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Surviving in cold environments: from microbes under glaciers to queer scientists in the current social context

Surviving in cold environments: from microbes under glaciers to queer scientists in the current social context

On the 5th of July we will celebrate the International Day of LGBTQ+ (lesbian, gay, bisexual, transsexual, queer, and people that do not identify themselves as cis and/or straight) People in Science, Technology, Engineering, and Maths (STEM). Many people will ask: “Why is this day important?” Being a queer scientist in particular, and a queer person in general, can sometimes reminds us of how living organisms feel in extreme environments. In this blog post, I will use the analogy of organisms thriving in harsh environments, to highlight the struggles of LGBTQ+ people in the science community.


I am a geomicrobiologist investigating how microorganisms interact with their surroundings in order to survive and what impact this activity has on the environment in which the microbes live. My PhD focused on the subglacial environment (underneath glaciers), and although it is a well-known fact that microorganisms can survive in extreme conditions, it was not until the late 1990s that the first subglacial bacteria were described (Priscu et al., 1999; Sharp et al., 1999). This discovery led to a shift in the way we regarded the subglacial environment: from a cold, dark, nutrient desert to a microbial oasis, an ironic “hot spot” for life within immense ice masses (Tung et al., 2006), showing a very high abundance of microorganisms (Toubes-Rodrigo et al., 2016).

 

How can microorganisms survive in a carbon poor and dark environment?

In illuminated environments, plants and photosynthetic bacteria are able to get energy from the sunlight, but this resource is not available under meters and meters of ice. At the bottom of glaciers, where the ice is in contact with the underlying ground, debris can entrain into the ice (Hubbard et al., 2009; Knight, 1997). Microorganisms are able to take advantage of the sediment and produce energy from the minerals to create organic matter in a process called chemolithotrophy. In addition, due to physical interactions between sediment and ice, there is always a thin layer of liquid water (even at sub-freezing temperatures) around the sediment grains, and it is well known that water is one of the most limiting factors for life. The bacteria which get their energy from the minerals and water under the glacier are called chemolithotrophs.

This process continues as glaciers flow across the ground. As glaciers flow, fresh minerals are picked up into the ice, becoming a supply for chemolithotrophs, which in turn enrich the sediment with carbon over time (Telling et al., 2015). The extra carbon then allows for the blooming of microorganisms capable of feeding on it (heterotrophs). Therefore, we have an active ecosystem in such a harsh environment.

 

How does this link to the LGBTQ+ Community?

This is a very good analogy for the conditions the LGBTQ+ community finds itself in: we usually find that our surroundings are very cold towards us. Just ask a homosexual person what reaction we receive when we are doing something as normal as holding with our partners or ask a trans person about the reaction they receive for their mere existence. Nevertheless, we queer people are capable of not only thriving but also making an impact and changing the mentality around us. As the visibility and representation of queer people continues to grow, people are becoming more educated about queer lives, queer history and the issues we still face. Much like the microbes that enrich the sediment, we enrich society through our diversity. Therefore, events such as the International Day of LGBTQ+ People in STEM are critical to maintaining and furthering the progress we have already made.

We can imagine glaciers as giant conveyor belts, able to transport sediment from the bedrock underneath the ice and release it downstream. The process of transport will not only affect the location of the sediment, but also the chemical makeup of it, due to the activity of microorganisms over years and years. The sediment released from glacier is richer in some of the nutrients, generating fertile soil. Yet again, this a wonderful metaphor: many people have questioned why LGBTQ+ Pride (in STEM) is needed, as LGBTQ+ rights have advanced so much in recent years. However, it is arguably more important now than ever before as, whilst we have made huge progress, we are still the target of hatred. For example, we still find attacks to queer people in cities such as London and Detroit only last week (see articles below) and in many countries around the world, queer existence is either passively ignored or actively threatened.

A number of museums associated with the University of Cambridge Museums are hosting LGBTQ+ Tours, to highlight research by the LGBTQ+ community and to educate the public. Just recently, the Scott Polar Museum ran the ‘Bridging Binaries Tour’ which included information about same-sex behaviour among penguins, and non-normative gender identities in the ancient world [Credit: University of Cambridge Museums].

How can LGBTQ+ initiatives help?

