Ahn Jungoh, Jung Joonki, Hyung Woochan, Haam Seungjoo, Shin Chulsoo
Biopilot Plant, Korea Research Institute of Bioscience and Biotechnology, Yusong, Taejeon 305-333, Korea.
Biotechnol Prog. 2006 Jan-Feb;22(1):338-40. doi: 10.1021/bp050275o.
In general, high broth viscosity is a key factor to be considered in a submerged fermentation of filamentous fungi. High broth viscosity was also observed in a batch fermentation of Monascus sp. J101 at 30 degrees C. In a batch culture at 30 degrees C, most cell growth was accomplished within 48 h, which induced highly entangled clumps. The resultant high viscosity induced heterogeneity inside the fermentor, poor oxygen transfer, and low pigment yield. However, these problems could be overcome by reducing fungal growth rate through culture at low temperature (25 degrees C). Cell growth was moderate and continued for 120 h, and low viscosity was maintained. The DO levels remained at 50% or higher with good mixing. As a result, the pigment yield at 25 degrees C was 10 times greater than at 30 degrees C.
一般来说，高发酵液粘度是丝状真菌深层发酵中需要考虑的关键因素。在红曲霉菌J101于30℃的分批发酵中也观察到了高发酵液粘度。在30℃的分批培养中，大部分细胞生长在48小时内完成，这导致了高度缠结的菌团。由此产生的高粘度导致发酵罐内的不均匀性、氧气传递不佳以及色素产量低。然而，通过在低温（25℃）下培养来降低真菌生长速率，可以克服这些问题。细胞生长适中并持续120小时，且保持低粘度。在良好混合的情况下，溶解氧水平保持在50%或更高。结果，25℃时的色素产量比30℃时高10倍。
