Alexander Boes

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P‐MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P‐MAPs effectively prevented infection of grapevine plants with downy mildew under semi‐field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P‐MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long‐term impact on the environment.

Widespread use of plant protection agents in agriculture is a major cause of pollution. Apart from active ingredients, the environmental impact of auxiliary synthetic polymers should be minimized if they are highly persistent. An alternative to synthetic polymers is the use of natural polysaccharides, which are abundant and biodegradable. In this study, we explore pectin microgels functionalized with anchor peptides (P‐MAPs) to be used as an alternative biobased pesticide delivery system. Using copper as the active ingredient, P‐MAPs effectively prevented infection of grapevine plants with downy mildew under semi‐field conditions on par with commercial copper pesticides. By using anchor peptides, the microgels tightly bind to the leaf surface, exhibiting excellent rain fastness and prolonged fungicidal activity. Finally, P‐MAPs are shown to be easily degradable by enzymes found in nature, demonstrating their negligible long‐term impact on the environment.

Continuous-flow biocatalysis utilizing immobilized enzymes emerged as a sustainable route for chemical synthesis. However, inadequate biocatalytic efficiency from current flow reactors, caused by non-productive enzyme immobilization or enzyme-carrier mismatches in size, hampers its widespread application. Here, we demonstrate a general-applicable and robust approach for the fabrication of a high-performance enzymatic continuous-flow reactor via integrating well-designed scalable isoporous block copolymer (BCP) membranes as carriers with an oriented and productive immobilization employing material binding peptides (MBP). Densely packed uniform enzyme-matched nanochannels of well-designed BCP membranes endow the desired nanoconfined environments towards a productive immobilized phytase. Tuning nanochannel properties can further regulate the complex reaction process and fortify the catalytic performance. The synergistic design of enzyme-matched carriers and efficient enzyme immobilization empowers an excellent catalytic performance with >1 month operational stability, superior productivity, and a high space-time yield (1.05 × 10⁵ g L⁻¹ d⁻¹) via a single-pass continuous-flow process. The obtained performance makes the designed nano- and isoporous block copolymer membrane reactor highly attractive for industrial applications.

The development of efficient and environmentally friendly plant protection systems is one of the major challenges for a sustainable agriculture of the future. Citrus canker caused by the pathogen Xanthomonas citri subsp. citri (X. citri) affects all cultivated citrus species worldwide and is responsible for enormous economic losses and restrictions in international trade. Currently used commercial copper‐based formulations are the origin of contamination for soil and groundwater, affecting local ecosystems and human health. A copper‐free sustainable microgel‐based plant protection system able to efficiently combat X. citri is developed. Microgels decorated with anchor peptides exhibit strong non‐covalent attachment to the surface of orange leaves and have the ability to release hexyl gallate, which inhibits the growth and spreading of pathogens. The tailored design of the microgel network allows high loadings of hexyl gallate (up to 40 wt.%) and a controlled release of gallates from microgels that provide long‐term protection. The antibacterial activity of the hexyl gallate‐loaded microgels is demonstrated by various in vitro assays as well as on orange plants in greenhouse settings. The experimental results suggest that the developed sustainable microgel‐based plant protection system for citrus trees allows efficient abatement of X. citri and reduces environmental pollution caused by copper formulations.

Summary: Plant cell suspension cultures can be used for the production of recombinant pharmaceutical proteins, but their potential is limited by modest production levels that may be unstable over long culture periods, reflecting initial culture heterogeneity and subsequent genetic and epigenetic changes. We used flow sorting to generate highly productive monoclonal cell lines from a heterogeneous population of tobacco BY‐2 cells expressing the human antibody M12 by selecting the co‐expressed fluorescent marker protein DsRed located on the same T‐DNA. Separation yielded ∼35% wells containing single protoplasts and ∼15% wells with monoclonal microcolonies that formed within 2 weeks. Thus, enriching the population of fluorescent cells from initially 24% to 90–96% in the six monoclonal lines resulted in an up to 13‐fold increase in M12 production that remained stable for 10–12 months. This is the first straightforward procedure allowing the generation of monoclonal plant cell suspension cultures by flow sorting, greatly increasing the potential of plant cells as an economical platform for the manufacture of recombinant pharmaceutical proteins.