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Portieles, R.

Publications and source records attributed to Portieles, R..

2 recordsLinked to original sources

Novel Bacillus altitudinis endolysin (ArtE2) targeting both Gram-positive and Gram-negative bacteria

Antibiotic resistance is a major global health concern. The development of new antibiotics and therapeutics is crucial for the future. Bacteriophages produce endolysins that induce bacterial lysis, making them a promising treatment option. Deep sequencing was used to identify and isolate genes encoding endolysins from Bacillus spp.. We characterized the biological activities of these endolysins. Additionally, this study focused on the design of a new chimeric endolysin, ArtE2, which combines endolysin-2 with a polycationic peptide to address the bacterial activity in gram-negative pathogenic bacteria. Using bioinformatic tools, we conducted three-dimensional modeling of the endolysin ArtE2 and its interactions with peptidoglycan fragments. In this study, we tested the activity of chimeric endolysins against both Gram-positive and Gram-negative bacteria. All endolysins share the same catalytic domain and diverse cell-binding domains. Some endolysins are highly specific to certain bacterial species or strains, whereas others have broader specificities. Histidine interactions are an important part of the mechanism by which ArtE2 connects with bacterial peptidoglycan. Additionally, the engineered endolysin ArtE2 was highly effective at killing Staphylococcus aureus and Escherichia coli. In silico analysis showed that the fusion did not negatively affect endolysin folding or activity. These findings suggest that ArtE2 could be used to develop efficient antibacterial controls targeting pathogenic Gram-positive and Gram-negative bacteria.

microbiology↗

Bioengineering of a Lactococcus lactis subsp. lactis strain enhances nisin production and bioactivity.

Lactococcus lactis subsp. lactis is a food bacterium that has been utilized for decades in food fermentation and the development of high-value industrial goods. Among these, nisin is produced by several strains of L. lactis subsp. lactis plays a crucial role as a food bio-preservative. The relative expression of the gene cluster involved in nisin production was evaluated using qPCR analysis. Additionally, a series of re-transformations of the strain introducing multi copies of the nisA and nisRK genes involved in nisin biosynthesis were developed. The simultaneous expression of nisA and nisZ genes was used to potentiate the effective inhibition of foodborne pathogens. Further, qPCR analysis revealed a low expression of the nisA and nisRK genes in wild-type L. lactis subsp. lactis. After several re-transformations of the strain with the nisA and nisRK genes, a high expression of these genes was obtained, contributing to improved nisin production. Also, the co-expression of nisA and nisZ genes results in highly efficient antimicrobial activity. Hence, this study would supply an approach to enhancing nisin production during industrial processes and antimicrobial activity.

microbiology↗