 Hello. So today I will be talking about contemporary issues and science and technology and society in the Philippines. And for today I will be talking a specific example of that issue entitled Magnetotactic Bacteria, Attractive Solutions to Toxic Heavy Metal Contamination from Small Scale Mining. So, magnetotactic bacteria are unlike your typical prokaryotic cells in which there are membrane bound organelles inside their cells. So this is your typical prokaryotic cells, but your magnetotactic bacteria inside their cells, they produce intracellular magnets. That straight line, those are actually magnetic particles. And magnetotactic bacteria, they come in different shapes, they can be spirilum or oblong. And their magnetic particles can be magnetite or gregyte. And different magnetotactic bacteria, they produce different shapes of magnetic particles inside their cells and they are perfectly shaped. Examples of the shapes are your bullet shape, they can be irregular or hexagonal. And there is no biotech company which can synthesize as perfect as the shapes of magnetic particles produced by magnetotactic bacteria. So these perfectly shaped magnetic particles are only biogenically produced. So if they are biogenically produced, so the production must be under intricate and precise biological control. So this is the strain from Japan, Magneto-Spirilum Magneticum AMB1. So it's a spirilum and this picture represents one magnetic particle. So what is so striking about this prokaryotic cell is that aside from the outer membrane, the lipid bilayer, each magnetic particle is also surrounded by a membrane similar to that in the outer membrane. So the magnet itself is called magnetite or gregyte. But the magnetite plus the membrane is called the magnetosome. And here's a picture of a chain of magnetic particles from strain AMB1. So why do these bacteria have to produce magnets? So they are very unusual. So the theory is because they use it for magneto navigation or magneto reception. Meaning they use the Earth's magnetic field lines in order to traverse, to migrate. Parang kalsada na yung kotsye dumadaan sa kalsada. Sela naman dumadaan sa magnetic field lines. Yung train dumadaan sa rail track ganon. So sila yung magnetic field lines ng Earth ang ginagamit nila para mag-swim. So where can you find them in the environment? So magnetotactic bacteria, they hate oxygen. So if you have a water level, so we have a zone called the Oxygen-Anoxic Transition Zone. Meaning that's the zone where there is very little oxygen until there is no oxygen. That's the borderline between the Oxygenated Zone and the Anoxygenated Zone. So from there, down is, there is totally no oxygen. That's where you can find them. So that's their first trait, they hate oxygen. The second is of course they are magnetotactic. They react to magnet. So if there is a magnetic field over here and there is very less or no oxygen, they will migrate towards that place. So there are magnetotactic bacteria which actually require very little oxygen. So if you put them in a tube like right here and this pink one is the level of oxygen, increasing gradient of oxygen and you put a magnet here, they will stay here. But if the level of oxygen, if you put a magnet over this place, they will migrate just right here, not near beside the magnet because they hate oxygen. They only require very small oxygen. But for strict and error, meaning they hate, totally hate oxygen. They don't, they require zero oxygen. So if you put a magnet over here, they will swim there and there is zero oxygen. And then if you put a magnet on the other side, then there is oxygen right here. But this one, they require zero oxygen. So they will not swim towards the magnet. They will just turn around because they do not like the oxygen. Unlike the other one, they require, they are micro-aero meaning they require little amount of oxygen. So they can swim just a little bit to the magnet. So what are the biotechnological applications of magnetotactic bacteria? First, we can harness what they produce outside their cells. Second is the magnetic particles themselves. We can isolate them and use them for biotechnological applications which I will discuss later. Number three, the whole living cells, the magnetosome plus the cells and their magnetotactic behavior. So how do we tap them? So number three, whole living cells and their magnetotactic behavior is my main topic which I will present. This is a graph of biopublications about biotechnological applications throughout the years. They are used in bioremediation meaning they are used for cleaning the environment and cell separation. This is for biomedical use, anti-mobilization, food, hypothermia and image contrast. Let us focus on bioremediation which is a very contemporary issue now especially here in our region in the Cordilleras. So these are the magnetic particles. You can isolate them. And magnetotactic bacteria are actually found in many different environments. They are found in freshwater, even in a lake, in a river. And this is from an estuary and from marine environment. So that means they are actually ubiquitous. They are unusual but you can isolate them from any type of aquatic environment in the sediment. So this is the latest isolated magnetotactic bacteria, magnetoglobulus