Characterization of lactococci and lactobacilli isolated from semihard goats' cheese

1991 ◽  
Vol 58 (1) ◽  
pp. 137-145 ◽  
Author(s):  
Teresa Requena ◽  
Carmen Peláez ◽  
Michel J. Desmazeaud
Keyword(s):  
Leucine Aminopeptidase ◽  
Sodium Dodecyl ◽  
Skim Milk ◽  
Titratable Acidity ◽  
Aminopeptidase Activity ◽  
Whole Cells ◽  
Alanine Aminopeptidase ◽  
Triton X ◽  
Hydrolysis Of

SummarySeveral strains ofLactococcus lactissubsp.lactis, Lactobacillus caseiandLactobacillus plantarumisolated from traditional goats' cheese have been studied for titratable acidity, proteolysis in milk and enzymic activities. Aminopeptidasc activities were measured with whole cells and cells permeabilized with Triton X-100. Caseinolytic activity was investigated using electrophoresis in polyacrylamide gel with sodium dodecyl sulphate.Lc. lactissubsp.lactishad a level of proteolytic activity in skim milk greater than that ofLb. casei, while this activity inLb. plantarumwas very low. Alanine aminopeptidase activity was almost non-existent for all strains tested, while lysine aminopeptidase activity appeared to be of fundamentally intracellular origin. Leucine aminopeptidase activity was also greater in cells that had been permeabilized than in whole cells forLb. caseiandLb. plantarum. Lc. lactissubsp.lactisleucine aminopeptidase activity was greater in whole cells. No significant hydrolysis of casein was found withLb. caseiI FPL 725 andLb. plantarumIFPL 722 permeabilized with Triton X-100 after 24 h incubation with whole bovine casein.

THE CHARACTERIZATION OF LACTOBACILLI FROM CHEDDAR CHEESE: I. AN EVALUATION OF PHYSIOLOGICAL AND BIOCHEMICAL TESTS

1962 ◽  
Vol 8 (5) ◽  
pp. 727-735 ◽  
Author(s):  
R. E. Smith ◽  
J. D. Cunningham
Keyword(s):  
Preliminary Investigation ◽  
Skim Milk ◽  
Cheddar Cheese ◽  
Titratable Acidity ◽  
Lactobacillus Brevis ◽  
Lactobacillus Helveticus ◽  
Biochemical Tests ◽  
Morphological Studies ◽  
Hydrolysis Of

Characterization studies were conducted on 230 cultures of lactobacilli isolated from Canadian Cheddar cheese, and on an additional 15 named cultures from various sources. Preliminary investigation included reactions with 19 carbohydrates, yeast glucose litmus milk, and arginine, hippurate, and aesculin broths. This resulted in the appearance of six major groups, tentatively designated as Lactobacillus plantarum, Lactobacillus casei, Lactobacillus helveticus, Lactobacillus brevis, Lactobacillus fermenti, and an unclassifiable group. Subgroups of the divisions were noted. Sixty-eight cultures were chosen for detailed study. Tests performed included the production of catalase, nitrite, hydrogen sulphide, indole, and polysaccharide; the hydrolysis of starch, gelatin, Tweens 40 and 60, polypectate, and casein; and tolerance of growth temperatures, sodium chloride, and phenol. Titratable acidity in skim milk was determined, and morphological studies were carried out. Accumulated data indicated that the group previously designated as L. helveticus, and the unclassified group, consisted of variants of L. plantarum, L. casei, or intermediates.

scholarly journals Purification and Characterization of an Inverting Stereo- and Enantioselective sec-Alkylsulfatase from the Gram-Positive Bacterium Rhodococcus ruber DSM 44541

2003 ◽  
Vol 69 (5) ◽  
pp. 2810-2815 ◽  
Author(s):  
Mateja Pogorevc ◽  
Kurt Faber
Keyword(s):  
Enzymatic Hydrolysis ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Rhodococcus Ruber ◽  
Whole Cells ◽  
Enantiomeric Ratio ◽  
Alkyl Sulfates ◽  
Substrate Tolerance ◽  
Hydrolysis Of

