Biology subjects

Preuss, L.

Publications and source records attributed to Preuss, L..

5 recordsLinked to original sources

bioRxiv2026

Rapid spread of nutritional Wolbachia symbionts across and within solitary bee species

Maternally inherited, intracellular Bacteria of the genus Wolbachia are extremely widespread among arthropods. Their evolutionary success is owed to frequent host shifts and rapid subsequent spread within host populations, often facilitated by Wolbachia-induced reproductive manipulations. Theory suggests that carrying Wolbachia must also be beneficial for a successful spread, however the nature of such benefits remains unclear. Here, we demonstrate that Wolbachias success in many solitary bee species is strongly associated with the presence of a gene cassette enabling Wolbachia to synthesize Biotin (vitamin B7). This ability is absent from almost all other Wolbachia strains but common among bee associated strains. We show that Wolbachia occurs in up to 70% of all bee species and that strains carrying this rare genomic element have independently spread into numerous bee hosts recently. We further demonstrate that the presence of the biotin operon is associated with specialised diets in several bee species, suggesting a previously overlooked nutritional role of Wolbachia in this group of important pollinators. Overall, our results suggest that nutritional benefits provided by symbionts may represent a more widespread and important mechanism by which reproductive manipulators spread into new host species than previously appreciated.

evolutionary biology↗

bioRxiv2025

Role of Dienelactone Hydrolases in PET Biodegradation by Flavobacteria Maribacter dokdonensis and Arenibacter palladensis

Dienelactone hydrolases (DLHs, EC 3.1.1.45) are enzymes that play a crucial role in the breakdown of cyclic esters and some have been found to act on substrates such as terephthalate esters, which are monomers of polyethylene terephthalate (PET). In the current study, we show that bacteria affiliated with the Bacteroidota (class Flavobacteria) harbor DLHs acting on PET foil and powder. We report on the isolation of two marine bacterial strains, Arenibacter palladensis UHH-Hm9b and Maribacter dokdonensis UHH-5R5, forming biofilms on PET foil and releasing {micro}M amounts of terephthalic acid after 5-7 days. Genome sequencing and functional analyses identified two secreted DHLs designated PET93 and PET 94 involved in PET degradation. While their predicted active sites and substrates binding pockets were identical to previously published PETases, both enzymes differed largely in their structural features from known PETases and represent novel scaffolds. Further they lacked the typical porC-domain of the known PETases from the Flavobacteria. Biochemical characterization of the two recombinant enzymes confirmed activity on PET, the primary degradation products Bis(2-Hydroxyethyl) terephthalate (BHET) and Mono-(Hydroxyethyl) terephthalate (MHET). These are the first DLHs to be reported being active on plastics and our findings indicate that Flavobacteria harbor an unexpectedly wide range of PET-active promiscuous enzymes. IMPORTANCEGlobal plastics pollution is a major environmental challenge, and we still have limited knowledge of marine microbiota involved in possible remediation. Our research shows that marine Flavobacteria harbor the potential for PET degradation using dienelactone hydrolases (DLHs, EC 3.1.1.45). The widespread distribution of these microorganisms and the notion that these enzymes are secreted may imply a possible role in marine PET remediation.

microbiology↗

bioRxiv2025

High Throughput Information Extraction of Printed Specimen Labels from Large-Scale Digitization of Entomological Collections using a Semi-Automated Pipeline

O_LINatural history museums curate billions of insect specimens, forming a vast but underutilized resource for biodiversity research. While digitization efforts have increased the availability of high-resolution specimen images, extracting metadata from labels remains a major bottleneck, often requiring manual transcription. C_LIO_LIWe developed a semi-automated pipeline, ELIE (Entomological Label Information Extraction), which combines computer vision, convolutional neural networks (CNNs), optical character recognition (OCR), and clustering algorithms to streamline label data extraction. Our pipeline operates in three stages: (1) label detection and classification (printed vs. handwritten), (2) OCR-based text extraction from printed labels using Tesseract or Google Vision, and (3) clustering of extracted text for human validation of outliers. C_LIO_LIBenchmarking on diverse datasets from multiple museum collections showed that our approach successfully extracted and clustered up to 98% of printed labels, significantly reducing manual effort. The pipeline improves efficiency in digitization workflows while maintaining high accuracy in label data capture. C_LIO_LIOur approach demonstrates the potential of integrating AI-driven methods with human validation to accelerate specimen digitization. By reducing manual transcription workload and enabling scalable extraction of insect label metadata, it unlocks biodiversity data for research in ecology, systematics, and conservation globally. C_LI

