The Zymomonas mobilis regulator hfq contributes to tolerance against multiple lignocellulosic pretreatment inhibitors

Table 2 Growth rate and final cell density of different Z. mobilis strains in the absence or presence of different sodium and acetate ions.

		ZM4	AcR	AcRIM0347	AcRIM0347 (p42-0347)	ZM4 (p42-0347)
Growth rate (hour ^-1 )	RM	0.42 ± 0.01	0.39 ± 0.01	0.32 ± 0.003	0.33 ± 0.002	0.38 ± 0.003
	RM (NaCl)	0.24 ± 0.008	0.29 ± 0.005	0.21 ± 0.008	0.22 ± 0.009	0.25 ± 0.008
	RM (NH ₄ OAc)	0.20 ± 0.008	0.19 ± 0.005	NA	0.22 ± 0.002	0.19 ± 0.007
	RM (Kac)	0.15 ± 0.004	0.12 ± 0.000	NA	0.09 ± 0.003	0.12 ± 0.006
	RM (NaAc)	NA	0.29 ± 0.04	0.12 ± 0.004	0.16 ± 0.002	0.27 ± 0.004
Final Cell Density (OD _{600 nm} )	RM	0.95 ± 0.006	1.01 ± 0.006	0.94 ± 0.004	0.92 ± 0.002	1.02 ± 0.004
	RM (NaCl)	0.73 ± 0.01	0.96 ± 0.01	0.73 ± 0.03	0.72 ± 0.02	0.84 ± 0.01
	RM (NH ₄ OAc)	0.43 ± 0.01	0.42 ± 0.006	NA	0.32 ± 0.007	0.37 ± 0.008
	RM (Kac)	0.42 ± 0.002	0.40 ± 0.000	NA	0.28 ± 0.007	0.34 ± 0.004
	RM (NaAc)	NA	0.63 ± 0.02	0.25 ± 0.001	0.45 ± 0.002	0.59 ± 0.002

"NA" indicates that the data are not available due to the lack of growth in that condition. The concentration for all the chemicals (NaCl, NH₄OAc, KAc, NaAc) supplemented into the RM is 195 mM. NaCl: sodium chloride, NH₄OAc: ammonium acetate, KAc: potassium acetate, NaAc: sodium acetate. Strains included in this study are: ZM4: Zymomonas mobilis ZM4 wild-type; AcR: previously described ZM4 acetate tolerant mutant; ZM4 (p42-0347): ZM4 containing a gateway plasmid p42-0347 to express ZM4 gene ZMO0347; AcRIM0347: AcR insertional mutant of ZMO0347; AcRIM0347 (p42-0347): AcRIM0347 containing gateway plasmid p42-0347. This experiment has been repeated at least three times with similar result. Duplicate biological replicates were used for each condition.

ISSN: 1471-2180