Study On Several Oxidoreductase Of Spirulina (Arthrospira) Under Low Temperature Stress

Spirulina is a group of autotrophic prokaryote, which has existed on the earth for 35 hundred million years. Spirulina platensis(S2)in Chad lake in Africa and Spirulina maxima(S3)in Sosa Texcoco lake in Mexico are mainly in industrialization at present. These two Spirulinas grow well in high temperature of 28~35℃. In 1996 Spirulina platensis(S1) bloom was found in the alkaline lake of Erdos plateau. Spirulina platensis was reported that its growth temperature ranged from 4 to 40℃, and its optical growth temperature was 24℃, which could be the important Spirulina strain resource for the industrialization in the north of China.In this paper, the enzyme activity of six oxidoreductases was determined using Spirulina as materials, after being low temperature treated under different temperature and time; and four isoenzymes of LDH,MDH,GR and SOD were extracted using PEGE. The reaction to the low temperature of six oxidoreductases of Spirulinas of different strains and in different species from middle latitude and low latitude was compared to study the low temperature reaction mechanism of Spirulina S1 from the alkaline lake of Erdos plateau, to enrich and improve the anti-physiological research content of Spirulina S1 from the alkaline lake of Erdos plateau, and to offer the usable low and wide temperature Spirulina strain resource for the broadening of the cultivation areas and seasons in Spirulina industrialization.The results showed that the enzyme activity of LDH,MDH,GR,APX and SOD showed increasing first and then decreasing trend with the drop of the temperature in the period of direct low temperature stress and the turning point was mostly at 5℃or 10℃; CAT activity also decreased. With the drop of the temperature and the prolonging of treatment time, all of the enzyme activity of six oxidoreductases of Spirulina S1 from the alkaline lake of Erdos plateau were higher than that of exotic species S2 and S3; with the drop of temperature intensified, the decrease degree of the enzyme activity of S1 was less than exotic species, which showed that the cold resistance of Spirulina S1 from the alkaline lake of Erdos plateau was stronger than that of the exotic species.No new induced isoenzyme band was produced after LDH being low temperature stressed; a few new induced isoenzyme bands of SOD were produced under some individual temperatutes; and low temperature could induce new isoenzyme bands of MDH and GR to be expressed. Especially being pretreated with low temperature and ABA, the express quantity of MDH and GR increased obviously and higher than exotic species.After low temperature acclimation or ABA pretreatment, the enzyme activity of LDH,MDH,GR,CAT and SOD was dramatically enhanced than that being direct low temperature treated, however the enzyme activity of few exotic species was enhanced. It indicated that low temperature acclimation and ABA pretreatment of Spirulina could enhance its low temperature adaptability, especially for S1 from the alkaline lake of Erdos plateau compared with cold sensitive exotic species.The enzyme activity of six oxidoreductases of three samples after being pretreated with ABA was enhanced compared with that after being pretreated with direct low temperature, exceptionally LDH of S2 in two treatments had significant difference and that of S1 and S3 had extremely significant difference. In the aspect of SOD, only that of S2 had significant difference. These indicated that ABA pretreatment could enhance Spirulina cold resistance more than low temperature acclimation, but varied on different enzymes and most enzymes in the two treatments had little difference.