Trends in biotechnology最新文献

Cultivated meat is a promising solution to global food security challenges, but cultivated ingredients offer an equally compelling and potentially more economically stable path forward. Components such as flavour enhancers, cultivated fat, and proteins present scalable opportunities for improving alternative proteins, highlighting the untapped potential of cultivated ingredient-focused strategies.

Infectious diseases remain a major impediment to livestock production, negatively impacting both productivity and welfare. Where key interactions between viruses and host proteins have been identified, it is possible to rationally devise intervention strategies. In vitro studies have identified the host protein DNAJC14 as a core component of the replicative cycle of classical pestiviruses. Outbreaks caused by this group of viruses cause enormous losses in stock farming due to culling and export restrictions. Using CRISPR/Cas9 gene editing, we produced a cohort of pigs with altered DNAJC14. Primary cells from these animals did not support replication of either classical swine fever virus (CSFV) or bovine viral diarrhoea virus (BVDV) in vitro. In vivo challenge with CSFV revealed that the edited pigs displayed complete resistance to infection. This establishes gene editing as an additional strategy that can contribute to the control of classical pestiviruses.

Ergothioneine (ERG) is a rare amino acid with diverse biological activities, making it valuable for applications in the food, cosmetics, and pharmaceutical industries. Compared with traditional extraction from edible fungi, microbial fermentation offers a more scalable alternative, but its feasibility is largely determined by production titer and cost. In this study, we developed a novel ERG biosynthesis strategy that eliminates the need for expensive methionine and cysteine supplementation during fermentation. By reconstructing a betaine-driven methyl supply system and an inorganic sulfur supply module in Escherichia coli, we engineered a highly efficient ERG-producing strain capable of utilizing betaine as a methyl donor and inorganic sulfur as a sulfur source. As a result, shake flask fermentations achieved an ERG titer of 456 ± 9 mg/l without exogenous methionine and cysteine supplementation. Further optimization strategies, including enhanced intracellular histidine synthesis, alleviation of methionine feedback inhibition, and improved ERG transport efficiency, increased the shake flask titer to 1.2 g/l, a 24-fold improvement over the initial strain. Scale-up in a 5-l fermenter further optimized fermentation conditions, yielding an ERG titer of 7.2 g/l. Thus, the metabolic engineering strategy described in this study provides a scalable and cost-effective platform for the industrial production of ERG and other methyl- and sulfur-containing natural products.

Flocculants are widely used for solid-liquid separation despite environmental risks such as microplastics accumulation or release of toxic compounds. Microbially-secreted biopolymers are potential biodegradable, nontoxic alternatives. We demonstrate the feasibility of overproducing microbial exopolymers [extracellular polymeric substances (EPS)] from glycerol- and carbohydrate-rich industrial waste(water) in open-culture bioreactors. Two semi-pilot scale airlift bioreactors were operated with (airlift-MBR) and without membrane (airlift) to treat pure glycerol, biodiesel wastewater, and potato starch hydrolysate. Efficiency of EPS production with respect to supplied chemical oxygen demand reached values of 42% from pure glycerol, 30% from biodiesel wastewater, and 22% from potato starch hydrolysate. The airlift bioreactor showed stable continuous operation compared to airlift-MBR which was affected by membrane fouling. The produced EPS had net anionic charge and high molecular weight between 1 and 2.5 MDa. Both untreated EPS-rich mixed liquor produced in the bioreactors and extracted EPS therefrom showed promising flocculation potential comparable to anionic polyacrylamide.

Clustered regularly interspaced short palindromic repeats (CRISPR)-based libraries with diverse gene-editing functions, such as gene knockdown and mutation, can significantly accelerate our understanding of complex metabolic networks in microorganisms, particularly for species beyond classical model organisms. Here, three distinct CRISPR-based libraries were designed in the electroactive microorganism Shewanella oneidensis MR-1: a CRISPR interference (CRISPRi) library covering 99.6% of genes in the genome, a protein mutation library focused on genes involved in carbon metabolism, and an inactivation library, with sizes of 30 804, 5963, and 4072 single guide (sg)RNAs, respectively. The principles for the design and construction of libraries were validated, and a conjugation-based library transformation method with high coverage and uniformity was developed. For the first time, we explored the potential essential genes of S. oneidensis MR-1, and expanded the substrate spectrum available for electricity generation, including glucose and chitin. These efforts enable deeper genomic interrogation of Shewanella, and provide a framework for applying genome-scale CRISPR-based tools to other undercharacterized microbial species.

The EU has been a leader in research and development of in vitro biotechnology (IVB), such as human 3D cell and tissue models used in disease research and drug development. However, it is struggling to convert scientific discoveries into business creation and competitiveness within a rapidly growing international market.

Immunotherapy based on live microorganisms has shown promise in preclinical studies, but its clinical translation has been hampered by limited efficacy and non-negligible toxicity. Here, we developed Macrophage-Bacteria encapsulation Lytic Autoactivated Synergistic Therapeutics (M-BLAST), a dual-gated macrophage-mediated bacterial tumor-targeted delivery and in situ activation system. M-BLAST incorporates density-regulated virulence-enhanced attenuated Salmonella strains as the therapeutic core, thermally controlled gasdermin D N-terminal fragment (GSDMD-N)-expressing macrophages as the delivery vector, and copper selenide, a photothermal material, as a heat shock 'primer'. Following systemic administration, localized near-infrared (NIR) irradiation at the tumor site triggers macrophage pyroptosis, ensuring rapid and complete bacterial release. This disrupts the immunosuppressive tumor microenvironment (TME) and elicits a widespread cascading antitumor response, just like a 'immune bomb', while the dual-gating design of bacterial density and heat shock ensures safety by preventing off-target activation in non-tumor regions. Thus, M-BLAST could enhance the therapeutic utility of living engineered bacteria for cancer while ensuring safety for patients.

Radiation therapy (RT) precisely targets tumors with ionizing radiation, aiming to achieve local control while minimizing collateral damage to surrounding healthy tissues. Radiation research is often carried out in animal models, but these suffer from ethical issues, high cost of operation, low throughput, and low correlation to responses in humans. The advent of microfluidic organ-on-a-chip (OoC) technology offers a promising alternative to precisely and reproducibly model the physiology of different tissues in a laboratory setting. Furthermore, organ-on-a-chip models can be constructed from patient-specific tissues to tailor therapies while enabling fine control over relevant microenvironmental factors. In this review, we highlight emerging research at the intersection of radiation biology and microphysiological models, with a focus on the unique capabilities enabled by these advanced technologies.

Genome-scale metabolic models are used in fields ranging from metabolic engineering to drug discovery and microbiome design. Although these models are often used to predict putatively optimal states, some applications, including modeling human tissues for drug development and microbial communities for synthetic ecology, may require sampling the whole space of feasible fluxes to obtain distributions of biologically relevant states. Additionally, many applications involve using transcriptomic or proteomic data to predict fluxes for specific tissues, diseases, or patients. We revisit different methods used toward these goals and focus on their limitations and challenges, providing guidelines on how to avoid some of the shortcomings of existing approaches and highlighting conceptual barriers that will require new methodologies and offer opportunities for future development.