Biology subjects

Cockell, C.

Publications and source records attributed to Cockell, C..

3 recordsLinked to original sources

bioRxiv2024

Testing microbial biomining from asteroidal material onboard the International Space Station

Expanding human space exploration beyond Earths orbit necessitates efficient technologies for self-sustainable acquisition of local resources to overcome unviable resupply missions from Earth. Potential source of materials are asteroids, some of which contain valuable metals, such as platinum group elements. The BioAsteroid experiment, performed onboard the International Space Station, tested the use of microorganisms (bacteria and fungi) to carry out mining of useful elements from asteroidal material (L-chondrite) under microgravity, in support of a long-term human presence in space. The fungus Penicillium simplicissimum, enhanced the mean release of palladium, platinum and other elements from the meteorite material in microgravity, compared to non-biological leaching. However, there was large variability in the results. For many elements, non-biological leaching under microgravity was enhanced compared to terrestrial gravity, while bioleaching was unaffected. Metabolomics results revealed clear patterns that highlight the influence of space conditions on the microbial metabolism, particularly for P. simplicissimum. We identified the presence of carboxylic acids, and molecules of potential biomining and pharmaceutical interest, enhanced in microgravity. These results show a non-trivial effect of microgravity on bioleaching, highlighting the requirement of an optimal combination of microorganism(s), rock substrate, and conditions for successful biomining, both in space and Earth.

microbiology↗

bioRxiv2020

Taking extreme measures: A quantitative study of multiple stress interactions at the limits of life.

Environments exposed to simultaneously occurring extremes are prevalent in the natural world, yet analysis of such settings tends to focus on the effect of single environmental stresses. In this study, quantitative multiplicative and minimising models previously used to study nutrient limitation were applied to the growth of the hydrothermal vent-dwelling organism Halomonas hydrothermalis when subjected to combined nutrient limitation and NaCl-salt stress. Results showed an interactive effect from both salt and nutrient stresses under optimal conditions. However, the fit became more non-interactive as salinity is increased; at which point NaCl-salt had a more dominating effect on growth than inorganic phosphate (Pi). We discuss biochemical hypotheses to explain these data. This work shows that models developed to understand nutrient limitation can be used to quantify and separate the contributions of stresses under other physical and chemical extremes, such as extreme salinity, and facilitate the development of biochemical hypotheses of how extremes may be influencing cell physiology. ImportanceVery few environments in the natural world are exposed to just one extreme or stress at a time. To understand lifes ability to survive in multiple-extreme environments, we must be able to quantify how different extremes interact. Using methods developed for the study of multiple nutrient limitation, this study uses kinetic growth models to investigate at the effect of extreme environments on bacterial growth. Results show that closer to the extremes of life, individual stresses dominate growth; whereas under optimal conditions there is a multiplicative effect from both salt and nutrient stresses. This approach offers a new way to quantify and potentially understand and develop hypotheses for how life operates under multiple extremes.

microbiology↗

bioRxiv2019

The International Space Station selects for microorganisms adapted to the extreme environment, but does not induce genomic and physiological changes relevant for human health

The International Space Station (ISS) is a unique, completely confined habitat for the human crew and co-inhabiting microorganisms. Here, we report on the results of the ISS experiment "EXTREMOPHILES". We aimed to exploit the microbial information obtained from three surface and air sampling events aboard the International Space Station during increments 51 and 52 (2017) with respect to: i) microbial sources, diversity and distribution within the ISS, ii) functional capacity of microbiome and microbial isolates, iii) extremotolerance and antibiotics-resistance (compared to ground controls), and iv) microbial behavior towards ISS-relevant materials such as biofilm formation, or potential for degradation. We used wipe samples and analyzed them by amplicon and metagenomics sequencing, cultivation, comparative physiological studies, antibiotic resistance tests, genome analysis of isolates and co-incubation experiments with ISS-relevant materials. The major findings were: i) the ISS microbiome profile is highly similar to ground-based confined indoor environments, ii) the ISS microbiome is subject to fluctuations and indicative for the (functional) location, although a core microbiome was present over time and independent from location, iii) the ISS selects for microorganisms adapted to the extreme environment, but does not necessarily induce genomic and physiological changes which might be relevant for human health, iv) cleanrooms and cargo seems to be a minor source of microbial contamination aboard, and v) microorganisms can attach to and grow on ISS-relevant materials. Biofilm formation might be a threat for spacecraft materials with the potential to induce instrument malfunctioning with consequences for mission success. We conclude that our data do not raise direct reason for concern with respect to crew health, but indicate a potential threat towards biofilm formation and material integrity in moist areas.

microbiology↗