Carbonic anhydrase(CA)was considered to be an important component of carbon concentrating mechanism(CCM)of algae.It was an inducible enzyme.Environmental factors,especially dissolved inorganic carbon and pH,were known...Carbonic anhydrase(CA)was considered to be an important component of carbon concentrating mechanism(CCM)of algae.It was an inducible enzyme.Environmental factors,especially dissolved inorganic carbon and pH,were known to affect CA activity.Effects of inorganic carbon(CO_(2)and HCO_(3)^(-))and pH on CA activity of gametophytes of Saccharina japonica were evaluated in this study.Under high-CO_(2)condition(3%CO_(2)),the activity of external CA(C_(Aext))was significantly decreased(P<0.05)from 33.92 REA/g FW to 27.69 REA/g FW.In contrast,the internal CA(CA_(int))and total CA activities were elevated significantly(p<0.01)from 36.83 REA/g FW to 48.80 REA/g FW,and from 70.75 REA/g FW to 76.49 REA/g FW,respectively.Addition of an appropriate concentration of HCO_(3)^(-)to the medium,CA_(int)and total CA activities were promoted significantly,although the activity of C_(Aext)was inhibited significantly(P<0.05).In higher HCO_(3)^(-)concentration(up to 1680 mg/L),the activity of CA_(int)was promoted to 60.81REA/g FW,which was twice that of the control.Higher activities of CA_(int)and total CA were induced at low pH.At pH 6.0,the highest activities of CA_(int)(110.85 REA/g FW)and total CA(128.17 REA/g FW)were induced.However,at pH 9.0,the activities of CA_(int)and total CA were reduced to the lowest of 23.31REA/g FW and 42.19 REA/g FW,respectively.This is the first report about the successful detection of C_(Aext)activity of gametophytes of S.japonica.The results would provide data for the analysis of Ci acquisition and transport mechanism in S.japonica gametophytes.展开更多
基金This research was supported by the National Key R&D Program of China(Grant No.2018YFD0901500)the National Natural Science Foundation of China(Grant No.41376136)the Double First-Class Discipline of Fisheries Science of China.
文摘Carbonic anhydrase(CA)was considered to be an important component of carbon concentrating mechanism(CCM)of algae.It was an inducible enzyme.Environmental factors,especially dissolved inorganic carbon and pH,were known to affect CA activity.Effects of inorganic carbon(CO_(2)and HCO_(3)^(-))and pH on CA activity of gametophytes of Saccharina japonica were evaluated in this study.Under high-CO_(2)condition(3%CO_(2)),the activity of external CA(C_(Aext))was significantly decreased(P<0.05)from 33.92 REA/g FW to 27.69 REA/g FW.In contrast,the internal CA(CA_(int))and total CA activities were elevated significantly(p<0.01)from 36.83 REA/g FW to 48.80 REA/g FW,and from 70.75 REA/g FW to 76.49 REA/g FW,respectively.Addition of an appropriate concentration of HCO_(3)^(-)to the medium,CA_(int)and total CA activities were promoted significantly,although the activity of C_(Aext)was inhibited significantly(P<0.05).In higher HCO_(3)^(-)concentration(up to 1680 mg/L),the activity of CA_(int)was promoted to 60.81REA/g FW,which was twice that of the control.Higher activities of CA_(int)and total CA were induced at low pH.At pH 6.0,the highest activities of CA_(int)(110.85 REA/g FW)and total CA(128.17 REA/g FW)were induced.However,at pH 9.0,the activities of CA_(int)and total CA were reduced to the lowest of 23.31REA/g FW and 42.19 REA/g FW,respectively.This is the first report about the successful detection of C_(Aext)activity of gametophytes of S.japonica.The results would provide data for the analysis of Ci acquisition and transport mechanism in S.japonica gametophytes.
