绿藻分批培养过程中细胞大小及密度与生物质干重的关系研究

Studies of the relationship between the changes of cell size,cell density and biomass dry weight of three green algae during batch culture

研究了3种常见绿藻在分批培养过程中细胞密度、细胞大小和生物质干重的变化,定量分析细胞大小与生物质干重的关系。分析表明,在培养前期细胞密度增加和体积增大共同影响干重,在培养后期细胞密度不再增加,细胞体积增大成为影响生物质干重的主要因素。细胞大小不仅影响生物质干重,还影响生物质干重与光密度的比值(DW/OD):对于同一种微藻,随着培养时间的延长,细胞增大,DW/OD上升;对于不同微藻,细胞越大,DW/OD越高。对于分批培养,无论是OD值还是细胞密度的变化都不能准确反映微藻的生长,只有利用干重变化计算生物质比增长速率是适用的。与比生长速率相比,生物质比增长速率反映藻细胞的生产特性,更适合于在微藻的生产中应用。

To investigate the proper method for determination and calculation of microalgal growth in batch culture,the changes of cell density,cell size and biomass dry weight during culture were determined,and the relationship between cell size and biomass dry weight was quantitative analyzed by using three familiar green microalgae. The analysis of relationship between cell size,cell density and biomass dry weight demonstrated that the biomass dry weight of microalgae were affected by the changes of both cell size and density in the early stage of culture, and in the later stage of culture,the biomass dry weight was mainly affected by the changes of cell size. Not only the biomass dry weight,but also the ratio of biomass dry weight to optical density（DW/OD） was affected by the cell size. For the same algae,DW/OD rose with the increase of cell size,for different algae, the larger the cell was,the higher the ratio of DW/OD was. The larger ratio of DW/OD implied more biomass dry weight for the same changes of OD value.For batch culture, neither the changes of OD values nor the changes of cell densities could accurately reflect the growth of microalgae,only the specific biomass growth rate based on the changes of biomass dry weight is applicable. Compared to the specific growth rate which reflects the growth characters of microalgae,the specific biomass growth rate reflects the production characters of microalgae,and it is more applicative in mass production of microalgae.