Journal of Applied Phycology

, Volume 14, Issue 5, pp 385–390 | Cite as

A procedure for axenic isolation of the marine microalga Isochrysis galbana from heavily contaminated mass cultures

  • Ji-Young Cho
  • Jae-Suk Choi
  • In-Soo Kong
  • Soo-Il Park
  • Russell G. Kerr
  • Yong-Ki Hong


Isochrysis galbana, one of the most widely usedmarine microalgae in the rearing of finfish and shellfish larvae, is masscultured frequently in outdoor tanks. Under prolonged and repeated culture,severe contamination occurs. Axenic isolation of I.galbanafrom such cultures was best achieved by using a ternary procedure involvingpercoll-gradient centrifugation, treatment with antibiotics, and growth on agarmedium. Protozoa and other algae were removed most effectively by isolation ofI. galbana at the 30–40% density layer on apercoll-gradient. Removal of bacteria was accomplished using a mixture of 5antibiotics (250 μg mL−1 ampicillin, 50μg mL−1 gentamycin, 100 μgmL−1 kanamycin, 500 μgmL−1 neomycin, 50 μgmL−1 streptomycin). Axenic colonies were isolated fromasolid medium prepared from 1% purified agar. The ternary procedure isconsideredapplicable to the isolation of other axenic single-celled microalgae fromheavily contaminated cultures.

Antibiotics Axenic isolation Gelling agent Isochrysis galbana Microalgae Percoll 


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Copyright information

© Kluwer Academic Publishers 2002

Authors and Affiliations

  • Ji-Young Cho
    • 1
  • Jae-Suk Choi
    • 1
  • In-Soo Kong
    • 1
  • Soo-Il Park
    • 2
  • Russell G. Kerr
    • 3
  • Yong-Ki Hong
    • 1
  1. 1.Department of BiotechnologyPukyong National UniversityNamkuKorea
  2. 2.Department of Aquatic Life MedicinePukyong National UniversityNamkuKorea
  3. 3.Department of Chemistry and Biochemistry, Center for Molecular Biology and BiotechnologyFlorida Atlantic UniversityBoca RatonUSA

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