This article relates epilithic dry- and wet-seasonal bacterial biofilm composition to water quality along Río de la Sabana near Acapulco, Mexico. Samples were taken from various locations including nearly pristine upland locations, adjacent to residential floodplain developments, and immediately upstream from an estuarine lagoon. Bacterial composition was identified through sequential DNA analysis at the phylum, class, order, and family levels, with most of these categorized as heterotrophs, autotrophs, denitrifiers, nitrogen fixers, pathogens, and/or potential bioremediators based on generalized literature-sourced assignments. The results were interpreted in terms of location by extent of effluent pollution, and by dry versus wet seasonal changes pertaining to biofilm composition, related bacterial functions, and the following water quality parameters: temperature, pH, dissolved oxygen, biological and chemical oxygen demand, fecal and total bacteria counts, methylene blue active substances, electrical conductivity, and nitrite, nitrate, ammonium, sulfate, and phosphate concentrations. It was found that epilithic bacterial biofilm diversity was richest during the wet season, was more varied in abundance along the upland locations, and was dominated by Proteobacteria and Bacteroidetes with bioremediation and pathogen functions along effluent-receiving river locations. Low-abundance families associated with anaerobic and denitrifying functions were more prevalent during the wet season, while low-abundance families associated with aerobic, N₂-fixing and pH-elevating functions were more prevalent during the dry season.

本文将上石器时代的干，湿季细菌生物膜成分与墨西哥阿卡普尔科附近的里奥德拉萨瓦纳河沿岸的水质相关。从不同地点取样，包括接近原始的高地地点，邻近住宅洪泛区开发区以及紧邻河口泻湖的上游。通过在门类，类别，顺序和家族水平上进行顺序DNA分析来鉴定细菌组成，其中大多数根据广泛的文献资料归类为异养生物，自养生物，反硝化剂，固氮剂，病原体和/或潜在的生物修复剂。根据废水污染程度的位置，与生物膜组成，相关细菌功能有关的干湿季节变化来解释结果。以及以下水质参数：温度，pH，溶解氧，生化需氧量，粪便和总细菌数，亚甲基蓝活性物质，电导率以及亚硝酸盐，硝酸盐，铵，硫酸盐和磷酸盐的浓度。发现在湿季上石器时代细菌生物膜的多样性最丰富，在高地位置的丰富度变化更大，并且以带有细菌修复作用和病原体功能的变形杆菌和拟杆菌在沿河接收污水的地方。在雨季，与厌氧和反硝化功能相关的低丰度家庭更为普遍，而与需氧，N ₂固定和pH升高功能相关的低丰度家庭在干旱季节更为普遍。