Environmentally Friendly Production of D(−) Lactic Acid by Sporolactobacillus nakayamae: Investigation of Fermentation Parameters and Fed-Batch Strategies

Table 4

Comparison of D-lactic acid fermentation by S. nakayamae using different neutralizing agents.

Neutralizing agent	Price	Used in fermentation	Cost in fermentation	D(−) lactic acid			RS
	R$/kg	g/300 mL	R$	g/L	g/L·h	g/g	g/L
CaCO3 5%	44.00	15.00	0.66	91.17	1.90	0.90	11.76
Ca(OH)2	40.00	11.11	0.44	88.95	1.85	0.81	3.52
NaOH	51.00	12.00	0.61	103.71	2.16	0.94	0.00
KOH	86.00	5.61	0.48	84.45	1.98	0.79	0.00
NH4OH	17.20	9.17	0.17	16.05	0.33	0.13	88.85
CaCO3 6%	44.00	18.00	0.79	37.46	0.78	0.85	65.99

  = productivity;   = Yield; RS = residual sucrose. Normalized lactic acid and sucrose titer was calculated from measured titer (not shown) from fermentation broth with dilution ratio of neutralizing agent used. Productivity and yield were calculated considering normalized data.