A polyphasic approach to highlight genotypic and phenotypic diversities of Lactobacillus helveticus strains isolated from dairy starter cultures and cheeses

2002 ◽  
Vol 69 (1) ◽  
pp. 139-149 ◽  
Author(s):  
ANGIOLELLA LOMBARDI ◽  
LUCIANA DAL MAISTRO ◽  
PAOLA DE DEA ◽  
MONICA GATTI ◽  
GIORGIO GIRAFFA ◽  
...  
Keyword(s):  
Cell Wall ◽  
Phenotypic Diversity ◽  
Protein Profile ◽  
Genotypic Diversity ◽  
Cell Wall Protein ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Protein Profiling ◽  
Rapd Pcr ◽  
Dairy Starter Cultures

In the present work, 67 strains of Lactobacillus helveticus isolated from whey starter cultures and cheeses were identified and grouped by genotypic and phenotypic methods. Strains were identified by sugar fermentation pattern, by cell-wall protein profile, and by probe hybridisation. Phenotypic diversity was evaluated by a chemometric model taking into account biochemical characteristics (i.e. acidifying and peptidase activities) of technological interest. Genotypic diversity was evidenced by RAPD-PCR, which provided strain-specific patterns and revealed the occurrence of different strains. The RAPD-PCR profiles were clustered according to their similarities; the groups obtained, together with the cell-wall protein profiling and the chemometric information, could be sometimes correlated with the type of cheese and/or dairy niches used as sources of strains. A computerised analysis of genotypic and phenotypic information could be successfully applied for rapid and reliable differentiation and characterisation of Lb. helveticus isolates occurring in different dairy products.

scholarly journals Effectiveness of Chemometric Techniques in Discrimination of Lactobacillus helveticus Biotypes from Natural Dairy Starter Cultures on the Basis of Phenotypic Characteristics

1999 ◽  
Vol 65 (4) ◽  
pp. 1450-1454 ◽  
Author(s):  
Monica Gatti ◽  
Giovanna Contarini ◽  
Erasmo Neviani
Keyword(s):  
Cell Wall ◽  
Cell Wall Protein ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Protein Patterns ◽  
Phenotypic Characteristics ◽  
Good Discrimination ◽  
Multivariate Statistical ◽  
Dairy Starter Cultures ◽  
Dairy Starter

ABSTRACT Lactobacillus helveticus is the dominant organism in natural starter cultures used for the production of typical Italian cheeses. In this study, 74 L. helveticus strains, isolated from grana and provolone cheese natural whey starters, were distinguished with respect to their origin by using both cell wall protein profiles and chemometric evaluation of some phenotypic parameters, such as the ability to acidify cultures and the presence of nonspecific proteolytic and peptidase activities. Cell wall protein patterns allowed L. helveticus strains to be distinguished with respect to their source of isolation. Among the different phenotypes studied, no single specific parameter permitted the two groups of strains to be separated. A good discrimination between the two groups of L. helveticus species was obtained by multivariate statistical techniques, which permitted the extraction of all of the discriminating information retained in the phenotypic activities. Associations between strain phenotype expression and dairy environmental ecosystem source are discussed.

scholarly journals Biodiversity among Lactobacillus helveticus Strains Isolated from Different Natural Whey Starter Cultures as Revealed by Classification Trees

2004 ◽  
Vol 70 (1) ◽  
pp. 182-190 ◽  
Author(s):  
Monica Gatti ◽  
Carlo Trivisano ◽  
Enrico Fabrizi ◽  
Erasmo Neviani ◽  
Fausto Gardini
Keyword(s):  
Dna Sequences ◽  
Classification Tree ◽  
Surface Protein ◽  
Genotypic Diversity ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Data Set ◽  
Grana Padano ◽  
Species Specific ◽  
Dairy Starter Cultures

ABSTRACT Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium used extensively for manufacturing Swiss type and aged Italian cheese. In this study, the phenotypic and genotypic diversity of strains isolated from different natural dairy starter cultures used for Grana Padano, Parmigiano Reggiano, and Provolone cheeses was investigated by a classification tree technique. A data set was used that consists of 119 L. helveticus strains, each of which was studied for its physiological characters, as well as surface protein profiles and hybridization with a species-specific DNA probe. The methodology employed in this work allowed the strains to be grouped into terminal nodes without difficult and subjective interpretation. In particular, good discrimination was obtained between L. helveticus strains isolated, respectively, from Grana Padano and from Provolone natural whey starter cultures. The method used in this work allowed identification of the main characteristics that permit discrimination of biotypes. In order to understand what kind of genes could code for phenotypes of technological relevance, evidence that specific DNA sequences are present only in particular biotypes may be of great interest.

