lactobacillus brevis | 5 Important Points

lactobacillus brevis

Can Lactobacillus Brevis Reduce the Risk of Foodborne Illnesses?

Recent studies have found that Lactobacillus brevis, a naturally occurring microorganism, can significantly decrease the number of harmful bacteria in our food. Its antimicrobial properties are particularly important for reducing the risk of foodborne illnesses. This study was conducted at the Key Laboratory of Dairy Science in Heilongjiang Province and Harbin, China. Here are some of the findings:

Phylogeny

Lactobacillus brevis is a ubiquitous species of bacteria found in plants, milk, cheese, and sewage. Specific strains have been isolated from the lungs of beaked whales and jaguars, and they have also been found in different birds, bees, and other organisms. Phylogenetic studies have also revealed the phylogeny of Lactobacillus brevis.

A genome-wide phylogenetic analysis of the L. brevis genome revealed three distinct clusters: NCFM, WCFS, and GG. Each cluster was named after the strain with the largest genome: NCFM, WCFS, and GG. The NCFM cluster was the largest and most coherent cluster of lactobacilli, but outgroup genomes dominated the GG cluster and WCFS.

The phylogenetic analyses of the genomes of the four major strains of L. brevis revealed that they have close similarities in terms of their common ancestry. They were found to be related to the species despite their different origins, and their phenotypes are quite similar to those of other genus L. brevis strains. If you are interested in learning more about lactobacillus brevis, read about its genome and its phylogenetics.

The study of L. brevis genomes was conducted using the Single-Molecule-Real-Time (SMRT) sequencing technology. The researchers sequenced six L. brevis strains, five isolated from beer, one from fermented foods, and one from silage. In conclusion, the study suggests that the six strains that belong to the L. brevis species are related, but their evolutionary relationships remain unclear.

The gene for GABA biosynthesis was found in L. brevis strain CD0817. Despite the lack of genes for extracellular proteinases, the strain’s GABA-producing ability was improved by co-culturing it with conventional dairy starters. Furthermore, the high GABA-producing strains exhibited improved viability. This study aims to uncover the genetic basis for the production of GABA.

Characterization

The purified bacteriocins produced by Lactobacillus brevis OG1 and F1 were evaluated for their antimicrobial activity against Helicobacter pylori. Both were found to exhibit good stability over a pH range of 2.0 to 8.0. Bacteriocins also showed high stability over a wide pH range and excellent heat resistance. Hence, these isolates could be used for various applications, including in food and cosmetics manufacturing.

The fatty acid composition of L. brevis strains involved in wine fermentation has been studied to understand the role of these bacteria in the production of wine. These bacteria produce biogenic amines through decarboxylation of amino acids produced by substrate-specific enzymes. High concentrations of biogenic amines may cause toxicological disturbances. In the following, we will discuss some of the most important steps in L. brevis characterization.

In addition, the purified SlpA protein was used in the mass spectrometric analysis. To do this, the bacterial cells were extracted in 5M LiCl before being dialyzed. Then, samples were centrifuged to remove insoluble materials and analyzed using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The samples were then stained with EZblue to identify the proteins, and mass spectrometry was used to determine their composition.

To identify different strains of L. brevis, we performed an electrophoretic mobility assay. This test enables us to identify the most resistant strains. Because some strains of L. brevis hybridize with other lactobacilli, electrophoretic mobility is a reliable way of identifying the species. The results from these assays provide valuable insight into the genetic makeup of this strain.

Hostility to pathogenic bacteria

Several new studies have examined the hostility of Lactobacillus brevis to pathogenic bacteria. These experiments were conducted using strains of LAB isolated from fermented aloe vera. After 48 hours, these bacteria were grown in a culture medium containing 0.3 to 2% bile salts. Single colonies were then picked and examined. The findings suggest that LAB can suppress the growth of enteropathogenic bacteria.

