Last Wednesday we went for a field trip at Bonanza in the Guadalquivir estuary to test our new field microsensor system.

The research group in Microbial Ecology and Biogeochemistry of the UCA (MEB-LAB) initiates the development of a new line of research on copper precipitation in environments contaminated by acid mine drainage in the framework of the project “Bioprecipitation of metallic copper from acid mine drainage in the Iberian Pyritic Belt” BIOCOBRE, funded by the Junta de Andalucía.

The objective of the project is to study precipitates of copper salts and oxides in environments contaminated by acid mine drainage (AMD). The biogeochemical conditions, the microbial community and the metabolic pathways involved in the precipitation of copper nanoparticles in biofilm growing in acid mine drainage (AMD) areas in the Faja Piritica Iberica (Huelva) will be investigated.

Precipitates of Cu2+ and Cu+ salts and oxides are common in acid mine drainage (AMD) contaminated environments, but Cu0 precipitates are not. BIOCOBRE will investigate the biogeochemical conditions, microbial community and metabolic pathways involved in the precipitation of metallic copper (Cu0) nanoparticles in a biofilm growing in the acid mine drainage (AMD) of the abandoned mine Mina Esperanza (Huelva). To understand the Cu0 bioprecipitation process, we will set the following objectives: 1) define the geochemical environment within the biofilm where Cu0 precipitates and accurately measure Cu0 precipitation rates under different conditions, 2) describe the evolution of the biofilm microbial community from colonization to maturity under different environmental conditions, 3) isolate and culture the biofilm microorganisms (mainly fungi and bacteria) potentially involved in the Cu0 precipitation process. To achieve these objectives, we will use a multidisciplinary approach in which we will combine state-of-the-art techniques from different scientific disciplines: microsensors (O2, H2S, pH and Eh), geochemical and mineralogical methods, scanning transmission electron microscopy (STEM), omics tools (metagenomics, metatranscriptomics, metaproteomics, metabolomics) and multispecific and axenic microbial cultures. The scientific and socioeconomic impact of BIOCOBRE, if we are able to achieve Cu0 precipitation, could be high. It could lead to patents and would probably open a new line of research focused on the bioengineering of the Cu0 precipitation process, to make it a technically and economically viable alternative to recover Cu0 from AMD, using an ecological approach at a reduced cost, in which Andalucia would be at the forefront.

The project (P20-01048) is co-financed by the European Union, within the framework of the Andalusia FEDER Operational Program “Smart growth: an economy based on knowledge and innovation, also responding to the Research and Innovation Strategy for the Smart Specialization of Andalusia (RISˑAndalusia) and the priorities and objectives set out in the Andalusian Plan for Research, Development and Innovation (PAIDI 2020).

Researchers from different departments and universities collaborate in the project:

Corzo Rodriguez, Alfonso, Dept Biología, Area de Ecología. Investigador principal, Coordinación general. Ecología microbiana
Papaspyrou, Sokratis, Dept Biología, Area de Ecología. Ecología microbiana.
García Robledo, Emilio Guillermo, Dept Biología, Area de Ecología. Ecología microbiana.
Duran Ruiz, Maria Del Carmen, Dept Biomedicina, Biotecnología y Salud Publica, Area de Bioquímica. Metaproteonómica.
Garrido Crespo, Carlos, Dept Biomedicina, Biotecnología y Salud Publica, Area de Microbiología. Aislamiento de microorganismos.
Lajaunie, Luc Cyrille Jacques, Dept de Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica. Microscopia electrónica y análisis mineralógicos

Fig. 1. Exit of the AMD of Mina Esperanza (Huelva) and precipitation channel (A, E). Biofilm surface in the channel (B). O2 microsensor coupled to a micromanipulator measuring in situ (F). Portions of the biofilm with accumulations of precipitated Cu (pink color) (C). SEM images of Cu precipitation within the pink masses at different magnifications (D, G, H). Precipitated Cuº is found in close association with amorphous and filamentous structures that could represent the EPS matrix of the biofilm and bacterial structures such as nanowires (H).

Also participating in the project are:

Castillo Hernández, Julio Cesar. Univeridad de Free State, Sudafrica. Geomicrobiología, herramientas moleculares y microscopia.
Valverde Portal, Angel, IRNASA-CSIC. Microbiología.
Taylor, Joe Daniel, UK Centre for Ecology & Hydrology. Metagenómica.

The project (P20-01048) is co-financed by the European Union, within the framework of the Andalusia FEDER Operational Program “Smart growth: an economy based on knowledge and innovation, also responding to the Research and Innovation Strategy for the Smart Specialization of Andalusia (RISˑAndalusia) and the priorities and objectives set out in the Andalusian Plan for Research, Development and Innovation (PAIDI 2020).

This month, Dr. Emilio Garcia participated in an oceanographic cruise in the East Tropical North Pacific Oxygen Minimum Zone on board of the research vessel Oceanus. During 3 weeks, 13 researchers from different countries (USA, Denmark, Island, Austria, Mexico and Spain) and institutions worked together to investigate the microbial community and the biogeochemical processes of the vast anoxic waters of the north Pacific. Different aspects of microbial ecology and biogeochemistry were studied, going from aerobic respiration at the oxygenated photic layer to the different processes involved in the complex nitrogen cycling (denitrification, anammox, nitrification, anaerobic methane oxidation…) going on inside the so called “dead zones”.

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Emilio (fourth from the left) with members from the cruise

In May, our research group finished a quarterly sampling in two transects conducted over one year. Aim of the study is to estimate the contribution of microphytobenthic production to the total primary production in the inner Cadiz Bay. Each transect has five sampling points, distributed along the intertidal zone. Sediment cores were collected by sediment sampler and were maintained in aquaria with sea water under constant irradiance. Microphytobenthic primary production was measured using oxygen microsensor. In addition, numerous samples (chlorophyll, molecular biology, bacterial abundance, extracellular polymeric substances,microbial community composition etc) were preserved for future analysis.

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Sediment core with seagrass