If you would like to find the explanation to the pictures, read my eBook, A Wetter Look At Climate Change.
Being old enough to remember when David Bowie brought out “Life on Mars” and watching him on Top Of The Pops, it’s great to see the renewed fascination with this planet. We get headlines about the findings from the various missions circling around and landing on the Mars surface. Behind those headlines there’s a fantastic amount of science going on that we don’t hear about unless you’re really into space exploration. Astrobiology is the area of science I’m drawing from to write this blog post. Especially about the limits for microbes to grow and how they get their water…….
A fact that has been known for many years is that microbes do not grow when the relative humidity of the air gets below 60%. In the FOOD section of my eBook A Wetter Look At Climate Change there is a table that shows the lowest %RH for one of the organisms is 61%. The two organisms at the bottom of the table are Xerophilic, which means, high tolerance and able to survive in dry conditions. This is where “Life on Mars” is relevant.
In South America there is an area that is the most “arid” place on Earth. An area defined as arid has little or no rain and is too dry or barren to support vegetation. The Atacama Desert, located in northern Chile, is accepted as being the driest and oldest part of our planet. Microbiologists have studied the bacteria and fungi from this region since the 1960’s. But in 2003, NASA published a paper describing Atacama as a model for Mars. That kicked off intense interest in engineering and scientific activity to mimic how to perform tests on the Martian terrain.
The big question “Is there life on Mars?”
Let’s start with “Is there water on Mars?” Pictures from the Mars missions compared to geographical features on Earth, indicate strongly that liquid water once flowed on the surface of Mars. Features that look just like riverbeds and erosion by water. We know for sure that water in the form of ice sits at the North and South poles of Mars. Also, there may be water deep underground. Future missions are planned to provide some answers.
Does water always mean life?
As far as we know, water is a prerequisite for life. On Earth no life exists that does not rely on water. Back to the arid Atacama Desert. Engineers and scientist have designed machines and testing techniques to detect the presence of microbes in this desolate part of our world. The technology will be placed on board Mars missions and the data from the tests will be beamed back to Earth.
All very exciting and high tech this stuff. In my reading of the published papers on the microbiology and molecular biology of the Atacama organisms, I went looking for evidence of microbial growth in an environment that is predominantly below 60%RH. I thought, if anybody can find such Xerophiles, these guys might.
I was encouraged when I found this statement in a review paper: “This work definitively validated the Atacama Desert as a Mars analogue and also as an unparalleled place to pursue studies on the dry limit for life.” In my mind, coloured by my quest for an explanation for the 60%RH microbial growth limit, I read this as a search for organisms that can scavenge in low moisture conditions. By low moisture conditions, I mean at a humidity below 60 %RH.
A problem with doing science outside of the laboratory is the things going on that are not under your control. Looking at the weather conditions for Atacama with less than 2mm annual rain and average %RH of 10, it is easy to classify this desert as the driest place on Earth. So, what can get in the way of looking for life in such a low moisture environment? Fog for one. Drifting in from the coast and around the coastal range of mountains into the desert this moisture can provide organisms with the necessary moisture to keep them alive. What the scientists observed is a fall off in the total number and different types of organisms as they went from the edges of the desert towards its middle.
After my initial excitement of maybe getting an answer to the 60 %RH growth limit for microbes, I was becoming disillusioned. Seemed like the microbes were simply scavenging moisture when it was carried across parts of the desert by fog. Frustrated by not making progress on the 60 %RH growth limit question I contacted one of the authors of a review paper “Life at the dry edge: Microorganisms of the Atacama Desert”. His name is Armando Azua-Bustos, an Astrobiologist working in Spain. We had a Skype call in which, at last, I saw hope on the horizon.
Armando told me about controlled laboratory experiments where he studied the Xerophiles from the Atacama Desert. Under low %RH conditions mimicking the Atacama Desert he detected one of the key signs of a living organism. All living creatures must have an active metabolism to live and certain molecules are produced and used within living cells. Using sensitive probes for the molecules of life, activity was seen in the Xerophiles at 10% and 30% humidity. Well below the 60% limit.
