Acclimation Response of Green Microalgae Chlorella Sorokiniana to 2,3′,4,4′,6‐Pentachlorobiphenyl

Abstract

The effect of the toxicant 2,3 0 ,4,4 0 ,6-pentachlorobiphenyl (PCB-119) on the growth, chlorophyll content, and PSII activity of C. sorokiniana cells was investigated. A strong negative effect of the toxicant was observed at PCB concentration of 0.05 lg mL À1 , when culture growth ceased, chlorophyll strongly bleached, and cell death occurred. The use of original highly sensitive fluorimeter to measure three types of high-resolution chlorophyll fluorescence kinetics allowed us to detect an initial dramatic decrease in the activity of primary photosynthetic reactions, followed by their almost complete recovery at the end of the incubation period when most cells were dead. The study of the distribution of individual cells in culture in terms of F v /F m parameter, which reflects the quantum yield of PSII photochemistry, revealed the existence of 2-3% of cells retaining high F v /F m (>0.7) in the presence of the toxicant. The treated cultures were able to resume growth after prolonged incubation in fresh medium. The high sensitivity fluorescence methods used made it possible to identify stress-resistant cells which maintain high photosynthetic activity in the presence of lethal doses of toxic substances; these cells provide recovery of the population after stress.

Reduction of Oxygen Production by Algal Cells in the Presence of O-Chlorobenzylidene Malononitrile

“…The interpretation of this modification could be associated with the fact that it accumulates toxic agents in the analyzed sample. C. pyrenoidosa destroys toxic CBM and it accumulates metabolic products resulting from the metabolism of CBM [ 54 , 55 , 56 , 57 , 58 , 59 ]. Images regarding the appearance of the surface structure by SEM spectroscopy of C. pyrenoidosa in the presence of different concentrations of CBM are shown in Figure 8 .…”

“…The membrane remains intact, which means that enzyme activity in the reaction center is possible. The addition of CBM in the reaction medium generates chemical stress in the bioreactors and affects the permeability of the cell by the fact that photosynthetic electron transport is blocked [56]. The chemical stress generated by CBM prevents the cellular development of the algae and destroys its enzymatic system, which generates cell death.…”

“…The chemical stress generated by CBM prevents the cellular development of the algae and destroys its enzymatic system, which generates cell death. C. pyrenoidosa has the highest survival rate in the environment contaminated with CBM and The addition of CBM in the reaction medium generates chemical stress in the bioreactors and affects the permeability of the cell by the fact that photosynthetic electron transport is blocked [56]. The chemical stress generated by CBM prevents the cellular development of the algae and destroys its enzymatic system, which generates cell death.…”

Modification of Oxygen Production of Algal Cells in the Presence of O-chlorobenzylidene Malononitrile, Biodegradation in the Eco-Friendly Way

“…The interpretation of this modification could be associated with the fact that it accumulates toxic agent in the analyzed sample, Chlorella destroy toxic CBM and it accumulates metabolic products resulting from the metabolism of CBM. [54][55][56][57][58][59] Images regarding the appearance of the surface structure by SEM spectroscopy of Chlorella sp. in the presence of different concentrations of CBM are shown in Figure 13.…”

“…The addition of CBM in the reaction medium generates chemical stress in the bioreactors and affects the permeability of the cell by the fact that photosynthetic electron transport is blocked. [56] The chemical stress generated by CBM prevents the cellular development of the algae, destroys its enzymatic system, which generates cell death. Chlorella has the highest survival rate in the environment contaminated with CBM and has a rapid response ability to toxic stimuli.…”