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

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.

scholarly journals Alginate Trisaccharide Binding Sites on the Surface of β-Lactoglobulin Identified by NMR Spectroscopy: Implications for Molecular Network Formation

ACS Omega ◽  
2019 ◽  
Vol 4 (4) ◽  
pp. 6165-6174 ◽  
Author(s):  
Emil G. P. Stender ◽  
Johnny Birch ◽  
Christian Kjeldsen ◽  
Lau D. Nielsen ◽  
Jens Ø. Duus ◽  
...  
Keyword(s):  
Nmr Spectroscopy ◽  
Binding Sites ◽  
Network Formation ◽  
Molecular Network ◽  
Β Lactoglobulin

scholarly journals Regulation of the Activity of Lactate Dehydrogenases from Four Lactic Acid Bacteria

2013 ◽  
Vol 288 (29) ◽  
pp. 21295-21306 ◽  
Author(s):  
Anna Feldman-Salit ◽  
Silvio Hering ◽  
Hanan L. Messiha ◽  
Nadine Veith ◽  
Vlad Cojocaru ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Ionic Strength ◽  
Lactic Acid Bacteria ◽  
Binding Sites ◽  
Binding Affinities ◽  
Nacl Concentration ◽  
Allosteric Binding Sites ◽  
Regulatory Effects ◽  
Fructose 1,6 Bisphosphate ◽  
Lactate Dehydrogenases

Despite high similarity in sequence and catalytic properties, the l-lactate dehydrogenases (LDHs) in lactic acid bacteria (LAB) display differences in their regulation that may arise from their adaptation to different habitats. We combined experimental and computational approaches to investigate the effects of fructose 1,6-bisphosphate (FBP), phosphate (Pi), and ionic strength (NaCl concentration) on six LDHs from four LABs studied at pH 6 and pH 7. We found that 1) the extent of activation by FBP (Kact) differs. Lactobacillus plantarum LDH is not regulated by FBP, but the other LDHs are activated with increasing sensitivity in the following order: Enterococcus faecalis LDH2 ≤ Lactococcus lactis LDH2 < E. faecalis LDH1 < L. lactis LDH1 ≤ Streptococcus pyogenes LDH. This trend reflects the electrostatic properties in the allosteric binding site of the LDH enzymes. 2) For L. plantarum, S. pyogenes, and E. faecalis, the effects of Pi are distinguishable from the effect of changing ionic strength by adding NaCl. 3) Addition of Pi inhibits E. faecalis LDH2, whereas in the absence of FBP, Pi is an activator of S. pyogenes LDH, E. faecalis LDH1, and L. lactis LDH1 and LDH2 at pH 6. These effects can be interpreted by considering the computed binding affinities of Pi to the catalytic and allosteric binding sites of the enzymes modeled in protonation states corresponding to pH 6 and pH 7. Overall, the results show a subtle interplay among the effects of Pi, FBP, and pH that results in different regulatory effects on the LDHs of different LABs.

Lactic acid bacteria and yeasts in kefir grains and kefir made from them

2002 ◽  
Vol 28 (1) ◽  
pp. 1-6 ◽  
Author(s):  
E Simova ◽  
D Beshkova ◽  
A Angelov ◽  
Ts Hristozova ◽  
G Frengova ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Kefir Grains

Development of biotechnology for gluten-free sourdough bakery products with a new microbial composition

2020 ◽  
Vol 29 (12) ◽  
pp. 59-63
Author(s):  
O.I. Parakhina ◽  
◽  
M.N. Lokachuk ◽  
L.I. Kuznetsova ◽  
E.N. Pavlovskaya ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Starter Culture ◽  
Comparative Assessment ◽  
Starter Cultures ◽  
Bakery Products ◽  
Gluten Free ◽  
Microbial Composition ◽  
Fermentative Activity ◽  
Theoretical Foundations

The research was carried out within the framework of the theme of state assignment № 0593–2019–0008 «To develop theoretical foundations for creating composite mixtures for bakery products using physical methods of exposure that ensure homogeneity, stability of mixtures and bioavailability of nutrients, to optimize diets population of Russia». The data on the species belonging of new strains of lactic acid bacteria and yeast isolated from samples of good quality gluten-free starter cultures are presented. A comparative assessment of the antagonistic and acid-forming activity of strains of lactic acid bacteria and the fermentative activity of yeast was carried out. The composition of microbial compositions from selected strains of LAB and yeast was developed. The influence of the starter culture on the new microbial composition on the physicochemical, organoleptic indicators of the bread quality and resistance to mold and ropy-disease was investigated.

Cryopreservation to be a progressive method for keeping up valuable strains of lactic acid bacteria and yeasts

2014 ◽  
pp. 112-119 ◽  
Author(s):  
O.A. Savkina ◽  
◽  
G.V. Ternovskoi ◽  
M.N. Lokachuk ◽  
E.N. Pavlovskaya ◽  
...  
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Progressive Method
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