Arizona State research team to fight algae contamination

The number one challenge the emerging algae industry faces today, according to Arizona State University professor Qiang Hu, is algal culture protection. Hu recently received a $1 million, five-year grant from the USDA to study how, why, when and where bugs like zooplankton can negatively affect or contaminate an algae culture. He spoke with Biorefining Magazine on why the issue is so important to the industry. “Basically, when you build them, they (the bugs) will come,” he said on algae research efforts that involve small- to even large-scale culture ponds or bioreactors.

As Hu describes it, a typical algal culture that is green in appearance and features green-colored water can be ruined in a few days or weeks if contaminated, turning into a black or dark brown mass, until there is only water left. “This,” he said, “is an absolutely serious growth block for the algae industry,” one that is often ignored because most research efforts are so small that when a contamination occurs, the water is disposed of and the culture starts new—something that would not work in large-scale production, Hu said. “Without solving this problem, you won’t have an industry for biofuels,” he said. “For high-valued products, it’s a different story because you are dealing with smaller quantities.”

The type of open pond used, bioreactor, geographic location or algae strain doesn’t matter, Hu said, as all will eventually be effected by outside contaminants like zooplankton or fungi. “We are trying to figure out why they come,” he said on his research effort, adding that within the algae development landscape the issue of algal culture crashes, as he calls them, is something “many companies don’t tell you.” But he also said his team is not smarter than other teams working on algae, but rather, it just has a vast amount of work and experience at one of the premier algae research centers in the country at ASU.

To fight against contamination, Hu and his team will employ two main methods. First, Hu said, “you have to identify what the bugs are, and it is not simple.” To do that, his team will use a bioimaging system of any bugs that show up in a culture and compare those images with a software program that contains a database of bug images like zooplankton. In addition to the imaging, they will also test the DNA fingerprints left on the algae by comparing the entire DNA with the general signature DNA of the similar bugs to see if there is a match. “This enables us to develop an early warn system and find a problem before a disaster occurs,” Hu said.

Being able to identify the problem before it gets out of hand will also do two things. It will allow his team to achieve the goal set forth in the grant’s mission to create a “best management practices” plan that could be made available to the industry. Also, in order to treat the bugs, the team will not only test on-the-shelf chemicals used as pesticides or herbicides in the agricultural sector, but the team will also look to create new chemicals “specifically for algae,” he said. There are at this point some chemicals he thinks would work, but nothing that has been significantly tested.

The research efforts will take place over the next five years, but Hu, who has been researching algae for the past 20 years, said that just like crop protection research on modern day agricultural crops, “this research,” he said on the subject of algae, “will never stop.”