腐乳酸浆水中产β-葡萄糖苷酶乳酸菌的研究

Study onβ-Glucosidase-Producing Lactic Acid Bacteria in Sour Slurry of Sufu

桂林腐乳酸浆水是桂林腐乳制作过程中的凝固剂,其富含的微生物赋予了腐乳特有的品质。而桂林腐乳酸浆水中乳酸菌的种类及其具有的优良功能活性尚不清晰。该研究从酸浆水中筛选出10株乳酸菌,其中5株具有产β-葡萄糖苷酶能力。经生理生化和16S rRNA鉴定,a1、a3、a7和b16为利莫西发酵乳杆菌(Limosilactobacillus fermentum),b8为德氏乳杆菌(Lactobacillus delbrueckii)。b8展现出最高的β-葡萄糖苷酶活力(发酵6 h时为(41.22±0.47)U/105 CFU),生长活力和产酸能力也显著高于其余4株产酶乳酸菌(P<0.05)。此外,德氏乳杆菌b8在培养12 h时的DPPH、ABTS自由基清除率分别为(16.29±2.22)%、(51.02±2.43)%。综上,德氏乳杆菌b8具有较好的功能活性和生长活力,该研究既丰富了对桂林腐乳酸浆水中乳酸菌的认识,又为豆制品行业提供了潜在的功能性发酵菌株。

Sour slurry of Guilin sufu is a coagulant in the production process of Guilin sufu.The microorganisms rich in it give unique quality to sufu.However,the types of lactic acid bacteria in the sour slurry of Guilin sufu and their excellent functional activities are still not clear.In this study,ten strains of lactic acid bacteria are screened out from sour slurry,among which,five strains have the capacity to produceβ-glucosidase.After physiological,biochemical and 16S rRNA identification,a1,a3,a7 and b16 are Limosilactobacillus fermentum,and b8 is Lactobacillus delbrueckii.b8 shows the highestβ-glucosidase activity((41.22±0.47)U/105 CFU at 6 hours of fermentation),and the growth activity and acid-producing capacity are significantly higher than those of the other four strains of lactic acid bacteria(P<0.05).In addition,at 12 hours'culture,the scavenging rates of Lactobacillus delbrueckii b8 on DPPH and ABTS radicals are(16.29±2.22)%,(51.02±2.43)%respectively.In conclusion,Lactobacillus delbrueckii b8 has good functional activity and growth activity.This study has not only enriched the understanding of lactic acid bacteria in sour slurry of Guilin sufu,but also provided potential functional fermentation strains for the soybean product industry.