title: The effects of palm oil breakdown products on lipid turnover and morphology of fungi.
abstract: The oleaginous fungi Cryptococcus curvatus and Mucor circinelloides were used to determine the effect of palm oil breakdown products, measured as polymerized triglycerides (PTGs), on lipid turnover and on fungal growth and morphology. In M. circinelloides, we found after 7 days of growth, a decrease in biomass and in lipid utilization and accumulation at increased PTG levels, both at low and neutral pH. In C. curvatus, there was also a decrease in lipid utilization and biomass production at increased PTG levels, at both low and neutral pH. However, an increase in oil accumulation was observed at low pH while it remained similar at neutral pH for all PTG levels tested. Hairy and warty protuberances on the cell surface were observed when C. curvatus was grown on oils with 15% and 45% PTGs, respectively. Using nano scanning Auger microscopy, we found no evidence to suggest a difference in elemental composition of the surfaces of the warty protuberances compared with the rest of the cell wall surface. We conclude that the warty protuberances are outgrowths of cell walls and that the changes observed in lipid turnover in both fungi are due to the presence of palm oil breakdown products.
authors.affiliation: Department of Microbial, Biochemical and Food Biotechnology, University of the Free State, P.O. Box 339, Bloemfontein, 9301, South Africa.
authors.forename: Ntsoaki J
authors.initials: NJ
authors.lastname: Leeuw
authors.forename: Chantel W
authors.initials: CW
authors.lastname: Swart
authors.forename: Manjusha
authors.initials: M
authors.lastname: Joseph
authors.forename: Carolina H
authors.initials: CH
authors.lastname: Pohl
authors.forename: Pieter W J
authors.initials: PW
authors.lastname: van Wyk
authors.forename: Elizabeth
authors.initials: E
authors.lastname: Coetsee
authors.forename: Hendrik C
authors.initials: HC
authors.lastname: Swart
authors.forename: Arno
authors.initials: A
authors.lastname: Hugo
authors.forename: Johan L F
authors.initials: JL
authors.lastname: Kock
mesh_terms: D018533:Biomass; D003454:Cryptococcus / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D006863:Hydrogen-Ion Concentration; D050356:Lipid Metabolism; D009089:Mucor / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D000073878:Palm Oil; D010938:Plant Oils / Q000378:metabolism*; D014280:Triglycerides / Q000378:metabolism / Q000494:pharmacology
chemical_list: D010938:Plant Oils; D014280:Triglycerides; D000073878:Palm Oil