The effect of marine polyunsaturated fatty acids on biofilm formation by the human pathogens Candida albicans and Candida dubliniensis was investigated. It was found that stearidonic acid (18:4 n-3), eicosapentaenoic acid (20:5 n-3), docosapentaenoic acid (22:5 n-3) and docosahexaenoic acid (22:6 n-3) have an inhibitory effect on mitochondrial metabolism of both C. albicans and C. dubliniensis and that the production of biofilm biomass by C. dubliniensis was more susceptible to these fatty acids than C. albicans. Ultrastructural differences, which may be due to increased oxidative stress, were observed between treated and untreated cells of C. albicans and C. dubliniensis with formation of rough cell walls by both species and fibrillar structures in C. dubliniensis. These results indicate that marine polyunsaturated fatty acids may be useful in the treatment and/or prevention of biofilms formed by these pathogenic yeasts.

Root-knot nematode (Meloidogyne sp.) is a major concern due to difficulty of control. Secondary metabolites naturally occurring in plants offer a method for combating invasion by root-knot nematode . The study was conducted to investigate nematocidal effects of plant parts of fermented Lantana camara L. collected around the Visage, George and Mooketsi areas, Limpopo Province, South Africa. Effective dosages of plant extracts, which could be applied through a drip irrigation system, on tomato (Solanum lycopersicum L) were determined against nematode infection. Extracts of L. camara were evaluated at aqueous concentrations of 0.92%, 2.76%, or 3.68% (v/v) for effects on plant parameters. Mortality rate of Meloidogyne javanica J2 treated with fermented Lantana camara at varying extract concentration, location and tissue was significant. Nematocidal activity of the extracts were mainly due to plant part and concentration. There was a significant location × tissue interaction for wet plant biomass, Meloidogyne javanica galling index, root egg mass, and soil egg mass. The reduction in final nematode population, root-knot index and soil egg hatching after 8 weeks following transplanting in pot trials is indicative of nematocidal activity of L. camara. There was no difference in location × tissue interaction for plant height, stem diameter, and number of fruit. Treatment with fermented L. camara was not phytotoxic. Fermented L. camara plant extracts may be used for management of root-knot nematode in tomato, but this must be validated in field trials.