Polynucleotide phosphorylase is involved in the control of lipopeptide fengycin production in Bacillus subtilis

Bacillus subtilis is a wealth source of lipopeptide molecules such as iturins, surfactins and fengycins or plipastatins endowed with a range of biological activities. These molecules, designated secondary metabolites, are synthesized via non-ribosomal peptides synthesis (NRPS) machinery and are most often subjected to a complex regulation with involvement of several regulatory factors. To gain novel insights on mechanism regulating fengycin production, we investigated the effect of the fascinating polynucleotide phosphorylase (PNPase), as well as the effect of lipopeptide surfactin. Compared to the wild type, the production of fengycin in the mutant strains B. subtilis BBG235 and BBG236 altered for PNPase has not only decreased to about 70 and 40%, respectively, but also hampered its antifungal activity towards the plant pathogen Botrytis cinerea. On the other hand, mutant strains BBG231 (srfAA−) and BBG232 (srfAC−) displayed different levels of fengycin production. BBG231 had registered an important decrease in fengycin production, comparable to that observed for BBG235 or BBG236. This study permitted to establish that the products of pnpA gene (PNPase), and srfAA− (surfactin synthetase) are involved in fengycin production. © 2018, Springer-Verlag GmbH Germany, part of Springer Nature

Year in review in Intensive Care Medicine 2011: III. ARDS and ECMO, weaning, mechanical ventilation, noninvasive ventilation, pediatrics and miscellanea

SCOPUS: re.jinfo:eu-repo/semantics/publishe

Leaf Volatile Compounds of Seven Citrus Somatic Tetraploid Hybrids Sharing Willow Leaf Mandarine (Citrus deliciosa Ten) as Their Common Parent

International audienc

Phenolic potential of new red hybrid grape varieties to produce quality wines and identification by the malvin

The hybrids are new varieties that are resistant to the cryptogamic diseases of vines, and they may be a good solution to the reduction of pesticide use. However, these new varieties have appeared recently and only few studies have been conducted to check the quality of the wine that they produce. In this study, wines originated from hybrids were chemically characterized (polyphenols, tannins, anthocyanins, and color analysis). Results show that their oenological parameters were close to those of the Vitis vinifera wines. The wines made from Vinifera (100%), with Vidoc, and all the resistant Bouquets studied are malvidin-3 glucoside dominant, and all the others hybrids varieties are cyanidin dominant. Furthermore, the hybrid wines had a higher concentration in condensed tannins and a lower one in molecular tannins compared with the Vitis vinifera wines, except for the Vidoc wines. As far as the anthocyanin content is concerned, the samples contained anthocyanin diglucosides, with the malvidin-3,5-diglucoside (malvin) the most abundant one. Also, their concentration in molecular anthocyanins were higher than the concentration in normal wines. The Vidoc wines do not contain any malvin. For the other wines, malvin co-eluted with cyanidin-3-O-glucoside and in this case, the cyanidin’s concentration was impressively higher than the Vidoc wines. The current OIV method gives different results for malvidol diglucoside compared to the use of an HPLC chromatography method (HPLC-DAD-QQQ). The current OIV method does not appear reliable in comparison with the HPLC method for detecting malvin. Finally, the hybrid wines had a darker blue/purplish color than the Vitis vinifera wines