To identify new genes involved in acetate uptake in Saccharomyces cerevisiae, an analysis of the gene expression profiles of cells shifted from glucose to acetic acid was performed. The gene expression reprogramming of yeast adapting to a poor non-fermentable carbon source was observed, including dramatic metabolic changes, global activation of translation machinery, mitochondria biogenesis and the induction of known or putative transporters. Among them, the gene ADY2/YCR010c was identified as a new key element for acetate transport, being homologous to the Yarrowia lipolytica GPR1 gene, which has a role in acetic acid sensitivity. Disruption of ADY2 in S. cerevisiae abolished the active transport of acetate. Microarray analyses of ady2 strains showed that this gene is not a critical regulator of acetate response and that its role is directly connected to acetate transport. Ady2p is predicted to be a membrane protein and is a valuable acetate transporter candidate.

In recent years, (bio)electrochemical systems (B)ES have emerged as an energy efficient alternative for the recovery of TAN (total ammonia nitrogen, including ammonia and ammonium) from wastewater. In these systems, TAN is removed or concentrated from the wastewater under the influence of an electrical current and transported to the cathode. Subsequently, it can be removed or recovered through stripping, chemisorption, or forward osmosis. A crucial parameter that determines the energy required to recover TAN is the load ratio: the ratio between TAN loading and applied current. For electrochemical TAN recovery, an energy input is required, while in bioelectrochemical recovery, electric energy can be recovered together with TAN. Bioelectrochemical recovery relies on the microbial oxidation of COD for the production of electrons, which drives TAN transport. Here, the state-of-the-art of (bio)electrochemical TAN recovery is described, the performance of (B)ES for TAN recovery is analyzed, the potential of different wastewaters for BES-based TAN recovery is evaluated, the microorganisms found on bioanodes that treat wastewater high in TAN are reported, and the toxic effect of the typical conditions in such systems (e.g., high pH, TAN, and salt concentrations) are described. For future application, toxicity effects for electrochemically active bacteria need better understanding, and the technologies need to be demonstrated on larger scale.

The Rho-guanine nucleotide exchange factor (RhoGEF) TRIO acts as a key regulator of neuronal migration, axonal outgrowth, axon guidance, and synaptogenesis by activating the GTPase RAC1 and modulating actin cytoskeleton remodeling. Pathogenic variants in TRIO are associated with neurodevelopmental diseases, including intellectual disability (ID) and autism spectrum disorders (ASD). Here, we report the largest international cohort of 24 individuals with confirmed pathogenic missense or nonsense variants in TRIO. The nonsense mutations are spread along the TRIO sequence, and affected individuals show variable neurodevelopmental phenotypes. In contrast, missense variants cluster into two mutational hotspots in the TRIO sequence, one in the seventh spectrin repeat and one in the RAC1-activating GEFD1. Although all individuals in this cohort present with developmental delay and a neuro-behavioral phenotype, individuals with a pathogenic variant in the seventh spectrin repeat have a more severe ID associated with macrocephaly than do most individuals with GEFD1 variants, who display milder ID and microcephaly. Functional studies show that the spectrin and GEFD1 variants cause a TRIO-mediated hyper-or hypo-activation of RAC1, respectively, and we observe a striking correlation between RAC1 activation levels and the head size of the affected individuals. In addition, truncations in TRIO GEFD1 in the vertebrate model X. tropicalis induce defects that are concordant with the human phenotype. This work demonstrates distinct clinical and molecular disorders clustering in the GEFD1 and seventh spectrin repeat domains and highlights the importance of tight control of TRIO-RAC1 signaling in neuronal development.

CREB3 proteins comprise a set of ER-localised bZip transcription factors defined by the presence of a transmembrane domain. They are regulated by inter-compartmental transport, Golgi cleavage and nuclear transport where they promote appropriate transcriptional responses. Although CREB3 proteins play key roles in differentiation, inflammation and metabolism, a general framework relating their defining features to these diverse activities is lacking. We identify unique features of CREB3 organisation including the ATB domain, which we show is essential for transcriptional activity. This domain is absent in all other human bZip factors, but conserved in Drosophila CREBA, which controls secretory pathway genes (SPGs). Furthermore, each of the five human CREB3 factors was capable of activating SPGs in Drosophila, dependent upon the ATB domain. Expression of the CREB3 protein, CREB-H, in 293 cells, upregulated genes involved in secretory capacity, extracellular matrix formation and lipid metabolism and increased secretion of specific cargos. In liver cells, which normally express CREB-H, the active form specifically induced secretion of apolipoproteins, including ApoA-IV, ApoAI, consistent with data implicating CREB-H in metabolic homeostasis. Based on these data and other recent studies, we propose of a general role for the CREB3 family in regulating secretory capacity, with particular relevance to specialised cargos.

The biochemical methane potential (BMP) of raw poultry litter waste was assessed in batch assays. Biological co-treatment with Clostridium cellulolyticum, Caldicellulosiruptor saccharolyticum and Clostridium thermocellum as bioaugmentation strains, and thermochemical pre-treatments with lime and sodium hydroxide performed at different temperatures and pressures were applied as strategies to improve the BMP by favouring the hydrolysis of the cellulolytic material in the waste. Anaerobic digestion of the raw waste allowed a specific methane production of 145 ± 14 LCH(4)kg(-1)VS, with 1% total solids and 0.72 g VS(inoculum)g(-1)VS(waste). The pre- and co-treatments contributed to a significant increase (up to 74%) in the waste solubilisation when using C. saccharolyticum, but methane production did not improve considerably. Therefore, the conversion of soluble organic matter to methane was the limiting step of the anaerobic digestion process of poultry litter waste.