Biology subjects

Della Valle, S.

Publications and source records attributed to Della Valle, S..

4 recordsLinked to original sources

bioRxiv2026

A Toolbox for Biomanufacturing of Functionalised PHA Nanoparticles with C. necator

Microbes have the potential to manufacture plastics from sustainable feedstocks while enabling novel material properties and functions that are not easily accessible through conventional chemical synthesis. Realising this potential requires a comprehensive genetic and process engineering framework that spans chassis and bioprocess optimisation, polymer property control, and downstream functionalisation. Here we develop such a platform in Cupriavidus necator, with a focus on high-value polyhydroxyalkanoate (PHA) nanoparticles. To this end we first optimise the transformation protocol for the organism. Next, we create a library of PhaC synthase variants from C. necator, Aeromonas caviae and Brevundimonas sp. in a {Delta}phaC background, demonstrating that they allow customisation of the material properties of produced PHA particles. Our results combine data from Flow cytometry, Transmission Electron Microscopy (TEM), Fourier Transform InfraRed Spectroscopy (FTIR), and Differential Scanning Calorimetry (DSC) to show that it is possible to generate materials ranging from highly crystalline PHAs to softer P(3HB-co-3HHx) copolymers and that an A. caviae PhaC variant can double the yield of large PHA granules. To improve bioprocess sustainability, we coupled C. necator with B. subtilis in sucrose-fed co-cultures, using tetracycline tolerance differences and inoculation ratios to enhance PHA production from inexpensive, sugar-rich feedstocks. Finally, we add function to the produced PHA nanoparticles by using the molecular protein-fusion technology SpyTag-SpyCatcher, showing it is possible to efficiently capture SpyCatcher-GFP on PHA granules as a proof of concept for PHAs use as a customisable bio-based nanoparticle. Together, our work offers an innovation to produce bio-PHA nanoparticles in a customisable way, with potential applications in sustainable biomanufacturing, biosensing, drug delivery and future bioremediation technologies.

synthetic biology↗

bioRxiv2025

Establishing Vibrio natriegens as a high-performance host for acetate-based poly-3-hydroxybutyrate production

Acetate can be a sustainable and renewable carbon source which holds significant promise for biotechnological production but is underutilized industrially due to limited microbial efficiency. Vibrio natriegens, recognized for exceptionally fast growth rates, represents a compelling host for developing efficient acetate-based bioprocesses. In this study, adaptive laboratory evolution significantly enhanced V. natriegens ability to grow on acetate as the sole carbon source, achieving an 89% increase in growth rate. Genetic and transcriptomic analyses revealed key adaptations improving acetate uptake and metabolism via increased salt tolerance, boosted Pta/AckA pathway activity, and rewired quorum sensing. Further metabolic engineering and bioprocess optimization enabled the evolved strain to reach high cell densities and efficiently convert acetate into the bioplastic poly-3-hydroxybutyrate (PHB), with productivities up to 0.27 g/L/h and PHB accumulation reaching 45.66% of cell biomass. These advances position V. natriegens as a highly promising microbial platform for sustainable, scalable, and cost-effective biomanufacturing using acetate as green feedstock. O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=143 SRC="FIGDIR/small/661028v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@ebd5b0org.highwire.dtl.DTLVardef@11a28bforg.highwire.dtl.DTLVardef@6950aforg.highwire.dtl.DTLVardef@303d7b_HPS_FORMAT_FIGEXP M_FIG C_FIG

synthetic biology↗

bioRxiv2024

Streamlined and efficient genome editing in Cupriavidus necator H16 using an optimised SIBR-Cas system

Cupriavidus necator H16 is a promising microbial platform strain for CO2 valorisation. While C. necator is amenable to genome editing, existing tools are often inefficient or rely on lengthy protocols, hindering its rapid transition to industrial applications. In this study, we simplified and accelerated the genome editing pipeline for C. necator by harnessing the Self-splicing Intron-Based Riboswitch (SIBR) system. We used SIBR to tightly control and delay Cas9-based counterselection, achieving >80% editing efficiency at two genomic loci within 48 hours after electroporation. To further increase the versatility of the genome editing toolbox, we upgraded SIBR to SIBR2.0 and used it to regulate the expression of Cas12a. SIBR2.0-Cas12a could mediate gene deletion in C. necator with [~]70% editing efficiency. Overall, we streamlined the genome editing pipeline for C. necator, facilitating its potential role in the transition to a bio-based economy.

bioengineering↗

bioRxiv2020

Neuronal perception of the social environment intergenerationally controls germline development and generation time in C. elegans

An old and controversial question in biology is whether information perceived by the nervous system of an animal can cross the Weismann barrier to alter the phenotypes and fitness of their progeny. Here we show that such intergenerational transmission of sensory information occurs in the model organism, C. elegans, with a major effect on fitness. Specifically, that perception of social pheromones by chemosensory neurons controls the post-embryonic timing of development of one tissue - the germline - relative to others in an animals progeny. Neuronal perception of the social environment thus intergenerationally controls the generation time of this animal.

genetics↗