Optimizations related to the use of <i>Lactobacillus helveticus</i>, Kluyveromyces<i> marxianus</i> in monoculture, and co-culture for production of Spirulina-based fermented products

Present study was carried out to optimize certain fermentation parameters when L. helveticus B-4526 and K. marxianus Y-329 were used in monoculture and co-culture in a medium supplemented with dried Spirulina platensis biomass (Spirulina medium). Maximum cell number increase for L. helveticus, K. marxianus in Spirulina medium was calculated as 2.40 and 3.80 log CFU mL-1, respectively. It was observed that proteins were rapidly hydrolyzed by L. helveticus. Consequently, the concentrations of some specific amino acids changed according to product type. The fermented Spirulina (FS) by K. marxianus resulted in higher trimethyl pyrazine content (2636.66 mu g kg- 1) than its unFS counterpart (2088.08 mu g kg- 1). All FS products resulted in increased inhibitory activity on acetylcholinesterase enzyme. FS product by co-culture of both organisms demonstrated a distinct suppressive effect on LPS-induced inflammatory NO secretion in RAW264.7 macrophage cell line. Besides, FS products did not show cytotoxicity in endothelial and macrophage cell lines, therefore presenting more biocompatible nature as compared to their unFS counterparts.