October 24, 2019
Published by Kshitij Kumar
With all the noise regarding colonising Mars one might wonder who would be Mars’ first residents. Maybe some of Earth’s most intelligent people with several degrees and training in astrophysics. Or it could even be a collection of microbes.
A paper in the journal FEMS Microbiology Ecology suggests that the primary colonists of Mars should be microorganisms such as viruses, fungi that support several life processes on Earth.
Jose Lopez, professor at Nova Southeastern University and the paper’s co-author suggested an approach to the colonisation of the planet starting with the study of microbes that might support life in foreign environments. Since life needs the support of essential microorganisms, surviving on barren planets ask for taking the essential microbes to that planet.
The ideas in the paper violate the strict no-contamination guidelines from NASA and other space programs which have been followed for decades. Every equipment carried to space are sterilised to make them free from germs since no-risk is taken to damage the environments previously untouched. However according to Lopez and his colleagues, helpful microbes might initiate the process of transforming Mars into a planet sustaining life. Exploring new planets without the possibility of delivering microbes is hypothetical.
The paper mentions that introduction of microbes should be considered as inevitable and not an accidental event. It also suggests that the most suitable microbes for this process would be the extremophiles that can survive and tolerate even the most cruel environments such as the tardigrades. But there is a lot of work to follow before permitting the delivery of microorganisms to Mars. They might be exposed to high radiation whereas the humans would evolve at high rates to live in that environment.
The paper mainly argues for change in perspective towards microbes, considering them useful and not dangerous. Scientists are not yet sure of the specific microbes that would be helpful in this effort.
Lopez said that the whole thing needs time for preparation, so they are not asking to rush in any order but to push it through only after proper research conducted on Earth. The paper also argues for a paradigm shift in the space policies essential for colonising space.
The decision to deliver microbes also depends on the final goal. Another fact for consideration is that, for our own planet neither humans nor plants were the first residents, they were the single-celled microorganisms.
August 19, 2019 (updated August 19, 2019)
Published by Sai Teja
Scientists ran a DNA analysis on a sediment core which was found on the floor of the Arctic Ocean in 2010. A previously unknown organism which belongs to the domain of microbes called Archaea appeared to have genomic characteristics of an entirely different domain known as Eukaryota. The discovery is named Lokiarchaeota, after the Loki’s Castle hydrothermal vent near Greenland where it was found. There were doubts about the contamination in the core but Japanese scientists have isolated Lokiarchaeota, and grown it in a lab. Researchers can now freely study and interact with Lokiarchaeota, which could help find our first ancestors on Earth. The work can be found here.
The tree of life has 3 major domains which start with bacteria – single-celled microbes without a nucleus and move around with flagella. Another domain is eukaryotes, which contain cells with a nucleus and a membrane which includes humans, plants, animals, etc. There is another domain Archaea which are like bacteria which lack nuclei and membrane-bound organs and move using flagella. The differences include their cells walls and RNA which are found to be different.
Later came the Lokiarchaeota followed by Thorarchaeota, Odinarchaeota and Heimdallarchaeota which show eukaryotic characteristics. They were collectively named Asgard archaea and is believed to be the origin of eukaryotic life. The sediment was retrieved from a seabed in Nankai Trough (2533 meters below sea level). On performing RNA analysis of their rich sample revealed the presence of a Lokiarchaeota-like organism. They cultivated their samples for 5 years in methane fed continuous flow bioreactor system which mimics deep-sea methane vents. Eventually, the microbes multiplied. The samples were placed in glass tubes in a bioreactor to keep it growing and finally, a very faint population of Lokiarchaeota grew after another year.
The team invested in isolation, cultivating and growing this slow dividing population. Lokiarchaeota took 20 days where a normal bacterium takes an hour and a half to double. The culture has 30-60 lag phase and 3 months to reach full-grown phase. Variation of growth parameters, combinations and concentrations did not significantly improve the lag phase and growth. The experiment took 12 years in total. The researchers named their cultivated microbe Prometheoarchaeum syntrophicum.
Various findings included Prometheoarchaeum which grows in the presence of one or two microbes (archaeon Methanogenium and bacterium Halodesulfovibrio). Prometheoarchaeum helps in breaking down amino acids into food, hydrogen is produced which is fed upon by other microbes. Prometheoarchaeum’s slow growth could be hampered by the presence of hydrogen. Examining the organisms in an electron microscope found the unusual shape for archaeon which has long tentacles sprouting from its body between which partner microbes are nested. With the increase of oxygen on Earth, it might have switched relationship to an oxygen-using bacteria, leading to eukaryotic life.
DNA sequencing revealed the eukaryotic characteristics that were observed in the rest of the Asgard archaea. More work has to be done as there is no definitive proof that eukaryotes evolved from archaea and Prometheoarchaeum might be quite different from the archaea of billions of years ago. The work is yet to be peer-reviewed but whatever be the results it is a monumental paper behind which a vast amount of perseverance.
