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Biology subjects

Malvankar, N.

Publications and source records attributed to Malvankar, N..

2 recordsLinked to original sources

A biofilm-derived peptide as an underwater adhesive

Wet adhesives that perform under water have broad applications in industrial and biomedical settings. To date, molecular designs for underwater adhesives have largely been inspired by marine animals including mussels and barnacles. Here, we propose bacterial biofilms as an alternative source of inspiration for underwater adhesives. Specifically, we demonstrate the application potential of a peptide derived from biofilms formed by the notorious pathogen Vibrio cholerae. We characterize the ability of this biofilm-derived peptide to adsorb onto various surfaces and to glue wet surfaces, by using a combination of confocal microscopy, molecular dynamics simulations, atomic force microscopy, lap shear tests, and spectroscopic tools. We further show that the peptide can co-aggregate with microspheres acting as an effective flocculant. Finally, we succeeded in purifying this peptide from E. coli in a functional form, setting the stage for large-scale production. Our results open new design possibilities for underwater adhesives inspired by natural biofilms. TeaserA peptide derived from biofilms adheres to diverse surfaces and shows promising potential as a wet adhesive and flocculant.

bioengineering↗

Borg extrachromosomal elements of methane-oxidizing archaea have conserved and expressed genetic repertoires

Borgs are huge extrachromosomal elements (ECE) of anaerobic methane-consuming "Candidatus Methanoperedens" archaea. Here, we used nanopore sequencing to validate published complete genomes curated from short reads and to reconstruct new genomes. 13 complete and four near-complete linear genomes share 40 genes that define a largely syntenous genome backbone. We use these conserved genes to identify new Borgs from peatland soil and to delineate Borg phylogeny, revealing two major clades. Remarkably, Borg genes encoding OmcZ nanowire-like electron-exporting cytochromes and cell surface proteins are more highly expressed than those of host Methanoperedens, indicating that Borgs augment the Methanoperedens activity in situ. We reconstructed the first complete 4.00 Mbp genome for a Methanoperedens that is inferred to be a Borg host and predicted its methylation motifs, which differ from pervasive TC and CC methylation motifs of the Borgs. Thus, methylation may enable Methanoperedens to distinguish their genomes from those of Borgs. Very high Borg to Methanoperedens ratios and structural predictions suggest that Borgs may be capable of encapsulation. The findings clearly define Borgs as a distinct class of ECE with shared genomic signatures, establish their diversification from a common ancestor with genetic inheritance, and raise the possibility of periodic existence outside of host cells.

microbiology↗