类植物乳杆菌的耐酸、耐胆盐及降胆固醇特性

Acid and bile tolerance and cholesterol reduction ability of Lactobacillus paraplantarum

摘要:

摘要：【目的】研究了类植物乳杆菌Ⅱ32的酸、胆盐耐受性和胆固醇去除能力，并通过菌株生长和胆固醇去除的关系探讨可能的机理。【方法】菌株Ⅱ32生长在高胆固醇MRS培养基中，胆固醇的检测通过气相色谱法。检测菌株在不同生长阶段对胆固醇的去除情况。【结果】菌株Ⅱ32具有酸耐受性、胆盐耐受性和一定的胆固醇清除能力。菌株在pH2.0培养2 h后仍能达到104 cfu/mL；加胆盐（0.3%～0.4%）对菌株生长量达到OD值0.6的时间延迟在0.5 h以内；热杀死的和休眠的细胞能去除很少的胆固醇，分别是5.64、5.90 mg/g细胞干重,而生长的细胞去除的胆固醇达到16.98 mg/g细胞干重。另外，研究表明胆固醇去除与菌体的生长有一定的相关性。【结论】菌株Ⅱ32去除胆固醇可能的机理是菌体对胆固醇的吸附及菌体在生长过程中对胆固醇的吸收利用，为此该菌株具有添加到食品中来降低血液胆固醇的潜能。

Abstract:

Abstract: [Objective] We studied the acid and bile tolerance of Lactobacillus paraplantarumⅡ32, and examined the possible mechanisms of cholesterol reduction. [Methods] StrainⅡ32 was incubated in MRS (de Man, Rogosa, Sharpe) broth supplemented with cholesterol, and the cholesterol in medium was determined using gas chromatography. We examined cholesterol reducing ability under different conditions, and the relation between growth and cholesterol reduction of strainⅡ32. [Results] StrainⅡ32 showed acid resistance, bile salt tolerance and the cholesterol- reducing ability. The results indicated that strainⅡ32 survived at pH2 after 2h culture and the living bacterial number could reach 104 cfu/mL. In addition, the growth of strainⅡ32 was delayed less than 0.5h in MRS broth with 0.3%-0.4% bile salt, when the absorbance value both increased to 0.6 unit. Cholesterol removed by dead and resting cells were 5.64 and 5.90 mg/g of dry weight compared with growing cells, which was 16.98 mg/g of dry weight. Cholesterol removal was greatly associated with growth of the bacteria. The possible mechanisms for removal of cholesterol from media were proposed: assimilation of cholesterol during growth, and binding of cholesterol to the cell surface. [Conclusion] StrainⅡ32 may be promising candidates for use as a dietary adjunct to lower serum cholesterol in vivo.