Research Paper: Isolation of an archaeon at the prokaryote-eukaryote interface
June 27, 2019
Published by Kalpit Veerwal
Scientists have recently discovered crust of plastic particles that were forming up on shoreline rocks. This ‘plasticrust’ is a huge threat to the creatures inhabiting on rocks and there could also be a possibility of plastic entering into their food chain. The study was published in Science of the Total Environment.
A Marine and Environmental Sciences Centre (MARE) team from Portugal has been observing the building up of plastics across the shore of the volcanic island of Madeira by evaluating their impact on the local ecosystem since 2016. Ignacio Gestoso, a marine ecologist said that the crusts are developed due to the crashing of large pieces of plastics against the rock shores similar to how algae or lichens do.
The plasticrust looks similar to a chewed piece of gum or a squeeze of toothpaste on the rocks and their shape is similar to that of inhabitants on the rock and this way the plastic is fixing itself into the environment. Several researchers like Gestoso are researching on the reason behind its formation and their effects and thus it was discovered that they are formed due to the usage of polyethylene, the material found in plastic bags and food packaging. Now according to the scientists, this polyethylene which is sticking to the shoreline covers nearly about 10 percent of the surface of the rock.
The researchers and their team also discovered a proof which shows that the winkle sea snails which eats algae are as comfortable being in the plasticrust as they are on the rocks and thus they might be sucking the plasticrust and the algae on the rock as well. As of now, the researchers just want us to make aware of this problem. If we don’t reduce the usage of plastics then the rocks which are getting covered by plastics will bring serious issues to the microorganisms.
However, sadly this is not the first time this has occurred. In the year 2014, there was a discovery of plastiglomerates which is a substance similar to rock made from melted plastics and organic debris. The scientists say that plastic is hugely used and if it continues this way then we’ll leave huge sediments of plastics for the future generation. Gestoso told that he, as a marine ecologist researcher would like to choose to report about other types of discoveries than describing a sad new way of plastic pollution in his research paper.
June 21, 2019 (updated June 21, 2019)
Published by Kalpit Veerwal
Researchers associated with numerous institutions across the U.S. have discovered a rare species of shipworms named Lithoredo abatanica that feeds on rocks and stones instead of woods. They published a paper in the Proceedings of the Royal Society B and described their study and the discovery.
The shipworms are water-dwelling mollusks which are known due to their ability to chew the wood and digest it. They are also popular for creating holes in wooden structures present in water and now, the researchers claim to have discovered a species of these shipworms that do not feed on wood at all but eats the limestone instead.
After breaking through the rocks to get a specimen of these worms, they reported their small size of 150mm and their close resemblance to worms than other mollusks. Unlike the wood-eating shipworms, these worms have large, flat teeth that could scrape away rocks unlike, sharp invisible teeth of the wood eater ship worms which could cover the shells and lacked the sac which was used to digest these woods. In addition to this, these shipworms were also found to excrete sand. Researchers, however, cannot determine any motive behind their rock eating nature but say that it does not impart any nutritional value.
These ship worms which eat rocks have the tendency to change the course of rivers as well. These shipworms have extremely shrunken shells, two in number which is modified into drill like heads.
The regular wood eating marine ship worms store the wood that they eat in a very special digestive sac which they ingest and scrape away to make a protective burrow for itself. The rock-eating ship worms do the same except that they differ from the usual ones in the fact that they lack the sac.
The rock-eating ship worms rely on the bacteria that reside in their gills to produce nutrients and food which is sucked in by this newly existing shipworms from the hind end for nourishment. The gills found in the stone-eating shipworms are quite larger than normal, which shows that they are important for their survival. Researchers are working on how their metabolism works.
June 14, 2019
Published by Kalpit Veerwal
Medical science and research is moving ahead at a huge pace. A new feature in a large class of pathogenic viruses was discovered recently that allows the development of new antiviral medicines for illnesses like common cold, polio and other illnesses. It was studied and published in the open access journal PLOS Biology by Rana Abdelnabi and Johan Neyts from the University of Leuven and a team of other scientists from the University of Helsinki.
Picornaviruses are a type of viruses which include rhinoviruses and enteroviruses. Rhinoviruses are known to cause millions of cases of upper respiratory infections like cold and asthma every year whereas enteroviruses are responsible for cases like meningitis, encephalitis and polio. There is no medication or treatment for the prevention of rhinoviruses and enteroviruses.
Viruses usually interact with the host cell for replication and while doing so they often change shape. If you stabilize the particle it is thought to be the best strategy for preventing replication. The authors found a compound that stabilizes antivirus which prevents replication. The researchers performed a cryo-electron microscopy of the complex to determine the effect of the drug. Cryo-electron microscopy establishes a detailed 3D image by combining close to a thousand images.
