出版社：Faculdade de Biociências, Pontifícia Universidade Católica do Rio Grande do Sul
摘要：Water is of vital importance to all living beings, and problems with the quality of fresh water have
become more serious due to pollution that watercourses suffer. Most severe consequences include the
economic losses and spreading of water-borne diseases. This study was designed to assess water bacterial
quality of a bathing site in the city of Porto Alegre, state of Rio Grande do Sul, Southern Brazil, through
coliform counts and identifying the bacterial population there present. Monthly sample collections took
place from July, 1999 to August, 2000. Samples were spreaded onto plates with tryptic soy agar (TSA)
and selective media eosin-methyl blue agar (EMB), xylose-lysin desoxycholate agar (XLD), xyloselysin
tergitol4 agar (XLT4), and Salmonella-Shigella agar (S-S). The isolated colonies were identified by
biochemical tests. Results showed a prevalence of genus Bacillus (45.3%), followed by genera
Enterobacter (17.8%) and Escherichia (10.7%). High coliform counts were observed, indicating that
the water of the bathing site received considerable load of fecal pollution. Thus on this condition the site
was unsuitable for bathing. These results are related to analyses done before the construction of a sewage
treatment plant at that region. Nowadays, a new evaluation of microbial population should be considered,
to see if there have been changes as expected.
关键词：surface waters, bacteria, total coliform counts, Escherichia coli.
