Project description:Brown macroalgae holds an enormous potential as a future feedstock because it rapidly forms large biomasses and has high carbohydrate content (35% of its dry weight consists of alginate and mannitol). However, utilization of brown macroalgae by conventional microbial platforms (e.g., Escherichia coli and Saccharomyces cerevisiae) has been limited due to the inability of these platforms to metabolize alginate. Although recent studies engineered them to utilize alginate, their growth rates and metabolic activities are still too low for industrial applications, likely due to the unoptimized expression of multiple xenogeneic genes. Here, we isolated Vibrio sp. dhg, a novel, fast-growing bacterium that has been naturally evolved for efficient alginate assimilation (growth rate = 0.98 h-1). Especially, both the growth rate and sugar uptake rate of V. sp. dhg are substantially higher than the rates of E. coli for most biomass-derivable sugars. Based on our systematic characterization of its metabolism and gene expression architecture, we were able to develop a genetic toolbox for its engineering. By using this microorganism, we successfully demonstrated its ability to produce a broad spectrum of chemicals from alginate-mannitol mixtures with high productivities (1.1 g ethanol/L/h, 1.3 g 2,3-butanediol and acetoin/L/h, and 0.69 mg lycopene/L/h). Collectively, the V. sp. dhg strain is a powerful platform for the conversion of brown macroalgae sugars whose usage will dramatically accelerate the production of value-added biochemicals in the future.
Project description:Haploid, diploid, and tetraploid yeast were experimentally evolved in 2% raffinose medium. After 250 generations, we assessed the gene expression alterations in 2 evolved haploids, 2 evolved diploids, and 4 evolved tetraploids relative to the diploid ancestor.
2017-10-04 | GSE95069 | GEO
Project description:Raffinose Family Oligosaccharide utilization by Bacteroides
Project description:The interplay between phenotypic plasticity and adaptive evolution has long been an important topic of evolutionary biology. This process is critical to our understanding of a species evolutionary potential in light of rapid climate changes. Despite recent theoretical work, empirical studies of natural populations, especially in marine invertebrates, are scarce. In this study, we investigated the relationship between adaptive divergence and plasticity by integrating genetic and phenotypic variation in Pacific oysters from its natural range in China. Genome resequencing of 371 oysters revealed unexpected fine-scale genetic structure that is largely consistent with phenotypic divergence in growth, physiology, thermal tolerance and gene expression across environmental gradient. These findings suggest that selection and local adaptation are pervasive and together with limited gene flow shape adaptive divergence. Plasticity in gene expression is positively correlated with evolved divergence, indicating that plasticity is adaptive and likely favored by selection in organisms facing dynamic environments such as oysters. Divergence in heat response and tolerance implies that the evolutionary potential to a warming climate differs among oyster populations. We suggest that trade-offs in energy allocation are important to adaptive divergence with acetylation playing a role in energy depression under thermal stress.
Project description:This study was aimed to further illustrate the expression files of REN between glucose and raffinose in MRS broth. Transcriptomic analysis combined with mutants of the key genes based on homologous recombination technology indicated that galA1 gene cluster plays an important role in raffinose metabolism. Gene rafP and galA1 are responsible for raffinose transport and α-galactoside hydrolysis, followed by galactose hydrolysis by galKTE and sucrose hydrolysis by scrB. Lactobacillus salivarius Ren expanded the carbon utilization spectrum to adapt the fluctuating carbohydrate sources in the environment and shifted its carbohydrate metabolism to mixed-acid fermentation and then generated extra energy to bacterial growth when exposed to raffinose.
Project description:We created a mutator protein. The mutator, was prepared by fusing a PmCDA1 (Petromyzon marinus Cytidine DeAminase) and E.coli RNA polymerase alpha subunit(EcoRNAP alpha). After 120 cycles, whole genome sequencing was performed on the wild type and evolved sample. After characterization of the mutation capacity of our mutator, we evolved a sucrose utilization strain and we sequenced Suc strain.