Mg-modified zeolite as a carrier for Lactobacillus rhamnosus in L(+) lactic acid production on distillery wastewater

• Published in: Journal of the Taiwan Institute of Chemical Engineers 2016-02, Vol.59, p.262-266
• Main Authors: Djukić-Vuković, Aleksandra P., Jokić, Bojan M., Kocić-Tanackov, Sunčica D., Pejin, Jelena D., Mojović, Ljiljana V.
• Format: Article
• Language: English
• Subjects: Lactic acid; Lactobacillus rhamnosus ATCC 7469; Probiotics feed additive; Stillage; Zeolite
• ISSN: 1876-1070; 1876-1089
• DOI: 10.1016/j.jtice.2015.07.035

•Simple method for modification of zeolite molecular sieves by Mg ions.•Efficient immobilization of L. rhamnosus ATCC 7469 onto Mg-modified zeolite.•Higher lactic acid productivity and yield in Mg-modified system than in Na system.•Improved stability of L. rhamnosus biofilm with Mg(OH)2 as a neutralizing agent. Biorefinery concept in lactic acid (LA) fermentation based on parallel production of LA and biomass enriched feed on a waste substrate was investigated. In this study, nitrogen opulent liquid stillage was used as a media for repeated batch L(+) LA fermentation by probiotic strain Lactobacillus rhamnosus ATCC 7469 immobilized onto non-modified and Mg-modified zeolite. The highest LA concentration of 47.60 g/L, overall productivity of 1.41 g/L/h, a yield of 0.86 g/g and yield coefficient of 0.96 g/g were obtained in fermentation with utilization of immobilized biocatalyst onto Mg-modified zeolite and Mg(OH)2 as a neutralizing agent. Very high number of 8 × 1010 CFU/g cells immobilized onto Mg-modified zeolite, proven beneficial effect of zeolite in animal health and probiotic characteristics of L. rhamnosus qualify solid remains after the fermentation as a high quality probiotic feed additive. High productivity of LA in the fermentation and valorization of the remains in animal nutrition could recommend this process which employs a simple modification of zeolite as a promising one for bio-based renewable LA production. [Display omitted]