The influence of different nutrients on biosurfactant production by Rhodococcus erythropolis was investigated. Increasing the concentration of phosphate buffer from 30 up through 150 mmol/L stimulated an increase in biosurfactant production, which reached a maximum concentration of 285 mg/L in shaken flasks. Statistical analysis showed that glycerol, NaNO3,MgSO4 and yeast extract had significant effects on production. The results were confirmed in a batchwise bioreactor, and semi-growth-associated production was detected. Reduction in the surface tension, which indicates the presence of biosurfactant, reached a value of 38 mN/m at the end of 35 hours. Use of the produced biosurfactant for washing crude oil-contaminated soil showed that 2 and 4 times the critical micellar concentration (CMC) were able to remove 97 and 99% of the oil, respectively, after 1 month of impregnation.

Cryptosporidium é um patógeno emergente que causa diarréia em humanos. Muitos surtos graves de criptosporodíase tem a água como possível origem da contaminação. Neste estudo foi investigada a presença do oocisto de Cryptosporidium sp. em águas de poço, usadas para consumo humano em Itaquaquecetuba - São Paulo. Os resultados evidenciaram a presença de oocistos em 2 fossas e em 8 poços analisados, mostrando o risco que esta água representa para consumo humano e a necessidade de práticas mais eficientes de desinfecção e monitoramento da presença deste parasita em amostras de águas no estado de São Paulo.

Cryptosporidium is an emergent pathogen that causes profuse diarrhea in humans. Outbreaks of human cryptosporidiosis have implicated water as a possible source of contamination. In this study the presence of Cryptosporidium sp. oocysts was investigated as well as the fecal contamination in groundwater for consumption in Itaquaquecetuba - São Paulo. Therefore, it was possible to notice that the septic tanks were located close to the wells, exposing them to risk of contamination. As a consequence of these results and observations efficient disinfecting practices and groundwater monitoring are recommended.