中文摘要：

发菜是一种陆生性蓝细菌,具有很好的经济和药用价值。发菜细胞可进行液体培养,光是其生长的限制因子。为了解光对发菜细胞液体培养生长的影响,研究了发菜细胞混合营养及自养过程中的光衰减规律。结果表明,Lambert-Beer’s定律可较好地描述细胞浓度及光程对发菜细胞光衰减的影响,回归得到发菜细胞在自养和混合营养培养液中的光衰减方程。随着发菜细胞密度的增加,两种培养体系透过发菜细胞液的光强在不断减少,特别是随着光程的增加,光衰减速度加快。当发菜细胞密度和入射光强相同时,光在光合自养培养的细胞液中比混合营养细胞液中衰减速度快。当初始入射光强为48.73μmol/m2·s时,在发菜细胞密度0.7715 g/L,光程2 cm处光合自养培养和混合营养培养液的透射光强分别为28.35、30.17μmol/m2·s。

英文摘要：

Nostoc flagelliforme is an edible terrestrial cyanobacterium with great economic and medicinal value.In liquid suspension culture,light is a limiting factor affecting N.flagelliforme cells growth.Light attenuations of N.flagelliforme cells in the mixotrophic and photoautotrophic cultivation were investigated in order to understand the effects of light on N.flagelliforme cells growth in liquid suspension culture.The results showed that the adapted Lambert-Beer＇s law could well simulate the influences of optical length and cell concentration on light attenuation,and the light attenuation equations of N.flagelliforme cells were established in photoautotrophic and mixotrophic cultivation,respectively.While the concentration of N.flagelliforme cellsdensity increased,light intensity obtained through N.flagelliforme cellsdeclined in the two culture systems.Especially,with the increase of optical length,the speed of light attenuation quickened evidently.When the biomass and incident light intensity were identical,the light attenuation inside photoautotrophic culture was faster than that in mixotrophic culture.For example,when the incident light intensity was 48.73 μmol/m2·s,the celldry weight of N.flagelliforme cells was 0.7715 g/L,the transmitted light intensity inside photoautotrophic culture and mixotrophic culture was28.35 μmol/m2·s and 30.17 μmol/m2·s at optical length of 2 cm,respectively.