title: Responses of Synechocystis sp. PCC 6803 to total dissolved solids in long-term continuous operation of a photobioreactor.
abstract: This study evaluated how Synechocystis sp. PCC 6803 responds to high total dissolved solids (TDS) associated with eliminating nutrient limitation during long-term operation of a photobioreactor. The unique feature is that the TDS were not dominated by Na(+) and Cl(-), as in seawater, but by HCO(3)(-) and NO(3)(-) from nutrient delivery. The TDS-stress threshold was about 10 g/L. Whereas inorganic N and P limitations slowed the rate of inorganic C (C(i)) uptake in the light, TDS stress was manifested most strongly as a substantial increase of endogenous respiration rate at night. Relief from TDS stress was incomplete when lowered pH led to a HCO(3)(-) increase (560 mgC/L as a threshold). Impaired photosynthesis led to a cascade of reduced C(i)-uptake, pH decrease, HCO(3)(-) accumulation, and HCO(3)(-)-associated stress. Thus, long-term photobioreactor operation requires balancing the delivery rates of CO(2), N, P, and other TDS components to avoid general and C(i)-associated TDS stresses.
authors.affiliation: Swette Center for Environmental Biotechnology, The Biodesign Institute at Arizona State University, PO Box 875701, Tempe, AZ 85287-5701, USA.
authors.forename: Hyun Woo
authors.initials: HW
authors.lastname: Kim
authors.forename: Raveender
authors.initials: R
authors.lastname: Vannela
authors.forename: Bruce E
authors.initials: BE
authors.lastname: Rittmann
mesh_terms: D061249:Batch Cell Culture Techniques / Q000379:methods*; D049109:Cell Proliferation / Q000528:radiation effects; D002470:Cell Survival / Q000528:radiation effects; D003470:Culture Media / Q000737:chemistry* / Q000378:metabolism* / Q000528:radiation effects; D008027:Light; D058433:Photobioreactors / Q000382:microbiology*; D046939:Synechocystis / Q000502:physiology* / Q000528:radiation effects*
chemical_list: D003470:Culture Media