scholarly journals Characterization of Lactic Acid Bacteria in Pecorino di Farindola Cheese and Manufacturing with a Lacticaseibacillus paracasei Autochthonous Culture

2021 ◽  
Vol 11 (17) ◽  
pp. 7897
Author(s):  
Giuseppe Aprea ◽  
Alessandra Alessiani ◽  
Franca Rossi ◽  
Lorena Sacchini ◽  
Arianna Boni ◽  
...  

This study focused on the characterization of lactic acid bacteria (LAB) in a renowned traditional Italian cheese, Pecorino di Farindola, in order to select an autochthonous culture and investigate its potential for the improvement of safety and functional properties. Two hundred and six LAB isolated throughout production and maturation from nine cheese lots of three farms were identified by 16S rRNA gene sequencing and tested for the presence of genes encoding virulence factors, vancomycin resistance (for enterococci), biogenic amines (BAs) and bacteriocin production for antimicrobial activity; and for the capacity to survive in the gastrointestinal tract (GIT) based on tolerance to low pH and bile salts and adhesion to CaCo-2 cells. A Lacticaseibacillus paracasei isolate was used in cheese making and determined a decline of spiked Listeria monocytogenes and Escherichia coli O157 faster than in the control cheese. The autochthonous bacterial groups were numerically unaffected, apart from lactobacilli that were recovered in higher numbers in cheese with the addition of the L. paracasei strain. Based on repetitive extragenic palyndrome (Rep) polymerase chain reaction (PCR) profiles, the added strain possibly dominated until day 88 in the cheese. Results encourage further trials with autochthonous cultures in order to efficiently inhibit hazardous bacteria and to enrich a functional microbiota in Pecorino di Farindola and similar cheeses.

Author(s):  
Giuseppe Aprea ◽  
Alessandra Alessiani ◽  
Franca Rossi ◽  
Lorena Sacchini ◽  
Arianna Boni ◽  
...  

This study focused on the characterization of lactic acid bacteria (LAB) in a renowned traditional Italian cheese, Pecorino di Farindola, to select an autochthonous culture and investigate its po-tential for the improvement of safety and functional properties. Two hundred and six LAB isolated throughout production and maturation from nine cheese lots of three farms were identified by 16S rRNA gene sequencing and tested for the presence of genes encoding virulence factors, vancomycin resistance (for enterococci), biogenic amines (BAs) and bacteriocin production, for antimicrobial activity, and for the capacity to survive in the gastro-intestinal tract (GIT) based on tolerance to low pH and bile salts and adhesion to CaCo-2 cells. A Lacticaseibacillus paracasei isolate was used in cheese making and determined a decline of spiked Listeria monocytogenes and Escherichia coli O157 faster than in control cheese. The autochthonous bacterial groups were numerically unaffected, apart from lactobacilli that were recovered in higher numbers in the cheese with added L. paracasei. Based on Repetitive Extragenic Palyndrome (Rep) PCR profiles, the added strain possibly dominated until day 88 in cheese. Results encourage further trials with autochthonous cultures to efficiently inhibit hazardous bacteria and enrich a functional microbiota in Pecorino di Farindola and similar cheeses.


2021 ◽  
Author(s):  
Akil LOMANI ◽  
Dennis S Nielsen ◽  
Larbi Ahmed Amine ◽  
Tahri Ahmed ◽  
Mediani Ahmed

Abstract Milk and indigenous fermented, milk based products are a rich source of lactic acid bacteria (LAB) and may serve as a source of potential probiotics. In the present study LAB were isolated from raw cows’ milk sampled at five different Algerian farms. A total of 24 Gram positive, catalase negative isolates where identified to species level using a combination of (GTG) 5-based rep-PCR fingerprinting and 16S rRNA gene sequencing. All isolates were identified as Enterococcus faecium and all isolates had highly similar rep-PCR profiles. Four representative isolates were screened for acid tolerance, bile salts tolerance, antimicrobial susceptibility, antibacterial activity and haemolysis. The four selected strains all exhibited good tolerance to low pH (2, 3, and 4), and to bile salts (concentrations of 0.5%, 1%, and 2%) and were sensitive to chloramphenicol, vancomycin, tetracycline, gentamicine and peniciline G, but were resistant to oxaciline. Cell-free supernatants of the four tested strains all inhibited Staphylococcus aureus, Escherichia coli and Listeria monocytogenes but not Salmonella Typhi. No haemolytic activity was observed.


