Abstract
The objective of this study was to investigate the feasibility and efficacy of alternative nitrogen sources in sweet potato-based medium for supporting the growth of Lactobacillus sp. Sweet potato is an intriguing candidate as a component of a growth medium for Lactobacillus sp. The sweet potato medium was supplemented with 2, 8, or 14 g/L of X-Seed Nucleo Max, X-Seed KAT, and NuCel 780 MG as nitrogen sources. Seven Lactobacillus sp strains were used in this study. At least two of the sweet potato medium compositions SPM2 which contain 2 g/L X-Seed Nucleo Max, 3 g/L X-Seed KAT, and 3 g/L NuCel 780 MG and SPM3 which contain 2 g/L X-Seed Nucleo Max, 6 g/L X-Seed KAT, and 6 g/L NuCel 780 MG were sufficient to grow Lactobacillus sp strains in a manner sufficiently similar or superior to that of MRS. At 12 hours of incubation, the population of Lactobacillus sp strains reached an average of 7.94 ± 0.11, 8.38 ± 0.11, and 8.57 ± 0.12 log CFU/mL for MRS, SPM2, and SPM3, respectively. Moreover, the buffering capacity of SPM2 and SPM3 was significantly higher than that in MRS (p ≤ 0.05). These findings thus demonstrate that the sweet potato based medium, SPM2, is suitable for the growth of Lactobacillus sp strains and can be used as an alternative to the standard media.