TY - JOUR
T1 - Polymer accumulation in mixed cyanobacterial cultures selected under the feast and famine strategy
AU - Arias, Dulce María
AU - Fradinho, Joana C.
AU - Uggetti, Enrica
AU - García, Joan
AU - Oehmen, Adrian
AU - Reis, Maria A. M.
N1 - The authors would like to acknowledge the Fundação para a Ciência e Tecnologia (Portugal) for funding through SFRH/BPD/101642/2014 and UCIBIO financed by national funds from FCT/MEC ( UID/Multi/04378/2013 ) and co-financed by ERDF under PT2020 Partnership Agreement ( POCI-01-0145-FEDER-007728 ). D. Arias kindly acknowledges her PhD scholarship funded by the National Council for Science and Technology (CONACYT) 328365. E. Uggetti would like to thank the Spanish Ministry of Economy, Industry and Competitiveness for her research grant ( IJCI-2014-21594 ).
PY - 2018/7/1
Y1 - 2018/7/1
N2 - In this study, a sequencing batch reactor (SBR), operated with transient carbon availability (feast and famine) and different nutrients loads, was used to select cyanobacteria accumulating poly (3-hydroxyalkanoate) (PHB) and carbohydrates from a mixed wastewater-borne microbial culture. The SBR was operated with 12 h aerobic light and 12 h anaerobic dark phases, evaluating the effect of three different operational conditions consisting on; 1) carbon limitation, 2) carbon and phosphorus limitation and 3) phosphorus limitation. Once a steady state was reached in each operational period of the SBR, part of the biomass was collected and submitted to separate batch tests in order to investigate the maximum PHB and carbohydrates accumulation levels. Batch tests were performed during 24 h of illuminated aerobic condition and 24 h of dark anaerobic condition, while inorganic carbon was constantly present. During the SBR operation, inorganic carbon was mostly used for biomass and carbohydrate production, showing very low PHB accumulation levels (<1%). Notwithstanding, in subsequent batch tests, PHB was accumulated after a complete depletion of nitrogen, reaching almost 4%. Concerning carbohydrates, it was found that phosphorus limitation (with and without carbon limitation) led to a culture mostly dominated by cyanobacteria and higher levels of carbohydrate content (43%–48%) than the culture with carbon limitation and high loads of nitrogen and phosphorus (29%). Such contents were obtained in only 24 h of incubation under aerobic illuminated conditions. Hence, these encouraging results indicate that carbon uptake and the consequent polymers production from cyanobacteria can be enhanced through carbon and nutrient feeding strategies.
AB - In this study, a sequencing batch reactor (SBR), operated with transient carbon availability (feast and famine) and different nutrients loads, was used to select cyanobacteria accumulating poly (3-hydroxyalkanoate) (PHB) and carbohydrates from a mixed wastewater-borne microbial culture. The SBR was operated with 12 h aerobic light and 12 h anaerobic dark phases, evaluating the effect of three different operational conditions consisting on; 1) carbon limitation, 2) carbon and phosphorus limitation and 3) phosphorus limitation. Once a steady state was reached in each operational period of the SBR, part of the biomass was collected and submitted to separate batch tests in order to investigate the maximum PHB and carbohydrates accumulation levels. Batch tests were performed during 24 h of illuminated aerobic condition and 24 h of dark anaerobic condition, while inorganic carbon was constantly present. During the SBR operation, inorganic carbon was mostly used for biomass and carbohydrate production, showing very low PHB accumulation levels (<1%). Notwithstanding, in subsequent batch tests, PHB was accumulated after a complete depletion of nitrogen, reaching almost 4%. Concerning carbohydrates, it was found that phosphorus limitation (with and without carbon limitation) led to a culture mostly dominated by cyanobacteria and higher levels of carbohydrate content (43%–48%) than the culture with carbon limitation and high loads of nitrogen and phosphorus (29%). Such contents were obtained in only 24 h of incubation under aerobic illuminated conditions. Hence, these encouraging results indicate that carbon uptake and the consequent polymers production from cyanobacteria can be enhanced through carbon and nutrient feeding strategies.
KW - Algae
KW - Bioproducts
KW - Wastewater
KW - Wastewater-borne cyanobacteria
UR - http://www.scopus.com/inward/record.url?scp=85046874015&partnerID=8YFLogxK
U2 - 10.1016/j.algal.2018.04.027
DO - 10.1016/j.algal.2018.04.027
M3 - Article
AN - SCOPUS:85046874015
SN - 2211-9264
VL - 33
SP - 99
EP - 108
JO - Algal Research
JF - Algal Research
ER -