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Biology subjects

Maury, J.

Publications and source records attributed to Maury, J..

3 recordsLinked to original sources

An automated workflow for multi-omics screening of microbial model organisms

Multi-omics datasets are becoming of key importance to drive discovery in fundamental research as much as generating knowledge for applied biotechnology. However, the construction of such large datasets is usually time-consuming and expensive. Automation is needed to overcome these issues by streamlining workflows from sample generation to data analysis. Here, we describe the construction of a complex workflow for the generation of high-throughput microbial multi-omics datasets. The workflow comprises a custom-built platform for automated cultivation and sampling of microbes, sample preparation protocols, analytical methods for sample analysis and automated scripts for raw data processing. We demonstrate possibilities and limitations of such workflow in generating data for three biotechnologically relevant model organisms, namely Escherichia coli, Saccharomyces cerevisiae, and Pseudomonas putida.

systems biology↗

Triterpenoid production with a minimally engineered Saccharomyces cerevisiae chassis

Triterpenoids, one of the most diverse classes of natural products, have been used for centuries as active ingredients in essential oils and Chinese medicines and are of interest for many industrial applications ranging from low-calorie sweeteners to cosmetic ingredients and vaccine adjuvants. However, not only can the extraction from plant material be cumbersome due to low concentrations of the specific triterpenoid, but concerns are also increasing regarding the sustainability of wild plant harvest while meeting market demands. The alternative is to produce triterpenoids with engineered microbes. Here, we present a generally applicable strategy for triterpenoid production in the yeast Saccharomyces cerevisiae based on a modified oxidosqualene cyclase Erg7. The modification reduces the flux into the sterol pathway while increasing the precursor supply for triterpenoid production. The minimally engineered strain was exploited for the exemplary production of the lupane triterpenoids betulin, betulin aldehyde, and betulinic acid at a total titer above 6 g/L, the highest reported so far. To further highlight the chassis concept, squalene, oleanane- and dammarane-type triterpenoids were synthesized to titers at a similar gram scale. We propose the developed bakers yeast as a host for the thousands of triterpenoid synthesis pathways from plants, reducing the pressure on the natural resources.

bioengineering↗

Adaptive laboratory evolution reveals general and specific chemical tolerance mechanisms and enhances biochemical production

Tolerance to high product concentrations is a major barrier to achieving economically viable processes for bio-based chemical production. Chemical tolerance mechanisms are often unknown, thus their rational design is not achievable. To reveal unknown tolerance mechanisms we used an automated platform to evolve Escherichia coli to grow in previously toxic concentrations of 11 chemicals that have applications as polymer precursors, chemical intermediates, or biofuels. Re-sequencing of isolates from 88 independently evolved populations, reconstruction of mutations, and cross-compound tolerance profiling was employed to uncover general and specific tolerance mechanisms. We found that: 1) the broad tolerance of strains towards chemicals varied significantly depending on the chemical stress condition under which the strain was evolved; 2) the strains that acquired high levels of NaCl tolerance also became broadly tolerant to most chemicals; 3) genetic tolerance mechanisms included alterations in regulatory, cell wall, transcriptional and translational functions, as well as more chemical-specific mechanisms related to transport and metabolism; 4) using pre-tolerized starting strains can significantly enhance subsequent production of chemicals when a production pathway is inserted; and 5) only a subset of the evolved isolates showed improved production indicating that this approach is especially useful when a large number of independently evolved isolates are screened for production. We provide a comprehensive genotype-phenotype map based on identified mutations and growth phenotypes for 224 chemical tolerant strains.

microbiology↗