ABSTRACT Whole cells of Rhodococcus ruber DSM 44541 were found to hydrolyze (±)-2-octyl sulfate in a stereo- and enantiospecific fashion. When growing on a complex medium, the cells produced two sec-alkylsulfatases and (at least) one prim-alkylsulfatase in the absence of an inducer, such as a sec-alkyl sulfate or a sec-alcohol. From the crude cell-free lysate, two proteins responsible for sulfate ester hydrolysis (designated RS1 and RS2) were separated from each other based on their different hydrophobicities and were subjected to further chromatographic purification. In contrast to sulfatase RS1, enzyme RS2 proved to be reasonably stable and thus could be purified to homogeneity. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a single band at a molecular mass of 43 kDa. Maximal enzyme activity was observed at 30°C and at pH 7.5. Sulfatase RS2 showed a clear preference for the hydrolysis of linear secondary alkyl sulfates, such as 2-, 3-, or 4-octyl sulfate, with remarkable enantioselectivity (an enantiomeric ratio of up to 21 [23]). Enzymatic hydrolysis of (R)-2-octyl sulfate furnished (S)-2-octanol without racemization, which revealed that the enzymatic hydrolysis proceeded through inversion of the configuration at the stereogenic carbon atom. Screening of a broad palette of potential substrates showed that the enzyme exhibited limited substrate tolerance; while simple linear sec-alkyl sulfates (C7 to C10) were freely accepted, no activity was found with branched and mixed aryl-alkyl sec-sulfates. Due to the fact that prim-sulfates were not accepted, the enzyme was classified as sec-alkylsulfatase (EC 3.1.6.X).

Quantification of small-scale heterogeneity in aquatic aminopeptidase activity

2020 ◽  
Vol 84 ◽  
pp. 127-140
Author(s):  
BM Gaas ◽  
JW Ammerman
Keyword(s):  
Chlorophyll Fluorescence ◽  
Leucine Aminopeptidase ◽  
Hudson River ◽  
Aminopeptidase Activity ◽  
Small Scale ◽  
Analysis Instrument ◽  
Sequential Samples ◽  
Degree Of Confidence ◽  
The Mean ◽  
Hydrolysis Of

Leucine aminopeptidase (LAP) is one of the enzymes involved in the hydrolysis of peptides, and is sometimes used to indicate potential nitrogen limitation in microbes. Small-scale variability has the potential to confound interpretation of underlying patterns in LAP activity in time or space. An automated flow-injection analysis instrument was used to address the small-scale variability of LAP activity within contiguous regions of the Hudson River plume (New Jersey, USA). LAP activity had a coefficient of variation (CV) of ca. 0.5 with occasional values above 1.0. The mean CVs for other biological parameters—chlorophyll fluorescence and nitrate concentration—were similar, and were much lower for salinity. LAP activity changed by an average of 35 nmol l-1 h-1 at different salinities, and variations in LAP activity were higher crossing region boundaries than within a region. Differences in LAP activity were ±100 nmol l-1 h-1 between sequential samples spaced <10 m apart. Variogram analysis indicated an inherent spatial variability of 52 nmol l-1 h-1 throughout the study area. Large changes in LAP activity were often associated with small changes in salinity and chlorophyll fluorescence, and were sensitive to the sampling frequency. This study concludes that LAP measurements in a sample could realistically be expected to range from zero to twice the average, and changes between areas or times should be at least 2-fold to have some degree of confidence that apparent patterns (or lack thereof) in activity are real.

scholarly journals Crystal structure of thermostable alkylsulfatase SdsAP from Pseudomonas sp. S9

2017 ◽  
Vol 37 (3) ◽  
Author(s):  
Lifang Sun ◽  
Pu Chen ◽  
Yintao Su ◽  
Zhixiong Cai ◽  
Lingwei Ruan ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Sodium Dodecyl ◽  
Titration Calorimetry ◽  
Pseudomonas Sp ◽  
Sterol Carrier Protein ◽  
Dimerization Domain ◽  
Alkyl Chains ◽  
Hydrolysis Of

