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.

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: II. A NUMERICAL ANALYSIS OF THE DATA BY MEANS OF AN ELECTRONIC COMPUTER

1964 ◽  
Vol 10 (5) ◽  
pp. 757-762 ◽  
Author(s):  
M. M. Hauser ◽  
R. E. Smith
Keyword(s):  
Numerical Analysis ◽  
Numerical Methods ◽  
Lactobacillus Casei ◽  
Electronic Computer ◽  
Cheddar Cheese ◽  
Lactobacillus Brevis ◽  
Computer Technique ◽  
Group Relationships ◽  
Biochemical Features

Data for 59 lactobacilli isolated from Canadian Cheddar cheese and 9 named species, previously characterized on the basis of morphological, cultural, and biochemical features, were analyzed by the Adansonian numerical methods of Sneath. Results confirmed the validity of groups, originally designated as Lactobacillus plantarum, Lactobacillus casei, Lactobacillus brevis, and Lactobacillus fermenti types. The computer technique provided numerical estimates of strain and group relationships, emphasizing the extreme heterogeneity of the groups.

scholarly journals Characterization of four plasmids harboured in a Lactobacillus brevis strain encoding a novel bacteriocin, brevicin 925A, and construction of a shuttle vector for lactic acid bacteria and Escherichia coli

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1726-1737 ◽  
Author(s):  
Takaomi Wada ◽  
Masafumi Noda ◽  
Fumi Kashiwabara ◽  
Hyung Joon Jeon ◽  
Ayano Shirakawa ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Shuttle Vector ◽  
Lactobacillus Brevis ◽  
Fermented Food ◽  
Lactobacillus Helveticus ◽  
Significant Similarity ◽  
Molecular Sizes

In this study we isolated over 250 lactic acid bacteria (LAB) candidates from fruit, flowers, vegetables and a fermented food to generate an LAB library. One strain, designated 925A, isolated from kimchi (a traditional Korean fermented dish made from Chinese cabbage) produced a novel type of bacteriocin, brevicin 925A, which is effective against certain LAB, including strains of Lactobacillus, Enterococcus, Streptococcus, Bacillus and Listeria. Strain 925A, identified as Lactobacillus brevis, harboured at least four plasmids and we determined the entire nucleotide sequence of each one. The four plasmids were designated pLB925A01–04, and have molecular sizes of 1815, 3524, 8881 and 65 037 bp, respectively. We obtained bacteriocin non-producing derivatives by treatment of strain 925A with novobiocin. All of these derivatives, which were susceptible to their own antibacterial product, lost the largest plasmid, pLB925A04, suggesting that the genes for bacteriocin biosynthesis (breB and breC) and immunity (breE) are located on pLB925A04. The partial amino acid sequence of purified brevicin 925A and sequence analysis of pLB925A04 showed that breB is the structural gene for brevicin 925A. We constructed a shuttle vector (pLES003, 6134 bp) that can replicate in both Escherichia coli and LAB such as Lactobacillus plantarum, Lb. brevis, Lactobacillus helveticus, Lactobacillus hilgardii and Enterococcus hirae. To determine the function of gene breE, which displays no significant similarity to any other sequences in the blast search database, the gene was inserted into pLES003. A pLB925A04-cured derivative transformed with pLES003 carrying breE acquired immunity to brevicin 925A, suggesting that breE encodes an immunity protein.

scholarly journals Genetic Characterization of a Cell Envelope-Associated Proteinase from Lactobacillus helveticus CNRZ32

1999 ◽  
Vol 181 (15) ◽  
pp. 4592-4597 ◽  
Author(s):  
Jeffrey A. Pederson ◽  
Gerald J. Mileski ◽  
Bart C. Weimer ◽  
James L. Steele
Keyword(s):  
Cell Surface ◽  
Deletion Mutant ◽  
Cell Envelope ◽  
Physiological Role ◽  
Lactobacillus Helveticus ◽  
Whole Cells ◽  
A Cell ◽  
Hydrolysis Of

ABSTRACT A cell envelope-associated proteinase gene (prtH) was identified in Lactobacillus helveticus CNRZ32. TheprtH gene encodes a protein of 1,849 amino acids and with a predicted molecular mass of 204 kDa. The deduced amino acid sequence of the prtH product has significant identity (45%) to that of the lactococcal PrtP proteinases. Southern blot analysis indicates thatprtH is not broadly distributed within L. helveticus. A prtH deletion mutant of CNRZ32 was constructed to evaluate the physiological role of PrtH. PrtH is not required for rapid growth or fast acid production in milk by CNRZ32. Cell surface proteinase activity and specificity were determined by hydrolysis of αs1-casein fragment 1-23 by whole cells. A comparison of CNRZ32 and its prtH deletion mutant indicates that CNRZ32 has at least two cell surface proteinases that differ in substrate specificity.