The authors have found a previously unknown pocket on the surface of the virus which was previously not even detected even after being studied for over a decade. The compound was lodged in the pocket thereby stabilizing the virus against the change in shape that would allow it to interact with the host cell. The team has started preparing multiple variants of the antiviral molecule.
Viruses are known to mutate very quickly, changing constantly in one way or the other which poses a major challenge in developing antiviral medication as the once useful drug may become ineffective. It may also happen that the newly discovered pocket might also undergo changes and make the drug-resistant to picornaviruses to the therapies which are already developed against them. The authors have predicted that this pocket may be a crucial discovery in the field of virus replication that viruses containing mutant versions may become less viable which makes the drug relatively resistance-proof.
The work of developing these compounds and making them into effective drugs is ongoing. This study and results have opened many opportunities and avenues for the design of broad-spectrum antivirus medicines against the major human pathogens which are rhinoviruses and enteroviruses.
May 12, 2019
Published by Kalpit Veerwal
In the 21st century, medical advancements have reached greater heights and continue to achieve new feats and higher levels of research has enabled scientists to scale greater heights in the field of medicine.
A recent medical case at the Great Ormond Street Hospital in London was a showcase of advances in medicinal science. A pair of teenagers had cystic fibrosis, it is a disease where the lungs cannot clear mucus and disease-causing bacteria. They had undergone lung transplant and soon after which the infections that stayed in the body erupted from their sutures and soon these bacteria began to stain and spread over their skin through the skin tissues, doctors were giving antibiotics but they were of no use, as the body was not responding to them and the bacteria continued to spread. This is when phages came to rescue.
The history of phages dates back to the late 1990s where Graham Hatfull, a microbiologist of the University of Pittsburgh had the collection on bacteriophages which are viruses that prey solely on bacteria. These phages were stored at -80˚C in the university research lab. The boy, unfortunately, succumbed to his infection as it was too late however the girl was able to get the recovery and survived on the edge as her body parts were on the brink of organ failure. The infusion of the phage cocktail was first given to Isabelle in June 2018. Within 72 hours, her sores began to dry. After 6 weeks of intravenous treatment every 12 hours, the infection was all gone, soon she became back to her normal teenage life.
The two teenagers and their recovery became a case study which was published in the Journal Nature Medicine which represents the first ever use of engineered phages in a human patient. There is an emerging phase of synthetic biology which the disease researcher Eric Rubin of Harvard T.H School of Public Health commented that there is a need for rigorous testing of this before final implementation.
Phages typically kill a single bacterial strain which means if it works on one person it may not always work on the other person. Leading US universities have launched Phages research in their laboratories. There are claims that even if the treatment succeeds there are a lot of practical difficulties in the implementation. For further implementation, we also need to gauge the affordability factor of the treatment so people in all economic strata can afford this treatment.
May 9, 2019
Published by Kalpit Veerwal
Oceans are a rich and biodiverse habitat on its own. We can find organisms and plants ranging from a few millimetres to a length of 12 meters which is the size of the largest whale which weights close 50 tonnes. The vastness and the richness of the oceans are a wonder to study and explore a curious mind.
Scientists for many decades have believed that arsenic is a poisonous chemical for almost all living beings but until recently researchers have found a microorganism that lives by breathing Arsenic and is found over a large area in the Pacific ocean. The study has been published in The Proceedings of the National Academy of Sciences. Scientists have believed that this species had used arsenic during the time of formation of Earth where the presence of oxygen was limited and microorganism had to survive on arsenic. In the face of global warming, there is a need to adapt which is slowly happening in the ocean ecosystem as organisms need to be able to adapt to lower levels of oxygen in the water.
Arsenic was known to be present in water for quite a long time but its use by microorganism for living was quite a new concept. These microorganisms were discovered off the coast of Mexico where there is a patch called anoxic where there is virtually no oxygen dissolved in water. Microorganisms which breath on sulphur and nitrogen were known for quite a long time but living on arsenic is still new to researchers.
Scientists have analyzed the DNA samples of these microorganisms and found two pathways which convert arsenic-based molecules to energy resource. It has opened gateways to explore the life where oxygen does not exist and also extraterrestrial life on other planets might take place. These arsenic-based microorganisms might account for around one percent of the total marine microbial community but there is scope to find and understand the complex chemical reactions which happen in oceans as a whole.
Scientists think that the best way to study these microorganisms is to artificially grow these samples in the lab and study their metabolism and how they respond to various levels of arsenic content in water.
Jaclyn Saunders, a researcher has commented that the coolest thing about these organisms is that they are expressing the genes in an environment that is very low on arsenic and that it opens up boundaries to finding other organisms that are respiring arsenic in poor arsenic conditions.
The amount of diversity one may find on the Earth may surprise anyone, there are a lot more opportunities and organisms that are waiting to be explored in the depth and the vastness of our Earth’s oceans.