Hydrogel Nanoparticle as a Functional Coating Layer in Biosensing, Tissue Engineering, and Drug Delivery

The development of functional coating materials has resulted in many breakthroughs in the discovery of energy, environmental, and biomedical applications. Responsive polymeric hydrogels are an example of smart coating materials due to their stimuli-responsive characteristics upon changes in their local environment. This review focuses on the introduction of hydrogel nanoparticles and their applications in functional layers as responsive coating materials. Hydrogels are explained by the composition of cross-links and monomers used for preparation. In particular, an important class of responsive hydrogels, that is, nanosized hydrogel particles (nanogels), are described for thee synthesis, modification, and application in assembly of functional coating layers. Finally, nanogel functional layers for biological applications will be discussed with recent advances in biosensing, tissue engineering, and drug delivery

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

Abstract A rod-shaped, motile, Gram-negative bacterial strain named DM-R-R2A-13T was isolated from the plant Cannabis sativa L. ‘Cheungsam’. The phylogenetic analysis of the 16S rRNA gene sequence revealed that strain DM-R-R2A-13T 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-13T and Massilia flava CGMCC 1.10685T and Massilia armeniaca ZMN-3Twere 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-13T 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-13T (= KCTC 92072T = GDMCC 1.2920T)

Subtercola endophyticus sp. nov., a cold-adapted bacterium isolated from Abies koreana

Abstract A novel Gram-stain-positive, aerobic bacterial strain, designated AK-R2A1-2 T, was isolated from the surface-sterilized needle leaves of an Abies koreana tree. Strain AK-R2A1-2 T had 97.3% and 96.7% 16S rRNA gene sequence similarities with Subtercola boreus K300T and Subtercola lobariae 9583bT, respectively, but formed a distinct phyletic lineage from these two strains. Growth of strain AK-R2A1-2 T was observed at 4–25 °C at pH 5.0–8.0. Strain AK-R2A1-2 T contained menaquinone 9 (MK-9) and menaquinone 10 (MK-10) as the predominant respiratory quinones. The major cellular fatty acids were anteiso-C15:0 and summed feature 8 (C18:1ω7c or/and C18:1ω6c), and the polar lipids included diphosphatidylglycerol (DPG) and three unknown aminolipids, AKL2, AKL3, and AKL4. The complete genome of strain AK-R2A1-2 T was sequenced to understand the genetic basis of its survival at low temperatures. Multiple copies of cold-associated genes involved in cold-active chaperon, stress response, and DNA repair supported survival of the strain at low temperatures. Strain AK-R2A1-2 T was also able to significantly improve rice seedling growth under low temperatures. Thus, this strain represents a novel species of the genus Subtercola, and the proposed name is Subtercola endophyticus sp. nov. The type strain is AK-R2A1-2 T (= KCTC 49721 T = GDMCC 1.2921 T)

Genome insights into the plant growth-promoting bacterium Saccharibacillus brassicae ATSA2T

Abstract Endophytes can facilitate the improvement of plant growth and health in agriculturally important crops, yet their genomes and secondary metabolites remain largely unexplored. We previously isolated Saccharibacillus brassicae strain ATSA2T from surface-sterilized seeds of kimchi cabbage and represented a novel species of the genus Saccharibacillus. In this study, we evaluated the plant growth-promoting (PGP) effect of strain ATSA2T in kimchi cabbage, bok choy, and pepper plants grown in soils. We found a significant effect on the shoot and root biomass, and chlorophyll contents following strain ATSA2T treatment. Strain ATSA2T displayed PGP traits such as indole acetic acid (IAA, 62.9 μg/mL) and siderophore production, and phosphate solubilization activity. Furthermore, genome analysis of this strain suggested the presence of gene clusters involved in iron acquisition (fhuABD, afuABC, fbpABC, and fepCDG) and phosphate solubilization (pstABCHS, phoABHLU, and phnCDEP) and other phytohormone biosynthesis genes, including indole-3-acetic acid (trpABCDEFG), in the genome. Interestingly, the secondary metabolites cerecidin, carotenoid, siderophore (staphylobactin), and bacillaene underlying plant growth promotion were found in the whole genome via antiSMASH analysis. Overall, physiological testing and genome analysis data provide comprehensive insights into plant growth-promoting mechanisms, suggesting the relevance of strain ATSA2T in agricultural biotechnology