Effects of temperature, salinity and light intensity on the growth, pigment and carrageenan of Betaphycus gelatinum
Zhu, Jun; Fang, Zhe; Liu, Min; Liang, Lei; Huang, Huiqin; Zou, Xiaoxiao; Lin, Xiangzhi; Bao, Shixiang
The red alga Betaphycus gelatinum is an important source for the extraction of both carrageenan and pigments, which are important industrial materials applied in many fields. However, the declined wild stock and low cultivation yield fail to meet the increasing demand for B. gelatinum. In order to increase the yield, it is essential to understand the environmental factors for growth of B. gelatinum. In this study, effects of temperature, salinity, and light intensity on growth, carrageenan and pigment of B. gelatinum were investigated. Our results showed that the growth rate and contents of both pigment and carrageenan shared a similar trend after temperature treatments. 27°C was found to be the suitable temperature for the highest growth rate and the highest contents of chlorophyll a, phycocyanin (PC), allophycocyanin (APC) and phycoerythrin (PE), respectively, while incubation at 30°C resulted the highest amounts of carrageenan. With respect to salinity, 30 ‰, 34 ‰, 32 ‰, 32 ‰, 26 ‰ and 32 ‰ were the best conditions for growth rate, as well as for contents of chlorophyll a, PC, APC, PE and carrageenan respectively. The suitable light intensities for growth rate, chlorophyll a, PC, APC, PE and carrageenan were 60, 40, 10, 10, 10 and 100 μmol photons·m-2·s-1, respectively. These results indicate that environmental factors do have effects on the growth and the contents of carrageenan and pigment of B. gelatinum.