Correction: De Vogel, F.A., et al. Comparative Genomics of Marine Bacteria from a Historically Defined Plastic Biodegradation Consortium with the Capacity to Biodegrade Polyhydroxyalkanoates. Microorganisms 2021, 9, 186.

The authors wish to make the following corrections to this paper [...].

Comparative Genomics of Marine Bacteria from a Historically Defined Plastic Biodegradation Consortium with the Capacity to Biodegrade Polyhydroxyalkanoates.

Biodegradable and compostable plastics are getting more attention as the environmental impacts of fossil-fuel-based plastics are revealed. Microbes can consume these plastics and biodegrade them within weeks to months under the proper conditions. The biobased polyhydroxyalkanoate (PHA) polymer family is an attractive alternative due to its physicochemical properties and biodegradability in soil, aquatic, and composting environments. Standard test methods are available for biodegradation that employ either natural inocula or defined communities, the latter being preferred for standardization and comparability. The original marine biodegradation standard test method ASTM D6691 employed such a defined consortium for testing PHA biodegradation. However, the taxonomic composition and metabolic potential of this consortium have never been confirmed using DNA sequencing technologies. To this end, we revived available members of this consortium and determined their phylogenetic placement, genomic sequence content, and metabolic potential. The revived members belonged to the Bacillaceae, Rhodobacteraceae, and Vibrionaceae families. Using a comparative genomics approach, we found all the necessary enzymes for both PHA production and utilization in most of the members. In a clearing-zone assay, three isolates also showed extracellular depolymerase activity. However, we did not find classical PHA depolymerases, but identified two potentially new extracellular depolymerases that resemble triacylglycerol lipases.

Cyanuric Chloride-Based Reactive Dyes for Use in the Antimicrobial Treatments of Polymeric Materials.

This study reports a simple and practical method to introduce antimicrobial and biofilm-controlling functions into hydroxyl- or amino-containing polymers such as cellulose using compounds derived from widely used reactive dyes. Two dichloro-s-triazine-based dyes, reactive blue 4 and sodium 4-(4,6-dichloro-1,3,5-triazinylamino)-benzenesulfonate (a colorless reactive "dye"), were covalently attached to cellulose at room temperature by replacing one chloride on the dyes with the hydroxyl groups on cellulose followed by hydrolysis under alkaline conditions to transform the remaining chloride into hydroxyl groups. The chemical reactions were confirmed by FT-IR studies, energy-dispersive X-ray spectroscopy, water contact angle measurement, and zeta potential analysis. The resulting cellulose provided powerful antimicrobial activities against Staphylococcus epidermidis (S. epidermidis, ATCC 35984, Gram-positive bacteria), Escherichia coli (E. coli, ATCC 15597, Gram-negative bacteria), and Candida albicans (C. albicans, ATCC 10231, yeast) and effectively prevented the formation of bacterial or fungal biofilms. The minimum inhibition concentrations of the hydrolyzed dyes were similar to that of phenol. In the zone of inhibition studies using phenolic compounds as positive controls, the hydrolyzed dyes and their model compound cyanuric acid demonstrated antimicrobial functions, suggesting that the antimicrobial activities were associated with the phenol-like hydroxyl groups on the triazine rings. Antimicrobial mechanism investigation indicated that the phenol-like structures on the dyed cellulose caused microbial lysis and leakage of intracellular components. The antimicrobial functions were durable upon repeated washing, and the dyed cellulose showed outstanding biocompatibility toward mammalian cells.

Serine-Lysine Peptides as Mediators for the Production of Titanium Dioxide: Investigating the Effects of Primary and Secondary Structures Using Solid-State NMR Spectroscopy and DFT Calculations.

A biomimetic approach to the formation of titania (TiO2) nanostructures is desirable because of the mild conditions required in this form of production. We have identified a series of serine-lysine peptides as candidates for the biomimetic production of TiO2 nanostructures. We have assayed these peptides for TiO2-precipitating activity upon exposure to titanium bis(ammonium lactato)dihydroxide and have characterized the resulting coprecipitates using scanning electron microscopy. A subset of these assayed peptides efficiently facilitates the production of TiO2 nanospheres. Here, we investigate the process of TiO2 nanosphere formation mediated by the S-K peptides KSSKK- and SKSK3SKS using one-dimensional and two-dimensional solid-state NMR (ssNMR) on peptide samples with uniformly 13C-enriched residues. ssNMR is used to assign 13C chemical shifts (CSs) site-specifically in each free peptide and TiO2-embedded peptide, which are used to derive secondary structures in the neat and TiO2 coprecipitated states. The backbone 13C CSs are used to assess secondary structural changes undergone during the coprecipitation process. Side-chain 13C CS changes are analyzed with density functional theory calculations and used to determine side-chain conformational changes that occur upon coprecipitation with TiO2 and to determine surface orientation of lysine side chains in TiO2-peptide composites.