scholarly journals Tolerance of autochthonous lactic acid bacteria to different processing conditions in vitro

2020 ◽  
Vol 47 (2) ◽  
pp. 119-129
Author(s):  
Mirjana Grujović ◽  
Katarina Mladenović ◽  
Ljiljana Čomić

In this paper, the effect of different temperatures, pH, and NaCl concentration on the growth of autochthonous lactic acid bacteria isolated from traditionally made Serbian cheese (Sokobanja area) was investigated by using the spectrophotometric method. Growth of tested Lactobacillus (Lb. fermentum, Lb. plantarum, and Lb. brevis) and Lactococcus lactis subsp. lactis biovar. diacetylactis five isolates were better in acidic pH, while the growth of Enterococcus isolates (E. durans, E. faecium, and E. faecalis) was better in basic pH, at 37 °C. At 4 °C after 24 h, none of the tested bacteria showed growth. Since the autochthonous isolates were tolerant to a tested range of dairy processing conditions, further studies need to include the characterization of enzymatic activity of selected isolates, as well as the ability to use these isolates like starter cultures or food supplements in dairy or non-dairy products.

2014 ◽  
Vol 5 (8) ◽  
pp. 561-579
Author(s):  
S. EL-Ghaish ◽  
Azza EL-Baz ◽  
N. Hwanhlem ◽  
M. Zommara ◽  
Eman Ayad ◽  
...  

LWT ◽  
2019 ◽  
Vol 104 ◽  
pp. 70-75 ◽  
Author(s):  
Hafiz Arbab Sakandar ◽  
Stan Kubow ◽  
Faizan Ahmed Sadiq

2019 ◽  
Vol 86 (4) ◽  
pp. 490-502 ◽  
Author(s):  
Saeed A. Hayek ◽  
Rabin Gyawali ◽  
Sulaiman O. Aljaloud ◽  
Albert Krastanov ◽  
Salam A. Ibrahim

AbstractThis review aims to familiarize the reader with research efforts on the cultivation media of lactic acid bacteria (LAB). We have also included a brief discussion on standard ingredients used in LAB media and chemically defined media as related to bacterial growth requirements. Recent research has focused on modifying standard media for the enumeration, differentiation, isolation, and identification of starter cultures and probiotics. Even though large numbers of these media have been developed to serve dairy microbial control, they have failed to provide consistent results. The research consequently points to the need to develop a reliable lactobacilli growth medium for the dairy industry.


2020 ◽  
Vol 322 ◽  
pp. 108547 ◽  
Author(s):  
Solange Aka ◽  
Bedis Dridi ◽  
Alexandre Bolotin ◽  
Elysée Armel Yapo ◽  
Marina Koussemon-Camara ◽  
...  

2018 ◽  
Vol 11 (1) ◽  
pp. 74-84 ◽  
Author(s):  
Matías S. Pellegrino ◽  
Ignacio D. Frola ◽  
Berardo Natanael ◽  
Dino Gobelli ◽  
María E.F. Nader-Macias ◽  
...  

1997 ◽  
Vol 64 (3) ◽  
pp. 409-421 ◽  
Author(s):  
TIMOTHY M. COGAN ◽  
MANUELA BARBOSA ◽  
ERIC BEUVIER ◽  
BRUNA BIANCHI-SALVADORI ◽  
PIER S. COCCONCELLI ◽  
...  

In all, 4379 isolates from 35 products, including 24 artisanal cheeses, were surveyed with a view to identifying strains that could be used as starters in commercial dairy fermentations. Of the isolates, 38% were classified as Lactococcus, 17% as Enterococcus, 14% as Streptococcus thermophilus, 12% as mesophilic Lactobacillus, 10% as Leuconostoc and 9% as thermophilic Lactobacillus. Acid production by the isolates varied considerably. Of the 1582 isolates of Lactococcus and 482 isolates of mesophilic Lactobacillus tested, only 8 and 2% respectively produced sufficient acid to lower the pH of milk to <5·3 in 6 h at 30°C. In contrast, 53, 32 and 13% of Str. thermophilus, thermophilic Lactobacillus and Enterococcus isolates respectively reduced the pH to 5·3. These isolates were found only in some French, Italian and Greek cheeses. Bacteriocins were produced by 11% of the 2257 isolates tested and 26 of them produced broad-spectrum bacteriocins which inhibited at least eight of the ten target strains used, which included lactic acid bacteria, clostridia and Listeria innocua. The most proteolytic of the 2469 isolates tested were Str. thermophilus from Fontina cheese followed by Enterococcus from Fiore Sardo and Toma cheese and thermophilic Lactobacillus from all sources. Exopolysaccharides were produced by 5·3% of the 2224 isolates tested.


2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Giusi Macaluso ◽  
Gerlando Fiorenza ◽  
Raimondo Gaglio ◽  
Isabella Mancuso ◽  
Maria Luisa Scatassa

Bacteriocins are antimicrobial proteins produced by bacteria that inhibit with a bactericidal or bacteriostatic mode of action, the growth of other bacteria. Many lactic acid bacteria (LAB) produce a high diversity of different bacteriocins. Bacteriocinogenic LAB are generally recognized as safe (GRAS) and useful to control the frequent development of pathogens and spoilage microorganisms; for this reason they are commonly used as starter cultures in food fermentations. In this study, the authors describe the results of a screening on 699 LAB isolated from wooden vat surfaces, raw milk and traditional Sicilian cheeses, for the production of bacteriocin-like inhibitory substances (BLIS), by comparing two alternative methods. The antagonistic activity of LAB and its proteinaceous nature were evaluated using the <em>spot on the lawn</em> and the <em>well-diffusion assay</em> and the sensitivity to proteolytic (proteinase K, protease B and trypsin), amylolytic (α-amylase) and lipolytic (lipase) enzymes. The indicator strains used were: <em>Listeria monocytogenes</em>, <em>Staphylococcus aureus</em>, <em>E. coli</em>, <em>Salmonella enteritidis</em>. A total of 223 strains (belonged to the species <em>Enterococcus</em> spp., <em>Lactobacillus</em> spp., <em>Pediococcus</em> spp., <em>Streptococcus</em> spp., <em>Leuconostoc</em> spp. and <em>Lactococcus lactis</em>) were found to inhibit the growth of <em>Listeria monocytogenes</em> by using the <em>spot on the lawn</em> method; only 37 of these were confirmed by using the well-diffusion assay. The direct addition of bacteriocin-producing cultures into dairy products can be a more practical and economic option for the improvement of the safety and quality of the final product.


2020 ◽  
Vol 44 (5) ◽  
pp. 523-537 ◽  
Author(s):  
Avery Roberts ◽  
Rodolphe Barrangou

ABSTRACT As a phenotypically and phylogenetically diverse group, lactic acid bacteria are found in a variety of natural environments and occupy important roles in medicine, biotechnology, food and agriculture. The widespread use of lactic acid bacteria across these industries fuels the need for new and functionally diverse strains that may be utilized as starter cultures or probiotics. Originally characterized in lactic acid bacteria, CRISPR-Cas systems and derived molecular machines can be used natively or exogenously to engineer new strains with enhanced functional attributes. Research on CRISPR-Cas biology and its applications has exploded over the past decade with studies spanning from the initial characterization of CRISPR-Cas immunity in Streptococcus thermophilus to the use of CRISPR-Cas for clinical gene therapies. Here, we discuss CRISPR-Cas classification, overview CRISPR biology and mechanism of action, and discuss current and future applications in lactic acid bacteria, opening new avenues for their industrial exploitation and manipulation of microbiomes.


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