Abstract
Natural bioactive agents, with antimicrobial and/or anticancer activity, such as polyunsaturated fatty acids (PUFAs), are at the forefront of biotechnological research due to the high interest in these compounds in pharmacy. This paper reports production of polyunsaturated lipids by the fungus Thamnidium elegans cultivated on raw glycerol, and the microalga Nannochloropsis salina cultivated under autotrophic conditions. Fungal lipids, containing gamma linolenic acid, consisted of 82 % neutral lipids. Algal lipids, containing eicosapentaenoic acid (EPA), consisted of 52.7 % glycolipids plus sphingolipids, 28.5 % neutral lipids and 18.8 % phospholipids. EPA was located mainly in polar lipids. Fatty acid potassium salts (FAPS) produced from the above lipids effectively inhibited the growth of many Gram negative bacteria [such as Serratia sp., Neisseria gonorrhoeae, Shigella sonnei, Proteus mirabilis, P. vulgaris, Escherichia coli ATCC BAA1001 Enterobacter cloacae, Klebsiella pneumoniae and Salmonella typhimurium but not E. coli ATCC 11229 and NCTC 12241 (ATCC 25922) and Moraxella catarrhalis], Gram positive bacteria (i.e. Micrococcus luteus, Staphylococcus aureus ATCC 25923 and ATCC 43330, S. epidermidis, S. saprophyticus, Enterococcus faecalis but not S. aureus ATCC 29213 and Streptococcus agalactiae) and Candida albicans and provoked a marked lethality on an MCF-7 cancer cell line, even at low concentrations. It was concluded that FAPS derived from polyunsaturated microbial lipids could be the basis for the development of new therapeutic agents.