Cabral de Melo Fernando Cesar Bazani, Borsato Dionísio, de Macedo Júnior Fernando César, Mantovani Mario Sérgio, Luiz Rodrigo Cabral, Colabone-Celligoi Maria Antonia-Pedrine
Department of Biochemistry and Biotechnology, Centre of Exact Science, State University of Londrina, Brazil.
Department of Chemistry, Centre of Exact Science, State University of Londrina, Brazil.
Pak J Pharm Sci. 2015 Nov;28(6):1917-26.
Levan productivity of Bacillus subtilis Natto was evaluated in submerged culture varying the pH, temperature and culture time, using factorial design and response surface methodology. The characterization of levan molecular weight was performed by HPSEC and its antitumor activity against HepG2 cells using metabolomic approach was also evaluated. At first, the variables investigated, as well as their interactions, demonstrated significant effect. Further, a second design using the same variables at different levels was developed. Thus, according to the model, an optimized value corresponding to 5.82 g.L⁻¹.h⁻¹ was achieved at pH 8, 39.5°C in 21 hours, the highest value reported so far. After analysis by HPSEC, two molecular weights were obtained corresponding to 72.37 and 4146 kDa. The levan promoted an increase of acetate, alanine, lactate and phosphocreatine in HepG2 cells suggesting an alteration in the bioenergetics pathways and cellular homeostasis by intracellular accumulation of lactate, justifying its antitumor activity.
采用析因设计和响应面法，在不同pH值、温度和培养时间的深层培养条件下，对纳豆芽孢杆菌的果聚糖产量进行了评估。通过高效体积排阻色谱法对果聚糖的分子量进行了表征，并采用代谢组学方法评估了其对肝癌细胞HepG2的抗肿瘤活性。首先，所研究的变量及其相互作用显示出显著影响。此外，还开发了一个使用相同变量但处于不同水平的二次设计。因此，根据该模型，在pH值为8、温度为39.5°C、培养21小时的条件下，获得了对应于5.82 g·L⁻¹·h⁻¹的优化值，这是迄今为止报道的最高值。通过高效体积排阻色谱法分析后，得到了两种分子量分别为72.37和4146 kDa的果聚糖。果聚糖促使肝癌细胞HepG2中的乙酸盐、丙氨酸、乳酸盐和磷酸肌酸增加，这表明生物能量途径和细胞内环境稳定因乳酸在细胞内的积累而发生改变，这也解释了其抗肿瘤活性。
