Production of anti-streptococcal liamocins from agricultural biomass by Aureobasidium pullulans

Authors: Leathers, Timothy; Price, Neil; MANITCHOTPISIT, PENNAPA - Illinois State University; Bischoff, Kenneth

Submitted to: World Journal of Microbiology and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/11/2016
Publication Date: 10/18/2016
Publication URL: http://handle.nal.usda.gov/10113/5561119
Citation: Leathers, T.D., Price, N.P.J., Manitchotpisit, P., Bischoff, K.M. 2016. Production of anti-streptococcal liamocins from agricultural biomass by Aureobasidium pullulans. World Journal of Microbiology and Biotechnology. 32(12):199. doi: 10.1007/s11274-016-2158-5.

Interpretive Summary: We demonstrate here for the first time the utilization of agricultural biomass substrates, particularly wheat straw, for production of valuable antimicrobial agents. Utilization of biomass substrates for the production of antimicrobials could provide new value-added products from agricultural residues. We identified promising microbial strains and determined conditions for production of antimicrobials from wheat straw. This work will be valuable to researchers developing new value-added bioproducts for the integrated biorefineries of the future.

Technical Abstract: Liamocins are unique heavier-than-water “oils” produced by certain strains of the fungus Aureobasidium pullulans. Liamocins have antibacterial activity with specificity for Streptococcus sp. Previous studies reported that liamocin yields were highest from strains of A. pullulans belonging to phylogenetic clades 8, 9, and 11, cultured on medium containing sucrose. In this study, 27 strains from these clades were examined for the first time for production of liamocins from agricultural biomass substrates. Liamocin yields were highest from strains in phylogenetic clade 11, and yields were higher from cultures grown on sucrose than from those grown on pretreated wheat straw. However, when supplementary enzymes (cellulase, ß-glucosidase, and xylanase) were added, liamocin production on pretreated wheat straw was equivalent to that on sucrose. Liamocins produced from wheat straw were free of the melanin contamination common in sucrose-grown cultures. Furthermore, matrix-assisted laser desorption/ionation mass spectronomy (MALDI-TOF MS) analysis showed that liamocins produced from wheat straw were under-acetylated, resulting in higher proportions of the mannitol A1 and B1 species of liamocin, the latter of which has the highest biological activity against Streptococcus sp.