Location: Renewable Product Technology ResearchTitle: Liamocins from Aureobasidium pullulans: New and highly selective anti-streptococcal agents
|MANITCHOTPISIT, PENNAPA - Illinois State University|
Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 11/23/2015
Publication Date: 11/23/2015
Citation: Price, N.P., Bischoff, K.M., Manitchotpisit, P., Leathers, T.D., Rich, J.O. 2015. Liamocins from Aureobasidium pullulans: New and highly selective anti-streptococcal agents [abstract]. University of Illinois College of Medicine at Peoria.
Technical Abstract: The ubiquitous, black yeast Aureobasidium pullulans, which is used commercially to produce pullulan polysaccharide, also produces several polyol-lipids that we have named liamocins. A survey of >50 strains of A. pullulans identified 21 diverse strains that produce liamocins. Typically the liamocins have a mannitol group ester linked to either three or four 3,5-dihydroxydecanoate chains, the latter joined together by 1,5-polyester bonds (liamocins Man-A1 and Man-B1). Similar 3’-O-acetylated analogs (Man-A2 and Man-B2) were also discovered. Various other liamocins are produced dependent upon the choice of strain and growth conditions, and noticeably selective growth on different polyols, but not sugars, resulted in considerable structural variation. Liamocins with galactitol, sorbitol, D-arabitol, D-xylitol, and D- or L-threitol headgroups were separated by HPLC and structurally characterized. These were tested for anti-bacterial activity. Enterococcus faecalis, Bacillus subtilis, Staphylococcus aureus, Lactobacillus fermentum, Escherichia coli, and Pseudomonas aeruginosa showed low susceptibility, but eight Streptococcus species are sensitive with MICs ranging from =10 - 78 mcg/ml. Liamocin Man-B1 had the most potent antibacterial activity against Streptococcus agalactiae (MIC = 16 mcg/ml), and at 39 mcg/ml reduced the viability of S. agalactiae from 6.7 to 3.4 log(CFU/ml) within 1 hour. Various other liamocins (with D-arabitol, D-threitol, or L-threitol headgroups) are also active against Streptococcus sp., but to a lesser extent. Thus, liamocins have potential as narrow spectrum antistreptococcal agents, the selectivity of which may reduce selection for antibiotic resistance.