Screening for lactic acid bacteria with potential to reduce antigenic response of β-lactoglobulin in bovine skim milk and sweet whey

2006 ◽  
Vol 7 (3) ◽  
pp. 233-238 ◽  
Author(s):  
Nicole Kleber ◽  
Ulrike Weyrich ◽  
Jörg Hinrichs
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Sweet Whey ◽  
Β Lactoglobulin

scholarly journals Binding Sites for Oligosaccharide Repeats from Lactic Acid Bacteria Exopolysaccharides on Bovine β-Lactoglobulin Identified by NMR Spectroscopy

ACS Omega ◽  
2021 ◽  
Author(s):  
Johnny Birch ◽  
Sanaullah Khan ◽  
Mikkel Madsen ◽  
Christian Kjeldsen ◽  
Marie Sofie Møller ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Nmr Spectroscopy ◽  
Lactic Acid Bacteria ◽  
Binding Sites ◽  
Β Lactoglobulin

Inactivation of Calcium-Dependent Lactic Acid Bacteria Phages by Phosphates

2007 ◽  
Vol 70 (6) ◽  
pp. 1518-1522 ◽  
Author(s):  
V. B. SUÁREZ ◽  
M. L. CAPRA ◽  
M. RIVERA ◽  
J. A. REINHEIMER
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Sodium Tripolyphosphate ◽  
Culture Media ◽  
Divalent Cations ◽  
Skim Milk ◽  
Inhibitory Effect ◽  
Lytic Cycle ◽  
High Solubility ◽  
Calcium Dependent

The capacity of three phosphates to interrupt the lytic cycle of four specific autochthonal bacteriophages of lactic acid bacteria used as starters was assayed. The phosphates used (polyphosphates A and B and sodium tripolyphosphate–high solubility [TAS]) were selected on the basis of their capacity to sequester divalent cations, which are involved in the lytic cycle of certain bacteriophages. The assays were performed in culture media (deMan Rogosa Sharpe and Elliker broths) and reconstituted (10%, wt/vol) commercial skim milk to which phosphates had been added at concentrations of 0.1, 0.3, and 0.5% (wt/vol). Phosphate TAS was the most inhibitory one, since it was able to inhibit the lytic cycle of all bacteriophages studied, in both broths and milk. In broth, polyphosphates A and B inhibited the lytic cycle of only two bacteriophages at the maximal concentration used (0.5%), whereas in milk, they were not capable of maintaining the same inhibitory effect.

Observation of exopolysaccharides (EPS) from Lactobacillus helveticus SBT2171 using the Tokuyasu method

Microscopy ◽  
2020 ◽  
Vol 69 (5) ◽  
pp. 286-290
Author(s):  
Takamichi Kamigaki ◽  
Akihiro Ogawa
Keyword(s):  
Electron Microscopy ◽  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Colloidal Gold ◽  
Ruthenium Red ◽  
Lactobacillus Helveticus ◽  
Ruthenium Red Staining ◽  
Observation Method ◽  
Β Lactoglobulin

Abstract Some species of lactic acid bacteria used for the production of natural cheese produce exopolysaccharides (EPS). Electron microscopy is useful for analyzing the microstructure of EPS produced by lactic acid bacteria. However, pretreatments used to observe the microstructure of EPS by electron microscopy, such as dehydration and resin embedding, can result in EPS flowing out easily from the cell. Therefore, in this study, the Tokuyasu method was conducted on cryosection to reduce EPS outflow. Two types of observation method, namely, using lectin and ruthenium red, were conducted in an attempt to observe EPS produced by Lactobacillus helveticus SBT2171. Observation using the lectin method confirmed that colloidal gold particles conjugated with a lectin recognizing β-galactoside were present in the capsule. Structures that appeared to be β-galactoside-containing slime polysaccharides that were released from the cell wall were also observed. Observation using ruthenium red showed that capsular polysaccharides (CPS) in the capsule were present as a net-like structure. Colloidal gold conjugation with an anti-β-lactoglobulin antibody, in addition to ruthenium red staining, allowed the identification of slime polysaccharides released from the cell wall in the milk protein network derived from the culture medium. Based on these results, the Tokuyasu method was considered to be a useful pretreatment method to clarify and observe the presence of EPS. In particular, both CPS in the capsule and slime exopolysaccharides released from the cell wall were visualized.