LAB’s resistance to antibiotics is an important factor in selecting probiotic strains. This criterion can alter growth rate and pH, jeopardizing vital applications. The present study found that LAB is normally sensitive to chloramphenicol. De Almeida Junior and colleagues found that 96% of disabling strains were susceptible to chloramphenicol. Moreover, Tulumoglu et al. reported that 90% of the strains studied were resistant to gentamicin and erythromycin.

L. brevis produces biogenic amines during fermentation. Strains of L. hilgardii and brevis produce these amines. Tyramine is produced during fermentation, giving spoiled foods a fishy smell. Another fermentation metabolic pathway produces Phenylethylamine. It is present in fermented foods and chocolate and can cause a fishy odor in other food products.

Similarly, L. brevis BBE-Y52 exhibits antimicrobial activity against Streptococcus mutans, the causative agent for tooth decay. This bacteria is susceptible to chloramphenicol and tetracycline but can adhere to oral epithelial cells. Moreover, L. brevis BBE-Y52 increases IL-10/IL-12p70 ratios.

Effect of MSG on brain activity in mice

Lactobacillus brevis has been known as a high-capacity GABA-producing organism for over a decade. It can convert 30 mM of L-monosodium glutamate to GABA within 4 hours. These bacteria are known to have a significant effect on the activity of neurons, particularly the vagus nerve. Animal studies have shown that Lactobacillus brevis influences brain activity by modulating the 5-HT3 receptors and the serotonin system. This study shows that the substance may be useful in treating nervous system disorders.

The bacteria responsible for producing MSG are found in many foods. Some strains are resistant to antibiotics, such as gentamycin. These bacteria may be useful in health-oriented dairy products because they produce a significant amount of GABA, the brain’s neurotransmitter. However, it is difficult to distinguish between these strains because the authors used a single strain of each type.

This study also indicated that MSG increases the activity of certain genes in the brain. In one study, lactobacillus brevis and DSM 32386 both up-regulated GABA production genes. However, DSM 32386 was the strain with the highest production of GABA. This finding suggests that Lactobacillus brevis and MSG have a complex relationship.

In addition to the metabolic effects, Lactobacillus brevis has been associated with reduced glucose levels and decreased blood pressure in animal models. Its immunomodulatory effects have also been noted in vitro studies. Further studies are necessary to determine if the substance has potential therapeutic use. It is important to remember that Lactobacillus brevis has been known for many years and has an impressive list of potential applications.

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lactobacillus brevis

Phylogenetic relationship between two strains of L. brevis

We have investigated the phylogenetic relationship between two strains of Lactobacillus brevis by comparing their genomes. These strains differ in morphology, but their respective genome sizes are similar. Thus, a maximum-likelihood tree was constructed using 1000 replications. The genome size of strain CD0817 was 2444 kb, and its gene family composition was 40. Gene synteny of the two strains revealed numerous gene translocations and inversions. We then constructed a neighbor-joining tree using 718 single-copy orthologous genes and 1000 replications. This tree revealed that strain CD0817 diverged from other strains of L. brevis by over a million base pairs.

Prophage encoding regions were identified in five L. brevis strains by hand sequencing. Four strains contained one to four prophage-encoding regions. The prophages were confirmed through DNA extraction and structural proteome analysis. Two strains harbored prophages that were 100% similar. In addition, the host strains of L. brevis share 99% nucleotide identity over 94% of their genomes.

The phylogenetic analysis of the multiple protein sequences suggests a reclassification of the Lactobacillus genus, with a new branch at the tree’s base representing streptococci and lactococci. Lb. casei is placed at the base of the Lb. delbrueckii group, which contradicts earlier classification.

The authors are grateful for technical support from Angela Back at the Max Rubner-Institut in Kiel, Germany. They also acknowledge Johan Mathijs for technical assistance with mass spectrometry. In 2006, Loeffler and colleagues published Isolation and characterization of two strains of Lactobacillus brevis. The two strains of Lactobacillus brevis co-fermented, but their genes differed in their phylogenetic relationship.

lactobacillus brevis | 5 Important Points

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