鮑芹根際乳酸菌的篩選及耐受性和抗氧化能力評價

于金慧　劉云鵬　徐貴祎　馬德源　烏日娜　武俊瑞　黃超　張娟　尤升波　畢玉平

摘要：為篩選既有優良果蔬發酵特性又有利于人體腸道微生態平衡的功能性果蔬發酵專用益生菌，本研究以新鮮鮑芹根為試材，結合傳統方法和分子生物學方法對其根際分離得到的乳酸菌進行鑒定，對篩選出產酸能力強、生長旺盛的菌株進行耐受性和抗氧化能力評價。經鑒定，分離得到的兩株乳酸菌分別為植物乳桿菌（產酸能力強、生長旺盛）和戊糖片球菌。對植物乳桿菌進行人工模擬耐受性評價發現，該菌在pH值為2.5、3.5、4.5的人工胃液中處理3 h后菌量仍保持在106 CFU/mL以上;人工腸液培養2、3 h的存活率分別為155.9%、191.9%，4 h后菌種數量開始下降，存活率仍為35.7%;隨鹽濃度增加，該菌的存活率下降，但7.5 mg/mL的膽鹽溶液和70 mg/mL鈉鹽溶液中菌量仍能維持在106 CFU/mL以上。抗氧化能力試驗表明，該菌發酵上清液的DPPH自由基清除率可達91.8%，固形物醇提液的亞鐵離子螯合能力比發酵上清液的高出13.7個百分點。綜上，植物乳桿菌具有較好的耐受性和抗氧化能力，后期可用于益生菌相關產品的研發。

關鍵詞：鮑芹;乳酸菌;植物乳桿菌;分離純化;鑒定;耐受性;抗氧化能力

中圖分類號：S636.3：TS201.3文獻標識號：A文章編號：1001-4942（2019）11-0074-07

Screening and Evaluation of Tolerance and Antioxidant

Capacity of Lactobacillus in Baoqin Rhizosphere

Yu Jinhui1， Liu Yunpeng1，2， Xu Guiyi3， Ma Deyuan1， Wu Rina4， Wu Junrui4，

Huang Chao1， Zhang Juan5， You Shengbo1， Bi Yuping1

（1. Biotechnology Research Center， Shandong Academy of Agricultural Sciences， Jinan 250100， China;

2. College of Life Sciences， Shandong Normal University， Jinan 250014， China;

3. School of Medicine and Life Sciences， University of Jinan-Shandong Academy of Medical Sciences， Jinan 250200， China;

4. College of Food Science， Shenyang Agricultural University， Shenyang 110866， China;

5. Shandong Institute for Product Quality Supervision and Inspection， Jinan 250100， China）

Abstract In order to screen out the special probiotics for functional fruit and vegetable fermentation， which not only have excellent fermentation characteristics， but also are benefit to the intestinal microecological balance of human body， the fresh Baoqin roots were used as the test material in this study， and the acid-producing bacteria isolated from its rhizosphere were identified by traditional methods and molecular biological methods， and the strains with strong acid production ability and vigorous growth were screened out for tolerance and antioxidant ability evaluation. The two bacteria were identified as Lactobacillus plantans and Gluconococcus glutinosa. The tolerance test showed that the amount of Lactobacillus plantatus remained above 106 CFU/mL treated in simulated gastric fluid with pH value as 2.5， 3.5 and 4.5 respectively after 3 hours. The survival rate of simulated intestinal fluid cultured for 2 hours and 3 hours was 155.9% and 191.9%， respectively. After 4 hours， the number of bacteria began to decline and the survival rate was still 35.7%. With the increase of salt concentration， the survival rate of bacteria decreased， but the bacteria content in 7.5 mg/mL bile salt solution and 70 mg/mL sodium salt solution could still maintain above 106 CFU/mL. The antioxidant evaluation results showed that the DPPH radical scavenging rate of the fermentation supernatant could reach 91.8%， and the chelating ability of ferrous ions in the thallus alcohol extract was 13.7 percentage points higher than that in the fermentation supernatant. In conclusion， the isolated strain had better tolerance and antioxidant ability， which could be used for the research and development of probiotics related products.

Keywords Baoqin; Lactic acid bacteria; Lactobacillus plantarum; Separation and purification; Identification; Tolerance; Antioxidant capacity

益生菌是指通過攝取適當的量對食用者身體健康能發揮有效作用的活菌，具有促進營養物質吸收、改善腸道功能、降低三高、提高免疫力、抗腫瘤等功效[1-4]，是當今生命科學領域研究的熱點。我國衛健委規定的可用于保健食品和功能食品的益生菌菌種名單中絕大多數為乳酸菌類，而乳酸菌也是目前商業化應用的主要益生菌。……