SHREVEPORT -- A chance discovery in the chemistry lab at LSU Shreveport could transform giant salvinia from a giant problem into a pollution-fighting superhero.
Salvinia is an invasive water weed that robs lakes of oxygen and crowds out native plants. It forms dense mats—and that’s the key to a potential new use as a natural sponge to trap toxic heavy metals like lead and arsenic.
Dr. Jack Baricuatro and his students stumbled on salvinia’s sponge-like nature by accident when they tossed methylene blue, a colorful chemical, onto dried salvinia. The result stunned them.
“We were disposing of chemicals from a chemistry magic show,” Dr. Baricuatro recalls. “The methylene blue solution decolorized, meaning the salvinia captured the dye. It’s very visual. It’s almost instant gratification.”
LSUS senior Carl Lindsey is measuring salvinia’s binding capacity in a series of experiments using methylene blue. If the results are promising, he’ll test whether salvinia attracts nontoxic metals like iron.
“I grew up in Caddo Parish, and I’ve been on Caddo Lake with my grandmother,” he said. “I’ve seen the salvinia there. It seems like you can’t really get rid of it, so if we could find some use for it that would be great.”
The recipe for perfectly prepared, lab-quality salvinia biomass is like one for good barbecue: low and slow.
“First we air dried it, then we left it in a 125-degree oven for an entire semester,” Lindsey said.
But once the salvinia was ready, it worked perfectly in Lindsey’s first experiments.
“It’s scary how well it takes in the methylene blue,” he said. “I expected about an hour to elapse, but it took about 20 minutes.”
Dr. Baricuatro’s research in his home country of the Philippines prompted him to look at uses for salvinia.
“I did a study before involving seaweed. We had lots of seaweed in the Philippines, and we used it for biomass,” Dr. Baricuatro said.
Dr. Baricuatro started his career as a generalist, teaching core chemistry classes at a local university in the Philippines. He has taught undergraduate and graduate classes for many years before he pursued research on ultrahigh vacuum science and electrochemistry. A specialist in the chemistry of metal surfaces, he worked as a staff scientist at the California Institute of Technology (Caltech) in Pasadena, California, before joining the faculty at LSUS. His research at Caltech focused on enhancing the rates of reactions in artificial photosynthesis, with a goal of producing vehicle fuels like ethanol from atmospheric carbon dioxide, water, and sunlight.
When Dr. Baricuatro decided to go back to teaching, he found that LSUS was a good fit.
“When I interviewed here, LSUS reminded me of my undergraduate university in the Philippines,” he said.
He noted that students at LSUS and in the Philippines face similar challenges in access and affordability. When students in one of his chemistry classes at LSUS kept asking for deferments because they couldn’t afford an online textbook, he was determined to remove that barrier to learning.
“I wrote a free online version of the homework and made it available,” he said. “It walks students through the lessons.”
Dr. Baricuatro also has added new lab equipment, like a potentiostat-galvanostat, so he and students can conduct research with real-word applications.
LSUS senior Kevin Brown is using the new equipment to characterize compounds created during electrochemical reactions of urea, a substance found in urine. He hopes to discover useful chemicals. He thinks the experiments have yielded one potential surface-active compound, but more research is needed to pinpoint what it is and how it could be used.
Brown followed a roundabout path to Dr. Baricuatro’s lab. A professional beer brewer, he decided to return to college and earn a bachelor’s degree in chemistry after leaving Great Raft Brewing in Shreveport. Besides conducting research on campus, he does water analysis for the LSU AgCenter as a student worker.
He graduated with an American Chemical Society-certified bachelor’s degree in chemistry in December.
“I’ve narrowed my focus to working with water chemistry, but that’s a lot of career options,” Brown said, laughing. “Ideally I’d like to continue and expand my work with the AgCenter.”
Brown praised Dr. Baricuatro’s mentorship, saying he’s always available to offer guidance and help – even when things don’t go as expected.
“I allow my students to fail in their research projects,” Dr. Baricuatro said. “Science is not always going to be positive results, but I teach my students, ‘You are always equipped with what to do next’.”