A novel alkylsulfatase from bacterium Pseudomonas sp. S9 (SdsAP) was identified as a thermostable alkylsulfatases (type III), which could hydrolyze the primary alkyl sulfate such as sodium dodecyl sulfate (SDS). Thus, it has a potential application of SDS biodegradation. The crystal structure of SdsAP has been solved to a resolution of 1.76 Å and reveals that SdsAP contains the characteristic metallo-β-lactamase-like fold domain, dimerization domain, and C-terminal sterol carrier protein type 2 (SCP-2)-like fold domain. Kinetic characterization of SdsAP to SDS by isothermal titration calorimetry (ITC) and enzymatic activity assays of constructed mutants demonstrate that Y246 and G263 are important residues for its preference for the hydrolysis of ‘primary alkyl’ chains, confirming that SdsAP is a primary alkylsulfatase.

Preparative isolation and characterization of the B875 complex from Rhodobacter sphaeroides 2.4.1

1988 ◽  
Vol 66 (5) ◽  
pp. 442-448 ◽  
Author(s):  
Rafael Picorel ◽  
Gabriel Gingras
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Phosphatidyl Ethanolamine ◽  
Sodium Dodecyl ◽  
Pigment Analysis ◽  
Preparative Isolation ◽  
Ethanolamine Phosphatidyl ◽  
Isolation And Characterization ◽  
Detergent System ◽  
Triton X

We have developed a simple and efficient method, using a mixed detergent system of sodium dodecyl sulfate and Triton X-100, for the preparative isolation of theB875 complex from Rhodobacter sphaeroides 2.4.1. As a bonus, the method allows the preparation of both the B875 and B800-850 complexes from the same batch of chromatophores. The preparations are spectrally pure, as indicated by absorption and circular dichroism spectroscopy. The latter method suggests that the Qy band of the B875 complex is due to weakly interacting bacteriochlorophyll molecules. Protein and pigment analysis shows that the B875 complex contains 2 mol of bacteriochlorophyll and 2 mol of sphaeroidene per mol of apoprotein (12 266 g), whereas the B800-850 complex contains 3 mol of bacteriochlorophyll and 1 mol of sphaeroidene per mol of apoprotein (11 497 g). While these stoichiometries are in accord with currently accepted models, they disagree with their published experimental basis. Phosphatidyl choline, phosphatidyl ethanolamine, phosphatidyl glycerol, and diphosphatidyl glycerol were found to be present in the B875 complex.

scholarly journals Purification and Characterization of 2,6-β-d-Fructan 6-Levanbiohydrolase fromStreptomyces exfoliatus F3-2

2000 ◽  
Vol 66 (1) ◽  
pp. 252-256 ◽  
Author(s):  
Katsuichi Saito ◽  
Kazuya Kondo ◽  
Ichiro Kojima ◽  
Atsushi Yokota ◽  
Fusao Tomita
Keyword(s):  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Extracellular Enzyme ◽  
Molecular Weights ◽  
Sds Page ◽  
Monomeric Structure ◽  
Ph Range ◽  
Hydrolysis Of

ABSTRACT Streptomyces exfoliatus F3-2 produced an extracellular enzyme that converted levan, a β-2,6-linked fructan, into levanbiose. The enzyme was purified 50-fold from culture supernatant to give a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The molecular weights of this enzyme were 54,000 by SDS-PAGE and 60,000 by gel filtration, suggesting the monomeric structure of the enzyme. The isoelectric point of the enzyme was determined to be 4.7. The optimal pH and temperature of the enzyme for levan degradation were pH 5.5 and 60°C, respectively. The enzyme was stable in the pH range 3.5 to 8.0 and also up to 50°C. The enzyme gave levanbiose as a major degradation product from levan in an exo-acting manner. It was also found that this enzyme catalyzed hydrolysis of such fructooligosaccharides as 1-kestose, nystose, and 1-fructosylnystose by liberating fructose. Thus, this enzyme appeared to hydrolyze not only β-2,6-linkage of levan, but also β-2,1-linkage of fructooligosaccharides. From these data, the enzyme from S. exfoliatus F3-2 was identified as a novel 2,6-β-d-fructan 6-levanbiohydrolase (EC 3.2.1.64 ).

