Project description:Screening of domesticated complex flora from wastewater can degrade high concentrations of thiocyanate, the molecular mechanism of this phenomenon remains unclear. In this study, macro-proteomics techniques were used to analyse the intracellular proteins of the composite flora. The researchers performed proteomic analysis using combined tandem mass spectrometry to identify the differential proteins of the colonies under glucose treatment and thiocyanate stress. A total of 4,747 differential proteins were detected across the three different periods. Of these, 1,213 differential proteins were detected in the pre-biodegradation period, 1,300 differential proteins in the mid-biodegradation period, and 1,413 differential proteins in the post-biodegradation period. Through the protein function annotation, it was found that the differential proteins were mainly concentrated in carbon metabolism, energy metabolism, two-component system and amino acid metabolism.
Project description:Gas-fermenting acetogens, such as Clostridium autoethanogenum, have emerged as promising biocatalysts capable of converting CO and CO2-containing gases into fuels and chemicals relevant for a circular economy. However, functionalities of the majority of genes in acetogens remain uncharacterised, hindering the development of acetogen cell factories through targeted genetic engineering. We previously identified gene targets through adaptive laboratory evolution (ALE) that potentially realise enhanced autotrophic phenotypes in C. autoethanogenum. In this study, we deleted one of the targets – CLAU_0471 (proposed amino acid permease) – with high mutation occurrence in ALE isolates and extensively characterised autotrophic growth of strain RE3 in batch bottle and bioreactor continuous cultures. In addition, we characterized two previously reverse-engineered strains RE1 (deletion of CLAU_3129; putative sporulation transcriptional activator Spo0A) and RE2 (SNP in CLAU_1957; proposed two component transcriptional regulator winged helix family). Strikingly, the strains recovered the superior phenotypes of ALE isolates, including faster autotrophic growth, no need for yeast extract, and robustness in bioreactor operation (e.g. low sensitivity to gas ramping, high biomass, and dilution rates). Notably, RE3 exhibited elevated 2,3-butanediol production while RE1 performed similar to the best-performing previously characterised ALE isolate LAbrini. The three reverse-engineered strains showed similarities in proteome expression and bioinformatic analyses suggest that the targeted genes may be involved in overlapping regulatory networks. Our work provides insights into genotype-phenotype relationships for a better understanding of the metabolism of an industrially-relevant acetogen.
Project description:rs07-09_bou - catma1-bou - Autotrophic growth acquisition is abolished in the bou mutant in Arabidopsis thaliana. BOU encodes a putative mitochondrial acyl carnitine carrier. bou mutant is blocked at the cotyledon stage. Autotrophic growth of the bou mutant can be achieved with addition of sugar in the medium or in darkness. Moreover, BOU gene expression is activated by light and depends on plant developmental stage. We wish to determine what are the consequences of bou gene mutation at the transcriptome level. We wish to understand whether bou growth arrest is due to the modification of specific genes expression or to a general effect on metabolism at the transition from heterotrophic to autotrophic growth. - Seeds from a heterozygous plants were grown for either 5 or 8 days after germination on synthetic medium (MS/2) without sugar under continuous light. We harvested cotyledon-stage blocked plants (bou phenotype) from three independent Petri dishes and also green seedlings with true leaves and fully developed root (heterozygotes with a wild-type phenotype) . We also grew independently Col-O plants for 5 and 8 days to compare them with the bou mutants. Keywords: gene knock in (transgenic),normal vs disease comparison,time course
Project description:The Wood-Ljungdahl pathway in acetogens converts C1 compounds, such as CO2 and CO, into acetyl-CoA. Similarly, the glycine synthase pathway assimilates C1 compounds into glycine. Partial glycine synthase genes are widely conserved in the Wood-Ljungdahl pathway gene cluster but functional relationship between the pathways in autotrophic condition remains unknown. To comprehend, we assembled Clostridium drakei genome (5.7-Mbp) with intact glycine synthase pathway and constructed a genome-scale metabolic model, iSL836, predicting increased metabolic flux rates of the Wood-Ljungdahl pathway and the glycine synthase-reductase associated reactions under autotrophic conditions. Along with the observation of significant transcriptional activation of genes in the pathways, surprisingly, 13C-labeling experiments and enzyme activity assays confirmed the strain synthesizes glycine and converts into acetyl-phosphate. This study suggests the Wood-Ljungdahl and the glycine synthase-reductase pathways convert CO2 into acetyl-CoA and acetyl-phosphate, respectively. In our knowledge, this is the first report on co-utilization of the pathways under autotrophic growth in acetogen.
Project description:The goal of this experiment was to explore the molecular network of glucose-TOR signaling in Arabidopsis seedling autotrophic transition stage. We used the whole-genome microarrays to detail the global program of gene expression mediated by glucose and TOR.