【目的】评估干酪乳酪杆菌Zhang(Lactobacillus casei Zhang,LCZ)在连续传代培养过程中的遗传稳定性。【方法】在MRS液体培养基中连续培养LCZ 100代,分别在第0、25、50、75、100代取样,分析其菌体形态、碳水化合物利用情况及基因组变化...【目的】评估干酪乳酪杆菌Zhang(Lactobacillus casei Zhang,LCZ)在连续传代培养过程中的遗传稳定性。【方法】在MRS液体培养基中连续培养LCZ 100代,分别在第0、25、50、75、100代取样,分析其菌体形态、碳水化合物利用情况及基因组变化。【结果】LCZ在第0、25、50、75、100代的菌体形态及碳水化合物利用情况无显著差异。基因组大小和GC占比在不同代数与原始基因组相比均无显著差异。SNP突变分析显示,不同代数的LCZ基因组高度保守,突变频率较低。平均核苷酸一致性(ANI)和系统发育树结果表明,不同代数的LCZ与原始基因组亲缘关系接近。不同代数的菌株所注释到的碳水化合物活性酶(CAZymes)无显著差异,表明其碳水化合物利用能力一致。【结论】LCZ在连续传代过程中表现出较高的遗传稳定性。展开更多
【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡...【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。展开更多
Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and K...Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.展开更多
文摘【目的】评估干酪乳酪杆菌Zhang(Lactobacillus casei Zhang,LCZ)在连续传代培养过程中的遗传稳定性。【方法】在MRS液体培养基中连续培养LCZ 100代,分别在第0、25、50、75、100代取样,分析其菌体形态、碳水化合物利用情况及基因组变化。【结果】LCZ在第0、25、50、75、100代的菌体形态及碳水化合物利用情况无显著差异。基因组大小和GC占比在不同代数与原始基因组相比均无显著差异。SNP突变分析显示,不同代数的LCZ基因组高度保守,突变频率较低。平均核苷酸一致性(ANI)和系统发育树结果表明,不同代数的LCZ与原始基因组亲缘关系接近。不同代数的菌株所注释到的碳水化合物活性酶(CAZymes)无显著差异,表明其碳水化合物利用能力一致。【结论】LCZ在连续传代过程中表现出较高的遗传稳定性。
文摘【目的】以葡萄汁为原料,植物乳杆菌Zhang-LL及马克斯克鲁维酵母M3为发酵菌株,优化葡萄汁酵素的发酵工艺条件。【方法】比较植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3在葡萄汁中的不同接种方式对益生菌活菌数和DPPH清除率的影响,筛选葡萄汁酵素最优接种发酵方式。进一步通过单因素试验及响应面试验,优化葡萄汁酵素最佳发酵工艺条件。【结果】植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵可以显著提高葡萄汁酵素中益生菌活菌数和DPPH清除率;植物乳杆菌Zhang-LL和马克斯克鲁维酵母M3共发酵的最佳工艺条件为:按照1∶1比例接种,初始接种量5.00 lg CFU/mL、大豆蛋白胨添加量0.46%、34℃发酵18 h,植物乳杆菌Zhang-LL活菌数达6.60×10^(8)CFU/mL,马克斯克鲁维酵母M3活菌数达8.20×10^(7)CFU/mL,酵素DPPH清除率85.25%。【结论】乳酸菌与酵母菌协同发酵,在缩短发酵时间的同时还能达到较高的活菌数和DPPH清除率,可为葡萄汁酵素的工业化制备及后续多功能产品研发提供理论依据。
基金supported by Undergraduate Training Program for Innovation and Entrepreneurship of China University of Mining and Technology (CUMT)(Grant No. 202110290059Z)Fundamental Research Funds for the Central Universities of CUMT (Grant No. 2020ZDPYMS33)。
文摘Extensive numerical simulations and scaling analysis are performed to investigate competitive growth between the linear and nonlinear stochastic dynamic growth systems, which belong to the Edwards–Wilkinson(EW) and Kardar–Parisi–Zhang(KPZ) universality classes, respectively. The linear growth systems include the EW equation and the model of random deposition with surface relaxation(RDSR), the nonlinear growth systems involve the KPZ equation and typical discrete models including ballistic deposition(BD), etching, and restricted solid on solid(RSOS). The scaling exponents are obtained in both the(1 + 1)-and(2 + 1)-dimensional competitive growth with the nonlinear growth probability p and the linear proportion 1-p. Our results show that, when p changes from 0 to 1, there exist non-trivial crossover effects from EW to KPZ universality classes based on different competitive growth rules. Furthermore, the growth rate and the porosity are also estimated within various linear and nonlinear growths of cooperation and competition.