My chat with Armando got even better. He told me about how cells can protect themselves against dehydration. Certain types of sugar molecules and proteins are produced by the Xerophiles. One of the key sugars is called Trehalose that can substitute for water molecules within the cell by interacting with other key molecules. I knew about Trehalose from my past where I used it to protect yeast from freezing when storing at -20°C. Another type of molecule mentioned by Armando is Dehydrins. These are small proteins that can also substitute for water molecules within the cell. Both Trehalose and Dehydrins are produced in cells that are under stress from dehydration. Armando described the inside of the cell becoming more like a gel rather than a watery soup.
The picture we now have of Xerophiles is that, when the environment gets drier, the protective molecules, Trehalose and Dehydrins, allow the cell to continue to metabolise with less water. However, further dehydration would stop metabolism completely, which means cell death. Armando suggested that Xerophiles have evolved biochemical pathways to counteract dehydration by producing within the cell a small amount of water for metabolism. This is what Armando and his colleagues are detecting using their probe for metabolic activity. In other words, the Xerophiles respond to drought by protecting themselves and then turn on a water production mechanism.
So, with my question answered about the 60% growth limit, what about the Big question, Life on Mars? Science is telling us that a key sign of life, metabolism, is looking feasible under the dry conditions present on Mars. Does that mean there could be the possibility of organisms growing in that environment? We don’t know yet.
Earth and Mars were created around the same time, about 4.6 billion years ago. Mars started to lose its atmosphere and ability to support liquid water about 4 billion years ago. But it took a further 0.5 billion years (3.5 billion years ago) for life to evolve on Earth. This raises the question of would there have been a sufficient time for life to have evolved on Mars before it became too dry? If life had evolved, is it possible that Martian Xerophiles would be able to sustain low level metabolic activity over the billions of years since it became dry? Armando and his fellow Astrobiologists will one day let us know.
NASA have discovered large underground lakes of water on Mars. One of these is frozen and is the size of Lake Superior, another is liquid. Also, it is possible that underground water could be warmed by the sun and trapped in caves where it could support life. This all adds to the thrill of there being Martians out there, albeit most likely micro-ones!
Welcome to my world of moisture
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A double meaning in the title. One, eventually after being very busy with Relequa I’ve found a little bit of time to publish the last episode. Two, we have completed the home for Relequa.
Back to the story. After we had thawed out after the Beast from the East the lads were back on site. Michael the Carpenter finishing off the roof, Eugene the Strong finishing off walls. In this blog, the fourth and last episode of finding Relequa a new home, I’ll take you to completion of the build to our fitted out “Alternative Alpine Lodge”.
The lads had recommended Munster Joinery, an Irish windows and doors company, that has built itself from a start-up in Munster to a large international company, supplying and fitting their products across Ireland and the UK. We were soon ready to act upon the quote from Munster Joinery. The Beast from the East did set a lot of people back and we had to wait longer than we expected for the windows and doors to arrive. But, arrive they did, and no problems with fitting. Surprisingly quick actually, with the fitters going off to another job on the same day.
Windows and doors in place we were on another cycle of Michael the Carpenter, Kieran the Plasterer and Mícheál the Electrician. Time now to introduce you to our last character, Gregor the Tiler, a giant of a man from Poland. Gregor the Tiler didn’t talk much. Three areas were planned for tiling; reception, toilet and my office come “sun” room.
The next sequence of events within my “sun” room was more or less the same as the garage refit with timber, plasterboard and plastering stages. While this was going on, I started painting the ceiling of what was to become the meeting room. After three coats of paint I surrendered and we got in painters. Apparently, I was using the wrong paint for the light in the room!
Apart from drying plaster that I talked about in Episode 3, there was nothing inside or outside relating to moisture to explore further in my “world of Moisture Matters”. Not until we were fully fitted out did an interesting moisture issue arise.
