MICROBIOLOGICAL ANALYSIS OF VEGETABLES FERTILIZED WITH TREATED DOMESTIC SEWAGE

Among the high-consumption vegetables in Brazil, lettuce stands out (Lactuca sativa). The use of treated sewage may represent a source of available nutrients for application in this crop. On the other hand, the safety of the use of this product must be consider the minimum treatments required for effluents. The purpose of this study was to evaluate the microbiological quality of vegetables fertilized with sewage treated by septic tank biodigestor in Rural Settlement in the municipality of Gurupi, Tocantins for the determination of indicators of environmental contamination and hygienic / sanitary conditions. Samples of lettuce and chives were collected, from each plot of land and were sterile polyethylene packages, previously identified, and transported to the Laboratory of Microbiology in box with thermal protection. For the analysis the samples were submitted to the multiple tubes technique to determination of the Most Likely Number (MPN) of total and thermotolerant coliforms, as recommended by RDC No. 12/2001, which deals with the Technical Regulation on Microbiological Standards for Food. All the lettuce samples presented presence of total coliforms, with 1,100 NMP/ g being observed in 100% of the samples. Already for chives the values found were & gt; 36NMP / g and> 1,100 NMP / g, respectively. RDC No. 12/2001 does not establish maximum permissible values for total coliforms in fresh vegetables, but total coliform counts & gt; 1,100 NMP / g, may be indicative of unsatisfactory hygienic sanitary conditions in the processing. The presence of thermotolerant coliforms in evaluated, and for chives, only one sample had 14 NMP / g being considere satisfactory, since DRC No. 12/2001 establishes a maximum of 10² NMP / g for this product. These results confirm that efficient preventative measures were taken in lettuce cultivation in relation to the use of organic fertilizer resulting from treated sanitary residue used in the fertilization of the soil of this vegetable crop. Thus, it is evidenced the efficiency of the biogas septic tank in the treatment of domestic sewage making a sustainable alternative that contributes to maximize the resources available in the context of family agriculture, besides being an option to improve the conditions of rural sanitation.