2019 ◽  
Vol 4 (1) ◽  
pp. 106-109
Author(s):  
Helen J. Lawalata ◽  
Jovialine A. Rungkat

Diversity of Lactic acid bacteria (LAB) that have ability to improved number of carnocine on bakasang were determind by application of molecular approach. Molecular characterization of LAB was based on 16S rRNA gene sequencing.  The result  showed that one isolate lactic acid bacteria (Pediococcus sp.B.5.1)   among 9 isolates LAB exhibited the highest ability to improved number of carnocine. The molecular characterization based on 16S rRNA gene sequence showed that the Pediococcus B.5.1 isolate  clearly belonged to members of species Pediococcus acidilactici. Therefore, lactic acid bacteria with the high ability to improved number of carnosine could be found from fermented fish bakasang and make bakasang as a functional food.


Author(s):  
Jinghui Yao ◽  
Jing Gao ◽  
Jianming Guo ◽  
Hengan Wang ◽  
En Zhang ◽  
...  

The consumption of cheese in China is increasing rapidly. Little is known about the microbiota, the presence of antibiotic-resistant bacteria, or the distribution of antibiotic resistance genes (ARGs) in commercially-produced cheeses sold in China. These are important criteria for evaluating quality and safety. Thus, this study assessed the metagenomics of fifteen types of cheese using 16S rRNA gene sequencing. Fourteen bacterial genera were detected. Lactococcus , Lactobacillus , and Streptococcus were dominant based on numbers of sequence reads. Multidrug-resistant lactic acid bacteria were isolated from most of the types of cheese. The isolates showed 100% and 91.7% resistance to streptomycin and sulfamethoxazole, respectively, and genes involved in acquired resistance to streptomycin ( strB) and sulfonamides ( sul2) were detected with high frequency. To analyze the distribution of ARGs in the cheeses in overall, 309 ARGs from eight categories of ARG and nine transposase genes were profiled. A total of 169 ARGs were detected in the 15 cheeses; their occurrence and abundance varied significantly between cheeses. Our study demonstrates that there is various diversity of the bacteria and ARGs in cheeses sold in China. The risks associated with multidrug resistance of dominant lactic acid bacteria are of great concern.


2020 ◽  
Vol 25 (6) ◽  
pp. 2079-2085
Author(s):  
LIN-HU NAN ◽  
◽  
YI-SHENG CHEN ◽  
HUI-CHUNG WU ◽  
YU-CHING SU ◽  
...  

Lychee is a popular fruit in China and southeastern Asia. Although it is very popular, the microbiota of lactic acid bacteria (LAB) associated with lychee remains poorly described. Lychee samples from seven different markets located in three cities in Taiwan were collected and a total of 104 LAB were isolated. Through RFLP analyses of 16S rDNA and rpoA genes for grouping and 16S rRNA gene sequencing, these isolates were finally divided into 6 groups (A to F). The most common genera of LAB in lychee samples were Weissella and Leuconostoc. Weissella confusa strain E was found to produce a bacteriocin active against Listeria monocytogenes and some other Gram-positive bacteria. Mass spectrometry analysis revealed the bacteriocin mass to be approximately 3426.77 Da, which is different to other known Weissella bacteriocins. In addition, strain MB7 included in the genus Leuconostoc was identified as potential novel species or subspecies on the basis of phylogenetic analysis of 16S rRNA, rpoA and pheS gene sequences. Thus, this is the first report describing the distribution and varieties of LAB associated with lychee fruits. In addition, one potential novel LAB species or subspecies and one potential novel bacteriocin were also reported in this study.


2019 ◽  
Vol 8 (1) ◽  
pp. 5 ◽  
Author(s):  
Anshul Sharma ◽  
Jasmine Kaur ◽  
Sulhee Lee ◽  
Young-Seo Park

The present work aimed at tracking intentionally inoculated lactic acid bacteria (LAB) strains in yogurt and probiotic powder. Leuconostoc (Leu.) mesenteroides (11251), Lactobacillus (L.) brevis (B151), and Lactobacillus plantarum (LB41K) strains were tracked in yogurt, and L. plantarum (LB41P) was tracked in a commercial probiotic powder. The yogurt was intentionally inoculated with the selected bacterial strains. Two types of yogurt with known and unknown bacterial pools were utilized. The standard 16S rRNA gene sequencing was used to evaluate the initial screening. The molecular typing tools, random amplified polymorphic DNA (RAPD), repetitive element palindromic PCR (rep-PCR), and comparative gene sequence analysis of selected housekeeping loci were used to track the inoculated dubious strains. Out of 30 random selections for each inoculation, the developed method identified seven (11251), nine (B151), and five (LB41K) colonies in the yogurt. The validation was performed by identifying 7 colonies (LB41P) out of 30 in the probiotic powder. The DNA banding profiles and the gene sequence alignments led to the identification of the correct inoculated strains. Overall, the study summarizes the use of molecular tools to identify the deliberately inoculated LAB strains. In conclusion, the proposed polyphasic approach effectively tracked the intentionally inoculated strains: Leu. mesenteroides, L. brevis, and L. plantarum (LB41K) in yogurt and L. plantarum (LB41P) in probiotic powder. The study demonstrates how to track industrially relevant misused LAB strains in marketable food products.


