Acidithiobacillus ferrooxidans's comprehensive model driven analysis of the electron transfer metabolism and synthetic strain design for biomining applications

Abstract

Acidithiobacillus ferrooxidans is a gram-negative chemolithoautotrophic γ-proteobacterium. It typically grows at an external pH of 2 using the oxidation of ferrous ions by oxygen, producing ferric ions and water, while fixing carbon dioxide from the environment. A. ferrooxidans is of great interest for biomining and environmental applications, as it can process mineral ores and alleviate the negative environmental consequences derived from the mining processes. In this study, the first genome-scale metabolic reconstruction of A. ferrooxidans ATCC 23270 was generated (iMC507). A total of 587 metabolic and transport/exchange reactions, 507 genes and 573 metabolites organized in over 42 subsystems were incorporated into the model. Based on a new genetic algorithm approach, that integrates flux balance analysis, chemiosmotic theory, and physiological data, the proton translocation stoichiometry for a number of enzymes and maintenance parameters under aerobic chemolithoautotrophic conditions using three different electron donors were estimated. Furthermore, a detailed electron transfer and carbon flux distributions during chemolithoautotrophic growth using ferrous ion, tetrathionate and thiosulfate were determined and reported. Finally, 134 growth-coupled designs were calculated that enables Extracellular Polysaccharide production. iMC507 serves as a knowledgebase for summarizing and categorizing the information currently available for A. ferrooxidans and enables the understanding and engineering of Acidithiobacillus and similar species from a comprehensive model-driven perspective for biomining applications.

Integration of Biological Networks for Acidithiobacillus thiooxidans Describes a Modular Gene Regulatory Organization of Bioleaching Pathways

“…With the exception of At. ferrooxidans ATCC23270, for which a genomescale reconstruction was built (Campodonico et al, 2016), bioleaching bacterial metabolic reconstructions corresponded to reduced and simplified representations of their networks in all cases. This was also the case for A. thiooxidans Licanantay, for which we previously built a small stoichiometric model used to predict its growth rate in different media containing different reduced sulfur compounds for oxidation (Bobadilla Fazzini et al, 2013).…”

Metals and minerals as a biotechnology feedstock: engineering biomining microbiology for bioenergy applications

“…ferrooxidans [13,15,16], A. thiooxidans [23] and A. caldus [20]. A recent model-driven study of genes in A. ferrooxidans suggested that an increase in extracellular polymer substances (EPS) could be achieved by introducing several genetic knock downs [54].…”

“…EPS is important in bioleaching applications as it facilitates bacterial adhesion to the sulfide minerals [54]. Other gene disruption studies and subsequent responses to various metal ions have been reported for Metallosphaera sedula and development of a more characterized genetic system is underway [55].…”

Biolixiviação Em Colunas Para Extração De Cobre a Partir De Minério Da Região Amazônica

“…Na extração por biolixiviação, o minério é grosseiramente fracionado, disposto em pilhas de 6 a 8 metros de altura sobre uma superfície impermeável e constantemente irrigadocom uma solução ácida (pH< 2,0) contendo o inóculo bacteriano [8,9]. Esta solução é constantemente recirculada através da pilha, sendo enriquecida em íons Fe 3+ e H + derivados do processo de oxidação do sulfeto metálico pelas bactérias oxidantes de ferro e enxofre, resultando na oxidação do Cu + em Cu 2+ , solúvel em água [9]. Posteriormente, o cobre metálico lixiviado é recuperado através de métodos eletroquímicos e a solução reciclada pela adição de nutrientes, voltando a ser irrigada no topo da pilha.…”