Chlorophyllase activity in kirchneriella lunaris cultures grown under salinity or salinity-calcium interactions

Abstract EN

Kirchneriella lunaris was grown under salinity stress and supplemental Ca2+.

Growth rate was inhibited by NaCl-salinity.

In Ca2+- containing cultures K.

lunaris exhibited higher rates of growth and pigment fractions than in those containing NaCl alone.

In Kirchneriella cultures grown for 7 days in successively increasing levels of NaCl salinity, chlorophyllase exhibited an enhanced activity by salinity stress.

Addition of Ca2+ in the growth media obviously retarded the enzyme activity.

The enzyme protein content of K.

lunaris cultures was increased by salinity stress.

Supplemental Ca2+ significantly lowered the enzyme protein contents of algal cultures.

In both levels of NaCl 120 mM and 300 mM, the enzyme activity, indicated by dephytylation of chlorophylls, was recorded to be the highest.

Upon addition of Ca2+ to algal cultures the enzyme activity was generally lowered.

The V max value of K.

lunaris cultures was relatively lowered by high salinity and further decreased upon inclusion of Ca2+ compared with low salinity.

Also, the Km value was the highest (lowest affinity) at high salinity while lowest (high affinity) at low salinity.

At Na+-Ca2+ combinations the Km value was the highest (lowest affinity) at low and high salinity.