Characterization of peptidases of adult Trichuris muris

Parasitology ◽  
1994 ◽  
Vol 109 (5) ◽  
pp. 623-630 ◽  
Author(s):  
L. J. Drake ◽  
A. E. Bianco ◽  
D. A. P. Bundy ◽  
F. Ashall
Keyword(s):  
Mammalian Cells ◽  
Culture Medium ◽  
Matrix Protein ◽  
Sodium Dodecyl ◽  
Time Dependent ◽  
Extracellular Matrix Protein ◽  
Peptidase Activity ◽  
Trichuris Muris ◽  
Hydrolysis Of

Excretory/secretory (E/S) material of Trichuris muris was found to contain 2 major peptidases, Mr 85 and 105 kDa, which degrade gelatin optimally at pH 6·0 in sodium dodecyl sulphate–polyacrylamide gels. The peptidases were inactivated diisopropylfluorophosphate, leupeptin and soybean trypsin inhibitor, but were unaffected by inhibitors of aspartic-, cysteine- and metallo-peptidases, indicating that they are serine peptidases. Both enzymes were detectable within 5 h after incubation of worms in culture medium and showed a time-dependent increase in levels. Neither peptidase was detected in worm extracts, suggesting that they are activated during or following secretion from worms. Live worms degraded radio-isotope labelled extracellular matrix protein substratum derived from mammalian cells. Aminopeptidase activities capable of catalysing hydrolysis of amino acyl aminomethylcoumarin (MCA) substrates and a Z-Phe-Arg-MCA-hydrolysing cysteine peptidase activity, were detected in extracts of adult worms but not in E/S material.

Characterization of Muscle Sarcoplasmic and Myofibrillar Protein Hydrolysis Caused by Lactobacillus plantarum

1999 ◽  
Vol 65 (8) ◽  
pp. 3540-3546 ◽  
Author(s):  
Silvina Fadda ◽  
Yolanda Sanz ◽  
Graciela Vignolo ◽  
M.-Concepción Aristoy ◽  
Guillermo Oliver ◽  
...  
Keyword(s):  
Lactobacillus Plantarum ◽  
Myofibrillar Protein ◽  
Myofibrillar Proteins ◽  
Muscle Proteins ◽  
Whole Cells ◽  
Sarcoplasmic Proteins ◽  
Cell Extracts ◽  
Hydrophobic Nature ◽  
Hydrolysis Of

ABSTRACT Strains of Lactobacillus plantarum originally isolated from sausages were screened for proteinase and aminopeptidase activities toward synthetic substrates; on the basis of that screening,L. plantarum CRL 681 was selected for further assays on muscle proteins. The activities of whole cells, cell extracts (CE), and a combination of both on sarcoplasmic and myofibrillar protein extracts were determined by protein, peptide, and free-amino-acid analyses. Proteinase from whole cells initiated the hydrolysis of sarcoplasmic proteins. The addition of CE intensified the proteolysis. Whole cells generated hydrophilic peptides from both sarcoplasmic and myofibrillar proteins. Other peptides of a hydrophobic nature resulted from the combination of whole cells and CE. The action of both enzymatic sources on myofibrillar proteins caused maximal increases in lysine, arginine, and leucine, while the action of those on sarcoplasmic proteins mainly released alanine. In general, pronounced hydrolysis of muscle proteins required enzyme activities from whole cells in addition to those supplied by CE.

scholarly journals The effect of chemical agents on the turnover of the bound phosphate associated with the sodium-and-potassium ion-stimulated adenosine triphosphatase in ox brain microsomes

1970 ◽  
Vol 120 (1) ◽  
pp. 1-13 ◽  
Author(s):  
R. Rodnight
Keyword(s):  
Sodium Chloride ◽  
Atp Hydrolysis ◽  
Sodium Dodecyl ◽  
Sodium Deoxycholate ◽  
Protein Ratio ◽  
Chemical Agents ◽  
Rapid Fall ◽  
Triton X ◽  
Hydrolysis Of ◽  
Sodium And Potassium

