Osaku Erica F, Menolli Rafael A, de M Costa Claudia R L, Tessaro Fernando Henrique G, de Melo Renan H, do Amaral Alex E, Duarte Péricles A D, de Santana Filho Arquimedes Paixão, Ruthes Andrea Caroline, da C Silva José Luis, Mello Rosiane G
Centro de Ciências Biológicas e da Saúde, Universidade Estadual do Oeste do Paraná, Caixa Postal 711, CEP 85819-110, Cascavel, PR, Brazil.
Centro de Ciências Médicas e Farmacêuticas, Universidade Estadual do Oeste do Paraná, Caixa Postal 711, Cascavel, PR, CEP 85819-110, Brazil.
Antonie Van Leeuwenhoek. 2018 Jun;111(6):981-994. doi: 10.1007/s10482-017-1000-x. Epub 2017 Dec 13.
Paecilomyces variotii is a filamentous fungus that occurs worldwide in soil and decaying vegetation. Optimization of the fermentation process for exopolysaccharide (EPS) production from the fungus P. variotii, structure determination and immuno-stimulating activity of EPS were performed. Response surface methodology (RSM) coupled with central composite design (CCD) was used to optimize the physical and chemical factors required to produce EPS in submerged fermentation. Preliminary investigations to choose the three factors for the present work were made using a factorial experimental design. Glucose, ammonium nitrate (NHNO) and pH were used as variables for which, with constant temperature of 28 °C and agitation of 90 rpm, the optimal process parameters were determined as glucose values of 0.96%, NHNO 0.26% and pH 8.0. The three parameters presented significant effects. In this condition of culture, the main composition of the isolated EPS was a linear β-(1 → 6)-linked-D-glucan, as determined by Nuclear Magnetic Resonance (NMR) and methylation analysis. This polysaccharide is a very unusual as an EPS from fungi, especially a filamentous fungus such as P. variotii. Murine peritoneal macrophages cultivated with β-glucan for 6 and 48 h showed an increase in TNF-α, IL-6 and nitric oxide release with increased polysaccharide concentrations. Therefore, we conclude that the β-(1 → 6)-linked-D-glucan produced in optimised conditions of P. variotii cultivation has an immune-stimulatory activity on murine macrophages.
变幻青霉是一种丝状真菌，广泛存在于世界各地的土壤和腐烂植被中。对变幻青霉产生胞外多糖（EPS）的发酵过程进行了优化，并对EPS的结构进行了测定以及免疫刺激活性进行了研究。采用响应面法（RSM）结合中心复合设计（CCD）对深层发酵生产EPS所需的物理和化学因素进行优化。使用析因实验设计对本研究的三个因素进行初步筛选。将葡萄糖、硝酸铵（NHNO）和pH值作为变量，在28℃恒温、90 rpm搅拌条件下，确定最佳工艺参数为葡萄糖0.96%、NHNO 0.26%、pH 8.0。这三个参数均呈现显著影响。在此培养条件下，通过核磁共振（NMR）和甲基化分析确定，分离得到的EPS的主要成分是线性β-(1→6)-连接的-D-葡聚糖。作为一种来自真菌尤其是像变幻青霉这样的丝状真菌的EPS，这种多糖非常特别。用β-葡聚糖培养6小时和48小时的小鼠腹腔巨噬细胞，随着多糖浓度的增加，肿瘤坏死因子-α、白细胞介素-6和一氧化氮的释放量增加。因此，我们得出结论，在优化的变幻青霉培养条件下产生的β-(1→6)-连接的-D-葡聚糖对小鼠巨噬细胞具有免疫刺激活性。
