利用糖蜜制备细菌纤维素的研究

Production of Bacterial Cellulose from Sugarcane Molasses

细菌纤维素(BC)是一类由微生物产生的纤维素。细菌纤维素以其独特的物理和化学性质被广泛应用于医药、食品、造纸、纺织等领域。然而,BC应用的最大挑战是其生产成本,尤其是发酵生产碳源的成本相对较高。以相对廉价的糖蜜为原料,研究比较了不同预处理方法(硫酸―热处理、热处理和未处理)以及生产菌种(木葡糖醋杆菌和红茶菌)对细菌纤维素产量的影响。结果表明,硫酸―热处理之后的糖蜜获得的细菌纤维素产量最高,可达6.0 g/L,比用葡萄糖制备细菌纤维素的产量提高了78%。当以红茶菌为菌种,细菌纤维素的产量可达12.0 g/L,是木葡糖醋杆菌作为菌种的两倍。与葡萄糖和果糖相比,糖蜜制备的细菌纤维素同样具有三维网状结构,但是含水率较低,杨氏模量较小。

Bacterial cellulose （BC） is a biopolymer produced by some bacteria. It has unique physical and chemical properties and can be applied in many fields such as medicine, food, paper and textile. A major challenge in BC applications is its relatively high production cost, especially on carbon source cost. Searching for cheap fermentation feedstocks is a way to reduce the cost. In this research, three different pretreatments （H2SOa-heat treatment, heat treatment and un-treatment） of sugarcane molasses and two microbial cultures （Gluconacetobacter xylinus and black tea fungus） were compared to investigate the difference in BC yield. It was found that after the H2SO4-heat treatment, BC yield was the highest （6.0 g/L）, which was 78% higher than that in glucose-medium. When black tea fungus was used to produce BC, BC yield could reach 12.0 g/L. Compared with the BC from glucose and fructose, that from molasses had a same 3D network structure but water-holding capacity and mechanical properties were weaker.