Initiatives such as Pride, LGBTQ+ people in STEM day or the Bridging Binaries Tours increase the visibility of the community: we prepare the soil for queer people to thrive. It helps internally-struggling individuals accept themselves, and highlights that it is ok to be different and that we exist. A discouraging fact for me when I was growing up was the lack of LGBTQ+ role models in science. A lack of role models has a terrible impact on LGBTQ+ people in STEM. Just to give a couple examples taken from PRIDE in STEM: more than 40% of LGBTQ+ people in STEM remain in the closet, having to disguise a fundamental part of themselves. Furthermore, gay, lesbian, and bisexual students are less likely to follow an academic career. When I first started my PhD, I was asked “edit it down” and be less overt about my sexuality, even by friends. Initiatives such as the International Day of LGBTQ+ People in STEM can make our surroundings more welcoming: it gives us a voice, a place. It gives us a space, in which we can express ourselves, and allows us to inspire the new generations of scientists, technologists, engineers, and mathematicians. As with microorganisms, the whole of society needs to stick together, interact and positively feedback all its members. Just as microorganisms thrive and diversify the community under glaciers, LGBTQ+ people should be able to thrive and add balance to the scientific community. This is why we need to nurture, nourish, and celebrate diversity with days such as International Day of LGBTQ+ (lesbian, gay, bisexual, transsexual, queer) People in Science, Technology, Engineering and Maths (STEM), especially in such politically divided and uncertain times. At the last EGU general assembly, a pride@EGU event was held which provided a meeting point for the LGBTQ+ community and allies (non-LGBTQ+ community members who support them). For more information about LGBTQ+ STEM day, please visit http://lgbtstemday.org.

At the last EGU general assembly, the pride@EGU event was well attended. Another event is being planned for the next general assembly in 2020 [Artwork/photo credit: Dr Stephanie Zihms].

Further reading

Edited by Jenny Turton


Dr Mario Toubes-Rodrigo is a post-doctoral research associate at the Open University, UK. Previously, he completed his PhD at the Manchester Metropolitan University. His research focuses on investigating microorganisms which inhabit extreme environments from the lowest layers of glaciers to sulphate-rich lakes, comparing their production of gases to those in the Martian Atmosphere. Mario is an active twitter user and goes by the handle: @micro_mario.

Image of the Week – Cure from the Cold?

Image of the Week – Cure from the Cold?

Humans rely on antibiotics for survival, but over time they are becoming less effective. So-called ‘superbugs’ are developing resistance to our most important drugs. The key to this global issue may be found in the cryosphere, where extreme microbiologists are hunting for new compounds in the cold that could help us win the war against antimicrobial resistance.


Discovering drugs in Earth’s coldest places

Antimicrobial resistance poses a global threat predicted to cause 10 million deaths per year by 2050.

Alexander Fleming’s 1928 discovery of penicillin- a compound produced from a fungus had an antimicrobial effect transformed life expectancy in the 20th century and kick-started the antibiotic revolution. Since then, most antibiotic drugs have been extracted from soil-dwelling microbes such as bacteria and fungi.

We can exploit these compounds produced by microbes to limit the growth of other microbes that are harmful to humans. The chemical structure of these compounds forms the basis of most antibiotics used today to treat microbial infections. However, soil has become an exhausted environment for drug discovery and researchers are turning to other environments in the search for new antimicrobial drugs.

One of these environments is the cryosphere, where diverse habitats in snow, glaciers, ice sheets and sea ice are dominated by microbes. Multiple stresses such as low temperature, high UV intensity, limited nutrient availability and variable salinity mean this extreme environment naturally favours only the hardiest microbes. In order to thrive, it is likely that microbes produce a variety of chemical warfare against their competitors, making the cryosphere a potentially rich reserve for bioprospecting new antimicrobial compounds.

Glacier microbes: all grown up!

Cultivation (growing microbes in a nutrient-containing growth medium in the laboratory) is a valuable technique for discovering new antimicrobial drugs because it allows scientists to take microbes from the environment and grow them in controlled conditions. In the cryosphere, glacier microbiologists have previously shown that many of the cultivable bacteria from these environments demonstrate potent antimicrobial activity. At least 219 novel natural products have been discovered thus far in polar organisms. In the face of widespread glacier and ice sheet melting, microbiologists must move quickly to find and cultivate these potential ‘cures from the cold’.

