Table 2.

Table 1 Effect of varying concentrations of urea (as nitrogen source) on ethanol and acetic acid production by two commercial strains* of yeast on sugarcane molasses in fed-batch cultures.

Urea concentration (ppm)	Analysis
	Ethanol yield (%v/v)		Residual sugar (%)		Final brix (°)		Final cell count (106/mL)		Acetic acid (mg/100 mL)		PTT (sec.)
	SI	ER	SI	ER	SI	ER	SI	ER	SI	ER	SI	ER
100	8.0	7.3	0.98	0.95	10.31	9.91	290	304	74.14	38.65	10	10
150	8.3	7.9	0.91	0.89	9.53	9.91	306	340	38.04	35.31	13	11
200	7.9	7.5	1.05	1.08	10.53	10.80	280	365	89.06	39.56	9	8
250	7.5	7.0	1.15	1.20	11.13	11.05	265	289	98.75	48.08	7	6

*SI: Saf-Instant and ER: Ethanol Red.