Biology subjects

Demaria, F.

Publications and source records attributed to Demaria, F..

4 recordsLinked to original sources

bioRxiv2025

Compost bacteria as a promising new solution for degradation of diclofenac and related pharmaceuticals for water treatment processes

Diclofenac, a widely used pharmaceutical, poses a significant environmental problem due to its persistence in aquatic systems and resistance to conventional degradation processes. Mesophilic microorganisms, commonly employed in wastewater treatment, often struggle to break down diclofenac, necessitating alternative approaches for its removal. In this study, we investigated thermophilic compost microorganisms and their ability to degrade diclofenac. Compost communities were cultivated for 20 weeks at 50{degrees}C in a membrane bioreactor, with a continuous supply of 2 mg/L diclofenac as the sole carbon source. After two weeks, the microbial community steadily enhanced its ability to remove diclofenac, achieving removal rates up to 60%. The consortium demonstrated flexibility in the degradation of further pollutants, namely sulfamethoxazole, paracetamol, and ciprofloxacin, with changes in their community structure depending on the substrates. In addition, thermophilic isolates Chelatococcus sp. strain D3 and Mycobacterium sp. strain D1 were characterized and demonstrated variation in the first reaction of transforming diclofenac, which is the crucial step in mineralization of this pollutant, resulting in either 4-hydroxy-diclofenac or diclofenac-lactam, respectively. Furthermore, Chelotococcus sp. strain D3 demonstrated the capability to catalyze the biotransformation of diclofenac into 4-hydroxydiclofenac in treated wastewater. Notably, this transformation was effectively carried out even at lower temperatures (25 {degrees}C and 37{degrees}C). These results show that the use of thermophilic consortia can be applied for efficient bioremediation in wastewater treatment plants, specifically for compounds that mesophilic organisms degrade poorly.

microbiology↗

bioRxiv2024

Model-guided metabolic engineering of curcuminoid Production in Pseudomonas putida

Production of value-added, plant-derived compounds in microbes increasingly attracts commercially interest in food and pharmaceutical industries. However, plant metabolic pathways are complex, require a robust balance of enzymes, cofactors, ATP and other metabolites, and often result in low production when transplanted to bacteria. This is exemplified by the biosynthesis of curcuminoids from the Curcuma longa plant. Here, we combine dynamic pathway modeling, systematic testing of isoenzymes, and the optimization of gene expression levels and substrate concentrations for the biosynthesis of curcuminoids in Pseudomonas putida, leading to unprecedented conversion rates of caffeic acid and tyrosine to curcumin. The development of kinetic ensemble models guided the design of production strains, emphasizing the necessity of high relative expression of c3h, curs2 and dcs and, the low relative expression of tal, comt, ccoaomt, and 4cl4. This optimization resulted in a strain that achieved a 10.8 {+/-}1.8% of the maximum theoretical yield of curcumin from tyrosine. This represents a 4.1-fold increase in production efficiency and the highest yield reported to date, demonstrating the potential of P. putida as a promising platform for curcuminoid production. Our findings highlight the effectiveness of our strategy not only in the advances in the production of curcuminoids but also in setting a framework for the biosynthesis of other complex compounds.

synthetic biology↗

bioRxiv2023

Pollutome complexity determines the removal of recalcitrant pharmaceuticals

Organic pollutants are an increasing threat for wildlife and humans. Managing their removal is however complicated by the difficulties in predicting degradation rates. In this work we demonstrate that the complexity of the pollutome, the set of co-existing contaminants, is a major driver of biodegradation. We built representative assemblages out of one to five common pharmaceuticals (caffeine, atenolol, paracetamol, ibuprofen, and enalapril) selected along a gradient of biodegradability. We followed their individual removal by wastewater microbial communities. The presence of multichemical background pollution was essential for the removal of recalcitrant molecules such as ibuprofen. Crucially, high order interactions between pollutants were a determinant, with the addition of new molecules particularly impacting assemblages of multiple compounds. We explain these interactions by shifts in the microbiome, with degradable molecules such as paracetamol enriching species and pathways involved in the removal of several organic molecules. We conclude that pollutants should be treated as part of a complex system, with emerging pollutants potentially showing cascading effects and offering leverage to promote bioremediation.

microbiology↗

bioRxiv2023

Identification of microbial communities and their removal efficiency of multiple pharmaceutical micropollutants combined in Membrane-Bioreactors

Pharmaceuticals are of concern to our planet and health as they can accumulate in the environment. The impact of these biologically active compounds on ecosystems is hard to predict and information on their biodegradation is necessary to establish sound risk assessment. Microbial communities are promising candidates for the biodegradation of pharmaceuticals such as ibuprofen, but little is known yet about their degradation-capacity of multiple micropollutants at higher concentrations (100 mg/L). In this work, microbial communities were cultivated in lab-scale Membrane Bioreactors (MBRs) exposed to increasing concentrations of a mixture of six micropollutants (ibuprofen, diclofenac, enalapril, caffeine, atenolol, paracetamol). Key players of biodegradation were identified using a combinatorial approach of 16S rRNA sequencing and analytics. Microbial community structure changed with increasing pharmaceutical intake (from 1 mg/L to 100 mg/L) and reached a steady-state during incubation for 7 weeks on 100 mg/L. HPLC analysis revealed a fluctuating but significant degradation (30-100%) of five pollutants (caffeine, paracetamol, ibuprofen, atenolol, enalapril) by an established and stable microbial community mainly composed of Achromobacter, Cupriavidus, Pseudomonas and Leucobacter. By using the microbial community from MBR1 as inoculum for further batch culture experiments on single micropollutants (400 mg/L substrate, respectively), different active microbial consortia were obtained for each single micropollutant. Microbial genera potentially responsible for degradation of the respective micropollutant were identified, i.e. Pseudomonas sp. and Sphingobacterium sp. for ibuprofen, caffeine and paracetamol, Sphingomonas sp. for atenolol, and Klebsiella sp. for enalapril. Our study demonstrates the feasibility of cultivating stable microbial communities capable of degrading simultaneously a mixture of highly concentrated pharmaceuticals in lab-scale MBRs and the identification of microbial genera potentially responsible for the degradation of specific pollutants. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=123 SRC="FIGDIR/small/536351v1_ufig1.gif" ALT="Figure 1"> View larger version (16K): org.highwire.dtl.DTLVardef@14ff045org.highwire.dtl.DTLVardef@12747d0org.highwire.dtl.DTLVardef@1dbbfd8org.highwire.dtl.DTLVardef@103640_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