Sulfur Starvation in Extremophilic Microalga : Can Glutathione Contribute to Stress Tolerance?

This study reports the effects of sulfur (S) deprivation in cultures of (Cyanidiophyceae). is a unicellular red alga that usually grows, forming biomats on rocks, in S-rich environments. These are volcanic areas, where S is widespread since HS is the prevalent form of gas. The glutathione content in is much higher than that found in the green algae and even under conditions of S deprivation for 7 days, it remains high. On the other hand, the S deprivation causes a decrease in the total protein content and a significant increase in soluble protein fraction. This suggests that in the conditions of S starvation, the synthesis of enzymatic proteins, that metabolically support the cell in the condition of nutritional stress, could be up regulated. Among these enzymatic proteins, those involved in cell detoxification, due to the accumulation of ROS species, have been counted.