multicellularis. And it was isolated from a brackish water in Brazil. What is so unusual about this magnetotactic bacterium, they are actually colonial. So this is the cross section. So each slice here, each section represents one cell. And this is the SEM of the cell and it's flagellated. They are multicellular. So all over the world magnetotactic bacteria have been already isolated. So the question is, do we also have magnetotactic bacteria in the Philippines? In the Philippines we have diverse aquatic environments. And in these environments where we can find magnetotactic bacteria. So me and my students, we endeavour to find out if we do have magnetotactic bacteria in our aquatic environment. This is in Bollinau, Silakibollinau, in Nagsasa, Sambales. And this is also in Nagsasa, in Land River where we first successfully isolated magnetotactic bacteria. So first, in order to isolate them, we have to review what are the two conditions for magnetosome formation. First, they require low or serial concentration of oxygen. And second is, they require extraordinary high amount of iron. The amount of iron they require is 200 times more than their typical bacteria. So if you put that amount of iron which the magnetotactic bacteria requires into for example an E. coli. The E. coli will burst but for magnetotactic bacteria it's okay for them. That's because they use it to form the magnetic particle. So the isolation is actually very simple. We get a sediment and then we just attach a magnet. And after a week we remove the soil or the sediment and the water. And what remains in the magnet, nung na magnetized sa side ng jar, we take them and most probably nandoon ang magnetotactic bacteria. And then we get that and then we put them in what we call a capillary racetrack. We resuspend the magnetized solutes and then we dip bakoton para matrap yung mga bacteria doon. And then we put them in this tube. And then yung mga bakoton natrap yung mga bacteria natrap sa koton. And then basically this is the principle. If this is the magnet, the bacteria will migrate towards the magnet. Which will separate them from the nandmagnetic. So we did try to find genes through what we call polymerase chain reaction for mom A gene which is the gene for magnetosome formation. And we found them. I have two students, Marge Messina and Erika Chua. They found magnetic particles, cells. And we identified them at the molecular level. So this is when we cultured the cells. This is a magnet, this round thing. And ordinary bacteria will settle at the bottom because of gravity. But if you put a magnet, this speck of biofilm, they remain there because of that magnet attached to the tube. And they have flagellum also and yung mga TEM. And we identified them also through 16S. So now how do we apply this isolated magnetotactic bacteria? Here in Benguet, there was a recent tragic issue which occurred in Itogon. And Itogon is a very nice place. It's one of our ecotourism destinations. So just a background of this Cordillera region, you can see from their artifacts but that long ago, they used metals, they used them as their accessories, as musical instruments. But when Ompong came, tragic struck. There was a tragic landslide because the land was riddled with small-scale mining operations. Many died because of the landslide because the soil was so loose because of the small-scale mining. So this is just one of the consequences of unregulated small-scale mining. So our study site is in Luneta, Antamok, Itogon, Benguet. So one of the consequences, aside from landslides of unregulated small-scale mining is actually the release of toxic materials like acidic mine water, which of course ends in environmental destruction and health problems to the community around these mine tailings. So one of the toxic contents of mine tailings is cadmium and it destroys the ecosystem because it's very toxic. It interferes with the food chain and of course with the human health. It can give painful disorders once humans are exposed to toxic levels of this heavy metal. And of course also respiratory dysfunctions. So this is the site. This is a mine tailings lake. It's an open pit mine tailings lake made by the community. And this lake is a lake where all the mine tailings throughout the decades, they accumulated in that lake. So it's a very toxic body of water. So that's where we tried to isolate magnetotactic bacteria because that means that this bacteria thriving in that toxic environment have become adapted to toxic conditions. So ito po yung mga ibang pictures which we took and these are toxic materials which they use for processing the ores from small-scale mining and they go down that lake. Which I showed you. That's mine tailings dripping into the lake. So mapapansin nyo rin it's green. So during the dry season nag-resid yung water and we tried to collect along the bank's sediment to collect magnetotactic bacteria. Those are my students. So we isolated the magnetotactic bacteria to bioremitiate the cadmium in the lake. But of course not exactly in the lake. But we had an in vitro experiment in which we have different cadmium concentrations in vitro and then we seeded the bacteria. Because remember magnetotactic bacteria can assimilate high concentrations of iron. So we found out that magnetotactic bacteria can also