SARS-CoV-2 infection has generated the biggest pandemic since the influenza outbreak of 1918–1919. One clear difference between these pandemics has been the ability to test for the presence of the virus or for evidence of infection. This review examined the performance characteristics of sample types via PCR detection of the virus, of antibody testing, of rapid viral antigen detection kits and computerised tomography (CT) scanning. It was found that combined detection approaches, such as the incorporation of CT scans, may reduce the levels of false negatives obtained by PCR detection in both symptomatic and asymptomatic patients, while sputum and oral throat washing sample types should take precedence over swabbing when available. Rt-PCR assays for detection of the virus remain the gold-standard method for SARS-CoV-2 diagnosis and can be used effectively on pooled samples for widespread screening. The novel Oxford antibody assay was found to have the highest sensitivity and specificity of four currently available commercial antibody kits but should only be used during a specific timeframe post-symptom onset. Further research into transmission modes between symptomatic and asymptomatic patients is needed. Analysis of the performance characteristics of different sampling and detection methods for SARS-CoV-2 showed that timing of sampling and testing methods used can greatly influence the rate of false-positive and false-negative test results, thereby influencing viral spread.

Mars is a focus of New Space Age exploration and colonisation, but there are significant challenges to successful colonisation by humankind. Environmental microbes play a key role in supporting the ecosystems of Earth, especially within the biodegradation and bioremediation sectors. However, the repurposed roles of microbes on Mars and their associated uses to colonists remain incompletely defined. The aim of this review was to examine the key roles of microbes on Earth and how they have been employed by humans to tackle four pivotal environmental challenges associated with the colonisation of Mars, namely the physical environment, the creation of a hospitable environment via terraforming, environmental sustainability and life support, and finally, renewable processing technologies. Some species of microbes were found to be tolerant of the ever-changing physical environment on Mars (freeze–thaw and UVC exposure) making them useful for bioremediation applications. Employing perchlorate-remediating microbes for their ability to bioremediate the soils of sodium perchlorate, which is present in Martian soils, in addition to their innate ability to cycle nutrients through the biosphere showed promise in establishing sustained crops to support colonists. The employment of terrestrial environmental microbes is a necessary part of overcoming key environmental challenges to successfully colonise Mars. Without this, future New Space exploration is unlikely to be successful.

As coral reefs continue to decline globally, a toolbox of new interventions such as nutritional supplementation are being considered. Low level supplementation of the trace element manganese (Mn) has increasingly been shown to enhance the resilience of photosynthetic Cnidarians to thermal stress, however, questions around the timing of Mn delivery relative to a thermal stress event remain unanswered. Here we explore how the timing of Mn additions influences the response of the common reef building coral Acropora millipora to thermal stress. Coral health was assessed using a variety of different metrics including photochemical efficiency, oxygen dynamics, elementomics and symbiont densities. A. millepora displayed significantly improved thermal tolerance when exposed to either intermittent pulse (19.34 µg L⁻¹ every second day) dosing or constant (4.24 µg L⁻¹) supply of dissolved Mn from 7 days before heat stress exposure (32 °C). Pulse dosed corals maintained higher photosynthetic efficiency and photosynthesis to respiration rates, as well as increased Symbiodiniaceae densities compared to thermally stressed corals without Mn supplementation. Elemental analysis revealed that both coral tissue and Symbiodiniaceae in Mn-treated corals accumulated significantly more Mn than non-Mn treated corals. Collectively, our results suggest that intermittent (pulse) Mn exposure prior to the onset of thermal stress may provide the greatest support for thermal resilience in corals. This study advances understanding on how essential elements like Mn could be strategically delivered as an active intervention to enhance coral tolerance during periods of thermal stress.

The purpose of this study was to determine survivability of Escherichia coli, Deinococcus radiodurans and Paraburkholderia fungorum under Mars-simulated conditions for freeze-thawing (−80 °C to +30 °C) and UV exposure alone and in combination. E. coli ATCC 25922, D. radiodurans and P. fungorum remained viable following 20 successive freeze-thaw cycles, exhibiting viabilities of 2.3%, 96% and 72.6%, respectively. E. coli ATCC 9079 was non-recoverable by cycle 9. When exposed to UV irradiation, cells withstood doses of 870 J/m² (E. coli ATCC 25922), 200 J/m² (E. coli ATCC 9079), 50,760 J/m² (D. radiodurans) and 44,415 J/m² (P. fungorum). Data suggests P. fungorum is highly UV-resistant. Combined freeze-thawing with UV irradiation showed freezing increased UV resistance in E. coli ATCC 25922, E. coli DSM 9079 and D. radiodurans by 6-fold, 30-fold and 1.2-fold, respectively. Conversely, freezing caused P. fungorum to exhibit a 1.75-fold increase in UV susceptibility. Strain-dependent experimentation demonstrated that freezing increases UV resistance and prolongs survival. These findings suggest that exposure to short wavelength UV rays (254 nm) and temperature cycles resembling the daily fluctuating conditions on Mars do not significantly affect survival of D. radiodurans, P. fungorum and E. coli ATCC 25922 following 20 days of exposure.

Sodium perchlorate is a toxic salt-based compound found both terrestrially, (due to pollution) and extraterrestrially on the surface of Mars. Perchlorate pollution poses a risk to agricultural-based activities as once it enters soils/waterways it can be passed through the food chain via bioaccumulation. The purpose of the current study was to observe the perchlorate reduction potential of putative candidate bioremediation strains; Escherichia coli 25922 and E. coli 9079, Paraburkholderia fungorum, Deinococcus radiodurans and Dechloromonas aromatica both independently and in co-cultures, when exposed to 3000 mg/L (0.3%) sodium perchlorate. This was carried out in both a minimal medium environment and within an environment void of nutrients, using Raman spectroscopy to assess their potential for the bioremediation of Martian soils. The perchlorate reducing potential of all strains was 16% higher in reverse osmosis deionised water than in minimal medium, the former having a total absence of Nitrate. It was found that E. coli 25922 is a perchlorate reducer, which has not been previously described. Additionally, co-culturing of bacterial strains was found to have a higher bioremediation potential than individual strains. These findings suggest that not only could perchlorate pollution be remediated, but that the perchlorate composition of the Martian surface may support bioremediation microbial life, aiding in future colonisation.

The global coral crisis continues to intensify the urgent need for conservation and restoration interventions. Heatwaves are the primary driver of coral declines, triggering coral bleaching by disrupting the symbiosis with the dinoflagellates that provide corals with essential nutrients and energy. Since oxidative stress and nutrient disruption are key processes associated with coral bleaching, we developed a novel, low-cost bioengineering approach to deliver antioxidant support to corals. We used the reef-building model coral Stylophora pistillata to test microparticle feeds containing antioxidants and phytoplankton cells during a simulated heatwave. Among five phytoplankton species, Pavlova lutheri, known to produce antioxidants de novo, offered the best protection to S. pistillata. Moreover, the encapsulated antioxidants curcumin and fucoxanthin outperformed P. lutheri, supporting corals by showing higher photosynthetic efficiency and total antioxidant capacity as well as lower lipid peroxidation impacts. Considering cost-effectiveness for upscaling, curcumin emerges as a promising, scalable intervention for coral conservation, allowing a direct delivery of antioxidant protection to fight oxidative stress associated with warming waters.