Enhancement of algicidal properties of immobilized Bacillus methylotrophicus ZJU by coating with magnetic Fe₃O₄ nanoparticles and wheat bran.
Algicidal bacteria offer a promising option for killing cyanobacteria. In this study, a newly isolated strain of Bacillus methylotrophicus, ZJU, was used to control Microcystis aeruginosa. Analyses of relative reactive oxygen level, malondialdehyde content, superoxide dismutase activity, and fluorescence staining indicated that oxidative damage caused by the algicidal supernatant of strain ZJU mainly affected the cell membrane and consequently the membrane permeability and membrane potential of M. aeruginosa cells. Furthermore, an embedded immobilization technique was employed to improve the practical application of strain ZJU as an algicidal agent. On this basis, we proposed a novel concept of enhancing the algicidal properties of immobilized ZJU by adding Fe3O4 nanoparticles and wheat bran in the process of immobilization. Our studies showed that Fe3O4 nanoparticles conferred the immobilized bacteria with a magnetization of 30.87 emu/g, and this magnetization enabled efficient re-collection of the immobilized bacteria by magnetic means. Moreover, wheat bran endowed the immobilized bacteria with 10.34% higher algicidal activity than immobilized bacteria without wheat bran. The results indicate a novel concept of enhancing the algicidal property of bacteria against M. aeruginosa by adding Fe3O4 nanoparticles and wheat bran.
College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
Pengfei
P
Sun
College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
Cai
C
Hui
College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
Sheng
S
Wang
College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
Rashid Azim
RA
Khan
College of Environmental and Resource Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China.
Qichun
Q
Zhang
College of Life Sciences, Zhejiang University, 310058 Hangzhou, Zhejiang, PR China. Electronic address: yhzhao225@zju.edu.cn.
Yu-Hua
YH
Zhao
D001407:Bacillus / Q000235:genetics / Q000302:isolation & purification; D061046:Biological Control Agents; D018914:Cells, Immobilized; D000460:Chlorophyta; D004269:DNA, Bacterial / Q000235:genetics; D004043:Dietary Fiber; D058185:Magnetite Nanoparticles; D008315:Malondialdehyde / Q000378:metabolism; D046931:Microcystis; D017382:Reactive Oxygen Species / Q000378:metabolism; D017422:Sequence Analysis, DNA; D013482:Superoxide Dismutase / Q000378:metabolism
D061046:Biological Control Agents; D004269:DNA, Bacterial; D004043:Dietary Fiber; D058185:Magnetite Nanoparticles; D017382:Reactive Oxygen Species; D008315:Malondialdehyde; D013482:Superoxide Dismutase
Algicidal mechanism; Bacillus methylotrophicus; Fe(3)O(4) nanoparticles; Microcystis aeruginosa; Wheat bran