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Biology subjects

Asin-Garcia, E.

Publications and source records attributed to Asin-Garcia, E..

4 recordsLinked to original sources

dAMN: a genome scale neural-mechanistic hybrid model to predict bacterial growth dynamics

SummaryThis study presents dAMN, a hybrid neural-mechanistic model that integrates neural networks with genome-scale dynamic flux balance analysis (dFBA) to predict bacterial growth curves across diverse nutrient environments. dAMN uses neural networks to infer dynamic behavior from initial metabolite concentrations, while mechanistic constraints ensure stoichiometric and thermodynamic consistency based on genome scale metabolic models. dAMN is trained on E. coli and P. putida experimental growth data from media containing various combinations of sugars, amino acids, and nucleobases, and evaluated on two test sets: one for forecasting over time and another for predicting growth dynamics on unseen media. dAMN achieved high predictive power (R2 [≥] 0.9), successfully reproducing growth and substrate depletion dynamics including acetate overflow and glucose-acetate consumption shift for E. coli. An interesting innovation of dAMN is the treatment of the lag phase, enabling realistic adaptation dynamics absent from standard dFBA models. dAMN stands out for its ability to generalize across combinatorial nutrient inputs and produce full growth-curve predictions from minimal input data. Availability and implementationThe dAMN software, along with the associated models and data, is available at https://github.com/brsynth/dAMN-main-release and via DOI 10.5281/zenodo.17908125

systems biology↗

Rhodo-Box: a Synthetic Biology Toolbox to Facilitate Metabolic Engineering of Rhodobacter sphaeroides

Rhodobacter sphaeroides is a purple non-sulphur alphaproteobacterium with a highly versatile metabolism. This microorganism holds promise as a chassis for sustainable biomanufacturing of numerous chemicals. Yet, its potential is constrained by a lack of standardized, well-characterized genetic elements to tune gene expression such as transcriptional promoters and ribosome binding sites (RBSs). In this study, we present Rhodo-Box, a comprehensive toolkit for R. sphaeroides created by adapting and extending the Zymo-Parts modular cloning framework. Using Rhodo-Box we built and characterized: (a) three broad-host origins of replication (pBBR1, RK2 and RSF1010), (b) a set of 13 promoters, (c) four inducible expression systems (NahR-PsalTTC, LacI-PlacT7A1_O3O4, VanR-PvanCC, and XylS-Pm), (d) 11 RBSs, and (e) four transcriptional terminators. Furthermore, we present a semi-automated, user-friendly cloning approach which enables rapid construction of R. sphaeroides strains. The Rhodo-Box toolkit equips R. sphaeroides with a standardized, automation-compatible collection of parts and workflows essential for efficient design-build-test-learn cycles and advanced metabolic engineering. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=106 SRC="FIGDIR/small/685836v1_ufig1.gif" ALT="Figure 1"> View larger version (31K): org.highwire.dtl.DTLVardef@fcb172org.highwire.dtl.DTLVardef@1e5eb44org.highwire.dtl.DTLVardef@1b8df28org.highwire.dtl.DTLVardef@42eb2a_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

Computer assisted multi-level optimization of malonyl-CoA availability in Pseudomonas putida

Malonyl-CoA is the major precursor for the biosynthesis of diverse industrially valuable products such as fatty acids/alcohols, flavonoids, and polyketides. However, its intracellular availability is limited in most microbial hosts, hampering the biological synthesis of such chemicals. To address this limitation, we present a multi-level optimization workflow using modern metabolic engineer-ing technologies to systematically increase the malonyl-CoA levels in Pseudomonas putida. The workflow involves the identification of gene downregulations, chassis selection, and optimization of the acetyl-CoA carboxylase complex through ribosome binding site engineering. Computa-tional tools and high-throughput screening with a malonyl-CoA biosensor enabled the rapid eval-uation of numerous genetic targets. Combining the most beneficial targets led to a 5.8-fold en-hancement in the production titer of the valuable polyketide phloroglucinol. This study demon-strates the effective integration of computational and genetic technologies for engineering P. putida, opening new avenues for the development of industrially relevant strains and the investi-gation of fundamental biological questions.

synthetic biology↗

Identification of Aspergillus niger aquaporins involved in hydrogen peroxide signaling

Aspergillus niger is a robust microbial cell factory for organic acids production. However, the regulation of many industrially important pathways is still poorly understood. Recently the regulation of glucose oxidase (GOx) expression system involved in the biosynthesis of gluconic acid has been uncovered. Hydrogen peroxide, a by-product of the enzymatic conversion of glucose to gluconate, has a pivotal role as a signaling molecule in the induction of this system. In this study, facilitated diffusion of hydrogen peroxide via aquaporin water channels (AQPs) was studied. AQPs are transmembrane proteins of the major intrinsic proteins (MIPs) superfamily. In addition to water and glycerol, they may also transport small solutes such as hydrogen peroxide. Accordingly, the genome sequence of A. niger N402 was screened for putative AQPs. Seven were found which could be classified in three main groups. Their ability to facilitate diffusion of hydrogen peroxide was identified using yeast phenotypic growth assays and by studying AQP gene knock-outs in A. niger. Complementing from both yeast and A. niger experiments, the X-intrinsic protein AQPF plays apparent roles in facilitating hydrogen peroxide transport across cellular membrane. IMPORTANCEAquaporins (AQP) are integral membrane proteins that facilitate transfer of water, small solutes and hydrogen peroxide across the plasma membrane. As they have conserved structural features, it is not difficult to detect their presence in fungal genomes. Their specific roles in fungi are however less understood. Previously we have elucidated the role of the hydrogen peroxide as a second messenger in the induction and regulation of the expression of glucose oxidase involved in the extracellular conversion of glucose in gluconate (1). Here we identified the involvement of AQPF, a member of the X-intrinsic protein class in facilitating transport of the hydrogen peroxide signal across the cell membrane.

molecular biology↗