a citric acid-producing Ascomycete fungus, specifically focusing on a hyper-producer strain used in industrial fermentation.
- - Researchers found that of 11,846 genes analyzed, 963 were significantly different in their expression when manganese was deficient compared to when it was sufficient, with a notable increase in genes related to extracellular proteins and enzymes for polysaccharide breakdown.
- - The deficiency in manganese led to upregulation of a citrate exporter gene, suggesting that the accumulation of citrate or acetyl-CoA plays a critical role in enhancing citric acid production, providing new insights into optimizing fermentation processes.
Alternative oxidase (Aox) is a terminal oxidase operating in branched electron transport. The activity correlates positively with overflow metabolisms in certain , converting intracellular glucose by the shortest possible path into organic acids, like citrate or itaconate. Aox is nearly ubiquitous in fungi, but gene multiplicity is rare.
View Article and Find Full Text PDFManganese(II) ions suppress the transcription of the citrate exporter encoding gene in .
Front Bioeng Biotechnol
November 2023
is an important filamentous fungus used for the industrial production of citric acid. One of the most important factors that affect citric acid production is the concentration of manganese(II) ions present in the culture broth. Under manganese(II)-limiting conditions, the fungus develops a pellet-like morphology that is crucial for high citric acid accumulation.
View Article and Find Full Text PDFArticle Synopsis
- Alternative oxidase serves as a key component in the mitochondrial electron transport chain of many fungi, particularly within the black aspergilli group.
- Some isolates exhibit a second related gene, leading to genetic diversity among these fungi, which are known to cause serious infections in immunocompromised patients.
- Analysis of various genome-sequenced strains has revealed five significant mutations affecting the alternative oxidase gene, highlighting the potential for rapid identification of different species based on these genetic variations.
Article Synopsis
- Citric acid production using the fungus Ascomycete is hindered by high manganese (II) ion concentrations, which need to be kept below 5 μg/L for optimal yield.
- Stainless-steel fermenters, commonly used for this process, contribute to manganese contamination due to leaching, negatively impacting fungal growth and citric acid output.
- Electrochemical polishing of stainless steel components can reduce manganese leaching, suggesting potential protocol modifications to lower costs in citric acid manufacturing.
Article Synopsis
- - The study investigates how copper(II) and manganese(II) ions affect the growth and itaconic acid production in a high-producing strain of fungus (NRRL1960), using different carbon sources that either go through glycolysis or the pentose phosphate pathway.
- - Low manganese concentrations are crucial for maximizing itaconic acid yield; however, higher manganese levels reduce yields and encourage biomass growth, which can be counteracted by adding more copper, especially with glucose or fructose.
- - The research found that high itaconic acid yields correlate with specific morphologies of the fungus, characterized by compact pellets and yeast-like cells, indicating that copper is essential for effective overflow metabolism during itaconic acid fermentation.
The formation of N-chloro-amino acids is of outmost importance in water treatment technologies and also in vivo processes. These compounds are considered as secondary disinfectants and play important role in the defense mechanism against invading pathogens in biological systems. Adversary effects, such as apoptosis or necrosis are also associated with these compounds and the intermediates and final products formed during their decomposition.
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