TABLE 2.

Lactic acid production by transformed PMI/C1(pEPL2) cells in a bioreactor

Test no.a	Elapsed time (h)	Total production (g liter−1)	Yield of lactic acidb	Final pH	Undissociated lactic acid
					%	g liter−1
1	137	109	1.19	4.5	19	20.7
2	97	35	0.88	3.0	88	30.8
3	72	29	0.70	2.8	92	26.7

^aLactic acid production was tested as follows: test 1, the fermentation pH was controlled at 4.5 throughout the fermentation (Fig. 4); test 2, the initial fermentation pH was maintained at 4.0 until 1 to 1.2 mol of ammonium hydroxide was added, then pH control was discontinued; and test 3, the initial fermentation pH was 5.0 and no neutralizing agent was added during the fermentation. The elapsed time was measured from the time of inoculation. Values are the highest measured, corresponding to the end point. 

^bYield is expressed as millimoles of lactic acid produced liter⁻¹ divided by millimoles of glucose consumed liter⁻¹.