New bioemulsifiers produced by Candida lipolytica using D-glucose and babassu oil as carbon sources

Candida lipolytica IA 1055 produced extracellular biosurfactants with emulsification activity by fermentation using babassu oil and D-glucose as carbon sources. Natural seawater diluted at 50 percent supplemented with urea, ammonium sulfate, and phosphate was used as economic basal medium. The best results were achieved with the YSW-B2 medium, which contained urea, ammonium sulfate, and babassu oil and with YSW-B3 medium, which contained urea, ammonium sulfate, phosphate, and babassu oil, kept under fed batch fermentation for 60 hours with 5 percent of babassu oil. For the two media, the maximum specific growth rates were 0.02 h-1 and 0.04 h-1; the generation times were 34.6 h-1 and 17.3 h-1, and the emulsification activities were 0.666 and 0.158 units, respectively. The molecules of these new bioemulsifiers were contituted of carbohydrates, proteins and lipids.

Detecção de atividade antibacteriana in vitro nos extratos brutos obtidos a partir do plasmódio de Physarella oblonga (Berk. & Curt.) Morgan (Myxomycetes)

Utilizando-se o teste de difusão em meio sólido, detectou-se atividade antibacteriana em extratos de Physarella oblonga (Physaraceae) obtidos a partir de imobilização plasmodial e do plasmódio in natura. Os extratos foram ativos contra Staphylococcus aureus (halos=14 mmf) e Mycobacterium smegmatis (halos=12 mmf e 13 mmf). Menor inibição foi observada frente a Bacillus subtilis (halos=10 mmf e 9 mmf) e Pseudomonas aeruginosa (halos=10 mmf e 8 mmf). Escherichia coli apresentou resistência a todos os extratos testados. O cromatograma evidenciou semelhanças na composição química dos extratos, justificando as similaridades no potencial inibitório de ambos, sendo as substâncias com Rf 0,91 e 0,82, presentes em ambas as amostras, os prováveis inibidores do crescimento bacteriano.

Diffusion solid medium test was used to detect antibacterial activity in Physarella oblonga (Physaraceae) extracts obtained from plasmodial immobilization and in natura plasmodium. The extracts presented activity against Staphylococcus aureus (halos=14 mmf) and Mycobacterium smegmatis (halos=12 mmf e 13 mmf). Slower inhibition was obtained against Bacillus subtilis (halos=10 mmf e 9 mmf) and Pseudomonas aeruginosa (halos=10 mmf e 8 mmf). Escherichia coli presented resistence to all tested extracts. The chromatogram revealed likeness in the chemical composition of the extracts, explaining similarities in inhibitory potential. The substances with Rf 0,91 and 0,82, present in both extracts, could be inhibitor agents of bacterial growth.