The Preparation For Axenic Green Algae And Research On The Physiological Property Of The Axenic Green Algae

Green algae is photosynthetic eukaryotic organism,it has a fast reproduction rate,short growth cycle and high energy conversion rate,a variety of high value-added products and high application value.No bacteria strain is the basis of biological engineering research.This paper include the preparation for axenic green algae and research the suitable culture condition and physiological property of it.1.Determine the process of the preparation for axenic green algae.According to the green algae situation in liquid medium and solid:Firstly,used antifungal drugs?concentration is 1.5 mg/mL clotrimazole?to remove fungus pollution;Then used physical methods such as direct filtration and dilute to remove suspended bacteria;Bacterial adhere on algae is not easy to removed and used the surfactant?polysorbate 80?and ultrasonic broken auxiliary to scattered miscellaneous adhesion;Finally,used disinfectant?sodium hypochlorite?1 mL of0.10%sodium hypochlorite solution added to the 5 mL of algal suspension liquid of processed 5 min and successed.2.Determine the appropriate culture condition of the axenic alage.Through selected the most appropriate media,pH,C,N,P sources.The experiment results show that:The most appropriate medium is BBM medium and organic material will makes the algae gathered into cluster and unfavorable to growth;Na2CO3 and NaHCO3 can promote the growth of alage and the concentration of NaHCO₃ is 0.2 g/L.The most appropriate of pH is 8;Nitrate is better than the ammonium salt and the concentration is 300 mg/L;the effects of P source is not obvious and have no regularity.3.Research on the physiological characteristics of the axenic algae.Determined the growth parameters such as the absorbance,wet weight,pH,dry weight of the above obtained axenic algae regularly.The experiment results show that:absorbance,wet weight,dry weight,pH have same change trend over time and nitrogen content is opposite,r_max=0.03024 g/L·d,?_max=0.01416 d^-1,Ks=110.55 mg/L,td=2.04 h;Absorbance and dry weight has a good linear relationship and the linear equation is Y=0.00413X-4.219×10^-4;Through the determination of parameters before and after the preparation for the axenic know that the absorbance changed no regularity and pH decrescent.