CHARACTERIZATION OF EXTRACELLULAR PROTEASE FROM VIBRIO METSCHNIKOVII STRAIN XMB 057

2017 ◽  
Vol 4 (36) ◽  
Author(s):  
Girase M. S. ◽  
Gaikwad V. B. ◽  
Patil S. N.
Keyword(s):  
Skim Milk ◽  
Hard Water ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Biochemical Tests ◽  
Natural Sources ◽  
Primary Screening ◽  
Secondary Screening ◽  
Vibrio Metschnikovii

From various natural sources on skim milk agar plates 51protease producer bacteria wereisolated by primary screening. Secondary screening was done by zone of clearanceformed by cell free broth on gelatin agar plates. From diameter of zone of clearance potent protease best protease producers Vibrio metschnikovii strain Xmb 057 was isolated. It was biochemically characterized by performing some common biochemical tests. Effect of temperature and pH on protease by Vibrio metschnikovii strain Xmb 057 was studied. Optimum temperature and pH was 500C and 9 respectively make it suitable to be used in leather and detergent industry. Protease was tolerant to Ca++ and Mg++ which suggest its activity in detergents used even in hard water.

scholarly journals MOLECULAR CHARACTERIZATION OF β-AGARASE PRODUCED BY SPHINGOMONAS PAUCIMOBILIS, A MARINE BACTERIUM

2021 ◽  
Vol 4 (2) ◽  
pp. e159
Author(s):  
Arunmozhi Bharathi Achudhan ◽  
Mahalakshmi Velrajan
Keyword(s):  
Extracellular Enzyme ◽  
Spectroscopy Analysis ◽  
Biochemical Tests ◽  
Ammonium Sulphate Precipitation ◽  
Sds Page ◽  
Marine Source ◽  
Solid Waste Generation ◽  
Automated Instrument ◽  
Hydrolysis Of

Agarases are enzymes that catalyze the hydrolysis of agar. The present study was carried out to isolate the agar degrading microorganisms from marine source. The characterization of agar degrading organism was done by VITEK 2.0 automated instrument, which confirmed the sample as Spinghomonas paucimobilis by a set of 64 biochemical tests. Production of agarase, an extracellular enzyme was done in mineral salt broth with agar and the enzyme was purified by ammonium sulphate precipitation and dialysis. The molecular weight of the enzyme was determined by SDS-PAGE method. Fourier transform infrared spectroscopy analysis was done to authenticate the degree of degradation of agar. The presence of agarase gene was targeted using the required primers and amplified by Polymerase chain reaction. Also the study addresses the problem of solid waste generation of agar waste by any microbiological laboratories and industries.

scholarly journals Screening and Characterization of a Mutant Fungal Aspartic Proteinase from Mucor pusillus

2015 ◽  
Vol 9 (1) ◽  
pp. 119-126
Author(s):  
Li Yuqiu ◽  
Tan Hua ◽  
Li Da ◽  
Li Zhoulin ◽  
Chi Yanping ◽  
...  
Keyword(s):  
Cheddar Cheese ◽  
Aspartic Proteinase ◽  
Site Directed Mutagenesis ◽  
Soluble Nitrogen ◽  
Milk Clotting ◽  
Sds Page ◽  
Wide Range ◽  
Hydrolysis Of ◽  
Pepstatin A

In this study, site-directed mutagenesis was carried out to alter properties of Mucor pusillus rennet (MPR) in order to find a potential substitution of commercial chymosin. Mutant G186D/E13D screened from thousands of mutants showed a significant milk-clotting activity (MCA). Mutant G186D/E13D rennet was purified and characterized. The molecular weight was estimated to be 44 kDa by SDS-PAGE. The maximum enzyme activity was at a wide range of pH (5.0-7.0) and 60ºC. The enzyme was inhibited by metal ions (Fe2+, Fe3+, Cu+ and Zn2+), 1.10-Phenantrolin and pepstatin A. Further texture analysis of types of cheddar cheese made by non-mutant rennet, mutant (G186D/E13D) rennet and commercial rennet suggested that the soluble nitrogen content and hardness of cheddar cheese made by chimeric mutant rennet was decreased without any significant change in flavor between these cheeses. The result implicated that, to some extent, the mutant rennet could decrease hydrolysis of protein during ripening of cheese, probably as a candidate for a useful milk coagulant.

scholarly journals Identification of Endopeptidase Genes from the Genomic Sequence of Lactobacillus helveticus CNRZ32 and the Role of These Genes in Hydrolysis of Model Bitter Peptides

2005 ◽  
Vol 71 (6) ◽  
pp. 3025-3032 ◽  
Author(s):  
Vidya R. Sridhar ◽  
Joanne E. Hughes ◽  
Dennis L. Welker ◽  
Jeffery R. Broadbent ◽  
James L. Steele
Keyword(s):  
Genomic Sequence ◽  
Cheddar Cheese ◽  
Lactobacillus Helveticus ◽  
Model Systems ◽  
Cheese Ripening ◽  
Bitter Peptides ◽  
Cell Extracts ◽  
Genes Encoding ◽  
Hydrolysis Of

