豌豆酸浆中微生物群落分析及淀粉絮凝菌分离鉴定

Analysis of Microbial Communities in Pea Sour Pulp and Isolation and Identification of Strain with Starch Flocculation Characteristics

以自然发酵豌豆酸浆为研究对象,利用高通量测序技术确定厚壁菌门为自然发酵豌豆酸浆中的优势菌门,乳杆菌属为优势菌属。通过比较絮凝率筛选出一株具有高絮凝淀粉活性的乳杆菌,结合菌体形态、生理生化实验以及16S rDNA测序结果,鉴定该菌株为发酵乳杆菌(Lactobacillus fermentum),并命名为Lactobacillus fermentum FLL5429。对该菌株的絮凝特性进行分析表明L.fermentum FLL5429分泌的絮凝活性物质位于菌体发酵液的上清液中;运用单因素实验对其絮凝特性进行分析,结果表明,Ca2+能够加速发酵液对淀粉的絮凝,当接种量为15%、30 ℃培养48 h时,L.fermentum FLL5429发酵液絮凝淀粉的效果最好。研究结果为进一步研发淀粉专用微生物絮凝剂奠定理论基础并提供技术参考。

Using natural fermented pea sour pulp as the research object,the Firmicutes was identified as the dominant phylum in natural fermented pea sour pulp using high-throughput sequencing technology,and the Lactobacillus was the dominant genus.On this basis,a strain of Lactobacillus with high flocculating starch activity was screened and identified as Lactobacillus fermentum based on its morphology,physiological and biochemical experiments and 16S rDNA sequencing results,and named Lactobacillus fermentum FLL5429.Analysis of the flocculation characteristics of this strain showed that the flocculating active substance secreted by L.fermentum FLL5429 was located in the supernatant of the fermentation broth of the bacterium.The results showed that Ca2+ accelerated the flocculation of starch in the fermentation broth,and the fermentation broth of L.fermentum FLL5429 was the most effective in flocculating starch when it was incubated at 30 ℃ for 48 h at an inoculum level of 15%.This study provides a theoretical basis and technical reference for further development of starch-specific microbial flocculants.