2017 ◽  
Vol 1 (1) ◽  
pp. 89-90 ◽  
Author(s):  
Hanna Aljaksandrauna Bareika ◽  
Anatasija Vyachaslavauna Sidarenka ◽  
Galina Ivanovna Novik

Abstract From fresh and fermented vegetables (cucumber, sauercraut, eggplant), cereals (wheat, rice), legumes (soy) 37 cultures of lactic acid bacteria were isolated. Based on biochemical characteristics, MALDI-TOF MS protein profiling and 16S rRNA gene sequencing they were identified as representatives of Lactobacillus, Lactococcus, Leuconostoc, Pediococcus and Enterococcus genera. Six members of Lactobacillus genera and two members of Leuconostoc genera actively producing EPS were selected for further investigation as components of starters for production of special dietetic foodstuffs.


Agronomy ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 1344
Author(s):  
Naima Lemjiber ◽  
Khalid Naamani ◽  
Annabelle Merieau ◽  
Abdelhi Dihazi ◽  
Nawal Zhar ◽  
...  

Bacterial burn is one of the major diseases affecting pear trees worldwide, with serious impacts on producers and economy. In Morocco, several pear trees (Pyrus communis) have shown leaf burns since 2015. To characterize the causal agent of this disease, we isolated fourteen bacterial strains from different parts of symptomatic pear trees (leaves, shoots, fruits and flowers) that were tested in planta for their pathogenicity on Louise bonne and Williams cultivars. The results showed necrotic lesions with a significant severity range from 47.63 to 57.77% on leaves of the Louise bonne cultivar inoculated with isolate B10, while the other bacterial isolates did not induce any disease symptom. 16S rRNA gene sequencing did not allow robust taxonomic discrimination of the incriminated isolate. Thus, we conducted whole-genome sequencing (WGS) and phylogenetic analyzes based on gyrA, gyrB and cdaA gene sequences, indicating that this isolate belongs to the Bacillus altitudinis species. This taxonomic classification was further confirmed by the Average Nucleotide Identity (ANI) and the in silico DNA-DNA hybridization (isDDH) analyzes compared to sixty-five Bacillus spp. type strains. The genome was mined for genes encoding carbohydrate-active enzymes (CAZymes) known to play a role in the vegetal tissue degradation. 177 candidates with functions that may support the in planta phytopathogenicity results were identified. To the best of our knowledge, this is the first data reporting B. altitudinis as agent of leaf burn in P. communis in Morocco. Our dataset will improve our knowledge on spread and pathogenicity of B. altitudinis genotypes that appears as emergent phytopathogenic agent, unveiling virulence factors and their genomic location (i.e., within genomic islands or the accessory genome) to induce trees disease.


2011 ◽  
Vol 61 (10) ◽  
pp. 2520-2524 ◽  
Author(s):  
Elisa Salvetti ◽  
Giovanna E. Felis ◽  
Franco Dellaglio ◽  
Anna Castioni ◽  
Sandra Torriani ◽  
...  

The development of molecular tools and in particular the use of 16S rRNA gene sequencing has had a profound effect on the taxonomy of many bacterial groups. Gram-positive organisms that encompass the genera Lactobacillus and Clostridium within the Firmicutes are examples of taxa that have undergone major revisions based on phylogenetic information. A consequence of these reorganizations is that a number of organisms are now recognized as being misclassified. Previous studies have demonstrated that Lactobacillus catenaformis and Lactobacillus vitulinus are phylogenetically unrelated to Lactobacillus sensu stricto, being placed within the Clostridia rRNA cluster XVII. Based on the phenotypic, chemotaxonomic and phylogenetic data presented, it is proposed that L. catenaformis and L. vitulinus be reclassified in two new genera, named respectively Eggerthia gen. nov., with the type species Eggerthia catenaformis gen. nov., comb. nov. (type strain DSM 20559T = ATCC 25536T = CCUG 48174T = CIP 104817T = JCM 1121T) and Kandleria gen. nov., with the type species Kandleria vitulina gen. nov., comb. nov. (type strain LMG 18931T = ATCC 27783T = CCUG 32236T = DSM 20405T = JCM 1143T).


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