Deformability-Based Microfluidic Microdroplet Screening to Obtain Agarolytic Bacterial Cells.

Environmental microorganisms possess enzymes that can digest macromolecules such as agarose into smaller molecules that can be utilized for growth. These enzymes could be valuable for the effective utilization of global resources. However, since most of the microorganisms on Earth remain uncultured, there is significant untapped enzymatic potential in nature. Therefore, it is necessary to develop innovative tools and strategies for exploring these enzymatic resources. To address this, we developed a method for screening microbial cells that secrete hydrogel-degrading enzymes using deformability-based microfluidic microdroplet sorting. In this method, microbial cells are encapsulated as single cells in water-in-oil (W/O) microdroplets with a hydrogel whose shape becomes deformable as the hydrogel is progressively degraded into smaller molecules. Screening is achieved using a microfluidic device that passively sorts the deformed W/O microdroplets. Using this method, we successfully sorted agarose-containing microdroplets, encapsulating single bacterial cells that hydrolyzed agarose. This method can be used to screen various hydrogel-degrading microbial cells.

Complete Genomic Sequences of Two Agarolytic Vibrio Species Isolates from the Red Algae Gracilaria.

We report the complete genomic sequences of two agarolytic Vibrio species strains, STUT-A11 and STUT-A16, isolated from the red algae Gracilaria. Genomic annotations revealed that both strains harbor four ß-agarases, α-neoagarooligosaccharide hydrolase, and agarolytic ß-galactosidase, which support efficient agarose catabolism.

Genome Mining-Based Discovery of Fungal Macrolides Modified by glycosylphosphatidylinositol (GPI)-Ethanolamine Phosphate Transferase Homologues.

Through genome mining for fungal macrolide natural products, we discovered a characteristic family of putative macrolide biosynthetic gene clusters that contain a glycosylphosphatidylinositol-ethanolamine phosphate transferase (GPI-EPT) homologue. Through the heterologous expression of two clusters from Aspergillus kawachii and Colletotrichum incanum, new macrolides, including those with phosphoethanolamine or phosphocholine moieties, were formed. This study is the first demonstration of the tailoring steps catalyzed by GPI-EPT homologues in natural product biosynthesis, and it uncovers a new gene resource for phospholipid-resembling fungal macrolides.