Xu Chun Ping, Sinha Jayanta, Bae Jun Tae, Kim Sang Woo, Yun Jong Won
Department of Biotechnology, Daegu University, Kyungbuk, Korea.
Lett Appl Microbiol. 2006 May;42(5):501-6. doi: 10.1111/j.1472-765X.2006.01884.x.
In the present study, two different optimization techniques were used to determine the suitable operating parameters for exo-biopolymer production in submerged mycelial cultures of two entomopathogenic fungi Paecilomyces japonica and Paecilomyces tenuipes.
First, the rotating simplex method, a nonstatistical optimization technique, was employed to obtain the best combination of physical parameters (viz. pH, agitation intensity, aeration rate) for maximum exo-biopolymer production by P. japonica in a batch bioreactor. The optimal combination was determined to be a pH of 8.06, an aeration of 3 vvm, without any impeller agitation, producing a 17-time increase in exopolymer production (34.5 g l(-1)) when compared with that achieved in unoptimized flask cultures. Second, the uniform design method, a statistical optimization technique, was employed to determine the best operating parameters for submerged culture of P. tenuipes. The optimal combination for mycelial growth was determined to be a pH of 4.88, an aeration of 2 vvm and an agitation of 350 rpm, while a pH of 4, an aeration of 2 vvm and an agitation of 150 rpm was best for exo-biopolymer production.
The exo-biopolymer production in P. japonica optimized by the rotating simplex method was strikingly improved (max. 34.5 g l(-1)), and the exo-biopolymer production in P. tenuipes optimized by the uniform design method was also significantly increased (max. 3.4 g l(-1)).
The successful application of these two different optimization techniques in this study implies that these methods are worthy of applying to other fermentation systems for the production of bioactive mycelial biomass and exo-biopolymers in liquid culture of higher fungi.
在本研究中，使用两种不同的优化技术来确定两种昆虫病原真菌日本拟青霉和细脚拟青霉的深层菌丝体培养中胞外生物聚合物生产的合适操作参数。
首先，采用旋转单形法这一非统计优化技术，以获得日本拟青霉在分批式生物反应器中产生最大胞外生物聚合物的物理参数（即pH值、搅拌强度、通气速率）的最佳组合。确定的最佳组合为pH值8.06、通气量3 vvm、无任何叶轮搅拌，与未优化的摇瓶培养相比，胞外聚合物产量提高了17倍（34.5 g l⁻¹）。其次，采用均匀设计法这一统计优化技术来确定细脚拟青霉深层培养的最佳操作参数。确定菌丝体生长的最佳组合为pH值4.88、通气量2 vvm和搅拌速度350 rpm，而对于胞外生物聚合物生产，pH值4、通气量2 vvm和搅拌速度150 rpm最佳。
通过旋转单形法优化的日本拟青霉胞外生物聚合物产量显著提高（最高34.5 g l⁻¹），通过均匀设计法优化的细脚拟青霉胞外生物聚合物产量也显著增加（最高3.4 g l⁻¹）。
这两种不同优化技术在本研究中的成功应用意味着这些方法值得应用于其他发酵系统，以在高等真菌的液体培养中生产生物活性菌丝体生物质和胞外生物聚合物。
