Papers by Keyword: Lactobacillus acidophilus

Abstract: Bifidobacterium lactis with oxalate-degrading capacity can efficiently reduce the oxalate in vivo, and it can be used to prevent and treat kidney stone diseases. While Bifidobacterium lactis is poorly oxygen-tolerant, which hinders it from being as microbial ecological agents. To obtain oxygen-tolerant and oxalate-degrading lactic acid bacteria, protoplast fusion technology was used between B. lactis and L. acidophilus. Under the optimum conditions of protoplast fusion with PEG 6000 concentration 50%, the fusion time 7 min, the fusion temperature 30°C, the concentration of CaCl₂ 0. 02mol/ L and the concentration of MgCl₂ 0.5mol/ L, the fusion rate reached 7.6%, and three oxygen-tolerant fusant showing that the level of oxalate degradation were similar with B. lactis was obtained. The fusants of SZY1-7 and SZY2-1 could tolerance to pH 2.5 and 0.5% (w/v) bile salt.

Abstract: Effect of four materials including trehalose, soluble starch, raffinose and galactose on survival of Lactobacillus acidophilus was studied by counting viable cells before and after freeze-drying. The concentrations of five carbohydrates were all 3%, 6%, 9%, 12% and 15%. Results showed as follows: the optimal concentrations of trehalose, soluble starch, raffinose and galactose were 12%, 9%, 3% and 15%, the survival of Lactobacillus acidophilus was 42.62%, 56.50%, 45.05% and 42.69% and the viable cells of lyophilized powder were 0.40×10¹¹cfu/g,0.45×10¹¹cfu/g, 0.52×10¹¹ and 1.09×10¹¹cfu/g, respectively.

Abstract: The value of Texture Profile Analysis (TPA) and microstructure of low- and full-fat cheese, fermented by L. acidophilus as starter culture and Str. Thermophilus as adjunct cultures, were changed after ripening for 90 d at 4 °C. The hardness, gumminess and chewiness of low-fat cheese were higher than that of full-fat cheese, while the springiness, cohesiveness and adhesiveness were less than that of full-fat cheese. The structure of low-fat cheese after ripening was more tightening and compact, while that of full-fat cheese had a lot of cavity.

Abstract: Effect of NaH₂PO₄, Na₂HPO₄, MgSO₄, and Ascorbic acid on survival of Lactobacillus acidophilus was investigated before and after freeze-drying. Editing different concentrations of protective agents respectively during freeze-drying. After completion of the pilot, the survival ratio of Lactobacillus acidophilus and the number of viable cells were being measured. Results were as follows: the highest survival rate and the largest number of viable cells was Na₂HPO₄ as the protective agent.

Abstract: In the present study, the experiments were investigated with the effecting of NaHCO3, KH2PO4, K2HPO4 and Sodium ascorbate on survival of Lactobacillus acidophilus during freeze-drying. Designing different concentrations of protective agents, respectively. The survival ratio of Lactobacillus acidophilus and the number of viable cells will be measured after completing drying. In the process, there were major differences between the different concentrations of protective agents in survival during freeze-drying. As the result, the protective agent was playing a key factor affecting the survival of Lactobacillus acidophilus. At present in the study of the experiments, the highest survival rate was NaHCO3 as the protective agent, and when the protective agent as K2HPO4 the number of viable cells was largest.

Abstract: Abstract. Low- and full-fat cheeses were fermented by Lactobacillus acidophilus and adjunct cultures Streptococcus thermophilus. After ripening for 90d at 4°C, the protein had been proteolysed in different degrees. The results showed that protein content of low- and full-fat cheese were all decreased after 90 d ripened, which the low-fat cheese was 40.45% and full-fat cheese was 28.68%. The soluble nitrogen contents at pH 4.6 (pH 4.6 SN) were 4.97% and 3.88%, and 12% (w/v) trichloracetic acid soluble nitrogen (12% TCA-SN) were 5.17% and 3.74% in low- and full-fat cheese respectively. After ripening for 90d at 4°C it was found that a part of protein in cheese were degraded into amino acids determined by automatic amino acid analyzer, total amino acids contents in low- and full-fat cheese were 29.17 mg•100g-1 and 16.02 mg•100g-1, respectively.

Abstract: Effect of Galaeto-oligosaccharide (GOS) and Isomalto-oligosaccharide (IMO) on growth of Lactobacillus acidophilus, Bifidobacterium longum and L. rhamnosus was studied. The addition of each substance (w/v) was 0.0%, 0.1%, 0.5%, 1.0% 1.5% and 2.0%.The methods were analyzed titratable acidity (°T), pH and enumeration that using reconstituted skim goat milk media as the control. All samples were incubated at 37 C for 18h. Results were as follows: addition of GOS has the significant inhibition on the growth of L. acidophilus and promotion on the growth of L. rhamnosus, while the effect on the growth of B. longum was not obviously. Addition of IMO could promote the growth of L. acidophilus, especially in low level. The growth of B. longum was increased with increase in IMO. While the effect on the growth of L. rhamnosus by adding IMO was inhibited and obviously in the high concentration.

Abstract: In the present study, the experiments were investigated with effecting of sucrose, lactose, glucose, maltose on survival of Lactobacillus acidophilus during freeze-drying. In order to reach sufficient numbers viable cells, so different concentrations of protective agents were designed in the experiment, which as 3%, 6%, 9%, 12% and 15%, respectively. Measuring the survival ratio of Lactobacillus acidophilus and number of viable cells after completed drying. There were significant differences in survival during freeze-drying. Results showed that the protective agent was a critical factor affecting the survival of Lactobacillus acidophilus. In the experiments, the highest survival rate was soluble starch as the protective agent, and when the protective agent as galactose the number of viable cells was largest.

Abstract: The cell surface hydrophobicity (CSH) of lactic acid bacteria was considered to colonization and adhesion, and playing a prebiotic function in the digestive tract. Therefore, CSH of yoghurt fermentation bacteria most commonly used was analyzed, such as Lactobacillus acidophilus, Lactobacillus bulgaricus and Streptococcus thermophilus to identify initially CSH and the influencing factors of CSH of these strains and provided a theoretical basis for the future production of high-quality dairy fermentation agents and probiotics. The method of bacterial adhesion to hydrocarbons (BATH) was utilized to determine CSH of these strains and used the different conditions to process the cell. Through this research, the results was that L. acidophilus had a strong CSH, greater than L. bulgaricus and S. thermophilus. And the influencing factors of CSH of L. acidophilus were time, temperature, pH, concentration, Ca²⁺ and protease. But CSH was significantly reduced by trypsin and pepsin. CSH L. acidophilus was connected with the adhesion ability. In addition, it was speculated that some substances which could mediate CSH of L. acidophilus may be a class of proteins. Therefore, in the process of dairy fermentation agent, these factors could be controlled to obtain high-quality products.

Abstract: Effect of the extract of Fructus tribuli (EFT) on growth of Lactobacillus acidophilus LA04, LA05, LA06 and LA09 was studied by measuring optical density at 600nm (OD600) and pH using MRS culture media as the control. The addition of EFT (v/v) was 1%, 2%, 3%, 4% and 5%. Results were as follows: addition of EFT could promote the growth of Lactobacillus acidophilus LA09, The optimum concentration of EFT in MRS media was 1% at incubation 24h, but addition of EFT on growth of Lactobacillus acidophilus LA04, LA05 and LA06 has no significant effect.