Water and Sediment Bacterial Communities in a Small Mediterranean, Oxygen-Stratified, Saline Lake (Lake Alboraj, SE Spain)

Lake Alboraj, located in southeast Spain, was declared natural Microreserve and included into European Natura-2000 Network due to its contribution environmental heritage. Unfortunately, the ecological status of lake has changed dramatically, mainly lowering water table caused by groundwater abstractions for irrigation. It is a permanent small karstic whose surface reduced last decades nearly third part historical level. The column shows marked seasonal oxycline, that splits an aerobic upper layer (epilimnion) from anaerobic below (hypolimnion). Sequencing 16S rRNA gene amplicons applying chemical tools at epilimnion, hypolimnion sediment, showed clear gradient bacterial community structure, which support co-existence assimilatory dissimilatory microbial mediated reactions. Results allows infer stratification could provide various physical environments different depths related biogeochemical reactions providing N-S-C- recycling processes.