Fig. 1. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML, in aerobic and anaerobic conditions. All cultures conducted in at 30 °C. Aerobic cultures were agitated 150 rpm and with air atmosphere. Anaerobic cultures were static and with nitrogen atmosphere. ● (LA) lactic acid (g l⁻¹), ♦ (AcA) acetic acid (g l⁻¹), × (ΣA) summation of acids (mol h l⁻¹), ▪ pH, (B) biomass (g l⁻¹), (AA) amylolytic activity, ○ (TS) total sugars (g l⁻¹). (BNML=Basic nutrient medium according to Giraud et al. (1998) with lactate added.)

Fig. 2. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML with 5 g l⁻¹ of starch, in aerobic and anaerobic conditions. Culture conditions, symbols and units are the same as in Fig. 1.

Fig. 3. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML with 5 g l⁻¹ of glycogen, in aerobic and anaerobic conditions. Culture conditions, symbols and units are the same as in Fig. 1.

Fig. 4. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML with 5 g l⁻¹ of glucose, in aerobic and anaerobic conditions. Culture conditions, symbols and units are the same as in Fig. 1.

Fig. 5. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML with 5 g l⁻¹ of maltose, in aerobic and anaerobic conditions. Culture conditions, symbols and units are the same as in Fig. 1.

Fig. 6. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium, washed and transferred to BNML with 5 g l⁻¹ of cellobiose, in aerobic and anaerobic conditions. Culture conditions, symbols and units are the same as in Fig. 1.

Fig. 7. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium washed and transferred to a 2-l bioreactor with 1 l of BNML, cultured at 30 °C in aerobic conditions (agitation 300 rpm and air flow 27.7 l h⁻¹) and with a single addition, at 50 h, of 5 g l⁻¹ of glucose (dotted line). Symbols and units are the same as in Fig. 1.

Fig. 8. Culture kinetics of a 20-h culture of L. plantarum A6 on MRS medium washed and transferred to a 2-l bioreactor with 1 l of BNML, cultured at 30 °C in aerobic conditions (agitation 300 rpm and air flow 27.7 l h⁻¹) and fed with glucose from 48 to 78.5 h (dotted lines) at a specific rate of 0.08 g l⁻¹ g⁻¹ of glucose (dotted line). Symbols and units are the same as in Fig. 1.

Table 1. Culture parameters of resting cells of L. plantarum A6 on BNML replacement medium with addition of different sugars in aerobic conditions

BNML=basic nutrient medium according to Giraud et al. (1998) with lactate added.

q_s: Specific sugar uptake rate (grams of substrate consumed per hour and per gram of biomass) in the lineal period (8 h for starch and glycogen, 4 h for glucose, maltose and cellobiose); Y_a/l: lactate to acetate conversion yield.