The effect of Lactococcus lactis and Bifidobacterium bifidum probiotics cell free supernatants on the expression of HDC and TDC genes in Staphylococcus strains isolated from milk

Abstract

The most important microorganisms contaminating milk, such as staphylococci, exert their influence by producing toxins and biogenic amines (BA). The purpose of this study was to evaluate the influence of cell-free supernatants (CFS) related to the probiotic strains of Lactococcus lactis and Bifidobacterium bifidum on the expression of BA-producing genes, histamine decarboxylase, and tyramine decarboxylase in staphylococci isolated from milk. Staphylococci isolates of cow raw milk were identified and isolated using standard methods. Samples containing these strains were analyzed by HPLC for BA production. Bacteria with target genes were treated with L. lactis and B. bifidum CFS, and the expression of target genes was measured by Real time PCR. Generally, 60 strains of Staphylococcus were isolated, and 90% of strains had HDC and TDC genes in genome. The levels of BAs were significantly higher on the second and third days after sampling compared with the first day (p <0.02). The analysis RT-PCR indicated that the under expression of target genes was statistically significant (P<0.05). This study showed that the use of probiotic bacteria can reduce the production of these amines and increase the quality of milk through reducing the expression of tyramine and histamine producing genes.

The sensory evaluation and antimicrobial efficacy of Lactobacillus acidophilus supernatant on Salmonella enteritidis in milk

“…The antimicrobial activity of postbiotics obtained in the present study has also been reported previously for other probiotic supernatants. The MIC of Staphylococcus strains isolated from milk treated with Bifidobacterium bifidum and Lactococcus lactis probiotic supernatant was reported at 125 μg/mL by Moghadam et al (Moghadam et al., 2021 ). In the same study, Gamal M. Hamad et al.…”

“…In our study, we determined the MIC of S. enteritidis treated with freeze-dried LAS by 96-cell microplate; likewise , many researchers suggested this method for the determination of microbial MIC in confront with the CFS of probiotic species (Ji & Yang, 2021;Moghadam et al, 2021).…”

“…The antimicrobial activity of postbiotics obtained in the present study has also been reported previously for other probiotic supernatants. The MIC of Staphylococcus strains isolated from milk treated with Bifidobacterium bifidum and Lactococcus lactis probiotic supernatant was reported at 125 μg/ mL by Moghadam et al (Moghadam et al, 2021). In the same study, Gamal M. Hamad et al surveyed the anti-Clostridium perfringens effect of four probiotic strain supernatants in Egyptian poultry, and they showed that Lactobacillus rhamnosous EMCC 1105 has a higher anti-clostridia potential (Hamad et al, 2020).…”

Use of pigmented rice as carrier and stingless bee honey as prebiotic to formulate novel synbiotic products mixed with three strains of probiotic bacteria

“…Probiotics are supposed to be beneficial or to prevent the production of biogenic amines and act as bactericidal components. Thus, the adhesion of probiotics would be promoted the strengthen of the beneficial effects of probiotics (Buran et al, 2022;Jiang et al, 2021;Moghadam et al, 2022). Probiotics are harmless microorganisms that, when delivered to humans in sufficient concentrations and for long enough periods of time, have certain beneficial effects on the host.…”

Establishment of ddPCR detection technology system for three contaminants in fermented milk

“…The effect of microbial contamination on fermented milk is the most serious and difficult to control (Nwamaka & Chike, 2010;Falenski et al, 2011;Poimenidou et al, 2009). Fermented milk production requires various fermenting bacteria, such as lactic acid bacteria, yeast and acetic acid bacteria in kefir (Saygili et al, 2021), and there are contaminating microorganisms in raw materials such as staphylococcus in raw milk (Moghadam et al, 2021). Thus, the fermentation of milk is easily susceptible to bacterial contamination.…”