Project description:The spread of antibiotic resistance genes (ARG) into agricultural soils, products, and foods severely limits the use of organic fertilizers in agriculture. In this study, experimental land plots were fertilized, sown, and harvested for two consecutive agricultural cycles using either mineral or three types of organic fertilizers: sewage sludge, pig slurry, or composted organic fraction of municipal solid waste. The analysis of the relative abundances of more than 200,000 ASV (Amplicon Sequence Variants) allowed the identification of a small, but significant (<10%) overlap between soil and fertilizer microbiomes, particularly in soils sampled the same day of the harvest (post-harvest soils). Loads of clinically relevant ARG were significantly higher (up to 100 fold) in fertilized soils relative to the initial soil. The highest increases corresponded to post-harvest soils treated with organic fertilizers, and they correlated with the extend of the contribution of fertilizers to the soil microbiome. Edible products (lettuce and radish) showed low, but measurable loads of ARG (sul1 for lettuces and radish, tetM for lettuces). These loads were minimal in mineral fertilized soils, and strongly dependent on the type of fertilizer. We concluded that at least part of the observed increase on ARG loads in soils and foodstuffs were actual contributions from the fertilizer microbiomes. Thus, we propose that adequate waste management and good pharmacological and veterinarian practices may significantly reduce the potential health risk posed by the presence of ARG in agricultural soils and plant products.
Project description:Untargeted proteomics approaches were shown to be suitable for composition and authenticity analyses of highly processed mixed food and feed products. In this work, a normal-flow tandem mass spectrometry-based proteomics method was setup for analysis and authentication of insect meal from five different species. Novel data acquired on a Q Exactive Orbitrap (QE) was compared with previously published data obtained on QTOF. Data from both proteomics workflows were compared using compareMS2 and a Trans-Proteomics Pipeline (TPP). The results obtained for species differentiation, peptides, and protein markers detection were comparable across both approaches. The collected mass spectrometry data from both instruments also were used to build spectral libraries for insect species and matching was performed successfully. Lastly, both datasets were screened for known allergens and arginine kinase and tropomyosin were consistently detected confirming the presence of potential allergenic risks associated with the consumption of edible insects.
Project description:Background. Transforming waste and non-food materials into bulk biofuels and chemicals represents a major stride in creating a sustainable bioindustry, optimizing the use of resources while reducing environmental footprints. Yet, despite these advancements, the production of high-value natural products often continues to rely on first-generation substrates, underscoring the intricate processes and specific requirements of their biosynthesis. This is also true for Streptomyces lividans, a renowned host organism celebrated for its capacity to produce and uncover a wide array of natural products, attributed to its genetic versatility and potent secondary metabolism. Given this context, it becomes imperative to assess and optimize this microorganism for the synthesis of natural products specifically from waste and non-food substrates. Results. We metabolically engineered S. lividans TK24 to heterologously produce the ribosomally synthesized and post-translationally modified peptide, bottromycin, as well as the polyketide, pamamycin. The modified strains successfully produced these compounds using waste and non-food model substrates like protocatechuate (derived from lignin), 4-hydroxybenzoate (sourced from plastic waste), and mannitol (from seaweed). Comprehensive transcriptomic and metabolomic analyses offered insights into how these substrates influenced the cellular metabolism of S. lividans. When evaluating production efficiency, S. lividans showcased remarkable tolerance, especially in a fed-batch process using a mineral medium containing the toxic aromatic 4-hydroxybenzoate, leading to enhanced and highly selective bottromycin production. Additionally, it generated a unique spectrum of pamamycins when cultured in mannitol-rich seaweed extract without the need for added nutrients. Conclusion. Our study showcases the successful production of high-value natural products using varied waste and non-food raw materials, thereby circumventing the reliance on costly, food-competing resources. S. lividans exhibited remarkable adaptability and resilience across these diverse substrates. When cultured on aromatic compounds, it displayed a distinct array of intracellular CoA esters, presenting promising avenues for polyketide production. Future research could focus on enhancing S. lividans' substrate utilization pathways to more efficiently process the intricate mixtures commonly found in waste and non-food sources.
Project description:Genetic engineering of filamentous fungi has promise for accelerating the transition to a more sustainable food system and enhancing the nutritional value, sensory appeal, and scalability of microbial foods. However, genetic tools and demonstrated use cases for bioengineered food production by edible strains are lacking. Here, we developed a synthetic biology toolkit for Aspergillus oryzae, an edible fungus traditionally used in fermented foods and currently used in protein production and meat alternatives. Our toolkit includes a CRISPR-Cas9 method for genome integration, neutral loci, and new promoters. We use these tools to enhance the elevate levels of the nutraceutical ergothioneine and intracellular heme in the edible biomass. The biomass overproducing heme is red in color and is readily formulated into imitation meat patties with minimal processing. These findings highlight the promise of genetic approaches to enhance fungal meat alternatives and provide useful engineering tools for diverse applications in fungal food production and beyond.