Comparative proteomic analysis of engineered Saccharomyces cerevisiae with enhanced free fatty acid accumulation

Resource recovery from wastewater by directing microbial metabolism toward production of value-added biochemicals

Dynamic oxygen fluctuations in activated sludge were investigated to enhance valuable biochemical production during wastewater treatment. Batch experiments compared constant aeration with rapid cycling between oxygen-rich and oxygen-poor states. Fluctuating oxygen concentrations (0-2 mg/L) significantly increased production of valuable biochemicals compared to constant oxygen concentration (2 mg/L). Continuous oxygen perturbations increased free amino acids by 35.7 ± 7.6 % and free fatty acids by 76.4 ± 13.0 %, while intermittent perturbations with anoxic periods enhanced free amino acids by 42.4 ± 8.1 % and free fatty acids by 39.3 ± 7.7 %. Fourteen standard amino acids showed significant increases, and most fatty acids had carbon chain lengths between C12-C22. Mechanistically, oxygen perturbations activated FNR and ArcA regulons, resulting in lower relative abundances of TCA cycle enzymes and higher abundances of amino acid and fatty acid biosynthetic enzymes. These findings demonstrate that controlled oxygen fluctuations in wastewater treatment can enhance the biochemical value of activated sludge with minimal process modifications, facilitating resource recovery.

Methodologies and Applications of Proteomics for Study of Yeast Strains: An Update

Yeasts are one of the mostly used microorganisms as models in several studies. A wide range of applications in different processes can be attributed to their intrinsic characteristics. They are eukaryotes and therefore valuable expression hosts that require elaborate post-translational modifications. Their arsenal of proteins has become a valuable biochemical tool for the catalysis of several reactions of great value to the food (beverages), pharmaceutical and energy industries. Currently, the main challenge in systemic yeast biology is the understanding of the expression, function and regulation of the protein pool encoded by such microorganisms. In this review, we will provide an overview of the proteomic methodologies used in the analysis of yeasts. This research focuses on the advantages and improvements in their most recent applications with an understanding of the functionality of the proteins of these microorganisms, as well as an update of the advances of methodologies employed in mass spectrometry.