ON THE USE OF FROTH FLOTATION IN THE RECOVERY OF Bacillus sphaericus SPORES

Abstract

- The recovery of Bacillus sphaericus strain 2362 spores from fermented medium by batch flotation was tested under different conditions. Flotation kinetic studies were performed at 800 rpm and 3 l air/min. The pH values were adjusted at the following set of values: 5.0, 7.0 and 9.0. The results showed that the spore removal rate is influenced by the pH value. At pH equal to 5.0 we observe an adverse effect on the spore concentrate obtention. In this situation the maximum value of the concentration factor was 1.4 when the recuperation percentage was 99%. At pH equal to 7.0 the concentration factor reached the highest value, 7.0, but the recuperation percentage stayed around 96%. Field experiments with the floated material demonstrated that its larvicide activity was sufficient to keep a Culex quinquefasciatus larvae population under control at in a breeding site, during 3 months with 2 application

Bio-purification of drinking water by froth flotation

“…The main aim of this work is to investigate whether it is possible to reach a suitable purification of water from microorganisms using a chemical free froth flotation. The driving force that leads this process is hydrophobicity and most of the microorganisms in water are hydrophobic and should be suitable for removal by such a technique (Boyles and Lincoln, 1958;Rubin et al, 1966;Bahr and Schugerl, 1992;Rios and Franca, 1997).…”

Recovery of Bacillus sphaericus 2362 spores from growth medium by flocculation/sedimentation

“…The use of flotation for the concentration of spores of B. sphaericus has been studied [3]. More recently, the influence of pH and hydrophobicity on the efficiency of flocculation of this bacterium was investigated [4].…”