University of Ottawa, Ontario, Canada.
Biotechnol Prog. 2011 Nov-Dec;27(6):1544-53. doi: 10.1002/btpr.667. Epub 2011 Jul 7.
Trichoderma reesei was grown in a stirred-tank bioreactor (STB) and a reciprocating plate bioreactor (RPB) at four different agitation speeds. A semiautomatic image analysis protocol that was developed to characterize the mycelium morphology during the fermentation process based on four morphological types (unbranched, branched, entangled, and clumped microorganisms) was applied to study the effect of agitation on the morphology of T. reesei. It was shown via statistical validation that broth samples used for image analysis represented the whole population of the fungi in the bioreactor. High shear was found to be damaging to T. reesei grown in the STB. The gentler shear produced in the RPB was not detrimental to the microorganism even at higher agitation speed. Better productivity was obtained for T. reesei grown in the STB and the highest productivity, 0.121 IU/mL h, was obtained at 400 rpm. The morphological parameter, the hyphal growth unit, was found to be correlated to the productivity. Understanding the effect of agitation on the morphology and productivity of T. reesei could lead to the design of better bioreactors and the selection of operating conditions of bioreactors to optimize the production of cellulase.
里氏木霉在搅拌罐生物反应器（STB）和往复式平板生物反应器（RPB）中以四种不同的搅拌速度进行培养。开发了一种半自动图像分析方案，用于根据四种形态类型（未分枝、分枝、缠结和团聚微生物）在发酵过程中对菌丝体形态进行特征描述，以研究搅拌对里氏木霉形态的影响。通过统计验证表明，用于图像分析的发酵液样本代表了生物反应器中真菌的整个种群。高剪切力被发现会损坏在 STB 中生长的里氏木霉。在 RPB 中产生的较柔和的剪切力甚至在更高的搅拌速度下也不会对微生物造成损害。在 STB 中生长的里氏木霉获得了更好的生产力，在 400rpm 时获得了最高的生产力，为 0.121IU/mL h。发现形态参数，菌丝生长单位，与生产力相关。了解搅拌对里氏木霉形态和生产力的影响，可以设计更好的生物反应器，并选择生物反应器的操作条件，以优化纤维素酶的生产。
