Made available in DSpace on 2014-12-17T15:54:55Z (GMT). No. of bitstreams: 1 AnaCLP_DISSERT_pagina 1_a_8.pdf: 8605712 bytes, checksum: a23b0324901ca6ee088750e19d1a57c3 (MD5) Previous issue date: 2009-04-24 / Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico / Density and biomass of bacterioplankton in parts of the Marechal Dutra reservoir were studied in periods of dry and rainy season. The averages of the total bacterial densities oscillated in the order of 107 organisms/ mL of sample. The cocci cells were numerically predominant, influencing considerably the total abundance of the bacterioplankton. The total bacterial biomass, was considered raised and varied from 2.431,82 to 2.739,01 ?gC.L-1, in function of the high values of biovolume of the filaments forms, and showed no marked spacial fluctuation. These high values of density and biomass alert for the necessity of a frequent monitoring of aquatic ecosystems of semi-arid region, where the quality of the water is affected by the occurrence of extensive dry periods, influencing considerably the quality of life of its population / Foram estudadas a densidade e a biomassa do bacteriopl?ncton nos per?odos seco e chuvoso em dois pontos do A?ude Marechal Dutra. As m?dias das densidades bacterianas totais oscilaram na ordem de 107 organismos por mL de amostra. As c?lulas em forma de cocos foram numericamente predominantes, influenciando consideravelmente a abund?ncia total do bacteriopl?ncton. A biomassa bacteriana total foi considerada elevada, variando de 2.431,82 a 2.739,01 ?gC.L-1 , em fun??o dos altos valores de biovolume dos filamentos. N?o foram encontradas varia??es espaciais nem sazonais marcantes. Os altos valores de densidade e biomassa encontrados alertam para a necessidade de um freq?ente monitoramento dos ecossistemas aqu?ticos de regi?o semi-?rida onde a qualidade da ?gua ? afetada pela ocorr?ncia de extensos per?odos de estiagem que influenciam a qualidade de vida de sua popula??o