Mikrobiološka transformacija sintetičkog laktona benzofuranskog tipa

The aim of this work was the investigation of the biotransformation ability of a synthetic benzofurane type g-lactone. This workwas basedon the microbiological reactions of Aspergillus niger, Saccharomyces cerevisiae, Bacillus mycoides, Agrobacterium tumefa- ciens,Pseudomonas glicinea and Pseudomonas fluorescens to obtain newactive derivatives. Four biotransformation products were determined. The lactone was used for two purposes, as an additive for the nutrient substrate and as a source of organic carbon.Cilj ovog rada je ispitivanje mogućnosti biotransformacije benzofuranskog derivata, sa a-metilen-g-butirolaktonskom strukturnom jedinicom, sa različitim sojevima mikroorganizama: Aspergillus niger, Saccharomyces cerrevisiae, Bacillus mycoides, Agrobacterium tumefaciens, Pseudomonas glicinea i Pseudomonas fluorescens u cilju dobivanja novih jedinjenja sa specifičnijom antimikrobnom aktivnošću. Takodje izolovani i identifikovani proizvodi su ukazali i potvrdili osnovne biodegradacione puteve ispitivanog laktona

Изоловање и антимикробна активност антрахинона неких врста лишајева рода Xanthoria

The isolation of six anthraquinones erythroglaucin, physcion, xanthorin, emodin, fallacinal, teloschistin, from three species of the lichen genus Xanthoria (X.fallax, X.elegans and X.policarpa) is reported. Physcion is the dominant anthraquinone in all species.The anthraquinones showed broad-spectrum and fungal and selective activity against some phytopathogenic bacterial species.Из три врсте лишајева рода Xanthoriа (X.fallax, X.elegans and X.policarpa) изоловани су следећи антрахинони : еритроглауцин, фисцион, ксанторин, емодин, фалацинал и фалацинол.Тестирани антрахинони показују широк спектар антифунгалне активности и селективну активност према неким врстама фитопатогених бактерија

In vitro synergistic antibacterial activity of Melissa officinalis L. and some preservatives

The aim of this study was to investigate the antibacterial activity of aqueous, ethanol and ethyl acetate extracts of the species Melissa officinalis L. and their in vitro synergistic action with preservatives, namely: sodium nitrite, sodium benzoate and potassium sorbate against selected food spoiling bacteria, for a potential use in food industry. Synergistic action was noticed in almost every combination between plant extracts and preservatives. This work showed that the active compounds from ethanol, ethyl acetate and aqueous extracts of Melissa officinalis L. significantly enhanced the effectiveness of tested preservatives. Synergism was established at plant extract and preservative concentrations corresponding to 1/4 and 1/8 minimal inhibitory concentration values, which indicated the possibility of avoiding the use of higher concentrations of tested preservatives