1. The effect of chemical agents on the turnover of the Na+-dependent bound phosphate and the simultaneous Na+-dependent hydrolysis of ATP by a membrane preparation from ox brain was studied at an ATP/protein ratio of 12.5pmol/μg. 2. The agents were added immediately after phosphorylation of the preparation in a medium containing 50mm-sodium chloride and 2.5μm-[γ-32P]ATP. 3. Concentrations of sodium chloride above 150mm, calcium chloride to 20mm and suramin to 1.4mm inhibited both phosphorylation and dephosphorylation and concomitantly slowed ATP hydrolysis. At 125mm-sodium chloride dephosphorylation and hydrolysis were slightly slowed without affecting phosphorylation. 4. Ethanol to 1.6m concentration inhibited dephosphorylation without affecting phosphorylation; the bound phosphate was increased and ATP hydrolysis slowed. 5. Ouabain to 4mm concentration partially inhibited ATP hydrolysis and caused a transient (1–2s) rise in bound phosphate followed by a rapid fall to a lower plateau value, which eventually declined to zero by the time ATP hydrolysis was complete. 6. Of the detergents examined Lubrol W, Triton X-100 and sodium deoxycholate had no significant effect on turnover. Sodium dodecyl sulphate and sodium decyl sulphate to 3.5mm and 20mm respectively completely inhibited turnover and ATP hydrolysis and stabilized the bound phosphate.

scholarly journals Input of Protein to Lake Water Microcosms Affects Expression of Proteolytic Enzymes and the Dynamics ofPseudomonas spp

2001 ◽  
Vol 67 (11) ◽  
pp. 4955-4962 ◽  
Author(s):  
Jakob Worm ◽  
Ole Nybroe
Keyword(s):  
Population Structure ◽  
Lake Water ◽  
Leucine Aminopeptidase ◽  
Proteolytic Enzymes ◽  
Extracellular Enzyme ◽  
Bacterial Consortium ◽  
Proteinase Activity ◽  
Aminopeptidase Activity ◽  
Growth Media ◽  
Hydrolysis Of

ABSTRACT The objective of this study was to determine how an input of protein to lake water affects expression of a proteolytic potential and influences the abundance and composition of a specific group of bacteria. Pseudomonas spp. were chosen as a target group that can be recovered on selective growth media and contain both proteolytic and nonproteolytic strains. Amendment with 2 mg of casein per liter increased total proteinase activity (hydrolysis of [3H]casein) by 74%, leucine-aminopeptidase activity (hydrolysis of leucine-methyl-coumarinylamide) by 133%, bacterial abundance by 44%, and phytoplankton biomass (chlorophylla) by 39%. The casein amendment also increased the abundance of culturable Pseudomonas spp. by fivefold relative to control microcosms but did not select for proteolytic isolates. Soluble proteins immunochemically related to thePseudomonas fluorescens alkaline proteinase, AprX, were detected in amended microcosms but not in the controls. The expression of this class of proteinase was confirmed exclusively for proteolyticPseudomonas isolates from the microcosms. The population structure of Pseudomonas isolates was determined from genomic fingerprints generated by universally primed PCR, and the analysis indicated that casein amendment led to only minor shifts in population structure. The appearance of AprX-like proteinases in the lake water might thus reflect a general induction of enzyme expression rather than pronounced shifts in the Pseudomonaspopulation structure. The limited effect of casein amendment onPseudomonas population structure might be due to the availability of casein hydrolysates to bacteria independent of their proteinase expression. In the lake water, 44% of the total proteinase activity was recovered in 0.22-μm-pore-size filtrates and thus without a direct association with the bacteria providing the extracellular enzyme activity. Since all Pseudomonasisolates expressed leucine-aminopeptidase in pure culture, proteolytic as well as nonproteolytic pseudomonads were likely members of the bacterial consortium that metabolized protein in the lake water.

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