Mineral Phosphate Solubilization in Burkholderia tropica Involves an Inducible PQQ-Glucose Dehydrogenase
Journal Title: Microbiology Research Journal International - Year 2016, Vol 13, Issue 4
Abstract
Aims: The objective of this work was to provide knowledgement about the mechanism and regulation of the mineral phosphate solubilization in Burkholderia tropica. To this end, the expression of the direct extracellular oxidative pathway in B. tropica was studied using different culture approaches. Study Design: Plate assays and batch cultures in flasks and bioreactor were carried out in this study with B. tropica Mto-293 like target organism. The experiments were achieved at least three times with two repetitions per time. Place and Duration of Study: Departamento de Química, Centro de Investigación y Desarrollo en Fermentaciones Industriales, UNLP, CCT-La Plata-CONICET, between November 2014-2015. Methodology: Qualitative plate assays with different Carbon sources were carried out for the evaluation of Mineral Phosphate Solubilization phenotype. Batch cultures in flasks were carried out with different Carbon, Phosphorus and Nitrogen sources to determine quantitatively soluble phosphorus, gluconic acid and other ketoacids in the supernatants, and also PQQ-linked glucose and gluconate dehydrogenase activities in whole cells. Cultures with some of the conditions mentioned before were carried out in bioreactor specifically to control pH. Results: This organism was able to produce significant amounts of gluconic acid via the expression of a PQQ-GDH and also showed a significant activity of GaDH. However, the direct oxidative pathway was only observed under conditions of Phosphorus starvation and/or Nitrogen fixation. Conclusion: The Mineral Phosphate Solubilization phenotype for B. tropica can be ascribed to the expression of the direct oxidative pathway which involves the expression of an active PQQ- linked glucose dehydrogenase. Nevertheless, this pathway is not expressed constitutively in this bacterium. Environmental conditions, like low P and N availability, led to an active extracellular glucose oxidation. Therefore, mineral phosphate solubilization in B. tropica involves an inducible pyrroloquinoline quinone-linked glucose dehydrogenase. These findings may contribute to the use of this bacterium as plant growth promoting bacteria reducing the dependence on chemical fertilizer.
Authors and Affiliations
Pamela Romina Bernabeu, Sabrina Soledad García, Gimena García Ferreyra, Verónica Inés Guidi, María Lina Galar, José Luis Boiardi, María Flavia Luna
Prevalence of Methicillin-resistant Staphylococcus aureus among Health Care Workers in Tripoli Hospital, Libya
Aims: Staphylococcus aureus is a common cause of community and a hospital infection, methicillin-resistant Staphylococcus aureus (MRSA), is a common nosocomial infection pathogen, its resistance to multiple antibiotics h...
Effect of Sulphur-Based Amino Acids with or without Formic Acid on Performance and Microbial Load of Broiler Chickens
The aim of the study was to investigate the effect of sulphur-based amino acids with or without formic acid on performance and microbial load of broiler chickens in a 56-day feeding trial. One hundred and ninety-two one-...
Relationship between Gingivitis and Autism in Children: A Matched Case-control Study
Autism is a neurodevelopmental disorder diagnosed in early childhood. Studies have shown that autistic children have poorer gingival health and hence chances of higher incidence of gingivitis may occur in autistic than n...
Optimization of Cultural Parameters for Cost Effective Production of Kojic Acid by Fungal species Isolated from Soil
Two different species of Aspergillus are able to produce kojic acid at higher concentrations under static conditions in the present study. Various physicochemical parameters which influence the production of kojic acid a...
Poly-β-hydroxybutyrate: A Biodegradable Polyester, Biosynthesis and Biodegradation
Bioplastic can be degraded in nature with time and produce carbon dioxide as an end product. It reduces the environmental pollution created by synthetic plastic. Biodegradable plastic can be used to make plastic bags and...