<i>Bacillus amyloliquefaciens</i> application to prevent biofilms in reclaimed water microirrigation systems*
Jiaxin Wen, Yang Xiao, Peng Song, Bo Sun, Tahir Muhammad, Lianghe Ma, An Waier Aosiman, Yunkai Li
Abstract
Abstract Reclaimed water (RW) applied in drip irrigation systems could be a solution to cope with the challenges of limited freshwater resources. Biofilm growth in irrigation systems is an unavoidable issue when using RW. To date, strong chemical bactericides mostly dominate the commercial market in controlling biofilms. However, recently scientists have been concerned about their real efficacy and environmental risks. This study assesses a low‐concentration microbial antagonist (i.e., Bacillus amyloliquefaciens inoculums, BAI) intermittently injected into the systems to mitigate biofilm formation in three types of drip emitters using two kinds of treated RW. The results indicated that the application of BAI significantly ( p < .05) mitigated the microbial biomass within biofilms when compared with the control groups (no‐BAI). In addition, BAI reduced the contents of extracellular polysaccharides and proteins of biofilms, which decreased the total biomass in BAI treatments by 44.9%–73.8%. Consequently, BAI effectively improved the emitter performances and increased the discharge variation rate by 31.9%–44.3%. These findings might provide a new perspective to control biofouling when applying RW in irrigation systems, with potential implications for sustainable water management in agricultural production.