Impact of chemical and microbiological water quality on bacterial community assemblage of San Juan River (Sierra del Rosario, Biosphere Reserve, Cuba)

Abstract

The objective of the present study was to analyze the influence of different physicochemical and microbiological indicators on bacterial assemblages in a freshwater ecosystem located in a Biosphere Res erve.The bacterioplankton communities composition was determined by denaturing gradient gel electrophoresis (DGGE) of 16S rDNA during three sampling campaigns in three sampling stations of San Juan Ri ver.Multivariate statistical analyses of gel patterns, in relat i on t o chemi cal , biological and physical parameters were performed. The analyses showed a seasonal variation of bacterial community at the l ess pol l ut ed stations. The correspondence canonical analysis showed that total dissolved solids (TDS), E. coli concentration and dissolved oxygen were significantly influencing the DGGE profiles at San Juan River, indicating that at least two of the three sampling stations analyzed possessed good water quality. With the combination of environmental variabl es and t he DGGE molecular data it could be appreciated the influence of chemical and microbial contamination on the bacterial community of San Juan River. At the less polluted stations low concentrations of TDS and bacterial indicators of fecal contamination were related with bacterial diversity. The present investigation constitutes the first cultureindependent analysis of freshwater bacterial communities in a Biosphere Reserve of the Caribbean islands.

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

“…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.…”

“…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).…”