As well as making our Relequa Moisture Profiling System, we also get involved in project work. Our first project was for a company called Sepha who make small scale pharmaceutical equipment for R&D laboratories and Clinical Trial manufacture and packing of tablets and capsules.
Sepha had just launched their new invention for testing how good the foil seal is (“integrity”) on blister packs. Up until this invention, pharmaceutical manufacturers had to take a statistical sample of blisters from a batch and test the “integrity” of the seal using a machine that forces dye into the blister pockets. Blister pockets picking up the dye would fail the test. This dye test, used for many, many years, works on the principle of having a significant fraction of the batch of blisters not failing, and so the rest of the batch is passed for use. Sepha’s new machine called VisionScan, uses a technique which allows 100% of the blisters in a batch to be checked for leaks without damaging the tablet or capsule in the pocket, or the blister pack itself.
The project with Relequa was devised to use moisture movement as a way for testing the “integrity” of blisters after treatment with VisionScan. If treatment affected the “integrity” of the blister seal then moisture would be taken up by a tablet inside the pocket. A gain in moisture of a tablet is easily detected using our Relequa Moisture Profiling System. Moisture Profiling of tablets was done before and after VisionScan treatment and then over a period of several weeks after storing the blisters at high humidity.
We showed that the tablets we chose could easily pick up moisture and this, if occurred, would be detected in tablets from VisionScan treated blisters. No difference in tablet moisture was seen between the tablets from blisters treated by VisionScan compared to untreated blisters. The conclusion was that the VisionScan treatment had no impact on the “integrity” of the seal. This project was written up by an independent author at Ulster University as a whitepaper in the European Journal of Pharmaceutical Science and is free to download.
Earlier I mentioned an interesting issue that came up. Due to technical reasons around making tablets, that I’ll not go into here, we chose to make the tablets for the Sepha project from a sugar called Xylitol. When the Sepha project was completed, I obtained the bulk of the tablets that were not packed into blisters. My intention was to use these for calibrating the MP-1000, our new Relequa Moisture Profiling System.
Customers who have bought an MP-1000 can check if the system is functioning as it should. To do this we supply them with tablets from a batch that we have already tested. These tablets are sealed in a moisture resistant pack. The pack is a bag made with a high moisture-barrier material. We put in a number of tablets and heat seal the bag.
Before releasing the calibration tablets for use, the sealed bags were put into high humidity conditions and at weekly intervals a bag was removed, the tablets taken out and immediately checked on the MP-1000. What happened next was unexpected.
Using my many years of experience working with moisture issues, I knew from i) the starting condition of the tablets, ii) the quality of moisture-barrier material of the bag and iii) the ambient humidity, that no moisture transfer should occur over the time the bags were stored. However, I couldn’t argue with data that clearly showed that the tablets from the sealed bags were picking up moisture. So what on earth was going on?
At times, to solve a problem, it’s only about using “all” the information that’s available to you, even when it’s not directly related to the thing you are investigating. When you hear the answer, you’ll probably think “of course it’s related” but that is the power of hindsight.
Back to the Sepha project for a clue. As part of the testing protocol I built in what is known as a “positive control”. Using a hypodermic needle, a tiny hole was put into some of the blister pockets of the packed Xylitol tablets. These were placed, along with the other blister packs, at high humidity. After a week the tablets from the pockets with a hole had dramatically picked up moisture. Other tablets from intact pockets were unchanged. When attempting to test the tablets from the pockets with a hole that had been at high humidity for two weeks, no testing could be done because the tablets had turned to mush!
That mush was the clue. Our Xylitol tablets were undergoing deliquescence, a property of salts and sugars that I’ve talked about before on my blog posts. These tablets were chosen because of their ability to take up moisture. Where this was an effective property for the Sepha project, it was too effective for using the same tablets as a stable source of moisture calibration material.