assimilate high concentrations of other heavy metals aside from iron and that is cadmium. So after so many hours after 24, 72, 12 hours the cadmium in our medium decrease na-assimulate nila yung cadmium. Inalis nila. They remove the cadmium from the solution and this cadmium are in toxic concentrations. And our final conclusion is we measured until 1.84 parts per million which is actually 360 times higher than the borderline toxic level of cadmium in humans which is .005 ppm which is set by the agency for toxic substances and disease registry. Meaning, ma-epectibo ang bacteria ito para linisin yung isang tubig na riddled with cadmium So, we identified it as a senetobacter, yung bacterium na yun. Ito naman po, inaral din namin yung lead. At itigig lang sabihin nito, habang ito yung toxic level ng lead, pababasha, habang nag-grow yung bacteria. Typical bacteria will die pag ganyang karaming lead, pero itong magnetotactic bacteria na another isolate na bubuhay siya habang inuubus niya yung lead. And lead, aside from cadmium, is also another toxic metal. Okay, so that means paring niyang linisin or alisin ang lead na toxic sa environment. So, iba-ibang concentration yan, ito naman higher concentration and much higher concentration. So, yung lead na bubuhay yung cells, tapos inaal yung blue yung yung pag-decrease ng lead. Okay, yun, in-identify din namin sila as a senetobacter. We named as na yung UPB MAG-06. Dun naman sa cadmium UPB MAG-05, ang tawag namin sa strain nung magnetotactic bacterium na yun. Okay, so ito po yung lake, papapansin nyo, sila po ay green. Dahil may mga microscopic na lumot yan, which we call microalgae, na na buhay yan. Na kahit napaka toxic sila ang na buhay yan kaya green yung tubig. So, aside from the magnetotactic bacteria, nag-isolate din kami ng microalgae kung kaya nang kaya nilang mag-asimulate ng toxic heavy metals like cadmium kasi napaka green nung tubig, that means adapted sila yan. So ito po yung na-isolate namin microalgae from that mind-tailing slake at ito yung growth nila. So, itong pangalawa yung red kaya niya pa rin mag-grow at a higher level of cadmium. Yung blue siya yung walang cadmium. Itong bars na tol, ito yung cadmium na initial concentration na nilagay namin. Tapos after 24 hours, ito na yung cadmium concentration. So about 50% kaya niyang i-rejuice or kainin yung initial amount ng cadmium doon. So, another ecotourism destination is dito sa Cordillera ay yung sagada because maraming attractions doon like your hanging coffins, yung waterfalls, ganyan. So, sikat na sikat ang sagada sa buong Pilipinas na pinupuntahan kasi malamig, maganda ang tanawin, yan, may mga rice terraces din. Ito po yung pakiat doon. So sadly, sa likod po nung pababa doon sa falls, meron po yung small-scale mining operation doon. So it's been operating for around 30 years. So, and this is one of their processing houses, yan po nagdidrip pababa yung mga mine tailings nila, papunta sa ilog sa baba. And this is the side of the mountain. When you go down the falls, you're just looking at terraces. But if you go on the other side of the track going down the falls, you can also actually see this side, this sad mine tailings. Small-scale mining operation. These are the mine tailings. At those mine tailings, they flow into a river like that, going down a big community called Bontok. There are human settlements here, especially in Bontok. These pictures, me and my students, we had a local guide. So ito yung we set up three stations, station one doon sa small-scale mining operation, then downstream and Bontok yung river doon. So we took sediment and water samples and we found na may mga toxic levels sila of cadmium. And from the same spots, we isolated bacteria. This time, it's not magnetic bacteria but just bacteria ordinary. So you can see that the water is still and it's very clear. So what we found out first is doon sa station B kami nakakita ng high level of cadmium toxicity. Not in Sagada where the mine tailings directly come from. But doon downstream in station B between Sagada and Bontok. Remember, I told you that the water is clear and still. Doon na man sa may Sagada, the current is so strong. So na they were washed away by the current and then nagsetal sila doon sa station B. So does it mean that clear water is clean water? They can have toxic materials there. So in summary, what we found out is even at very high level toxic concentration, different toxic concentrations of cadmium, the cells can still grow and assimilate the cadmium just like the magnetotactic bacteria. But after 15 days, the cells die. That's why bababasha na ganya. And we identified this bacteria as Delphia at a molecular level using 16S sequencing. So this study was actually funded by the Cordillera Study Center of UP Baguio. Yung study on magnetotactic bacteria. And I would like to all give credit to the students who work on this with me. We started it in Ateneo, Laura Hine and Camille Edmilao. And then we have more students. Yan sila. And ito yung nag-work. These are the students who work in Itogon, Benguet who isolated the magnetotactic bacteria which can assimilate cadmium, can do bioremediation with cadmium. And this is the next batch who followed up the study. And these are the students who work on cadmium bioremediation in Sagada. And thank you very much.