Fig. 2: A range of different single colonies isolated from a dilute sample of cryoconite, collected from the Foxfonna glacier, Svalbard in 2016. Samples have been grown on a range of different growth mediums [Credit: A. Debbonaire].

Microbial wars help humanity

Once bacteria have grown, we can exploit them. Any weaponry they produce to fend off competition can be extracted and tested against other microbes. We can assess their array of weapons by placing the growing bacteria under different stresses and seeing what compounds they produce to counteract it. Moreover, bacteria can be grown alongside other bacteria/fungi, increasing the likelihood that they fight each other by producing new chemical warfare that we can then use (Figure 3).

We can also test how powerful these weapons of microbial war are using a simple 24-hour test. By adding them to known concentrations of harmful bacteria such as Staphylococcus aureus (think MRSA) we can then monitor the bacterial growth over time after adding the potential antibiotic compounds. Little growth indicates that the new compounds are wreaking havoc and inhibiting growth – we have a new defence!

Fig. 3: Microbes grown from glacier samples compete with one another in a biochemical arms race [Credit: A. Debbonaire].

Cultivation’s “1% problem”

Cultivation is not the only way to bioprospect in the cold, especially because only 1% of the total microbial diversity of an environment is able to grow on growth media, meaning 99% of that diversity goes undiscovered. Our alternative is a technique known as metagenomics, which has been increasingly applied in the cryosphere over the past few years.

Metagenomics is an expensive but fast method of sequencing all DNA within an environmental sample to identify the microbial population that has been demonstrated to be extremely useful for glacier surface ecosystems and can even now be achieved on-site in extreme locations in the cryosphere in a relatively short time. However, metagenomics will only identify which microbes are present, not necessarily their capability, or more importantly, what compounds they produce when under stress. Both techniques combined are now applicable to exploring the cryosphere and provide the most robust approach to drug discovery in the cryosphere. In the war of microbe versus microbe, metagenomics shows which weapons may, or may not, be used; but cultivation provides a detailed analysis of the battle plan.

In summary…

The battle against drug-resistant microbes may be one of the major challenges facing humanity in the twenty-first century. Traditional sites for drug-discovery are being exhausted and researchers are turning to Earth’s coldest reaches to find stressed-out microbes that could provide us with new weaponry to fight the emerging ‘superbugs’. In this melting biome, researchers must act fast to gather the ‘cures from the cold’, exploiting the microbial life in the cryosphere to tackle a global threat to humanity.

 

Further reading

Edited by Joe Cook and Clara Burgard


Aliyah Debbonaire is a PhD student at the Interdisciplinary Centre for Environmental Microbiology (Aberystwyth University). Her research aims to bioprospect extreme environments for life-saving drug candidates. She tweets as @Gnarliyah.

Image of the week – Micro-organisms on Ice!

Image of the week – Micro-organisms on Ice!

The cold icy surface of a glacier doesn’t seem like an environment where life should exist, but if you look closely you may be surprised! Glaciers are not only locations studied by glaciologists and physical scientists, but are also of great interest to microbiologists and ecologists. In fact, understanding the interaction between ice and microbiology is essential to fully understand the glacier system!


Why study micro-organisms on glaciers?

Micro-plants, micro-animals and bacteria live and reproduce in cryoconite ecosystems on the surface of glaciers. Cryoconite is a dark coloured material (Fig. 2) found at the bottom of cylindrical water-filled melt holes (cryoconite holes) on a glacier surface; it consists of dust and mineral powders transported by the wind, and micro-organisms. Cryoconite holes are formed as the dark coloured material causes localised melting, due to reduced albedo (ability of a surface to reflect solar energy).

Figure 2: Example of a Cryoconite hole filled with dark cryoconite material (markers are 10×10 cm) [Credit: Tommaso Santagata – La Venta Esplorazioni Geografiche]

Because organisms in cryoconite thrive in extreme conditions, they are very unique and interesting to study. Information about their genetic makeup and chemical structure can help to inform, for example, medical and pharmaceutical sciences. Currently, however, information on their community structure is still limited.

