Microcystis aeruginosa is the most common species responsible for toxic cyanobacterial blooms and is considered a significant contributor to the production of cyanotoxins, particularly the potent liver toxins called microcystins. Numerous studies investigating Microcystis spp. blooms have revealed their deleterious effects in freshwater environments. However, the available knowledge regarding the global phosphoproteomics of M. aeruginosa and their regulatory roles in toxin generation is limited. In this study, we conducted comparative phosphoproteomic profiling of non-toxic and toxin-producing strains of M. aeruginosa. We identified 59 phosphorylation sites in 37 proteins in a non-toxic strain and 26 phosphorylation sites in 18 proteins in a toxin-producing strain. The analysis of protein phosphorylation abundances and functions in redox homeostasis, energy metabolism, light absorption and photosynthesis showed marked differences between the non-toxic and toxin-producing strains of M. aeruginosa, indicating that these processes are strongly related to toxin generation. Moreover, the protein-protein interaction results indicated that BJ0JVG8 can directly interact with the PemK-like toxin protein B0JQN8. Thus, the phosphorylation of B0JQN8 appears to be associated with the regulatory roles of toxins in physiological activity.

The South-to-North Water Diversion Project (SNWDP) is the largest water transfer project in the world, and its purpose is to relax water constraints in a region facing severe water scarcity. Bacterial communities from these reservoirs are important to human health, and analyzing their diversity and structure is crucial to water safety. Here, we investigated the dynamics of bacterial communities and their relationship with environmental parameters in the terminal reservoir (Miyun Reservoir) of the Middle Route of the SNWDP by high-throughput sequencing technology. Our results showed that Firmicutes, Proteobacteria, Cyanobacteria and Bacterioidetes were the most abundant phyla in the water column, and the community composition fluctuated seasonally. Moreover, the detected diversity of the bacterial community composition provided novel insights into the ongoing biogeochemical processes. The temperature was positively correlated with the dominant bacteria, with other factors, including the total dissolved solids, total phosphorus, dissolved oxygen and total nitrogen, shaping the structure and distribution of the microbial community. Furthermore, the metagenome showed broad phylogenetic diversity, indicating that organisms were involved in multiple essential environmental processes. This work is important for building a database to understand how microbial communities change after water transfers.

In this paper, a recirculating aquaculture purification system (RAPS) was designed to solve the problems of aquaculture pollution and shortage of freshwater resource according to the characteristic of northern freshwater ponds of China. The system were arranged in series and composed of high density culture pond, deposit pond, floating and submerged plant pond, ecological floating bed pond and biofilm filtrate pond. At the fish density of 20~30kg/m³ in the high density culture pond, the water quality parameters were monitored seasonally. The results indicated that the removal rate of total nitrogen, total phosphorus, ammonia nitrogen and nitrite nitrogen in the recirculating aquaculture system were 69.59%, 77.89%, 72.54% and 68.68%, respectively. The floating and submerged plant pond and ecological floating bed pond can remove TN and TP obviously, and increase dissolved oxygen and transparency significantly. And the biofilm filtrate pond has good effect of removing ammonium nitrogen and nitrite nitrogen, meanwhile, the microbial communities in the recirculating aquaculture system regulate on the water quality. Therefore, the RAPS show significant effects on water saving and pollution emission reducing.

This paper represents to propose an effective extraction procedure for traditional toxin determination techniques in urban lake. Efficiency of each extraction solvent as well as other key parameters affecting extraction efficiency including ultrasonication time and extraction pH were evaluated and optimized. The present study results indicated that 40% acidified methanol (pH~3) with sonication 15~20min has been shown to be a rapid and efficient method for the routine analysis of a wide range of microcystins in water samples. Our study also suggested that analytical method based on HPLC–MS/MS with SPE techniques provides a simplified enrichment procedure and rich information for both quantization and identification effective tool for analysis of urban landscape water quality. The development of this method may facilitate the understanding of the best extraction method for the routine analysis of microcystins in water bodies. Moreover, it may be valuable for purification scale

The genetic biodiversity and differentiation of three representative goldfish species in Beijing were studied using SRAP molecular markers. A total of 122 sites were amplified from 10 primer combinations with good polymorphism, including 99 polymorphic sites. The average polymorphism rate was 80.47% and the average polymorphism information content was 0.264. Diversity indexes of Nei’s genes in short-tailed Bubble-eye goldfish, Redhead goldfish and Black Dragon-eye goldfish were 0.225, 0.208 and 0.238, respectively. The Shannon information index of the three groups was 0.342, 0.299 and 0.363, respectively. The proportions of polymorphic loci in the three populations were 69%, 65% and 72%, respectively. The genetic distance indicated that genetic divergence existed between the three groups. The genetic relationship between Bubble-eye goldfish and Redhead goldfish was far, while Redhead goldfish and Black Dragon-eye goldfish was close. This study is of great importance for the research of molecular marker-assisted biodiversity conservation of goldfish.