柑橘果渣固态发酵产聚半乳糖醛酸酶

Production of polygalacturonase from citrus pomace by solid-state fermentation

通过固态发酵,实现黑曲霉(Aspergillus niger)发酵生产聚半乳糖醛酸酶(PG)。以葡萄渣、苹果渣和柑橘渣为底物,利用黑曲霉18-23发酵生产聚半乳糖醛酸酶,考察不同果渣底物、可溶性碳源对胞外聚半乳糖醛酸酶合成的影响,并对该酶酶学性质进行研究。结果表明,柑橘渣最适合聚半乳糖醛酸酶的生产,苹果渣次之,二者的PG酶活力分别为56.9 U/g和42.1 U/g。乳糖对聚半乳糖醛酸酶的合成有诱导作用,可促进酶活力的增加,而槐糖无诱导作用,葡萄糖会抑制聚半乳糖醛酸酶的合成。聚半乳糖醛酸酶最适温度为50℃,最适p H值为5.5,且在温度40~50℃、p H 4.0~5.5稳定性良好,表明该酶在食品工业中具有潜在的应用价值。

Polygalacturonase(PG)production by Aspergillus niger was carried out by solid-state fermentation.Using grape pomace,apple pomace and citrus pomace as the substrates,the PG was produced by A.niger 18-23.The effects of different pomaces and water-soluble carbon sources on extracellular PG production were investigated,and the enzyme properties were analyzed.The results indicated that citrus pomace was most suitable for the production of PG,followed by apple pomace,and the enzyme activity of polygalacturonase was 56.9 U/g and 42.1 U/g,respectively.Lactose had induction effect on the synthesis of PG,which could increase enzyme activity.While sophorose had no induction effect,and glucose could inhibit the synthesis of PG.The optimum temperature and pH of PG was 50℃and 5.5,respectively,and the stability was good at 40-50℃and pH 4.0-5.5,indicating the PG had potential application value in food industry.