Abstract Carbon-limited chemostat cultures were performed using different carbon sources (glucose, 10 and 20 g/L; sucrose, 10 g/L; fructose/glucose, 5.26/5.26 g/L; carboxymethyl cellulose, 10 g/L; and carboxymethyl cellulose/glucose, 5/5 g/L) to verify the capability of the wild type strain Trichoderma harzianum to produce extracellular enzymes. All chemostat cultures were carried out at a fixed dilution rate of 0.05 h−1. Experiments using glucose, fructose/glucose and sucrose were performed in duplicate. Glucose condition was found to induce the production of enzymes that can catalyse the hydrolysis of p-nitrophenyl-β- d -glucopyranoside (PNPGase). A concentration of 20 g/L of glucose in the feed provided the highest productivity (1048 ± 16 U/mol h). Extracellular polysaccharides were considered the source of inducers. Based on the obtained results, a new PNPGase production process was developed using mainly glucose. This process raises interesting possibilities of synthesizing the inducer substrate and the induced enzymes in a single step using an easily assimilated carbon source under carbon-limited conditions.

中文翻译：

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哈茨木霉 P49P11 在碳限制条件下连续生产酶

摘要 使用不同碳源（葡萄糖，10 和 20 g/L；蔗糖，10 g/L；果糖/葡萄糖，5.26/5.26 g/L；羧甲基纤维素，10 g/L；和羧甲基纤维素/葡萄糖，5/5 g/L) 以验证野生型菌株哈茨木霉产生胞外酶的能力。所有恒化器培养均以 0.05 h-1 的固定稀释率进行。使用葡萄糖、果糖/葡萄糖和蔗糖的实验一式两份进行。发现葡萄糖条件可诱导产生可催化对硝基苯基-β-d-吡喃葡萄糖苷 (PNPGase) 水解的酶。进料中 20 g/L 的葡萄糖浓度提供了最高的生产率 (1048 ± 16 U/mol h)。细胞外多糖被认为是诱导剂的来源。基于获得的结果，开发了一种主要使用葡萄糖的新 PNPGase 生产工艺。该过程提出了在碳限制条件下使用易于同化的碳源在单个步骤中合成诱导底物和诱导酶的有趣可能性。