Characterization of Lactiplantibacillus plantarum Tw226 strain and its use for the production of a new membrane-bound biosurfactant

This study aimed to evaluate the viability for biotechnological uses of a new cell-bound biosurfactant produced by a lactic acid bacterium isolated from the intestinal tract of Odontesthes bonariensis. For this purpose, the bacterial strain was characterized, and the conditions for biosurfactant production were optimized. Moreover, the biosurfactant was chemically characterized, and its possible use as an emulsi-fying agent assessed. The bacterium was identified as Lactiplantibacillus plantarum Tw226 and qualified as safe for biotechnological uses according to the genomic and antibiotic resistance studies. The agitation did not influence the biosurfactant productivity, which reached its maximum value, using MRS medium as a nutrient source, before 48 h of incubation at a temperature of 35 degrees C. The glyco-lipo-peptide nature of the biosurfactant was confirmed by the analysis of its chemical composition. It showed stable surface activity in the pH range of 5-7 and a remarkable functionality as an emulsifier, especially in emulsions containing NaCl. (c) 2022 Elsevier B.V. All rights reserved

DNA Photodamage and Repair: Computational Photobiology in Action

International audienc

Computational Modeling of Photoexcitation in DNA Single and Double Strands

The photoexcitation of DNA strands triggers extremely complex photoinduced processes, which cannot be understood solely on the basis of the behavior of the nucleobase building blocks. Decisive factors in DNA oligomers and polymers include collective electronic effects, excitonic coupling, hydrogen-bonding interactions, local steric hindrance, charge transfer, and environmental and solvent effects. This chapter surveys recent theoretical and computational efforts to model real-world excited-state DNA strands using a variety of established and emerging theoretical methods. One central issue is the role of localized vs delocalized excitations and the extent to which they determine the nature and the temporal evolution of the initial photoexcitation in DNA strands