Hiroshima Prefectural Food Technical Center, 12-70 Hijijama Hon-machi, Minami-ku, Hiroshima 730, Japan.
Biotechnol Bioeng. 1990 Jun 20;36(2):198-206. doi: 10.1002/bit.260360212.
The energy of the total transmitted light was subtracted from that of the incident light in a culture vessel and the difference was divided by the weight of cells. The value thus obtained was defined as the amount, E(x), of light energy absorbed per unit cell weight per unit time.Batch and continuous cultures of Chlorella vulgaris were carried out at 30 degrees C in the pH range of 6.4-6.7 while restricting illumination. Next the specific growth rate, mu, in the batch culture and the fixed dilution rate, D, in the continuous culture were plotted against E(x). The results showed that the relation between D and E(x) can be expressed in a Michaelis-Menten equation, where the maximal specific growth rate is 0.24 h (-1) and the saturation constant is 6.58 kcal/g . h.Cell concentration calculated by substituting the apparent concentration, X(e), of incubated cells and the apparent maintenance constant, M(e), for this equation agreed with that observed in almost all growth phases. Furthermore, from the change of chlorophyll productivity and the relationship between D and E(x) expressed in this equation, it is assumed that E(x) involves the light energy directly utilized in photosynthesis in the cells and that which is converted into, e.g., heat. This equation also indicated that a maximum in the growth yield existed. Then the growth yield of 0.029 g/kcal obtained at the incident light of 1.46 or 2.63 cal/cm(2) . h was maximum (maximal conversion efficiency of light energy, 15.6%).These results indicate that this method of deriving the equation for the growth rate from this study is a useful procedure for obtaining bioengineering findings.
在培养容器中，从总透射光的能量中减去入射光的能量，然后将差值除以细胞的重量。由此得到的值被定义为单位细胞重量单位时间吸收的光能量的量，E(x)。在 30°C 下，限制光照条件下对普通小球藻进行分批和连续培养，pH 值范围为 6.4-6.7。然后，在分批培养中绘制比生长速率μ与 E(x)的关系，以及在连续培养中绘制固定稀释速率 D 与 E(x)的关系。结果表明，D 与 E(x)之间的关系可以用米氏方程表示，其中最大比生长速率为 0.24 h(-1)，饱和常数为 6.58 kcal/g. h。通过将培养细胞的表观浓度 X(e)和表观维持常数 M(e)代入该方程，可以计算出细胞浓度，该浓度与几乎所有生长阶段的观察值一致。此外，根据叶绿素生产力的变化和该方程中 D 与 E(x)的关系，可以假设 E(x)涉及细胞光合作用中直接利用的光能，以及转化为例如热量的光能。该方程还表明存在最大生长产率。然后，在入射光为 1.46 或 2.63 cal/cm(2). h 时，获得的 0.029 g/kcal 的生长产率最大（光能最大转化率，15.6%）。这些结果表明，从本研究中推导出生长速率方程的这种方法是获得生物工程发现的一种有用方法。