scholarly journals Molecular Diversity within Lactobacillus helveticus as Revealed by Genotypic Characterization

2000 ◽  
Vol 66 (4) ◽  
pp. 1259-1265 ◽  
Author(s):  
Giorgio Giraffa ◽  
Monica Gatti ◽  
Lia Rossetti ◽  
Lucia Senini ◽  
Erasmo Neviani
Keyword(s):  
Genotypic Diversity ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Rrna Gene ◽  
Polymorphism Analysis ◽  
Multivariate Statistical ◽  
Specific Strain ◽  
Dairy Starter Cultures ◽  
Dairy Starter ◽  
The 16S Rrna Gene

ABSTRACT Lactobacillus helveticus is a homofermentative thermophilic lactic acid bacterium that is used in the manufacture of Swiss type and long-ripened Italian cheeses, such as Emmental, Grana, and Provolone cheeses. Substantial differences in several technologically important characteristics are found among L. helveticus strains isolated from natural dairy starter cultures. In the present study we investigated the genotypic diversity of 74 strains isolated from different dairy cultures used for manufacturing Grana and Provolone cheeses and six collection strains. A restriction fragment length polymorphism analysis of both total genomic DNA and the 16S rRNA gene (ribotyping) was used as genotypic fingerprinting. A multivariate statistical analysis of the data enabled us to identify significant genotypic heterogeneity inL. helveticus. We found that genotypic fingerprinting could be used to distinguish strains; in particular, it was possible to associate the presence of specific strain genotypes with dairy ecosystem sources (e.g., Grana or Provolone cheese). Our data contribute to the description of microbial heterogeneity in L. helveticus and provide a more solid basis for understanding the functional and ecological significance of the presence of differentL. helveticus biotypes in natural dairy starter cultures.

Biodiversity ofLactobacillus helveticusbacteriophages isolated from cheese whey starters

2015 ◽  
Vol 82 (2) ◽  
pp. 242-247 ◽  
Author(s):  
Miriam Zago ◽  
Barbara Bonvini ◽  
Lia Rossetti ◽  
Aurora Meucci ◽  
Giorgio Giraffa ◽  
...  
Keyword(s):  
Cheese Whey ◽  
Burst Size ◽  
Starter Cultures ◽  
Lactobacillus Helveticus ◽  
Enzyme Analysis ◽  
Restriction Enzyme Analysis ◽  
Structural Protein ◽  
Rapd Pcr ◽  
Total Dna

Twenty-oneLactobacillus helveticusbacteriophages, 18 isolated from different cheese whey starters and three from CNRZ collection, were phenotypically and genetically characterised. A biodiversity between phages was evidenced both by host range and molecular (RAPD-PCR) typing. A more detailed characterisation of six phages showed similar structural protein profiles and a relevant genetic biodiversity, as shown by restriction enzyme analysis of total DNA. Latent period, burst time and burst size data evidenced that phages were active and virulent. Overall, data highlighted the biodiversity ofLb. helveticusphages isolated from cheese whey starters, which were confirmed to be one of the most common phage contamination source in dairy factories. More research is required to further unravel the ecological role ofLb. helveticusphages and to evaluate their impact on the dairy fermentation processes where whey starter cultures are used.

scholarly journals 586 Cell Wall Protein Differences in Fruits of Two Tabasco Pepper Lines

HortScience ◽  
2000 ◽  
Vol 35 (3) ◽  
pp. 497D-497
Author(s):  
Ramon A. Arancibia ◽  
Carl E. Motsenbocker
Keyword(s):  
Cell Wall ◽  
Protein Profile ◽  
Cell Wall Protein ◽  
Abscission Zone ◽  
Capsicum Frutescens ◽  
Factors Affecting ◽  
Fruit Abscission ◽  
Detachment Force ◽  
Isolation And Characterization

`McIlhenny Select' (easy detachment) and `Hard Pick' are two lines of tabasco pepper (Capsicum frutescens L.) that differ in the fruit detachment characteristics. Cellulase (Cx) and polygalacturonase (PG) activity, extracted from the fruit abscission zone, correlated inversely with the force needed to separate the fruit from the pedicel. A trend of higher Cx and PG is associated with the lower detachment force in the McIlhenny Select line. Differences in the fruit cell wall protein profile between both lines occurred during ripening. Two bands of 23 kDa and 40 kDa were higher in `McIlhenny Select'. A band of approximately 30 kDa was higher in `Hard Pick', while a band of ≈70 kDa increased in both lines. Isolation and characterization of these bands as well as Cx and PG is needed to understand the factors affecting fruit detachment in tabasco pepper.

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