Environmental factors affecting the beta-carotene content in Spirulina platensis
Aran Incharoensakdi, Chulalongkorn Univ., Bangkok (Thailand). Faculty of Science. Dept. of Biochemistry
Spirulina platensis was grown in a normal Zarrouk medium. The effect of various environmental factors on the beta-carotene content in S. platensis was investigated. The initial pH of the medium in the range 8.0-11.0 did not affect bata-carotene content although the growth of the cells was retarded at pH 10.5 and 11.0. The temperature during growth of the cells higher than 35 deg C caused at drop in beta-carotene content. Increased light intensity up to 10,000 lux resulted in an increased beta-carotene content. When the cells were grown under red light illumination, beta-carotene content was highest followed by that under blue light and white light respectively. Nitrate deficiency in the growth medium did not appear to cause an increase in beta-carotene content The influence of the salinity of the medium was also studied. It was found that beta-carotene content was increased with increasing NaCl in the medium. However, a drastic rise in beta-carotene content could be obtained by either growing the cells initially in the medium containing 20g/l NaCl and then transferring the cells to the new medium with 30g/l NaCl or initially acclimating the cells in the medium with 40 g/l NaCl and then transferring the cells to the new medium containing the same content of NaCl at 40g/l.
显示更多 [+] 显示较少 [-]