Enhanced lactic acid bacteria viability with yeast coincubation under acidic conditions

Figures & data

Table 1. Coaggregation activity of LAB and M. guilliermondii in LA solution or sterile water at room temperature.

Co-aggregation activity
Solution		L. pentosus			L. paracasei
Lactic acid solution	pH 1.0	0.09	±	0.00	0.16	±	0.01
	pH 2.0	0.56	±	0.10	0.61	±	0.05
	pH 3.0	0.34	±	0.11	0.73	±	0.13
	pH 4.0	0.16	±	0.01	0.35	±	0.08
	pH 5.0	0.09	±	0.02	0.19	±	0.03
Water	ー	0.10	±	0.03	0.11	±	0.03

Coaggregation activity = (A₀–A₃₀)/A₀, where A₀ and A₃₀ are OD₆₀₀ at 0 and 30 min, respectively. Values are expressed as means of triplicate experiments (n = 3) ± SD.

Figure 1. Effect of coincubating M. guilliermondii and their metabolites on the viability of L. pentosus and L. paracasei in LA buffer (pH 3.0) at 10°C. Values are expressed as the means of triplicate experiments (n = 3), with error bars representing the SD. Different letters indicate significant differences (p < 0.05, by Scheffe’s test) within the same day.

Table 2. The effect of M. guilliermondii on the LA concentration in the supernatant of LA buffer in which LAB cells were incubated at 10°C.

Lactic acid (mM)
	L. pentosus						L. paracasei
Day	LAB only			with yeast			LAB only			with yeast
0	57	±	1	57	±	1	58	±	1	56	±	1
5	57	±	0	57	±	2	58	±	2	56	±	0
10	56	±	1	52	±	4	61	±	2	55	±	2
15	57	±	0	52	±	3	61	±	3	55	±	2

Values are expressed as the means of two independent experiments (n = 2) ± SD.

Figure 2. Effect of coincubating non-coaggregative yeast and MnO₂ on the viability of L. pentosus and L. paracasei in LA buffer (pH 3.0) at 10°C. Values are expressed as means of triplicate experiments (n = 3), with error bars representing the SD. Different letters indicate significant differences (p < 0.05, by Scheffe’s test) within the same day.

Figure 3. Effect of coincubating yeast or MnO₂ on the extracellular H₂O₂ concentration in LA buffer in which LAB cells were incubated at 10°C. Values are expressed as means of triplicate experiments (n = 3), with error bars representing the SD. Different letters indicate significant differences (p < 0.05, by Scheffe’s test) throughout the 15-day experiment.

Figure 4. Effect of antioxidants on the viability of L. paracasei in LA buffer (pH 3.0) at 10°C. Values are expressed as means of triplicate experiments (n = 3), with error bars representing the SD. Different letters indicate significant differences (p < 0.05, by Scheffe’s test) within the same day.