Project description:Polyhydroxyalkanoates (PHAs) production using cellulosic biomass is a promising way for sustainable manufacturing of bioplastics. The famous bacterium, Priestia megaterium, is an ideal choice because it can utilize glucose and xylose for PHA synthesis. In the present study, we engineered the genome of P. megaterium by CRISPR-Cas9 system to enhance cellobiose utilization and PHA production. The genes encoding for β-glucosidases (Bgls) from different microbes were introduced into the P. megaterium to improve the cellobiose utilization.
Project description:Glyphosate and 2,4-D are among the most widely used herbicides globally, leading to environmental presence, food contamination, and human contact. Investigations based on current toxicological limits or populational-based herbicide exposures are warranted, and in vitro bioassays provide useful tools for toxicological screening. Thus, this study evaluated the transcriptomic implications of non-cytotoxic exposures to glyphosate, its metabolite aminomethylphosphonic acid (AMPA), or 2,4-D - or to their mixes - on hepatic cells. The half maximal effective concentration (IC50) of each herbicide was calculated (cell viability) in human hepatic C3A cells and 1000-fold lower concentrations were used for transcriptomic analysis (RNA-Seq) after 48h exposure, resembling current toxicological limits and considering herbicide water levels (glyphosate: 0.95 µg/mL; AMPA: 3.7 µg/mL; 2,4-D: 0.56 µg/mL). Glyphosate exposure enriched MAPK-related biological processes (upregulated TNF, FOS, IGF1, and PDGFB), and downregulated genes associated with lipid metabolism (CD36 and PPARA). Many AMPA exposure-related differentially expressed genes (DEGs, such as PFKFB3, HK2, and ALDOA) were associated with glucose metabolic pathways. Glyphosate and its metabolite yielded a common molecular signature, as illustrated by principal component analysis and the function of 212 shared DEGs. The exposure to 2,4-D was associated with the JNK cascade and the solute carrier family annotations. The herbicide mixtures had a discrete effect on enhancing the impact of individual herbicides, although important epithelial-mesenchymal transition genes were exclusively modified by the mixes (COL11A2, LOXL3, SNAI1). Altogether, our data reveals new perspectives on the short-term molecular effects of herbicide exposure in liver cells, emphasizing potential avenues for further exploration.
