Development of a Bacillus sphaericus tablet formulation and its evaluation as a larvicide in the biological control of Culex quinquefasciatus

This study aimed to analyze the final fermentation culture of Bacillus sphaericus 2362, standardize it and develop an active tablet formulation for use in urban mosquito breeding sites. It was performed in three phases: analysis and standardization of a B. sphaericus fermented culture; physical, chemical, and biological analysis of the active powder (solubility, residual humidity, particle size, resting angle, flowing off time, compacted density, and biological activity against Culex quinquefasciatus larvae); and the development of fast-disintegrating tablets. Five formulations with differing compositions were developed and a UV protector was added to the selected formulation. The formulation products with or without UV protector, as well as the active powder caused 100 percent larval mortality from 1 day to 2 months after a single treatment under simulated field conditions. These results show that the UV protector does not affect the initial larvicide activity of B. sphaericus, nor its persistence over a period of two months.

Integrated control measures against Culex quinquefasciatus, the vector of filariasis in Recife

Integrated control measures against Culex quinquefasciastus have been implemented in a pilot urban area in Recife, Brazil. About 3,000 breeding sites found within the operational area were responsible for very high mosquito densities recorded during the pretrial period. Physical control measures have been applied to cess pits before starting a series of 37 treatments of the other sites with Bacillus sphaericus strain 2362, over 27 months. In spite of the difficulties due to environmental conditions, very significant reductions in preimaginal population of C. quinquefasciatus were achieved and, as a consequence, low adult mosquito densities were maintained for a relatively long period of time. Entomological and environmental data gathered in this pilot project can contribute to design an integrated mosquito control program in Recife city.

Efeito do tamanho do inóculo na fermentaçäo alcoólica por Zymomonas mobilis ZAP / Effects of inoculum size on alcoholic fermentation by Zymomonas mobilis ZAP

The effects of inoculon size, centrifuged or not, on the batch alcoholit fermentation by Zymomonas mobilis (strain ZAP) were studied. The results show that the ethanol yeld factor, the "economical" and the biochemical" efficiencies and the productivity increase with the elevation of inoculum independently of the inoculation methodology (centrifuged or not). The specific rates of cells growth (micronx), glucose uptake (microngs) and ethanol production (microngp) decrease with the elevation of inoculum level. It was observed an apparente limitation of growth with the increase above 20% (0,50 g/l) of the uncentrifuged inoculum