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Stougaard, P.

Publications and source records attributed to Stougaard, P..

2 recordsLinked to original sources

TriMic: a Triticum aestivum microbial culture collection and synthetic community for dissecting wheat-microbe interactions

Understanding the molecular mechanisms underlying plant-microbe interactions is essential for developing innovative microbe-based agrotechnologies. However, deciphering these mechanisms within the complexity of natural microbial communities remains challenging. Such challenges can be addressed by employing synthetic microbial communities (SynComs) derived from well characterized microbial culture collections. Despite their importance, plant-associated microbial collections from major agricultural crops remain scarce. To bridge this gap, we established TriMic, a taxonomically and functionally representative culture collection of wheat root-associated bacteria. Complementing this collection, we include high quality genome sequences and an overview of genes involved in plant colonization, nutrient cycling, and plant growth promotion. Furthermore, we expanded this experimental toolkit by designing a reduced complexity SynCom that enables controlled dissection of plant-microbe interactions. Together, these resources lay the groundwork for mechanistic studies of plant-microbe interactions to accelerate biostimulant development aimed at enhancing agricultural productivity and sustainability. The TriMic collection and whole genomes are publicly available at the DSMZ (https://www.dsmz.de/collection/catalogue/microorganisms/microbiota/trimic) and NCBI. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=166 SRC="FIGDIR/small/740170v1_ufig1.gif" ALT="Figure 1"> View larger version (54K): org.highwire.dtl.DTLVardef@91bda0org.highwire.dtl.DTLVardef@386c49org.highwire.dtl.DTLVardef@4d455aorg.highwire.dtl.DTLVardef@1043ccb_HPS_FORMAT_FIGEXP M_FIG C_FIG Overview of the workflow for development of the wheat root bacterial collection and SynCom. (a) Bacterial isolates were recovered from roots of wheat grown in natural soil using two strategies after a root slurry was prepared: directly plating or host-mediated, which involved producing a secondary root slurry from wheat roots inoculated with the original root slurry (Ben Niu et al. 2017). Both root slurries were diluted and then plated onto four different types of media (1/10 R2A, 1/20 R2A, 1/100 R2A, and VxylG). Colonies were picked based on morphology and time of appearance. (b) Non-redundant strains of 88 purified isolates were made publicly available at the German Collection of Microorganisms and Cell cultures GmbH (DSMZ). (c) A 15-species synthetic community (SynCom) was developed after evaluating community dynamics in wheat roots inoculated with a 27-member consortium selected across genera in the collection. (d) Isolate genomes were sequenced using either short-read or hybrid assemblies with long-reads. Following functional annotation, genomes were screened for traits associated with plant-microbe interactions and secondary metabolite production.

microbiology↗

Two marine GH29 α-L-fucosidases from an uncultured Paraglaciecola sp. specifically hydrolyze fucosyl-N-acetylglucosamine regioisomers

O_SCPLOWLC_SCPLOW-Fucose is the most widely distributed O_SCPLOWLC_SCPLOW-hexose in marine and terrestrial environments, and presents a variety of functional roles. O_SCPLOWLC_SCPLOW-Fucose is the major monosaccharide in the polysaccharide fucoidan from cell walls of brown algae, and is found in human milk oligosaccharides and the Lewis blood group system, where it is important in cell signaling and immune response stimulation. Removal of fucose from these biomolecules is catalyzed by fucosidases belonging to different carbohydrate-active enzyme (CAZy) families. Fucosidases of glycoside hydrolase family 29 (GH29) release -O_SCPLOWLC_SCPLOW-fucose from non-reducing ends of glycans and display activities targeting different substrate compositions and linkage types. While several GH29 fucosidases from terrestrial environments have been characterized, much less is known about marine members of GH29 and their substrate specificities, as only four marine GH29 enzymes were previously characterized. Here, five GH29 fucosidases originating from an uncultured fucoidan-degrading marine bacterium (Paraglaciecola sp.) were cloned and produced recombinantly in E. coli. All five enzymes (Fp231, Fp239, Fp240, Fp251, Fp284) hydrolyzed the synthetic substrate CNP--O_SCPLOWLC_SCPLOW-fucose. By screening each of these enzymes against up to 17 fucose-containing oligosaccharides Fp231 and Fp284 showed strict substrate specificities against the fucosyl-N-acetylglucosamine regioisomers Fuc(1,4)GlcNAc and Fuc(1,6)GlcNAc, respectively, the former representing a new specificity. Fp231 is a monomeric enzyme with pH and temperature optima at pH 5.6-6.0 and 25{degrees}C, hydrolyzing Fuc(1,4)GlcNAc with kcat = 1.3 s-1 and Km = 660 M. Altogether, the findings extend our knowledge about GH29 family members from the marine environment, which are so far largely unexplored.

biochemistry↗