Microbiological analysis of Bacacheri River water, Curitiba (PR), Brazil

ABSTRACT The planet Earth is made up of a large percentage of water, being only 3% of fresh water. Of this fresh water, approximately 0.3% is available to be used by the planet’s inhabitants. For the evaluation of the health conditions of the water, bacteria of the coliform group are use, being their presence in the aquatic environment a potential indicative of pollution, as well as of the risk for presence of pathogenic organisms. Brazil has the highest availability of water on the planet, but in several parts of the country, many rivers are polluted. The objective of the study was to perform the microbiological analysis of the Bacacheri River water, located in the city of Curitiba, Paraná, which is included in the section of fresh waters, aimed at preserving the natural balance of aquatic communities, in order to determine the level of pollution in five pre-determined points, following the growth of colonies of fecal coliforms and total coliforms, through the membrane filter technique. The results show proliferation of fecal and total coliforms in values above the limit proposed by CONAMA no. 357/2005 Brazilian determination in all harvest points observed. In addition, points # P1, # P2, and # P5 are the most affected ones, whereas points # P3 and # P4 seem to be less affected, probably due to the presence of ciliary forest, as well as the channeling of the banks and the bottom of the river.摘要 地球表面以水为主要组成部分，其中淡水仅占总水量的3%。在全部淡水资源中，仅有约0.3%可供地球各类生物利用。为评估水体健康状况，大肠菌群被作为常用指示菌——其在水环境中的存在是水体污染及致病微生物存在风险的潜在指征。 巴西拥有全球最丰富的淡水资源，但该国多个区域的众多河流仍面临污染问题。本研究旨在对位于巴拉那州库里提巴市的巴萨凯里河（Bacacheri River）水体开展微生物学分析：该河段属于淡水水域，以保护水生群落的自然平衡为目标；研究通过膜过滤（membrane filter）技术，计数粪大肠菌群与总大肠菌群的菌落生长量，在预设的5个采样点开展污染水平评估。 研究结果显示，所有观测采样点的粪大肠菌群与总大肠菌群数值均超出巴西国家环境委员会（CONAMA）第357/2005号决议规定的限值。此外，P1、P2及P5点位污染最为严重，而P3与P4点位受影响程度相对更低，这可能与沿岸及河床存在的河岸林以及河道岸线与河床的整治工程有关。