Análise da diversidade bacteriana e de bactérias fixadoras de nitrogênio no sedimento do rio Cuiabá - Mato Grosso

Abstract

The impacts produced from rapid agrobusiness evolution in Mato Grosso besides population growth and industrials and agricultural increase resulted series of pressure related to hydric resources, such as the growth in using water demand and in consequence the deterioration of water quality and sediment. The purpose of the current research consists in classify the diversity of heterotrophic bacterias amount and nitrogen fixers in Cuiabá river sediments, by using microbiology and molecular biology's convencional technics. The sediment samples were collected in bimestral periods which comprehend dry and flood, and were realized in four locations: Cuiabazinho, Passagem da Conceição, Ribeirão dos Cocais e Barão de Melgaço. The Samples were collected and processed through serial dilutions ( 10-2 to 10-7 ) in 0.85 % saline . Were then cultured in a Petri dish using the technique of surface scattering in the culture medium Trypic Soy Agar (TSA ) for total heterotrophic bacteria and nitrifying bacteria used for the selective media ( NFB , JMV and Part 79 ), and then incubated at 35°C. Subsequently, the bacterial strains were re-isolated on Nutrient Agar ( NA) in order to obtain pure cultures for analysis morfotintorial Gram , of which 202 bacterial isolates , showed the presence of 59 % rods positive , 15% negative rods , 25% positive cocci and 1% negative cocci . And by graphic type " box-plot " ; using the nonparametric Kruskal - Wallis test, the bacterial count data presented similariadade between data sampled over space, and a dissimilarity between the results obtained with respect to time , a variation in bacterial growth , especially in relation to the culture medium TSA , with a larger quantification by colony forming unit , in relation to specific media. The profile of the bacterial community , presented mostly bacteria Bacillaceae family with 28 % , while the same were used for molecular analysis by Box - PCR and introduced species richness with a dissimilarity between the sampling points . By conventional techniques was possible to verify and quantify the diversity of total heterotrophic bacteria , but the specific means results were not expected , given the fact finding heterotrophic bacteria in the media that should be selective . By Gram staining technique was verified that had an abundance of gram- positive family Bacillaceae where molecular analysis revealed a wealth of species . Being of utmost importance to this study because you can enter the state of Mato Grosso in research on microbial diversity of sediments using molecular techniques .