Bioplastic (poly-3-hydroxybutyrate)-producing Massilia endophytica sp. nov., isolated from Cannabis sativa L. ‘Cheungsam’

A rod-shaped, motile, Gram-negative bacterial strain named DM-R-R2A-13 T was isolated from the plant Cannabis sativa L. ‘Cheungsam’. The phylogenetic analysis of the 16S rRNA gene sequence revealed that strain DM-R-R2A-13 T belongs to the family Oxalobacteraceae and is closely related to members of the genus Massilia , with Massilia flava (97.58% sequence similarity) and Massilia armeniaca (97.37% sequence similarity) being the closest members. The digital DNA-DNA hybridization (dDDH) values between strain DM-R-R2A-13 T and Massilia flava CGMCC 1.10685 T and Massilia armeniaca ZMN-3 T were 22.2% and 23.3%, while the average nucleotide identity (ANI) values were 78.85% and 79.63%, respectively. The DNA G+C content was measured to be 64.6 mol%. Moreover, the bacterium was found to contain polyhydroxyalkanoate (PHA) granules based on transmission electron microscopy, indicating its potential to produce bioplastic. Genome annotation revealed the presence of PHA synthase genes ( phaC , phaR , phaP, and phaZ ), and the biopolymer was identified as poly-3-hydroxybutyrate (PHB) based on nuclear magnetic resonance (NMR) and Fourier transform infrared spectroscopy (FTIR) analyses. Using maltose as a carbon source, the strain produced PHB of up to 58.06% of its dry cell weight. Based on the phenotypic, chemotaxonomic, and phylogenetic characteristics, it has been determined that DM-R-R2A-13 T represents a novel species belonging to the genus Massilia . As such, the name Massilia endophytica sp. nov. is proposed for this newly identified species. The type strain is DM-R-R2A-13 T (= KCTC 92072 T = GDMCC 1.2920 T ).