Lactic acid bacteria and related strains isolated from Hibiscus sabdariffa L. calyces: from isolation to evaluation of technological potential

The isolation and identification of native lactic acid bacteria (LAB) from plant matrix and flowers, which are potential sources of novel strains for fermented food development. Accordingly, this study aimed to determine the presence and bacterial diversity in Hibiscus sabdariffa L. calyces, and to characterize their technological properties for potential food application. Nine isolates were identified by 16S rRNA gene sequencing, belonging to the genera Leuconostoc (JC1 and JC2), Bacillus (JC3), Limosilactobacillus (JC4), Lentilactobacillus (JC5 and JC6), Enterococcus (JC7 and JC8), and Lactococcus (JC9). Cell growth kinetics, lactic acid production, and pH reduction were used to characterize the isolated bacteria. Additionally, the technological potential of the isolates was evaluated by assessing their survival under refrigeration (4°C), freezing (-20°C), and pasteurization (both fast and slow) conditions. Susceptibility/resistance to 12 antibiotics was also determined. Results showed that isolate JC3 (Bacillus velezensis) exhibited outstanding growth parameters, tolerance to pasteurization thermal conditions (63°C/30 min and 72°C/15 s) and susceptibility to the 12 tested antibiotics. These results highlight the potential of Hibiscus calyces as a valuable source of diverse native LAB and related strains with promising technological traits. Further studies on the functionality and safety of these bacteria are required to confirm their probiotic potential.