Biotechnology Bulletin ›› 2020, Vol. 36 ›› Issue (11): 55-62.doi: 10.13560/j.cnki.biotech.bull.1985.2020-0394

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Isolation and Identification of an Algicidal Bacterium CBA02 and Its Algae-lysing Characteristics

YANG Bing-jie1,2(), XIANG Wen-zhou1,3, JIN Xue-Jie1, CHEN Zi-shuo1,2, WANG Ling1,2, WU Hou-bo1,3()   

  1. 1. Key Laboratory of Tropical Marine Bio-resources and Ecology,South China Sea Institute of Oceanology,Chinese Academy of Sciences,Guangzhou 510301
    2. University of Chinese Academy of Sciences,Beijing 100049
    3. Southern Marine Science and Engineering Guangdong Laboratory,Guangzhou 510301
  • Received:2020-04-08 Online:2020-11-26 Published:2020-11-20
  • Contact: WU Hou-bo E-mail:ybj125660@163.com;wuhoubo@scsio.ac.cn

Abstract:

Microalgae is susceptible to be contaminated by algae-lysing microorganisms in large-scale culture. This work aims to isolate and identify an algae-lysing bacterial strain CBA02,and to study its algae-lysing effect and mechanism. The 2216E plate method was used to isolate and purify this strain,and 16S rDNA sequences to identify the strain. The algae-lysing characteristics and approaches were determined using Dunaliella salina. The strain CBA02 was identified as Ponticoccus sp. CBA02 by 16S rDNA sequences. The algicidal efficiency of CBA02 to D. salina increased with the increasing of the fermentation time and the dose of bacterial solution,while decreased with the increasing of the initial concentration of algae. The concentration of chlorophyll a of D. salina significantly decreased in the group of bacterial solution,cell-free supernatant and high-temperature treated cell-free supernatant(P<0.05). The algicidal efficiency of the cell-free supernatant after pH treatment increased with the increasing of pH. The strain Ponticoccus sp. CBA02 presented a strong algicidal effect on D. salina,and its algicidal effect was influenced by fermentation time of bacterial solution,the dose of bacterial solution,initial concentration of algal cells and pH. CBA02 indirectly causes the lysis of D. salina by releasing water-soluble algicidal substances which have thermal stability and suitable for high pH.

Key words: algicidal bacteria, microalgae cultivation, Dunaliella salina, algae-lytic characteristics, algicidal substance