Design of a stable ethanologenic bacterial strain without heterologous plasmids and antibiotic resistance genes for efficient ethanol production from concentrated dairy waste

Table 2 Fermentation performance indicators in pH-controlled bioreactor experiments

Strain	Medium	Inoculum ratio	Ethanol titer (g/L)^a	Maximum production rate (g/L/h)	Yield (%)^a	KOH (mmol/L)	Residual sugars (%)^a
W_ΔLFP-pL13^b	CWP_R	1:5	43.77 (1.2)^c	0.82 (0.01)	62.97 (0.49)	192.5 (45.96)	5.6 (4.46)
W105F	CWP_R	1:5	43.69 (1.04)	1 (0.02)	61.96 (0.39)	232.5 (45.96)	13.63 (5.49)
W105F	CWP	1:5	43.07 (0.14)	0.75 (0)	80.05 (1.99)	142.5 (24.75)	27.45 (1.43)
W105F	CWP_3:4	1:5	37.19	0.67	70.95	110	13.5
W105F	CWP_2:3	1:5	34.24 (2.33)	0.68 (0.16)	74.8 (6.22)	170 (28.28)	4.33 (3.66)
W105F	CWP_1:2	1:5	31.51	0.65	88.95	150	0
W105F	CWP_2:3	1:10	28.82	0.45	86.67	110	30.44
W105F	CWP_2:3	1:50	19.9 (0.64)	0.31 (0.08)	74.54 (3.42)	140 (0)	46.36 (5.35)
W105F^d	CWP + (NH₄)₂SO₄^e	1:5	45.83 (0.99)	0.91 (0.13)	97.33 (30.04)	157.5 (95.46)	31.08 (15.69)
W105Fe	CWP	1:5	37	0.79	87.3	125	32.65
W105Fe^d	CWP + (NH₄)₂SO₄	1:5	54.11 (0.95)	1.2 (0.14)	82.54 (3.3)	125 (21.21)	12.8 (10.79)
W105Fe	CWP + (NH₄)₂SO₄	1:50	54.84	1.06	95.68	170	29.7
W105Fe	CWP + (NH₄)₂SO₄	1:500	35.59	1.43	79.31	130	45.96

^aCorrected by considering the volume of dispensed KOH to adjust pH, measured at the end of the experiments
^bChloramphenicol was added to the fermentation medium
^cNumbers in brackets represent standard deviations, for the experiments with replicates
^dIn one of the two replicates, the experiment was stopped at 72 h instead of 96 h
^eAmmonium sulphate concentration is 0.05% w/v

ISSN: 2731-3654