Development and application of a method for determination of activity and vitality of Hansenula polymorpha by carboxyfluorescein diacetate-propidium iodide dua fluorescent staining / 中国生物制品学杂志

ABSTRACT

@#Objective To develop a method for determination of activity and viability of Hansenula polymorpha by dual fluorescent staining with carboxyfluorescein diacetate(CFDA)and propidium iodide(PI).Methods The time durations(5,10,20,40,60 and 120 min for CFDA,5,10,15,20 and 25 min for PI)and working solution concentrations(50,100,200and 300 μg for CFDA,2,10,20 and 30 μmol/L for PI)for the dual fluorescent staining were optimized by single factor test. Under the optimal condition,the H.polymorpha samples at theoretical survival rates of 0,25%,50%,75% and 100%were determined,of which the fluorescent intensity was observed under fluorescent microscope,and the gray value was analyzed by ImageJ software. The live and dead cells were counted,based on which the actual survival and death rates were calculated. Meanwhile,the relationships of actual gray value,actual survival rate and actual death rate to the corresponding theoretical values were analyzed. Activity and viability of three batches of cultured H.polymorpha were detected by CFDA-PI dual fluorescence staining.Results The optimal time durations for staining with CFDA and PI were 60 and 5 min,while the optimal working solution concentrations were 200 and 2 μmol/L,respectively. The actual gray value,actual survival rate and actual death rate of H.polymorpha samples at various theoretical survival rates were significantly correlated to the corresponding theoretical values(R~2=0. 998 3～0. 999 2,P < 0. 05). The CVs of activity and viability values in three detections of three batches of H.polymorpha culture were 3. 20%～4. 03% and 1. 10%～2. 27%, respectively.Conclusion The CFDA-PI dual fluorescent staining was successfully developed,which may be used for determination of activity and vitality of H.polymorpha.