Cryoconite ecosystems are very isolated and must work together to survive and thrive. Some micro-organisms (e.g. micro-algae) can photosynthesise and are able to live autonomously inside cryoconite holes using atmospheric carbon dioxide, sunlight, water and chlorophyll. By this same mechanism, they can find all the molecules essential for their vital and structural needs and consequently they generate most of the molecules necessary for all other living things. For example, the waste product of photosynthesis, oxygen, is essential for the survival of all organisms living in aerobiosis in these communities. Due to their key role in the ecosystem, the micro-algae are known as “primary producers”.

As around 70% of the earth is covered in water, which is colonised by micro-algae, studying the way they survive in extreme conditions and how they contribute to the ecosystem is of global importance – especially at this time of climate change.

The diversity of highly active bacterial communities in cryoconite holes makes them the most biologically active habitats within glacial ecosystems.

Data collections – Six days on THE glacier

The Perito Moreno glacier (Fig. 3) is known as one of the most important tourist attraction in Argentinian Patagonia (see our previous IOW post). Each day, hundreds of people observe the impressive front of this glacier and wait to see ice detachments and hear the loud sound of it’s impacts in the water of Lake Argentino. The glacier takes it’s name from the explorer Francisco Moreno, who studied the Patagonian region in the 19th century. The glacier is more than 30 km in length and an area of about 250 km2, Perito Moreno is one of the main outlet glaciers of Hielo Patagonico Sur (southern Patagonia icefield).

Figure 3: Aerial view of the Perito Moreno
[Credit : Tommaso Santagata – La Venta Esplorazioni Geografiche]

In April 2017, after several missions to the Greenland Ice Sheet to study extremophilic micro-organisms (organism that thrive in extreme environments) of ice, a team of Italian and French scientists organised a scientific expedition to study the microbiology of Perito Moreno. The expedition was organised by La Venta and Spélé’Ice and included researchers from several French and Italian Universities (see below for full list)

Perito Moreno is very well known, especially to the La Venta team, who have been organising scientific expeditions in Patagonia since 1991. The microbiological research objectives of this mission were to study the micro-organisms that live on the surface of Perito Moreno and compare them to results obtained in the other polar, sub-polar and alpine regions. The multi-disciplinary research team were able to set up a complex field laboratory, which included a microscope and an innovative small tool size capable of DNA sequencing. This meant that samples could be analysed immediately after their extraction from the ice (Fig. 1).

Getting all the equipment and personnel to achieve this expedition onto the ice was not an easy task. The team and their equipment were transported by boat to a site near the front of the glacier. Equipment then needed to be transported to the Buscaini Refugee, a shelter used as a base-camp by the team (Fig. 4). This took two trips, on foot, of about 7 hours (12 km of trail along the lateral moraine and the ice of the glacier with very heavy backpacks) – not an easy start! Luckily this hardship was somewhat mitigated by the absence of extreme cold, in fact, abnormally hot weather tallowed the team to move and work in t-shirts – not bad!

Figure 4: Walking into the field site along the ice of Perito Moreno – part of the 12km of trail to the Buscaini Refugee shelter
[Credit: Alessio Romeo – La Venta Esplorazioni Geografiche]

Thanks to these favourable weather conditions, all the goals were achieved in the short amount of time the team were allowed to camp on the glacier (special permission is needed from the national park to do this). During the five days of activity, many samples were taken and sequenced directly at the camp by the researches. Other important goals, such as morphological comparisons and measurements of the velocity of the glacier through the use of GPS, laser scanning and unmanned aerial vehicles were achieved by another team of researchers (stay tuned for another blog post about this!).

Universities and research institutes involved: University Bicocca of Milan – Italy, University of Milano – Italy, Sciences of the Earth A.Desio – Italy, Natural History Museum of Paris – France, University Diderot of Paris – France, University of Florence – Sciences of the Earth – Italy, University of Bologna – Italy.

Further Reading

Edited by Emma Smith


Tommaso Santagata is a survey technician and geology student at the University of Modena and Reggio Emilia. As speleologist and member of the Italian association La Venta Esplorazioni Geografiche, he carries out research projects on glaciers using UAV’s, terrestrial laser scanning and 3D photogrammetry techniques to study the ice caves of Patagonia, the in-cave glacier of the Cenote Abyss (Dolomiti Mountains, Italy), the moulins of Gorner Glacier (Switzerland) and other underground environments as the lava tunnels of Mount Etna. He tweets as @tommysgeo