Table 2.

Comparison of FFA production and host strain traits of three model cyanobacterial strains.

Property	Synechococcus sp. PCC 7002	S. elongatus PCC 7942	Synechocystis sp. PCC 6803
FFA productivity (mg/L/h)a	0.273 (This study)	0.103 (Ruffing and Jones, 2012)	0.438 (Liu et al., 2011)
Final FFA concentration (mg/L)	131 (This study)	49.3 (Ruffing and Jones, 2012)	197 (Liu et al., 2011)
Exogenous FFA tolerance	Saturated FFA: no growth inhibition, polyunsaturated FFA: tolerant to <1 μM before growth is inhibited (Ruffing and Trahan, submitted)	Saturated FFA: no growth inhibition, polyunsaturated FFA: tolerant to 5 μM before growth is inhibited (Ruffing and Trahan, submitted)	Saturated FFA: no growth inhibition, polyunsaturated FFA: tolerant to 25 μM before growth is inhibited (Ruffing and Trahan, submitted)
Doubling time (h)	2.6–4 (Sakamoto and Bryant, 1997; Ludwig and Bryant, 2012)	5–6 (Kondo et al., 1997)	6 (Tu et al., 2004)
Light tolerance	Can grow under 4,500 μmol photons m−2 s−1 (Nomura et al., 2006)	Significant photodamage occurs with light intensities of 500–1000 μmol photons m−2 s−1 (Clarke et al., 1995; Kulkarni and Golden, 1995)	At 900 μmol photons m−2 s−1, rate of photodamage = rate of repair (Allakhverdiev and Murata, 2004)
Salt tolerance	1.7 M NaCl (Batterton and Baalen, 1971)	0.5 M NaCl (Fulda et al., 1999)	1.2 M NaCl (Fulda et al., 1999)
Temperature tolerance	Optimum = 34–38°C [this study (Ludwig and Bryant, 2012)], maximum growth temperature not determined	Optimum = 30–35°C (Mori et al., 2002), maximum growth temperature not determined	Optimum = 30°C, cannot grow above 43°C (Inoue et al., 2001)

^aFFA productivity calculated by taking the final concentration of excreted FFA concentration and dividing by the total time of cultivation.