Exploring the Probiotic and Compound Feed Fermentative Applications of Lactobacillus plantarum SK1305 Isolated from Korean Green Chili Pickled Pepper

Abstract

Herein, we explore the probiotic potentials and soybean meal (SBM) compound feed fermentative applications of Lactobacillus plantarum SK1305 strain isolated previously from Korean green chili pickled pepper (gochu-jangajji). The isolate exhibited higher acid (pH 2.5) and bile tolerance (0.3%, w/v) up to 2 h and 4 h, respectively. The cell-free culture supernatant (CFCS) displayed a broad spectrum antibacterial activities against various pathogens, which may be ascribed to high lactic acid production (L-form, 86.8 +/- 0.8 mM and D-form, 44.8 +/- 0.2 mM). Further, the strain displayed high cell-surface hydrophobicity (92.7 +/- 1.0%), coupled with low auto-aggregation (23.6 +/- 4.4%) but relatively higher coaggregation properties with C. perfringens (49.6 +/- 0.6%) as well as H2O2 (1.0 mM) resistant property. Additionally, the isolate displayed significant DPPH free radical scavenging activity (55.2 +/- 0.6%) and superoxide reducing ability in MAC-T cells. Considering safety, the isolate has no transmissible antibiotic resistant genes and harmful enzymes as well as nonhemolytic activities. Ushered by these appreciable probiotic properties, the isolate was used for solid state fermentation (SSF) of SBM compound feed. Notably, we observed a higher strain adaptability (> 10(10) CFU/g) following the production of L- (> 6.0 +/- 0.0 mM) and D-form (> 5.2 +/- 0.3 mM) lactic acid during fermentation for 8 h. The methanolic extracts of fermented feed displayed high antibacterial and antioxidant activities, affirming the potential functional activities of fermented compound feeds. Therefore, L. plantarum SK1305 may act as a worthy inoculum toward fermentation of feed with enhanced nutritional properties.