Environmental changes affect picoplanktonic composition in Antarctic Peninsula ponds

Antarctic Peninsula is experiencing one of the largest global warming events worldwide.Shallow water bodies generated by the melting of snow in summer are numerous,and they might act as sentinels of climate change due to their rapid response and ability to integrate catchment information.Shifts in climate can influence the structure of microbial communities which dominate these freshwaters ecosystems.Here,we characterize three ponds at Cierva Point(Antarctic Peninsula)by examining their physico-chemical and morphological characteristics and we explored how different factors modify the structure of the microbial community.We studied the abundance and biomass of heterotrophic bacteria,picocyanobacteria and picoeukaryote algae during January and February of two consecutive summers(2017 and 2018).We found that ponds had different limnological characteristics,due to their location,geomorphological features and presence of the surrounding flora and fauna.Physico-chemical parameters as well as microbial community differed between ponds,months and years.In 2017,most ponds were oligo to mesotrophic states.The larger accumulated rainfall(as a result of environmental changes on the Antarctic Peninsula)during 2018,particularly in February,causes nutrient runoff into water bodies.This affects those ponds with the highest seabird circulation,such as gentoo penguin,increasing eutrophication.As a result,picoplanktonic abundances were higher,and the community structure shifts to a largely heterotrophic bacteria dominated one.These results suggest that these communities could act as sentinels to environmental changes,anticipating a future with mostly hypertrophic ponds.

Effect of Domestic Wastewater as Co-Substrate on Biological Stain Wastewater Treatment Using Fungal/Bacterial Consortia in Pilot Plant and Greenhouse Reuse

In this study, a pilot wastewater treatment plant was used to evaluate the co-treatment of biological-staining residues and domestic wastewater under non-sterile conditions. A novel microbial consortia formed by Trametes versicolor, Trametes sp, Pleurotus ostreatus, Pseudomonas fluorescens, Pseudomonas azotoformans, Pseudomonas sp, Enterobacter xianfangensis and Bacillus subtillis was inoculated in an extended aeration type bio-reactor. The treatment units were operated during three consecutive cycles during a period of 147 h. After the last operating cycle, the concentrations of Chemical Oxygen Demand, Biochemical Oxygen Demand, Color Units, Total suspended solids, and the pH value were 1695 mg/L, 105 mg/L, 106 CU, 5), 1367 (CU), 566 mg/L (TSS) and 7.0 (pH) respectively. The reduction of pollutants load was related with the ratio of the two types of wastewater (3.5:0.5) combined to increase biodegradability, the concentration of fungi and bacteria used in the consortia (30 × 103 - 55 × 106 CUF/mL Total Fungi and 70 × 107 - 83 × 108 CFU/mL of Total Bacteria) and ligninolytic enzymes production, Laccase (13 - 96 U/L), MnP (9.8 - 39 U/L) and LiP (0.3 - 5.3 U/L). The post-treated effluent was used as irrigation water. Lolium perenne plants were watered during 60 days with post-treated effluent. The results of root weight showed that there are significant differences between the initial water and the effluent obtained after the operational cycles (p = 0.00470). The highest root weights (1 - 1.12 g) were found in plants irrigated with water obtained from the last treatment cycle.