Photosynthetical Responses Of Two Economic Marine Macroaglae To Organic Pollutants

The environmental pollution has been becoming a focus in the world and has being a serious problem for the production and life of the human being. Organic pollution especially has serious impact on human being and other orgnisms. The economic seaweed has a very important economic, nutritional, medicinal and ecological value. This paper aimed to investigate the responses of growth, photosynthesis, respiration and biochemical components with exposure to different concentrations of two common antibiotics (chloramphenicol and benzylpenicillin sodium salt) and PAHs(fluoranthene and naphthalene) in the red seaweed, Gracilaria lemaneiformis (Bory) Weber–van Bosse and the brown seaweed, Hizikia fusiforme. The mainly results were as follows:The results showed that the growth of G. lemaneiformis was negatively affected by both antibiotics, with the sensitivity being more in chloramphenicol than benzylpenicillin sodium salt. In the treatments of chloramphenicol, photosynthesis, effective quantum efficiencies (Yield), phycobiliproteins, and the contents of soluble proteins were sharply reduced with the increasing concentrations of chloramphenicol. However, respiration rates of G. lemaneiformis were enhanced by the chloramphenicol. The contents of pigments in G. lemaneiformis were not significantly affected by chloramphenicol. In the treatments of benzylpenicillin sodium salt, both of photosynthesis and Yield were progressively decreased with the increasing concentrations of benzylpenicillin sodium salt. However, the contents of pigments exhibited the opposite performance. The contents of phycobiliproteins and soluble proteins were not significantly affected by benzylpenicillin sodium salt. The results suggest that reduced growth was mainly due to the reduced photosynthesis rates and reduced synthesis of proteins in case of chloramphenicol, or could be ascribed to the increased respiration rates in case of benzylpenicillin sodium salt.The relative of growth rates of H. fusiforme was negatively affected by both antibiotics, with the sensitivity being more in chloramphenicol than benzylpenicillin sodium salt. The rETR of H. fusiforme decreased deeply with the increasing of concentrations of chloramphenicol, when the concentration of chloramphenicol higher than 100mg/L, the value of rETR almost decreased to zero, the electronic transport was almost close to the end. It was similar with rETR in the results of photosynthesis, the net photosynthesis of H. fusiforme was negative. The concentration of chlorophylla increased in low concentrations, while high decreased in concentrations. Both the content of soluble protein and the activity of algae in body systems were negatively affected by chloramphenicol. All of these results bringed on the inhibition of the growth in H. fusiforme. In the treatment of benzylpenicillin sodium salt, the content of pigments had no evidence difference in all the treatments, but the content of soluble protein was stimulated by the chloramphenicol. There were different impacts of two kinds of PAHs(fluoranthene and naphthalene) on growth of G. lemaneiformis, showing the toxicity of both PAHs on the macroalgae. The relative growth rate was reduced with the increasing of the concentrations of PAHs. When the concentration of fluoranthene and naphthalene were at low level (below 0.2mg/L), the photosynthesis was stimulated. while at high concentrations (fluoranthene:5mg/L, 10mg/L, naphthalene concentration: 25mg/L), inhibition happened. That showed low does-"physiological excitement, high concentrations-toxic inhibition. However, the respiration was ascended with the treatment of PAHs. The content of pigments in G. lemaneiformis was generally not affected by PAHs, except that the content of carotenoid gradually increased with the increasing concentration of fluoranthene. Within the treatment of PAHs on phycobiliproteins, just the content of phycoerythrin(R–PE) was stimulated.In conclusion, as for the extent of impact on seaweed to organic pollution, chloramphenicol > benzylpenicillin sodium salt; fluoranthene > naphthalene.