Exploring cyanobacteria seed resources and corresponding gas-vesicle-biosynthetic elements for producing ultrasound molecular imaging probes

Use of gas vesicles (GVs) as biosynthetic ultrasound molecular imaging (UMI) probes has become a hot topic of research in recent years owing to their advantages of high stability, low risk of toxicity, genetic engineering characterization, easy post-modification, and drug-loading potential. Exploration of natural GV biosynthetic resources and their corresponding biosynthetic elements for various ultrasonic diagnosis and treatment needs to be developed in this field. In this study, we utilized the sequenced cyanobacteria resources preserved in the Freshwater Algae Culture Collection at the Institute of Hydrobiology (FACHB) to screen seed cells and corresponding synthetic elements for biosynthesis of UMI probes. GV operons from the genomes of 158 strains of cyanobacteria were analyzed to identify their natural GV biosynthetic elements. Based on the ultrasound screening method (VINNO D860LAB, 2D transducer X6-16L, 50 % output power mode, MI: 1.116), 57 seed resources with biosynthetic UMI probe potential from 10 genera were selected from 158 strains of cyanobacteria, corresponding to 28 types of effective biosynthetic elements. These results provide a theoretical basis for future mass production of customized GVs in chassis cells and their application in UMI.