Walter Christian, Steinau Torsten, Gerbsch Norbert, Buchholz Rainer
Bioprocess Engineering, Friedrich-Alexander University Erlangen-Nuremberg, Paul-Gordan-Str. 3, 91052 Erlangen, Germany.
Biomol Eng. 2003 Jul;20(4-6):261-71. doi: 10.1016/s1389-0344(03)00068-6.
The use of phototrophic microorganisms as sources of biological active substances in photoautotrophic and mixotrophic cultivation modes requires an adequate cultivation system with thermal sterilization. A corresponding photobioreactor system in the 10, 25 and 100 l scales was developed. This "Medusa"-photobioreactor system represents a concept based on the air-lift loop principle, whose working volume is irradiated by external light sources. The incident irradiation can be varied by a light control system. An effective CO(2)/O(2) gas exchange is enabled due to the efficient supply with process gas by several gas supply nozzles within the system and a large degassing surface. Using a model to describe the growth characteristics of the organisms, the volumetric irradiation coefficient I(DX) was defined as scale-up parameter. On this basis the scale-up from 1 l bubble columns to the 10 and 100 l scales was realized. The scale-up was performed successfully with Chlorella salina as model organism. A maximum biomass concentration of 7.89 g (dry weight) l(-1) at a maximum specific growth rate of 0.058 h(-1) and a yield of 35 mg l(-1) h(-1) was obtained in a batch cultivation in the 100 l scale under photoautotrophic conditions with an initial biomass concentration of approx. 0.03 g l(-1).
在光自养和混合营养培养模式下，将光合微生物用作生物活性物质的来源需要一个具备热灭菌功能的合适培养系统。开发了10升、25升和100升规模的相应光生物反应器系统。这种“美杜莎”光生物反应器系统代表了一种基于气升环原理的概念，其工作体积由外部光源照射。入射辐照可通过光控制系统进行调节。由于系统内多个气体供应喷嘴能有效供应工艺气体以及有较大的脱气表面，从而实现了有效的CO₂/O₂气体交换。利用一个模型来描述生物体的生长特性，将体积辐照系数I(DX)定义为放大参数。在此基础上，实现了从1升鼓泡塔到10升和100升规模的放大。以盐生小球藻为模式生物成功进行了放大。在光自养条件下，初始生物量浓度约为0.03克/升的100升规模分批培养中，获得了最大生物量浓度7.89克（干重）/升、最大比生长速率0.058小时⁻¹和产量35毫克/升·小时⁻¹。