bioinformatics↗

bioRxiv2025

Arabidopsis root lipid droplets are hubs for membrane homeostasis under heat stress, and triterpenoid synthesis and storage.

O_LIPlant lipid droplets (LDs) and their associated proteins have numerous subcellular and physiological functions. While considerable progress has been made for LDs in many tissues, the function and composition of LDs in roots remains largely unexplored. C_LIO_LIWe investigated the changes of the number of LDs and of the lipidome in heat-stressed Arabidopsis thaliana roots. Furthermore, we isolated root LDs from the Arabidopsis mutant trigalactosyldiacylglycerol 1-1 sugar dependent 1-4 and investigated their proteome and lipidome. C_LIO_LIHeat stress lead to a degradation of membrane lipids and an increase in TAGs and LDs. while, fatty acid SEs decreased, probably acting as precursors for acylated sterol glycosides. A variety of proteins were enriched in root LDs, which are thus far not described as LD proteins. Transient expression of these proteins in many cases confirmed their LD localization, for example of the triterpene biosynthetic enzymes thalianol synthase and marneral synthase. We could furthermore show that the educts and products of these enzymes are enriched in root LDs, too. C_LIO_LIWe conclude that root LDs simultaneously act as a sink and source during heat stress-induced membrane remodeling. Furthermore, root LDs play a pivotal role in triperpene synthesis and storage, thereby highlighting LDs as hubs in specialized metabolism. C_LI

plant biology↗

bioRxiv2025

Polyethylene terephthalate (PET) primary degradation products affect c-di-GMP-, cAMP-signaling and quorum sensing (QS) in Vibrio gazogenes DSM 21264

Global plastic pollution in oceans and estuaries is increasing rapidly and its well known that bacteria colonize plastic particles of all sizes. Vibrio spp. are frequently found as part of the plastisphere. We recently showed that Vibrio gazogenes DSM 21264 harbors a promiscuous esterase designated PET6. We now provide evidence that the pet6 gene is expressed under a wide range of environmental conditions in its native host. However, in PET- and PE-grown biofilms the pet6 gene expression was not affected by the type of surface. The pet6 transcription was sufficient to allow enzyme production and release of {micro}M amounts of mono-(2-hydroxyethyl) terephthalate (MHET) and terephthalic acid (TPA) already after 24 hours of incubation on PET foil. Notably, the highest pet6 gene transcription was observed in planktonic lifestyle in the presence of bis(2-hydroxyethyl) terephthalate (BHET) one of the primary degradation products of PET. BHET was further hydrolyzed by PET6 and UlaG, a lactonase that had not been known to be involved in BHET degradation. Elevated concentrations of BHET affected the major signaling circuits involved in bacterial quorum sensing (QS), c-di-GMP and cAMP-CRP signaling. This resulted in failure to form biofilms, synthesis of the red pigment prodigiosin and altered colony morphologies. While BHET had a very wide impact, TPA interfered mainly with the bacterial QS by attenuating the expression of the CAI-I autoinducer synthase gene. These observations imply a potential role of BHET and TPA as nutritional signals in Vibrio gazogenes and that may affect its growth and survival in the plastisphere. IMPORTANCEThis study provides first evidence that Vibrio gazogenes DSM 21264 secretes an active PET hydrolase and degrades the polymer using PET6 when growing in biofilms on foils and microplastic particles. The study further provides evidence that the primary PET degradation products BHET and TPA may have a profound impact on the global QS, c-di-GMP and cAMP-CRP signaling of V. gazogenes and its capability to colonize plastic particles in the marine environment.

microbiology↗