Background: Magnetic nanoparticles (MNPs) are becoming more important as carriers, because of their large specific surface area and easy separability. They are increasingly used in enzyme technology, diagnostics, and drug delivery. Major results: For the directed and almost irreversible immobilization of proteins on MNPs, we have developed a new selective (His-Arg) 4 peptide-tag, that binds fusion proteins directly from an E. coli cell lysate to non-functionalized, low-cost MNPs. Using the immobilization of an ene-reductase as an example, we could demonstrate that the fusion with this tag increases thermostability without reducing overall activity (ER w/o tag: t 1/2 = 3.7 h, (HR) 4-ER: t 1/2 = 9.9 h). Immobilization by adsorption in Tris buffer resulted in very high enzyme loads with approx. 380 mg g-1 and 67% residual activity. The immobilization on the MNPs allowed a fast concentration, buffer exchange, and reuse. While about 50% of the activity was lost after the first reuse, we were able to show that the activity did not decrease further and was stable for another nine cycles. Conclusion: According to our studies, our tag highly works for any kind of immobilization on MNPs and holds the potential for enzyme immobilizations as well as for drug delivery and sensors. K E Y W O R D S affinity tag, ene-reductase, enzyme immobilization, iron oxides, magnetic nanoparticles 1 INTRODUCTION Magnetic nanoparticles are used in all kinds of applications, such as enzyme immobilization, bioimaging, biosensors, drug delivery, enrichment of bacteria, and many more. [1-5] The high specific surface areas Abbreviations: (HR) 4 , dipeptide histidine-arginine repeated four times; AEX, anion exchange chromatography; Arg, arginine; BCA, bicinchoninic acid; ER, ene-reductase; ER w/o tag, ene-reductase without a tag; FMN, flavin mononucleotide; GFP, green fluorescent protein; His, histidine; HPLC, high-performance liquid chromatography; IMAC, immobilized metal affinity chromatography; Lys, lysine; MNPB, bound proteins on magnetic nanoparticles; MNPs, magnetic nanoparticles; MNPS, supernatant of magnetic nanoparticles after magnetic separation; MNPW, wash supernatant of magnetic nanoparticles after magnetic separation; NADH, nicotinamide adenine dinucleotide; NADPH, nicotinamide adenine dinucleotide phosphate; SDS-PAGE, sodium dodecyl sulfate-polyacrylamide gel electrophoresis; SEC, size exclusion chromatography; TBS, Tris-buffered saline This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non-commercial and no modifications or adaptations are made.

Caryopteris x Clandonensis, also known as bluebeard, is an ornamental plant containing a large variety of terpenes and terpene-like compounds. Four different cultivars were subjected to a principal component analysis to elucidate variations in terpenoid-biosynthesis and consequently, two representative cultivars were sequenced on a genomic level. Functional annotation of genes as well as comparative genome analysis on long read datasets enabled the identification of cultivar-specific terpene synthase and cytochrome p450 enzyme sequences. This enables new insights, especially since terpenoids in research and industry are gaining increasing interest due to their importance in areas such as food preservation, fragrances, or as active ingredients in pharmaceutical formulations. According to BUSCO assessments, the presented genomes have an average size of 355 Mb and about 96.8% completeness. An average of 52,090 genes could be annotated as putative proteins, whereas about 42 were associated with terpene synthases and about 1340 with cytochrome p450 enzymes.

Lichens are symbiotic associations consisting of a photobiont (algae or cyanobacteria) and a mycobiont (fungus). They are known to produce a variety of unique secondary metabolites. To access this biosynthetic potential for biotechnological applications, deeper insights into the biosynthetic pathways and corresponding gene clusters are necessary. Here we provide a comprehensive view of the biosynthetic gene clusters of all organisms comprising a lichen thallus: fungi, green algae, and bacteria. We present two high-quality PacBio metagenomes, in which we identified a total of 460 biosynthetic gene clusters. Lichen mycobionts yielded 73–114 clusters, other lichen associated ascomycetes 8–40, green algae of the genus Trebouxia 14–19, and lichen-associated bacteria 101–105 clusters. The mycobionts contained mainly T1PKSs, followed by NRPSs, and terpenes; Trebouxia reads harbored mainly clusters linked to terpenes, followed by NRPSs and T3PKSs. Other lichen-associated ascomycetes and bacteria contained a mix of diverse biosynthetic gene clusters. In this study, we identified for the first time the biosynthetic gene clusters of entire lichen holobionts. The yet untapped biosynthetic potential of two species of the genus Hypogymnia is made accessible for further research.