. 2023 Jun 16;11:1218099. doi: 10.3389/fbioe.2023.1218099

TABLE 2.

Summary of the IBE production achieved here and in comparable studies.

Study	IPA (g/L)	BuOH (g/L)	EtOH (g/L)	IBE (g/L)	Gene Location ^b	Strain ^a	IBE gene promoters			pH control	Comment
Study	IPA (g/L)	BuOH (g/L)	EtOH (g/L)	IBE (g/L)	Gene Location ^b	Strain ^a	sadh	ctfA/B	adc
This study	4.40	13.49	3.09	19.80	Chr	ATCC 824	P_tcdB	P_tcdB	P_tcdB	Yes	tcdR integrated downstream of pyrE under control of P_bgl , ctfA/B-adc and sadh integrated downstream of purD and pheA, respectively, under control of P_tcdB
						bgaR::tcdR
						integrant
Banker et al. (2015)	2.51	10.78	2.0	15.30	Chr	DSM 792	P_adc	native	native	Yes	sadh under P_adc promoter integrated in Chr, ctfA/B-adc genes on the pSOL megaplasmid
Banker et al. (2015)	2.51	10.78	2.0	15.30	Chr	wildtype	P_adc	native	native	Yes
Wang et al. (2018)	6.62	10.51	1.24	17.77	pIMP1	XY16	P_ptb	native	native	Yes	sadh expressed from P_ptb on multicopy plasmid, ctfA/B-adc on megaplasmid. Regulation of intracellular NAD(P)H levels by CaCO_3.
Wang et al. (2018)	6.62	10.51	1.24	17.77	(pIM13)	wildtype	P_ptb	native	native	Yes
Dusseaux et al. (2013)	4.22	13.8	0.46	18.48	pCLF942	ATCC 824	P_ptb	P_ptb	P_ptb	Yes	Δbuk made in a Δcac15Δupp mutant. ctfA/B-sadh-adc expressed from P_ptb on a multicopy plasmid.
Dusseaux et al. (2013)	4.22	13.8	0.46	18.48	(pIM13)	Δbuk	P_ptb	P_ptb	P_ptb	Yes
Dusseaux et al. (2013)	4.75	14.63	1.01	20.40	pCLF952	ATCC 824 Δbuk	P_thl	P_thl	P_thl	Yes	Δbuk made in a Δcac15Δupp mutant. ctfA/B-sadh-adc expressed from P_thl on a multicopy plasmid.
Dusseaux et al. (2013)	4.75	14.63	1.01	20.40	(pIM13)	ATCC 824 Δbuk	P_thl	P_thl	P_thl	Yes
Jang et al. (2013)	3.60	14.80	9.5	27.90	pIPA100	ATCC 824 (BKM19)	P_thl	native	native	Yes	BKM19 (hyper-ABE producer) buk-mutant carrying sadh-hydG expressed from P_thl on multicopy plasmid.
Jang et al. (2013)	3.60	14.80	9.5	27.90	(pIM13)	ATCC 824 (BKM19)	P_thl	native	native	Yes
Dai et al. (2012)	7.60	15.00	1.28	23.88	pIMP1	DSM 1731 (Rh8)	P_thl	native	native	Yes	Rh8 (butanol tolerant mutant) carries P_thl -sadh on a pIMP1 and ctfA/B-adc on the pSMBa megaplasmid.
Dai et al. (2012)	7.60	15.00	1.28	23.88	(pIM13)	DSM 1731 (Rh8)	P_thl	native	native	Yes
Collas et al. (2012)	8.80	13.70	1.5	24.00	pFC007	ATCC 824	P_thl	P_thl	P_thl	No	harbouring P_thl -sadh-ctfA/B-adc genes expressed from P_thl on multicopy plasmid based on pAMβl
Collas et al. (2012)	8.80	13.70	1.5	24.00	(pAMβl)	wildtype	P_thl	P_thl	P_thl	No
Lee et al. (2012)	5.10	8.00	0.80	13.90	pIPA3	ATCC 824	P_adc	P_adc	P_adc	No	ctfA/B-adc-sadh under control of P_adc promoter on multicopy plasmid—batch fermentation in flasks.
Lee et al. (2012)	5.10	8.00	0.80	13.90	(pIM13)	wildtype	P_adc	P_adc	P_adc	No
Lee et al. (2012)	6.10	10.20	0.80	17.10	pIPA3	ATCC 824	P_adc	P_adc	P_adc	Yes	ctfA/B-adc-sadh under control of P_adc promoter on multicopy plasmid—in a fermentator.
Lee et al. (2012)	6.10	10.20	0.80	17.10	(pIM13)	wildtype	P_adc	P_adc	P_adc	Yes
Lee et al. (2012)	4.40	14.10	1.90	20.40	pIPA3	ATCC 824	P_adc	P_adc	P_adc	Yes	As above but undertaken in a buk- mutant as opposed to the wildtype.
Lee et al. (2012)	4.40	14.10	1.90	20.40	(pIM13)	buk ^-	P_adc	P_adc	P_adc	Yes

^{^a}

All strains described in Table 2 are C. acetobutylicum carrying the megaplasmid pSOL, or equivalent.

^{^b}

Chr indicates chromosome.