Table 2.

Effects of different nitrogen sources and mineral salts on d-Lactic acid production after 36 h

Nitrogen source and mineral salts	Lactic acid (g/l)	Reducing sugar remaining (g/l)	Reducing sugar conversion (%)d	Yield (%)e	Optical purity (%)f
2 g YEa	26.8 ± 1.19	11.5 ± 0.88	68.5 ± 1.53	33.4 ± 1.49	99.6 ± 0.02
2 g YE and 3 g peptonea	32.2 ± 0.12	6.53 ± 0.70	82.6 ± 0.15	40.3 ± 0.15	99.7 ± 0
3 g YEa	34.4 ± 0.57	2.96 ± 0.16	88.1 ± 0.74	42.9 ± 0.72	99.6 ± 0.21
3 g YE and 3 g peptonea	36.7 ± 0.34	2.93 ± 0.33	94.2 ± 0.44	45.9 ± 0.43	99.7 ± 0.01
5 g YEa	36.5 ± 0.57	2.89 ± 0.49	93.7 ± 0.73	45.7 ± 0.71	99.7 ± 0.04
5 g YE and 3 g peptonea	36 ± 0.01	3.15 ± 0.02	92.2 ± 0.01	45.0 ± 0.01	99.7 ± 0.02
5 g YE and 5 g peptonea	36.2 ± 0.31	3.1 ± 0.12	92.9 ± 0.39	45.3 ± 0.38	99.6 ± 0.02
7 g YE and 5 g peptonea	36.8 ± 0.42	3.0 ± 0.21	94.2 ± 0.54	45.9 ± 0.53	99.6 ± 0.02
3 g YE and 3 g peptoneb	37.0 ± 1.21	2.85 ± 0.66	94.8 ± 1.55	46.2 ± 1.51	99.6 ± 0.03
3 g YE and 3 g peptonec	36.7 ± 0.84	2.96 ± 0.5	94.2 ± 1.08	45.9 ± 1.05	99.6 ± 0.04

^aThe mineral salts consisted of 0.05 g MnSO₄, 2 g K₂HPO₄, 5 g sodium acetate, 0.2 g MgSO₄, 2 g triammonium citrate and 1 g Tween 80

^bThe medium contained yeast extract (YE) as a nitrogen source and MnSO₄ as a mineral salt

^cThe medium contained only YE as a nitrogen source

^dLactic acid (g/l) × 100/reducing sugar in the Hydrodictyon reticulatum material (g/l) ± SD

^eLactic acid (g/l)/material (g/l) ± SD

^f d-Lactic acid (g/l) × 100/(l-Lactic acid [g/l] + d-Lactic acid [g/l]) ± SD