Heterologous production and characterization of a pyomelanin of Antarctic Pseudomonas sp. ANT_H4: a metabolite protecting against UV and free radicals, interacting with iron from minerals and exhibiting priming properties toward plant hairy roots.

BACKGROUND: Antarctica has one of the most extreme environments in the world. This region is inhabited by specifically adapted microorganisms that produce various unique secondary metabolites (e.g. pigments) enabling their survival under the harsh environmental conditions. It was already shown that these natural, biologically active molecules may find application in various fields of biotechnology. RESULTS: In this study, a cold-active brown-pigment-producing Pseudomonas sp. ANT_H4 strain was characterized. In-depth genomic analysis combined with the application of a fosmid expression system revealed two different pathways of melanin-like compounds biosynthesis by the ANT_H4 strain. The chromatographic behavior and Fourier-transform infrared spectroscopic analyses allowed for the identification of the extracted melanin-like compound as a pyomelanin. Furthermore, optimization of the production and thorough functional analyses of the pyomelanin were performed to test its usability in biotechnology. It was confirmed that ANT_H4-derived pyomelanin increases the sun protection factor, enables scavenging of free radicals, and interacts with the iron from minerals. Moreover, it was shown for the first time that pyomelanin exhibits priming properties toward Calendula officinalis hairy roots in in vitro cultures. CONCLUSIONS: Results of the study indicate the significant biotechnological potential of ANT_H4-derived pyomelanin and open opportunities for future applications. Taking into account protective features of analyzed pyomelanin it may be potentially used in medical biotechnology and cosmetology. Especially interesting was showing that pyomelanin exhibits priming properties toward hairy roots, which creates a perspective for its usage for the development of novel and sustainable agrotechnical solutions.

Clinical Utility of Disease Activity Indices in Predicting Short-Term Response to Biologics in Patients with Ulcerative Colitis.

Background: The Mayo Score [MS], endoscopic Mayo Score [eMS] and the Ulcerative Colitis Index of Severity [UCEIS] are employed in the assessment of ulcerative colitis [UC] severity. This study compared the aforementioned indices in terms of predictory value for response to remission induction treatment with anti-TNF and anti-integrin biologics. Methods: A total of 38 patients were retrospectively evaluated in the study, 23 male and 15 female, aged 18-74 years old who had undergone a total of 53 biological therapy courses with either infliximab [IFX] or vedolizumab [VDZ] at the Department of Gastroenterology of the Medical University of Lódz. The clinical and endoscopic activity of UC was assessed at the outset of biological therapy and the 14th week remission induction assessment juncture. Results: The study analyzed 19 IFX and 34 VDZ treatment courses. The response rate of patients receiving IFX reached 73.67% and the response rate was 58.82% for VDZ. The mean MS, eMS and UCEIS improved among all patient groups: 8.316 ± 1.974 to 4.158 ± 2.218 (p < 0.05), 2.632 ± 0.597 to 1.790 ± 0.713 (p < 0.05) and 4.790 ± 1.745 to 3.000 ± 1.453 (p < 0.05) for IFX, 7.088 ± 2.234 to 3.618 ± 2.412 (p < 0.05), 2.706 ± 0.524 to 1.677 ± 1.065 (p < 0.05) and 4.235 ± 1.350 to 2.735 ± 1.880 (p < 0.05) for VDZ. Conclusions: The outcome assessment in induction treatment of UC includes clinical data and endoscopic evaluation. Severity of inflammatory lesion activity according to the eMS and UCEIS indices correlates with the overall disease presentation as evaluated with MS. The UCEIS provides an overall better predictor for biological induction treatment when compared with the eMS in both patient groups, particularly in those receiving VDZ. It provides a promising alternative to the eMS and can be employed for both initial disease severity assessment as well as for treatment response monitoring.