This study evaluated a potential sterilization process that uses calcium hypochlorite (Ca(ClO)2) as a disinfectant and hydrogen peroxide (H2O2) as a neutralizing agent for monoculture processes of microalgae (Nannochloropsis oculata). The results showed that no contaminants (prokaryote) were present when the Ca(ClO)2 concentration was greater than 0.010%. The use of an equivalent amount of H2O2 completely neutralized Ca(ClO)2 and had an additional bactericidal effect because of the formation of singlet oxygen. No substantial difference was observed in the biomass accumulation and chlorophyll contents compared to those in cultures sterilized using conventional physical methods such as autoclaving. Therefore, chemical sterilization using Ca(ClO)2 and H2O2 has an excellent economic advantage, and we expect the proposed ecofriendly chemical sterilization method to become a critical culture technology for microalgae-related industrialization.

Introduction
Material and Methods
    1. Isolation of bacteria from seawater
    2. Determination of bacterial disinfection by Ca(ClO)2
    3. Monitoring degradation of Ca(ClO)2
    4. Cultivation of N. oculata UTEX 216 after directdecomposition of Ca(ClO)2
    5. Cellular growth and pigment measurements
Results and Discussion
    1. Identification of contaminants
    2. Sterilization of medium with Ca(ClO)2 anddecomposition of Ca(ClO)2 by reaction with H2O2
    3. Chemical reaction of Ca(ClO)2 with equivalentH2O2
    4. N. oculata cultivation by chemical sterilization process
Acknowledgements

• Joo Young Jung(Division of Applied Life Sciences (BK21) Research Professor, Gyeongsang National University, Jinju 52828, Korea)
• Chang Su Lee(Division of Applied Life Sciences (BK21) Research Professor, Gyeongsang National University, Jinju 52828, Korea)
• Gyeong In Lee(Division of Applied Life Sciences (BK21) Master, Gyeongsang National University, Jinju 52828, Korea)
• Jong Hee Kwon(Department of Food Science & Technology Professor, and Institute of Agriculture & Life Science Senior Researcher, Division of Applied Life Sciences (BK21) Professor, Gyeongsang National University, Jinju 52828, Korea) Corresponding author