2.1. Microalgae and culture conditions
The marine microalga Chlorella sp. was gifted from the
Institute of Oceanology, Chinese Academy of Sciences. For
inoculation, 1 ml culture in the exponential growth phase
was transferred into 50 ml artificial seawater [10], which
contained initially different concentration of sodium thiosulphate
and glucose, as described in Table 1. Cells were
grown at 22 8C and with continuous light (70 mE m2 s1)
by shaking at 135 rpm on an orbital shaker in a culture
chamber (Cabinet Model RXZ 300B; Jiangnan Instrument
Factory, Ningbo, China).