ABSTRACT Genes encoding three putative endopeptidases were identified from a draft-quality genome sequence of Lactobacillus helveticus CNRZ32 and designated pepO3, pepF, and pepE2. The ability of cell extracts from Escherichia coli DH5α derivatives expressing CNRZ32 endopeptidases PepE, PepE2, PepF, PepO, PepO2, and PepO3 to hydrolyze the model bitter peptides, β-casein (β-CN) (f193-209) and αS1-casein (αS1-CN) (f1-9), under cheese-ripening conditions (pH 5.1, 4% NaCl, and 10°C) was examined. CNRZ32 PepO3 was determined to be a functional paralog of PepO2 and hydrolyzed both peptides, while PepE and PepF had unique specificities towards αS1-CN (f1-9) and β-CN (f193-209), respectively. CNRZ32 PepE2 and PepO did not hydrolyze either peptide under these conditions. To demonstrate the utility of these peptidases in cheese, PepE, PepO2, and PepO3 were expressed in Lactococcus lactis, a common cheese starter, using a high-copy vector pTRKH2 and under the control of the pepO3 promoter. Cell extracts of L. lactis derivatives expressing these peptidases were used to hydrolyze β-CN (f193-209) and αS1-CN (f1-9) under cheese-ripening conditions in single-peptide reactions, in a defined peptide mix, and in Cheddar cheese serum. Peptides αS1-CN (f1-9), αS1-CN (f1-13), and αS1-CN (f1-16) were identified from Cheddar cheese serum and included in the defined peptide mix. Our results demonstrate that in all systems examined, PepO2 and PepO3 had the highest activity with β-CN (f193-209) and αS1-CN (f1-9). Cheese-derived peptides were observed to affect the activity of some of the enzymes examined, underscoring the importance of incorporating such peptides in model systems. These data indicate that L. helveticus CNRZ32 endopeptidases PepO2 and PepO3 are likely to play a key role in this strain's ability to reduce bitterness in cheese.

Fine Structural Localization of Acyltransferases Involved in Lipid Synthesis in Intestinal Mucosa.

1970 ◽  
Vol 28 ◽  
pp. 54-55
Author(s):  
R. J. Barrnett ◽  
J. A. Higgins
Keyword(s):  
Smooth Endoplasmic Reticulum ◽  
Lipid Synthesis ◽  
Mucosal Cell ◽  
Structural Localization ◽  
Morphological Studies ◽  
Mucosal Cells ◽  
Initial Appearance ◽  
Sh Group ◽  
Hydrolysis Of ◽  
Intestinal Mucosal Cells

The main products of intestinal hydrolysis of dietary triglycerides are free fatty acids and monoglycerides. These form micelles from which the lipids are absorbed across the mucosal cell brush border. Biochemical studies have indicated that intestinal mucosal cells possess a triglyceride synthesising system, which uses monoglyceride directly as an acylacceptor as well as the system found in other tissues in which alphaglycerophosphate is the acylacceptor. The former pathway is used preferentially for the resynthesis of triglyceride from absorbed lipid, while the latter is used mainly for phospholipid synthesis. Both lipids are incorporated into chylomicrons. Morphological studies have shown that during fat absorption there is an initial appearance of fat droplets within the cisternae of the smooth endoplasmic reticulum and that these subsequently accumulate in the golgi elements from which they are released at the lateral borders of the cell as chylomicrons.We have recently developed several methods for the fine structural localization of acyltransferases dependent on the precipitation, in an electron dense form, of CoA released during the transfer of the acyl group to an acceptor, and have now applied these methods to a study of the fine structural localization of the enzymes involved in chylomicron lipid biosynthesis. These methods are based on the reduction of ferricyanide ions by the free SH group of CoA.

Phylogeny Characterization of Seb Gene Encoding Enterotoxins in Staphylococcus aureus Isolated from Raw Milk and Cheese

2019 ◽  
Vol 9 (o3) ◽  
Author(s):  
Fatima N. Aziz ◽  
Laith Abdul Hassan Mohammed-Jawad
Keyword(s):  
Staphylococcus Aureus ◽  
Food Poisoning ◽  
Raw Milk ◽  
Staphylococcal Enterotoxin B ◽  
Human Pathogen ◽  
Conventional Pcr ◽  
Biochemical Tests ◽  
Specific Primers ◽  
Gene Encoding

Food poisoning due to the bacteria is a big global problem in economically and human's health. This problem refers to an illness which is due to infection or the toxin exists in nature and the food that use. Milk is considered a nutritious food because it contains proteins and vitamins. The aim of this study is to detect and phylogeny characterization of staphylococcal enterotoxin B gene (Seb). A total of 200 milk and cheese samples were screened. One hundred ten isolates of Staphylococcus aureus pre-confirmed using selective and differential media with biochemical tests. Genomic DNA was extracted from the isolates and the SEB gene detects using conventional PCR with specific primers. Three staphylococcus aureus isolates were found to be positive for Seb gene using PCR and confirmed by sequencing. Sequence homology showed variety range of identity starting from (100% to 38%). Phylogenetic tree analyses show that samples (6 and 5) are correlated with S. epidermidis. This study discovered that isolates (A6-RLQ and A5-RLQ) are significantly clustered in a group with non- human pathogen Staphylococcus agnetis.

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