Behavior of Listeria monocytogenes in Skim Milk during Fermentation with Mesophilic Lactic Starter Cultures

1988 ◽  
Vol 51 (8) ◽  
pp. 600-606 ◽  
Author(s):  
MICHELLE M. SCHAACK ◽  
ELMER H. MARTH
Keyword(s):  
Lactic Acid ◽  
Listeria Monocytogenes ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Starter Cultures ◽  
Plate Count ◽  
Inoculum Level ◽  
Plate Count Agar ◽  
Streptococcus Lactis ◽  
Streptococcus Cremoris

The ability of Listeria monocytogenes to grow and compete with mesophilic lactic acid bacteria was examined. Autoclaved skim milk was inoculated with 103 cells of L. monocytogenes (strain V7 or Ohio)/ml, and with 5.0, 1.0, 0.5 or 0.1% of a milk culture of either Streptococcus cremoris or Streptococcus lactis. Inoculated milks were fermented for 15 h at 21 or 30°C, followed by refrigeration at 4°C. Samples were plated on McBride Listeria Agar to enumerate L. monocytogenes and on either APT Agar or plate count agar to enumerate lactic acid bacteria. L. monocytogenes survived in all fermentations, and commonly also grew to some extent. Incubation at 30°C with 5% S. lactis as inoculum appeared to be the most inhibitory combination for strain V7, causing 100% inhibition in growth based on maximum population attained. S. cremoris at the 5.0% and 0.1% inoculum levels, was slightly less inhibitory to L. monocytogenes at 37°C, but it was slightly more inhibitory to L. monocytogenes at the 1.0% inoculum level than was S. lactis. In general, S. lactis reduced the pH of fermented milks more than did S. cremoris. The population of L. monocytogenes began to decrease before 15 h in only one test combination, which was use of a 5.0% inoculum of S. cremoris and 30°C incubation. In most instances, growth of the pathogen appeared to be completely inhibited when the pH dropped below 4.75.

scholarly journals Beneficial Preventive Effects of Gastric Mucosal Lesion for Soy−Skim Milk Fermented by Lactic Acid Bacteria

2009 ◽  
Vol 57 (10) ◽  
pp. 4433-4438 ◽  
Author(s):  
Chin-Feng Liu ◽  
Chun-Ling Hu ◽  
Shen-Shih Chiang ◽  
Kuo-Chuan Tseng ◽  
Roch-Chui Yu ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Mucosal Lesion ◽  
Gastric Mucosal Lesion ◽  
Preventive Effects

The mechanisms of the protective effects of reconstituted skim milk during convective droplet drying of lactic acid bacteria

2015 ◽  
Vol 76 ◽  
pp. 478-488 ◽  
Author(s):  
Xufeng Zheng ◽  
Nan Fu ◽  
Manlei Duan ◽  
Meng Wai Woo ◽  
Cordelia Selomulya ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Protective Effects ◽  
Droplet Drying

scholarly journals Screening and enumeration of lactic acid bacteria in milk using three different culture media in Petrifilm™ Aerobic Count plates and conventional pour plate methodology

2007 ◽  
Vol 74 (4) ◽  
pp. 387-391 ◽  
Author(s):  
Maria BT Ortolani ◽  
Gabriela N Viçosa ◽  
Vanerli Beloti ◽  
Luís A Nero
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Culture Media ◽  
Skim Milk ◽  
Raw Milk ◽  
Excellent Correlation ◽  
Anaerobic Conditions ◽  
Milk Samples ◽  
Experimental Inoculation