The moisture barrier bags, in which the Xylitol tablets were packed as calibration tablets, are only moisture resistant and not an absolute barrier to moisture transfer. With the external humidity fluctuating around 65% RH a small amount of moisture passed through the material of the bag. The driving force for this to happen is that the tablets are continuously absorbing moisture as they move towards deliquescence.
My only option was to have different types of tablets prepared and start again with a moisture testing time course experiment.
Welcome to my world of moisture
Next topic: Life on Mars.
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I always finish at the end of my blog posts with the words “Welcome to my world of moisture”. A simple thing happened in my world of moisture that would have most people guessing “what’s gone on here?” or maybe “who’s done this?” That thing was a pool of clear liquid around a candle holder, shown in the picture, which was sitting on a glass table. Where had this liquid come from? Who had split water or something on the table? Nothing had been split. The candle holder had been left untouched for weeks. Magically this liquid had appeared out of thin air! A mystical apparition materialising from the ether? Help, somebody call a medium. A “sign from above” warning of looming storms and flooding. Or maybe we can find an answer from science….. Continue reading
“The impact of moisture on yield & quality”
This could be the first ever moisture seminar that is not focussed on a particular analysis technique or application area.
I’m giving two talks!
A brief introduction to relative humidity explaining some of the terms and concepts for an understanding of how humidity works.
The story of the progress made at key points in our understanding of the way materials interact with moisture. This leading to my development of Relequa’s Moisture Profiling.
To view the moisture seminar flyer click on MORE Continue reading
About a year ago I posted on this blog an article that looked into what can happen when moisture gets into the oil used in electrical transformers. This was a completely new topic for me and something I had never come across before. My ignorance in this area surprised me. With the real possibility of moisture causing catastrophic and spectacular failure of transformers and loss of power supply, I thought I would have picked up on this somewhere along the way. It was, however, a webinar on “Moisture in Transformer Oils” that captured my attention. Here we are one year on and there’s been an updated webinar on the same subject that was very, very interesting and significant in a number of ways…….. Continue reading
I am very fortunate to be living in beautiful County Waterford in Ireland. Of course I don’t feel fortunate all of the time. Just like growing up in the beautiful city of Edinburgh, I didn’t really appreciate it until I left. So it takes little reminders every now and then, away from everyday life, to regain that sense of appreciation. Like some of the spectacular sunsets we’ve had in the past few months. Glowing red, orange and pink clouds on a background of vivid blue stretching across the nearby estuary and surrounded by black silhouetted mountains. Then only a very short drive into the countryside to be immersed in fields. Although, a lot of fields look like no more than a lot of fields, until one day something big and pink is seen sitting in them.…….. Continue reading
So there I was, standing in front of an audience, wearing a headset and my voice booming out through large speakers, when suddenly, two minutes into my talk, the screen goes blank! I was giving a presentation called “Fidelity of Moisture Status in the Pharmaceutical Supply Chain” at a conference in Dublin. Nothing else for it, with no slides to show, I switched to talking about “Moisture Matters”. After a few minutes talking about the way materials interact with moisture, I brought my talk back towards the theme of my presentation. With about five minutes left, the screen came back on and I flicked through the key slides at speed, highlighting the points I had just talked about. A further twist in events was that the next speaker, who was talking about getting the right packaging for transporting products, started showing pictures of cardboard boxes and mentioned that magic word to my ears “humidity”.…….. Continue reading
It’s been two months since my last blog article. That sounds like a confession of a sin and in some ways it is, as I have deliberately stayed away from blogging over the past weeks. I was told by Sophie who set me up for blogging, that I “must” write one, or better two articles, a week. Sorry Sophie but two articles a week is just too tough for me. My reason for the recent lapse is I had to focus, even over Christmas, on my company Relequa. We are at a very exciting and very busy stage of developing and launching a new instrument for looking at the way moisture interacts with materials. During this activity I visited a printing company in Belfast. The owner of the printing company asked what Relequa was about and when I explained he said “air conditioning was invented for the printing industry”. Immediately that comment was lodged in my brain with a label “must investigate if that’s true”.…….. Continue reading