Cellular Adaptation: Culture conditions of R. opacus and bioflotation of apatite and quartz

• Autor(a) principal: Merma,Antonio Gutiérrez
• Data de Publicação: 2017
• Outros Autores: Hacha,Ronald Rojas, Torem,Maurício Leonardo
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: REM - International Engineering Journal
• Texto Completo: http://old.scielo.br/scielo.php?script=sci_arttext&pid=S2448-167X2017000100067
• topic: Rhodococcus opacus; bioflotation; cellular adaptation; apatite; quartz

Abstract It is well known that the culture conditions of microorganisms may affect their surface properties, zeta potential and hydrophobicity via the modification of the cell wall functional groups or metabolic products. The R. opacus bacteria strain was separately adapted to the presence of apatite and quartz, after which a cellular adaptation procedure was developed by repeated sub-culturing with a successive increase in the mineral content. Zeta potential, surface tension, FTIR and microflotation studies were used to evaluate the behavior of the cells that were developed under defined culture conditions. The cellular adaptation induced a modification of the bacterial surface charge. The FTIR results showed a modification of its functional groups. The surface tension results suggested that longer growing time promoted a higher production of metabolites. The use of mineral-adapted cells promoted an improvement in the flotability of both minerals, but it was more significant for apatite flotation. Additionally, the mineral flotability remained unchanged when the cells developed under a longer culture time. Nevertheless, there was a reduction in the surface tension.