Cadmium exposure induces alterations on the volatile metabolome of Rhizobium

• Autor(a) principal: Cardoso, Paulo Jorge da Rocha
• Data de Publicação: 2015
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10773/14863
• topic: Biologia; Fertilizantes - Poluição do solo; Cádmio - Toxicidade; Bactérias - Exposição aos poluentes; Metabolismo

In agricultural systems the use of phosphate fertilizers is a major input of Cd into the soil, and Cd may reach concentrations interfering with soil microorganisms. The secondary metabolism might provide clues or even deliver sensitive biomarkers that could be used to detect small modifications induced by the environment, such as metal exposure. In this work, comprehensive two-dimensional gas chromatography coupled to mass spectrometry with a high resolution time of flight analyzer (GC×GC–ToFMS) combined with headspace solid phase microextraction (HS-SPME) was used to screen for alterations in the volatile metabolome of rhizobia exposed to cadmium. The results showed that exposure to cadmium altered the number and amount of metabolites, both intra and extracelullarly. Specifically, peak areas of low chain aliphatic alcohols increased linearly with the increment of cadmium concentration, reflecting the intracellular redox environment of the bacteria. Ethyl acetate emerged as an excellent biomarker for metal stress in bacteria. Apart from providing data on the effects of metal exposure in the volatile metabolome of bacteria, data about bioactive compounds synthesized by this group of soil bacteria that interact with other organisms was also collected, thus widening the role of this group of bacteria beyond nitrogen fixation and legumes.