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

A strong negative effect of the toxicant 2,3 ′,4,4′,6-pentachlorobiphenyl (PCB-119) on Chlorella sorokiniana cells was observed at PCB concentration of 0.05 μg mL−1. Photosynthetic activity measured in cell suspension was fully inhibited at 24  h, whereas recovery of photosynthetic activity was observed at 96 h. The study of the distribution of individual cells in culture revealed the existence of 2–3% of cells retaining high photosynthetic activity at 96 h, when almost all cells were dead. These cells enabled treated cultures to resume growth after prolonged incubation in fresh medium. AbstractThe effect of the toxicant 2,3 ′,4,4′,6-pentachlorobiphenyl (PCB-119) on the growth, chlorophyll content, and PSII activity ofC. sorokiniana cells was investigated. A strong negative effect of the toxicant was observed at PCB concentration of 0.05  μg mL−1, 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 ofFv/Fm parameter, which reflects the quantum yield of PSII photochemistry, revealed the existence of 2 –3% of cells ret...
Source: Photochemistry and Photobiology - Category: Science Authors: Tags: Research Article Source Type: research