[Effects of Different Colored Polycarbonate Plastics on Growth and Community Structure of Periphytic Algae].

Periphytic algae are important primary producers in water bodies, which play an important role in maintaining ecological function and water purification. Previous studies have shown that plastic is a good substrate for periphytic algae, and different plastic materials have different effects on the colonization of periphytic algae; however, there are few reports on the effects of plastic color on the growth of periphytic algae. In this study, polycarbonate plastic (PC) of various colors were used as the substrate to study the effects of different colors on the growth and community structure of periphytic algae by measuring the biomass, photosynthetic activity, and community composition. The results showed that the growth of periphytic algae was inhibited by the brown PC plastic, and the contents of chlorophyll a and dry weight in this group were significantly lower than those in other groups. Green PC plastic inhibited the photosynthetic activity of periphytic algae, and the actual photosynthetic efficiency (Yield) of the group was significantly lower than that of the other groups. The influence of PC plastic with different colors on periphytic algae occurred mainly in the early colonization/development stage but was not significant in the late community maturity stage. On day seven of the experiment, the community composition of periphytic algae was significantly different between the transparent PC plastic group and the green PC plastic group. By contrast, on days 25 and 40, there were no significant differences in the community structure of periphytic algae. In the early stage of the experiment, the dominant genus was Pseudoranea (Cyanophyta), and in the middle and mature stages, the dominant genus was Mougeotia (Chlorophyta). In this study, the effects of different colors of polycarbonate plastics on periphytic algae were investigated, which provided new insights for selecting suitable substrates for water pollution treatment by using periphyton biotechnology.

[Utilization and growth response of Chrysosporum ovalisporum to different phosphorus compounds]. / 卵孢金孢藻对不同磷化合物的利用及生长响应.

To explore the ability of bloom-forming cyanobacterium Chrysosporum ovalisporum to utilize different kinds of phosphorus compounds in the water column, we examined the growth response of C. ovalisporum in the laboratory by taking dipotassium hydrogen phosphate as the control and set different treatments of phosphorus substrates. The results showed that C. ovalisporum could utilize sodium tripolyphosphate and terasodium pyrophosphate decahydrate, with better utilization of sodium tripolyphosphate. After 15 days, it had the highest biomass and chlorophyll a concentrations under the treatment of sodium tripolyphosphate, with a value of (426.96±47.42) mg·L-1 and (1852.34±116.60) µg·L-1, respectively. Compared with the control, there was no significant difference in biomass of C. ovalisporum under both the (2-aminoethyl)-phosphonic acid and disodium ß-glycerol phosphate pentahydrate treatments. The change characteristics of dissolved inorganic phosphate were related to the alkaline phosphatase activity, indicating that C. ovalisporum was able to utilize these two organophosphorus compounds via enzyme hydrolysis. The concentration of dissolved inorganic phosphate reached 0 mg·L-1 during the whole experiment when the C. ovalisporum were fed with glyphosate. Biomass, specific growth rate, chlorophyll a concentration and photosynthetic activity of algal cells were significantly lower than those of the control, indicating that C. ova-lisporum could not uptake phosphorus compounds in the glyphosate substrate and thus their growth being inhibited. Our results present new insights to understand the diffusion mechanism of C. ovalisporum into different aquatic ecosystems and had theoretical reference value for the prevention and control of new cyanobacterial blooms.