Tailoring the potential of Yarrowia lipolytica for bioconversion of raw palm fat for antimicrobials production

The need for natural antimicrobials with reference to food preservation and food safety highlights the importance of vegetable fats that can be an essential source of fatty acids with antimicrobial properties. The hydrolysis of raw palm fat was evaluated using the in vitro solid state cultivation of eight strains of Yarrowia lipolytica. Therefore, the solid state enzymatic conversion of raw fat at different water activity values and time periods (up to 7 days) was performed. The best results were obtained with Y. lipolytica MIUG D14 at 25 \ub0C, aw 0.98, after 7 days of solid state cultivation. The free fatty acids profile was analyzed by GC-MS and the results revealed a higher concentration of some acids, recognized for their antimicrobial effects, i.e 50% palmitic acid (C16:0), 20% linoleic acid (C18:2) and over 6% for the lauric (C12:0) and myristic (C14:0) acids. The results revealed that under controlled conditions, the solid state enzymatic conversion of raw palm is an effective method for free fatty acids with antimicrobial activity production, at reduced costs. This process can be successfully used for obtaining a biopreservation effect in various applications in food industry and related fields, such as cosmetics

Lipolytic activity of lipases from different strains of Yarrowia lipolytica in hydrolysed vegetable fats at low temperature and water activity

Yarrowia lipolytica is a very important yeast because many strains from this yeast are able to produce the extracelular lipases. Cold active lipase is one of the important and widely used enzymes whose spectrum of applications has widened in many industries such as in detergent formulations. food industry, leather processing, environmental bioremediations. and fine chemical synthesis as well as in pharmaceutical industries. Cold active lipases are largely distributed in microorganisms surviving at low temperatures. near 4 degrees C. Although a number of lipase producing sources are available. only a few bacteria and yeasts were exploited for the production of active lipases. Attempts have been made from time to time to isolate cold active lipases from these microorganisms having high activity at low temperatures. These lipases show great interests in different applications of food and chemistry industry. In this study, it was evaluated the lipolytic activity of lipases from different strains of Yarrowia lipolytica in the critical conditions. The aim of this research was to evaluate the ability of different Yarrowia lipolytica strains, having different origin. to grow and to produce the lipases at low temperature (4 degrees C). 13 Lipases from Yarrowia lipolytica coded as PO1, PO11. RO3, RO15, Y10, Y22. LP PAST to la, LC TL TO 4b, LP TQ to 1a, LN2, 1 II YL 4, 16B and 27D. were used for enzymatic hydrolysis of two crude exotic fats, like: white palm kernel fat and shea fat. The conditions of hydrolysis was a low temperature (4 degrees C) and low values water activity (aw 0.98 and 0.96). The lipolytic activity of lipases was evaluated by measuring the diameters of hydrolysis zone. At 4 degrees C and aw 0.98, the Yarrowia lipolytica strains such as : RO3, 1 II YL4 and LC TL to 4b produced the cold active lipases that had the higher lipolytic activity on the palm kernel fat. In the same conditions, lipases from yeast strains like: RO3, RO15 and 1 II YL4 demonstrated a strong lipolytic activity on the shea fat At aw 0.96, the lipase produced by the same strains of Yarrowia lipolytica shows a higher specificity of palm kernel fat and shea f

Extraction and characterization of volatile compounds and fatty acids from red and green macroalgae from the Romanian Black Sea in order to obtain valuable bioadditives and biopreservatives

Three species of macroalgae, Ceramium virgatum (Rhodophyta), Ulva intestinalis, and Cladophora vagabunda (Chlorophyta), harvested from the Romanian Black Sea coast, were studied as sources of valuable compounds that could be used as additives and biopreservatives. Volatile compounds including hexanal (11.2 %), octane (9.8 %), nonanal (7.0 %), octanal (6.7 %), 2,5,5-trimethyl-2-hexene (4.7 %), 3-hexen-2-one (4 %), and o-cymene (3.6 %) were identified as the major components in the biomass extract of C. vagabunda. In C. virgatum, the major volatile components were 3-hexen-2-one (27.9 %), acetone (12.4 %), hexanal (3.4 %), and o-cymene (2.7 %). The major volatile compounds of U. intestinalis were hexanal (14.6 %), trichloromethane (7.3 %), nonanal (5.6 %), 3-hexen-2-one (5.3 %), and octanal (3.1 %). Some of these compounds have industrial applications as additives in the food, pharmaceutical, or cosmetics industries. The U. intestinalis extract had a greater content of mono- and polyunsaturated fatty acids around 46.0 % as compared with 42.0 % for C. vagabunda and 31.9 % for C. virgatum. The most abundant fatty acids were palmitic acid (C16:0), arachidonic acid (C20:4n-6), and oleic acid (C18:1\u3c9-9cis). The antimicrobial effect of fatty acid extracts was tested against four pathogenic bacteria. The minimum inhibitory concentrations of C. vagabunda, C. virgatum, and U. intestinalis fatty acids extracts were 1.8, 3.8, and 3.8 mg mL-1, respectively, for all bacterial strains. This study can help the efforts of finding new, value-added uses for natural marine resources. \ua9 2013 Springer Science+Business Media Dordrecht

Whole-cells of Yarrowia lipolytica applied in “one pot” indolizine biosynthesis

International audienceA series of yeast strains was tested in order to evaluate their catalytic potential in biocatalysis of one-pot indolizine’s synthesis. Yeast cultivation was performed in a submerged system at 28◦ C for 72 h at 180 rpm. An assessment of the reagents’ toxicity on yeast viability and metabolic functionality concluded that the growth potential of three Yarrowia lipolytica strains were least affected by the reactants compared to the other yeast strains. Further, crude fermentation products (biomass and cell-free supernatant)—obtained by submerged cultivation of these yeasts—were used in multistep cascade reactions for the production of fluorescent indolizine compounds with important biologic activities. A whole–cell catalyzed multicomponent reaction of activated alkynes, α-bromo-carbonyl reagents and 4,4′-bipyridine, at room temperature in buffer solution led to the efficient synthesis of bis-indolizines 4a, 4b and 4c, in good-to-excellent yields (47%–77%). The metabolites of the selected Y. lipolytica strains can be considered effective biocatalysts in cycloaddition reactions and the high purity and bioconversion yields of the synthesized indolizines indicates a great potential of this type of “green” catalysts. Seeds of Triticum estivum L. were used to investigate the impact of the final products on the germination and seedling growth. The most sensitive physiological parameters suggest that indolizines, at the concentrations tested, have non-toxic effect on germination and seedling growth of wheat, fact also confirmed by confocal laser scanning microscopy images