Tolonen M, Saris P E J, Siika-Aho M
Department of Applied Chemistry and Microbiology, University of Helsinki, PO Box 56, 00014, Helsinki, Finland.
Appl Microbiol Biotechnol. 2004 Feb;63(6):659-65. doi: 10.1007/s00253-003-1413-5. Epub 2003 Aug 9.
The production of nisin, biomass and lactic acid in pH-controlled and uncontrolled batch fermentation and batch fermentation (pH 5.5) with continuous removal of nisin was examined in the parent strain Lactococcus lactis N8 and LAC48. Strain LAC48 in batch fermentor (pH not controlled) gave a maximum nisin concentration of 2.5 x 10(6) IU g dcw(-1). The nisin concentration remained high (2.0 x 10(6) IU g dcw(-1)) after the logarithmic growth phase (10-22 h), whereas nisin production of strain N8 decreased after the logarithmic growth phase. The maximum nisin production of strain LAC48 was not directly related to the biomass formation and not associated with growth. In order to study end product inhibition in nisin production, a system was built for adsorption of nisin during fermentation. The adsorbent Amberlite XAD-4 was found to have an effective binding capacity for nisin. Cells of LAC48 and N8 compensated for the removal of nisin, indicating that nisin production also occurs in the stationary phase.
在亲本菌株乳酸乳球菌N8和LAC48中，研究了在pH值受控和不受控的分批发酵以及pH值为5.5且持续去除乳链菌肽的分批发酵中乳链菌肽、生物量和乳酸的产生情况。在分批发酵罐中（pH值不受控）的菌株LAC48产生的乳链菌肽最大浓度为2.5×10⁶ IU g干重⁻¹。在对数生长期（10 - 22小时）后，乳链菌肽浓度仍保持较高水平（2.0×10⁶ IU g干重⁻¹），而菌株N8的乳链菌肽产量在对数生长期后下降。菌株LAC48的最大乳链菌肽产量与生物量形成没有直接关系，也与生长无关。为了研究乳链菌肽生产中的终产物抑制作用，构建了一个在发酵过程中吸附乳链菌肽的系统。发现吸附剂Amberlite XAD - 4对乳链菌肽具有有效的结合能力。LAC48和N8菌株的细胞弥补了乳链菌肽的去除，表明在稳定期也会产生乳链菌肽。
