Primary Studies On The Effect Of Temperature On The Growth And Stress Temperature Induced Proteins In Spirulina

In this paper we studied the effect of different temperatures on the growth, protein content and protein species of three Spirulina species which were the only three species cultivated for food in the world, with the purpose of providing basic data for Spirulina cultivation and improvement. The results are listed below.(1)Under constant temperature, 12-hour-light/12-hour-dark photoperiod with photo flux density 180μmol·m^-2·s^-1, optimal growth temperature is verified for the three species: 20 to 35℃for Spirulina innermongoliansis, 20 to 30℃for S. platensis and 25 to 35℃for S. maxima. Their resistance to low temperature above 0℃and also to high temperature is: S. innermongoliansis > S. maxima > S. platensis.(2)The extreme living temperatures of the three species are dependent on the lasting time of the temperatures. The extreme low temperature for the three species is: -7℃lasting 36h or -18℃lasting 12h for S. innermongoliansis, -18℃lasting 18h for S. platensis, and -7℃lasting 36h or -18℃lasting 12h for S. maxima. Their extreme high temperatures for the three species are all 60℃lasting 10min. With the stress time going on, their extreme low temperatures will rise and extreme high temperatures will go down.(3)For the three species tested, the effect of temperature on their protein content is significantly different. At the first 24 hours, S. innermongoliansis tends to accumulate more protein at higher temperature (40℃), while S. platensis is just opposite, and S. maxima accumulates more protein at its optimal temperature. But longer time (96h) of stress temperatures can cause the decrease of protein content. The effect of stress temperatures on protein content of S. platensis and S. maxima is more severe than for S. innermongoliansis. Long-time (96h) constant temperature, even though it is not stress temperature, is not good for the accumulation of protein in Spirulina.(4)New proteins are detected at low and high temperature stress for the three species. Under low or high temperature stress, change of non-denatured protein profiles of the three is different between species, and their new peptides are different in the number, lasting time in cells and molecular weights between species, too. A certain correlation exists between the chill resistance of Spirulina and the molecular weight, lasting time of low-temperature-induced peptides: species with steady and higher molecular-weight low-temperature-induced polypeptides tends to show higher tolerance to low temperature. A certain correlation exists between the heat resistance of Spirulina and the molecular...