by Douglas Hill
On October 14th 2016 Scott Sanchez stopped by the TEC Center to see what we were up to. He is one of the Alumni who had worked on the bioreactor project. We were having a group discussion on some problems facing the indigenous people in Panama with the current members of the Center. After our meeting, which he sat in on, he let me know that he was currently working at Amgen (a biotechnology company). I asked him if they had anything like the MEC system at Amgen. He said the answer was yes and no. He said they had an industrial building block type system, which worked at a much larger scale than the MEC system. They would be working with 100 liters to 2000 liters of biomaterial at a time. The components were on wheels. The interconnecting pipes were stainless steel. They had a wraparound connector similar to what I had designed, but the two pipes that came together both had a round slot at the end that a rubber gasket fit into. The clamp wrapped around that. The connections could withstand high pressures. With the MEC system I am often having interconnection problems, so I am always eager to find out how others are doing it. He also let me know they were using single use bioreactors. The bioreactors were single chamber hexagon bags, heat sealed on edges, with six connection ports, three per side. Often a filter is attached to a port on the bioreactor bag. The bag walls were made of three different layers laminated together. The inner layer allowed no air diffusion. The middle layer was for strength. The outer layer was biologically inert, which simply means that nothing will grow on it. The names he gave me for the bags was Sartorius Stedim (Filter/ biotech supplies), Flexboy Bags, Xcellerex Subs-single use bioreactors.
Low total organic carbon (TOC) is important in water quality. One of the more interesting areas we talked about was how to maintain water quality. The topic came from the group discussion we had been having on Panama. Here, Scott let me know that you want very low levels of organic material in your water. To determine this, you can measure the TOC level. To do this you first want to remove the inorganic carbon from the water. This can be done by adding an acid. He said to bring the PH down to 2 and this would do it. Next, you want to allow the water to vaporize, He was not sure what the optimum temperature for this was. It was less than 100 degrees C. You did not want it boiling (more like 50 degrees C). Then, you measure the CO2 level in the vapor and that gives you the TOC level. What was exciting for me about this type of process (which he was describing), is that it is well suited to the MEC system. This makes it a great project for my students. I also realized that if we developed such a device it would be great if we could have a partner like Amgen who could verify our results.
Low endotoxins is important in water quality. The next area we covered on water quality was endotoxins. This includes things that make you sick, like many strains of gram positive bacteria. You want very low levels of endotoxins like .01 endotoxins/ml. His company goes to great lengths to insure there is no contamination of bio-materials. If someone were to sneeze on a bio-sample it could contaminate an entire batch, which they would have to get rid of. They use a LAL test to measure endotoxin levels. LAL stands for Limulas Anbeocyte Lysate. This is the blood of a Limules organism, which, in this case, is a blue horseshoe crab. Their blood is blue, and reacts with endotoxins.
Low conductivity is important in water quality. This is one of the simplest tests. The higher the salt content in water, the higher the conductivity. I always have to remember that when I say higher salt content, I am not just talking about table salt but a salt in chemistry. The term salt in chemistry means an ionic component, which is neutrally charged. It is made up of cations (positive charged ions), and anions (negative charged ions). They usually dissolve in water and are conductive.
“We know more about the movement of celestial bodies than about the soil underfoot.” This was a quote by Leonardo Da Vinci. The point is that soil is very complex, and this was an area of interest to him. There is a lot going on; worms, fungus, and bacteria are breaking down fecal matter mixed in dirt into nutrients, which is what plants need. When students are teaching me about their interest, my mind usually swings back to a problem I am trying to solve. In this case, it is growing food in Panama. I have briefly been looking at vertical farming, micro farms, hydroponics, and green houses. The one aspect all these things have in common is a controlled environment. I maybe should be asking myself; should I be trying to create a closed controlled system? People have been farming successfully in open systems for a long time, but maybe it is the scientist in me; I like repeatable results, which usually happens because of control. What I was asking Scott about, was that I want to be able to add nutrients in a controlled fashion to my plants. Most people who have these types of closed systems buy fertilizers and do just that, but we would be in a poor Panamanian community, so how could we take all the positive things out of the local soil, like nutrients, and leave all the negative stuff like types of fungus, and bacteria that harm plants? One thought I had was autoclaving the dirt. Scott thought this might work. The question would be, would you damage the things you wanted, or not remove all the things you did not? Also, would it be cheaper than just buying fertilizer?
When I have these types of conversations, which I am happy to say happens fairly often, it helps me realize how much there is to learn, and how much I need to know if I am going to solve many of the problems I have challenged myself with. Luckily, I have many students and professors willing to teach me. As a designer, things always seem easiest at first. I know that. As you learn more, the harder it seems, but the closer you are to a solution. As a last request I asked Scott to give me a list of the professors at UCR who helped teach him. He said that he would be happy to, and if I had any further questions to give him a call. I told him I would send him the list of problems the indigenous people in Panama were facing. He was excited to help where he could.