Sánchez Olga, Mas Jordi
Microbiology (Reading). 1999 Apr;145 ( Pt 4):827-833. doi: 10.1099/13500872-145-4-827.
Continuous cultures of Chromatium vinosum DSM 185 were shifted from a high to a low irradiance (67 to 4 microE m(-2) s(-1)) and vice versa (4 to 67 microE m(-2) s(-1)). The kinetics of photoacclimation of the cultures were analysed during these transitions until steady state was reached. When irradiance was shifted from 4 to 67 microE m(-2) s(-1), bacteriochlorophyll synthesis halted for 4 h. During this period, pigments were progressively diluted in the newly formed biomass, resulting in a lower specific pigment content. The specific growth rate of the organisms did not change immediately after the shift, but rather underwent a gradual increase during the following 10 h. This transition was accompanied by a transient increase in the levels of glycogen, indicating that CO2 fixation rates increased immediately after the shift, and that unused photosynthate was stored as glycogen. The shift from a high to a low irradiance was characterized by an immediate drop in the specific growth rate to virtually zero, and by comparatively sharp decreases in the specific rates of sulfur and sulfide oxidation and in the specific rate of glycogen accumulation. The specific content of bacteriochlorophyll a increased during the first 10 h. During the same period the specific content of glycogen decreased.
对嗜硫色杆菌DSM 185的连续培养物进行光照强度转换，从高光照强度（67微爱因斯坦·米⁻²·秒⁻¹）转换到低光照强度（4微爱因斯坦·米⁻²·秒⁻¹），反之亦然（从4微爱因斯坦·米⁻²·秒⁻¹转换到67微爱因斯坦·米⁻²·秒⁻¹）。在这些转换过程中分析培养物的光适应动力学，直至达到稳态。当光照强度从4微爱因斯坦·米⁻²·秒⁻¹转换到67微爱因斯坦·米⁻²·秒⁻¹时，细菌叶绿素合成停止4小时。在此期间，色素在新形成的生物量中逐渐稀释，导致特定色素含量降低。光照强度转换后，生物体的比生长速率并没有立即改变，而是在接下来的10小时内逐渐增加。这种转换伴随着糖原水平的短暂升高，这表明光照强度转换后二氧化碳固定速率立即增加，未使用的光合产物以糖原形式储存。从高光照强度转换到低光照强度的特征是比生长速率立即降至几乎为零，以及硫和硫化物氧化的比速率以及糖原积累的比速率相对急剧下降。细菌叶绿素a的特定含量在最初10小时内增加。在同一时期，糖原的特定含量下降。