This study aimed to compare Petrifilm™ Aerobic Count (AC) plates and the conventional pour plate methodology using de Mann-Rogosa-Sharpe (MRS), Kang-Fung (KF) and Kang-Fung-Sol (KFS) culture media for screening and enumeration of lactic acid bacteria (LAB) in milk. Suspensions of 10 LAB species in reconstituted powder skim milk and 30 raw milk samples, without experimental inoculation, were tested. For selective enumeration, all samples were previously diluted in MRS, KF and KFS broths and then plated in Petrifilm™ AC and conventional pour plate methodology, using the same culture media with added agar. All plates were incubated at 37°C for 48 h in anaerobic conditions. Differences in the counts were observed only for raw milk samples using KFS in conventional methodology, when compared with the counts obtained from MRS and KF (P⩽0·05). The results showed excellent correlation indexes between both methodologies using the three culture media for LAB suspensions (r=0·97 for MRS, KF and KFS). For raw milk samples, the correlation indexes were excellent (r=0·97, for MRS) and good (r=0·84 for KF, and r=0·82 for KFS), showing some interference in Petrifilm™ AC when supplements were added, especially lactic acid. These results indicate the possibility of using Petrifilm™ AC plates for enumeration of LAB in milk, even with the use of selective supplements.

Microstructure and rheology of an acid-coagulated cheese (Karish) made with an exopolysaccharide-producing Streptococcus thermophilus strain and its exopolysaccharide non-producing genetic variant

2004 ◽  
Vol 71 (1) ◽  
pp. 116-120 ◽  
Author(s):  
Ashraf N Hassan ◽  
Milena Corredig ◽  
Joseph F Frank ◽  
Morsi Elsoda
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Physical Properties ◽  
Creep Test ◽  
Genetic Variant ◽  
Skim Milk ◽  
Streptococcus Thermophilus ◽  
Protein Network ◽  
Dynamic Rheology ◽  
Soft Acid

The objective of this research was to determine the effect of exopolysaccharide (EPS) production by lactic acid bacteria on the microstructure and rheology of Karish cheese, a soft acid coagulated cheese made using skim milk. An EPS-producing strain of Streptococcus thermophilus, and its EPS non-producing genetic variant were used to make comparable batches of the cheese. EPS in cheese was visualized by cryo-SEM as a large, dense, filamentous mass. Cheese made with the EPS non-producing culture was characterized by a dense protein network with smaller pores compared to that prepared with the EPS-producing culture. High elastic and viscous moduli measured by dynamic rheology were observed for EPS negative cheese and was attributed to its dense protein network. Creep test experiments demonstrated that cheese prepared with the EPS non-producing strain was more rigid and recovered its deformation, while cheese made using the EPS producing culture was more deformable. These results indicate that EPS-producing cultures can improve the physical properties of Karish cheese by reducing undesirable rigidity.

Yogurt production from reconstituted skim milk powders using different polymer and non-polymer forming starter cultures

1993 ◽  
Vol 60 (2) ◽  
pp. 247-254 ◽  
Author(s):  
Carmen Wacher-Rodarte ◽  
Marcia V. Galvan ◽  
Amelia Farres ◽  
Francisco Gallardo ◽  
Valerie M. E. Marshall ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Skim Milk ◽  
Starter Cultures ◽  
Synergic Effect ◽  
Total Solids ◽  
Total Milk ◽  
Solids Content ◽  
Milk Solids ◽  
Viscosity Polymer

SummaryUsing polymer producing (ropy) strains of lactic acid bacteria it was possible to reduce considerably the syneresis of yogurt, even with 12% total milk solids. The viscosities obtained with these strains were also similar to those obtained using normal strains and milk with 17% total solids content. The concentration of milk and the polymer produced by ropy starters had a synergic effect in increasing viscosity. Polymer production was not affected in most cases by milk concentration. One type of ropy culture (Wiesby) seemed to produce a different kind of polymer as it could not be determined by alcohol precipitation, in spite of being able to reduce syneresis and increase viscosity in yogurt. A limited number of yogurts were evaluated organoleptically, one prepared with a ropy starter strain (NCFB at 12, 14·5 and 17% total solids) and one prepared with a non-ropy strain (LL-I at 17% total solids). The results suggest that the ropy strain yogurts had different mouthfeel from the non-ropy strain yogurts; the most acceptable product overall was the ropy strain made with 12% total solids.

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