Huge volumes of harmful algal bloom residues (ABR) are collected during emergency treatment of cyanobacteria blooms, and phycocyanin-extracted algal bloom residues (PE-ABR) are produced after extraction of phycocyanin from ABR.

a b s t r a c tA bacterial strain named CH-22 showing phytoplankton-lytic activity against bloom-forming cyanobacterium Microcystis aeruginosa was isolated from Lake Chaohu of Anhui Province, China. The isolated strain was identified as Pseudomonas putida by morphology and homology research based on 16S rDNA. The phytoplankton-lytic activity was confirmed by reduction in cell number and chlorophyll a concentration of M. aeruginosa in an infected culture for a defined period. The initial bacterial and M. aeruginosa densities affected the phytoplankton-lytic activity significantly. When the 15% (150 mL/mL) concentration of bacterial cultures was infected, the highest phytoplankton-lytic activity reached to 98.8% after 7 days. When the initial M. aeruginosa density was less than 3 Â 10 6 cells/mL, about 90.0% of chlorophyll a was removed. Obvious reduction in phycocyanin concentration in the treated M. aeruginosa suggests that isolated strain may possibly inhibit the synthesis of photosynthetic apparatus. Supernatants of bacterial cultures showed higher phytoplankton-lytic activity, suggesting that phytoplankton-lytic bacterium P. putida indirectly attacked M. aeruginosa cells by secretion of extracellular antialgal substances, which is characterized as anti-heat shock. The isolated P. putida also showed effective phytoplankton-lytic activity against a wide range of phytoplankton. These results suggest that indigenous bacteria isolated from eutrophic lake may be employed to regulate the ecological balance between the phytoplankton and bacteria, and consequently, to reduce the occurrence of cyanobacterial blooms in freshwaters.

In order to realize the resource utilization of bloom algae from Lake Chao, this study presents the use of fresh algae to improve the mechanical and biological properties of low-density polyethylene (LDPE). In this study, the algae and LDPE were used as raw materials, maleic anhydride grafted polyethylene (PE-g-MAH), polyethylene wax (PE-wax) and white oil, and glycerin were used as the compatibilizer, lubricant, and plasticizer, respectively. The single factor experiments were conducted with these three individual factors, and the response surface methodology technique was used to optimize the process conditions. In the single factor experiments, the mechanical properties of the composites increased with additions of PE-g-MAH, PE-wax/white oil, and glycerin. Both flexural strength and flexural modulus were maximized to optimize the preparation conditions. The optimum preparation conditions were found as follows: algae powder of 15.00 wt%, LDPE of 85.00 wt%, PE-g-MAH of 4.00 wt%, lubricant of 2.67 wt%, and glycerin of 3.00 wt%. This resulted in 11.60 MPa of tensile strength, 9.95 MPa of flexural strength, and 241.00 MPa of flexural modulus. The mechanical properties of composites were greatly improved compared with the absence of additives. In addition, compared with LDPE resin, the degradability of the composite was improved, and the weight loss rate was 7.73% after 6 months. The results recommended that the composites of the algae from Lake Chao and LDPE resin could be a useful material in the packaging field. Generally, the prepared composite particles can be used to produce foam products, packaging bags, or hard packing boxes with special shapes. It is more environmentally friendly, and more able to meet the challenges of sustainable development.

This research was carried out to extract and purify phycocyan in from blue algae from Chaohu Lake by utilizing salting out methods. Thus a two-step salting out was performed using Ammonium sulphate, Triammonium citrate, Sodium citrate and Sodium sulfate. The phycocyanin and the impurity solution collected at each phase were subjected to analysis by using UV-Vis spectrophotometer to identify the optimal dose of ammonium sulfate, triammonium citrate, sodium citrate and sodium sulfate. The optimal molar concentration for Ammonium sulphate, Triammonium citrate , Sodium citrate and Sodium sulfate in the first and second salting out process were 1.0 mol/L and 1.7mol/L for Ammonium sulphate (NH 4) 2 SO 4, 0.7, mol/L and 1.3 mol/L for Triammonium citrate C 6 H 17 N 3 O 7 , 0.5mol/L and 0.9 mol/L for Sodium citrate C 6 H 5 Na 3 O 7 , 1.0mol/L and 1.3 mol/L for Sodium sulfate Na 2 S0 4. After the two-step salting out processes, it was observed that higher molar concentrations can remove impurities in large quantities, and both purity and yield was greatly increased. The results indicate a purity of phycocyanin above 2.0 with a phycocyanin recovery relatively high. This was carried out to affirm and estimate if result from the salt use will vary from a previous experiment carried out on the same river by the authors with three (3) different kinds of salt K 3 C 6 H 5 O 7 H 2 O, C 6 H 5 O 7 (NH 4) 3 and (NH 4) 2 SO 4 as compared to the four (4) salt compound used in this experiment.