3.4 Polysaccharides, proteins, chlorophyll and carotenoids
Compared to the control, the soluble and cell surface proteins had no significant change at Mt treatments (Fig. 4A). However, the content of intracellular protein increased gradually with the elevation of Mt concentration, reaching 6.0 mg 10-12 cell at Mt200 and 7.6 mg 10-12 cell at Mt500. After Pal addition, the soluble proteins rose from 1.6 mg 10-12cell to 2.0 and 3.0 mg 10-12 cells for Pal200 and Pal500, respectively (Fig. 4A). However, the intracellular protein declined significantly from 5.5 to 3.7 mg 10-12 cells at Pal200 and increased slightly to 4.0 mg 10-12 cells at Pal500.
The contents of soluble and intracellular polysaccharides decreased with the elevation of Mt, i.e., from 2.9 to 2.3 mg 10-12cells and from 7.2 to 5.8 mg 10-12 cells, respectively (Fig. 4B). In contrast, these polysaccharides increased with the elevation of Pal. Upon Pal500, the intracellular polysaccharides increased remarkably from 7.2 to 13.4 mg 10-12 cells. The cell surface polysaccharides contents hence showed an increasing trend under Pal addition.
The changes of chlorophyll a , chlorophyll b and carotenoids in cells showed an upward trend under Mt and Pal addition (Fig. 4C). Following the addition of Mt500, chlorophylla increased from 21.9 to 23.9 mg 10-12 cells, whereas this value increased to 28.5 mg 10-12 cells at Pal500. In addition, upon the 500 mg/L Mt and Pal treatment, the content of chlorophyll b rose from 12.2 to 15.3 mg 10-12cells and to 17.4 mg 10-12 cells, respectively. The carotenoids content did not change significantly at Mt500, but increased from 1.6 to 2.7 mg 10-12 cells at Pal500 (Fig. 4C).