Continuous cultivation of photosynthetic bacteria for fatty acids production.
In the present work, we introduced a novel approach for microbial fatty acids (FA) production. Photosynthetic bacteria, Rhodobacter sphaeroides KD131, were cultivated in a continuous-flow, stirred-tank reactor (CFSTR) at various substrate (lactate) concentrations. At hydraulic retention time (HRT) 4d, cell concentration continuously increased from 0.97 g dcw/L to 2.05 g dcw/L as lactate concentration increased from 30 mM to 60mM. At 70 mM, however, cell concentration fluctuated with incomplete substrate degradation. By installing a membrane unit to CFSTR, a stable performance was observed under much higher substrate loading (lactate 100mM and HRT 1.5d). A maximum cell concentration of 16.2g dcw/L, cell productivity of 1.9 g dcw/L/d, and FA productivity of 665 mg FA/L/d were attained, and these values were comparable with those achieved using microalgae. The FA content of R. sphaeroides was around 35% of dry cell weight, mainly composed of vaccenic acid (C18:1, omega-7).
Clean Fuel Department, Korea Institute of Energy Research, 102 Gajeong-ro, Yuseong-gu, Daejeon 305-343, Republic of Korea.
Dong-Hoon
DH
Kim
Ji-Hye
JH
Lee
Yuhoon
Y
Hwang
Seoktae
S
Kang
Mi-Sun
MS
Kim
D001673:Biodegradation, Environmental; D019149:Bioreactors / Q000382:microbiology; D018929:Cell Culture Techniques / Q000379:methods*; D005227:Fatty Acids / Q000096:biosynthesis*; D019344:Lactic Acid / Q000378:metabolism; D008567:Membranes, Artificial; D058086:Microalgae / Q000378:metabolism; D010788:Photosynthesis; D016992:Rhodobacter / Q000166:cytology / Q000254:growth & development*; D013997:Time Factors
D005227:Fatty Acids; D008567:Membranes, Artificial; D019344:Lactic Acid
Cell productivity; Fatty acids; Lactate; Membrane-coupled bioreactor; Photosynthetic bacteria