γ-聚谷氨酸发酵液预处理的研究

Pretreatment of Fermented Mash Containing Poly-γ-glutamic acid(γ-PGA)

为了提高γ-聚谷氨酸(γ-PGA)的质量,基于γ-PGA发酵液的物化特性,采用单因素试验逐个确定影响硅藻土除杂质的因子的最佳条件,最后在单因素试验的基础上用硅藻土层模拟板框模式过滤除菌体。以除菌率、杂蛋白质量浓度、γ-PGA质量浓度为指标,研究硅藻土的用量。结果表明:发酵液加热至50℃,4倍稀释,以1.6cm厚(约25g)的硅藻土层作为滤饼层,连续过滤4次后,能除去130mL原发酵液中几乎全部的菌体,发酵液中蛋白质质量浓度为0.32mg/mL,γ-PGA的损失率为34.8%。

In order to improve the quality of γ-PGA, single factor experiment was used to determine the best conditions of removing bacteria cells using diatomite, basing on physical and chemical properties of the γ- PGA fermented mash. Diatomite was used to simulating plate and frame model to remove bacteria cells, basing on the single factor experiment. The amount of diatomite was studied using bacterial eliminating rate, protein concentration，γ-PGA concentration as the target. The results showed that： when the fermented mash was heated 50 ℃ before diluted 4 multiples, then filtered by 1.6cm thickness （about 25g） diatomite four times ,the bacteria cells were almost completely removed from the 130mL γ-PGA fermented mash. The protein concentration was 0.32 mg/mL, the loss rate of γ-PGA was 34.8 %.with bacterial eliminating rate，protein concentration，γ-PGA concentration, the amount of diatomite was studied.And the results showed that the bacteria cells were almost completely removed from the 130mL γ-PGA fermented mash which were heated 50 ℃ before diluted 4 multiples,then filtered by diatomite that thickness was 1.6cm （about 25g） four times. The protein concentration was 0.023 mg/mL, the loss rate of γ-PGA was 34.8 %.