Proteolytic Enzyme Activity and Its Relationship with Physicochemical and Microbiological Indicators in Freshwater Ecosystems of Western Cuba

Acid Phosphatase Activity in Freshwater Ecosystems of Western Cuba and its Relationship with Water Quality

“…In April, the highest NPI values were obtained at the Presa el San Juan and Baños del San Juan stations, classifying them as very high polluted and considerably polluted respectively. This result is in correspondence with the water quality index values reported byIzquierdo et al (2020) for these two stations. The month of April constitutes one of the months that are within the dry season in Cuba.…”

“…Havana and receives little or no treatment wastewater of domestic and industrial origin from the city that contributes to the pollution of the ecosystem(Romeu et al 2015b). The high phosphate concentrations determined in the Almendares River [seeIzquierdo et al (2020) and Online Resource 3 for values of physicochemical and microbiological indicators] contributed to the high NPI values obtained in this study.In the case of the San Juan River, the NPI indicated that this is a moderately polluted ecosystem (Table1), which is in correspondence with previous studies carried out in this river(Izquierdo et al 2020;Larrea et al 2021). The San Juan River is located in the province of Artemisa, in the "Sierra del Rosario" Biosphere Reserve, where it does not receive the same anthropogenic impact as the Almendares River because it is in a rural area where there is no presence of industries.…”

“…Almendares River. In the San Juan River, pH correlated negatively with the AcPA, where fundamentally, in the months of February and April values of pH > 8 were obtained(Izquierdo et al 2020). At these pH values, the activity of acid phosphatases is practically null because their activity occurs at pH 2.6-6.8(Torres et al 2017).…”

“…In the San Juan River, the opposite occurs, detecting a phosphate limitation (Table2). The nitrate limitation conditions found in the Almendares River are associated with the anthropogenic activities carried out in this ecosystem, the low concentrations of dissolved oxygen and high concentrations of phosphate(Izquierdo et al 2020) and possibly due to denitri cation (Isiuku and Enyoh 2020;Wemedo et al 2021). All of which leads to the eutrophication conditions that this river presents(Arpajón et al 2011).…”

“…All of which leads to the eutrophication conditions that this river presents(Arpajón et al 2011). In the San Juan River, the limitation by phosphate implies higher concentrations of nitrate, less addition of phosphates from polluting sources and therefore, less risk of eutrophication and better water quality(Izquierdo et al 2020;Larrea et al 2021).…”