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
地球表面水资源占比极高，但其中仅3%为淡水。在这些淡水中，仅有约0.3%可供地球生物利用。为评估水体健康状况，科研人员常以大肠菌群作为指示生物——其在水环境中的检出可作为污染的潜在指征，同时也提示致病微生物存在的风险。巴西拥有全球最丰富的淡水资源，但该国诸多区域的河流仍面临污染问题。本研究以维持水生群落自然平衡为目标，对位于巴拉那州库里提巴市的巴拉切里河（Bacacheri River）水体开展微生物学分析；研究通过滤膜法检测粪大肠菌群与总大肠菌群的菌落生长情况，在5个预设采样点评估水体污染程度。结果显示，所有观测采样点的粪大肠菌群与总大肠菌群菌落数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，采样点P1、P2与P5受污染程度最为严重，而P3、P4受影响相对较轻，这可能与该河段沿岸及河床存在的纤毛林（ciliary forest）以及河岸与河床的渠化改造有关。