Sequencing of the Tyrosine Decarboxylase Cluster of Lactococcus lactis IPLA 655 and the Development of a PCR Method for Detecting Tyrosine Decarboxylating Lactic Acid Bacteria

2004 ◽  
Vol 67 (11) ◽  
pp. 2521-2529 ◽  
Author(s):  
MARÍA FERNÁNDEZ ◽  
DANIEL M. LINARES ◽  
MIGUEL A. ALVAREZ

The enzymatic decarboxylation of tyrosine produces tyramine, the most abundant biogenic amine in dairy products—especially in cheeses. The screening of lactic acid bacteria isolated from different artisanal cheeses and a number of microbial collections identified 22 tyramine-producing strains belonging to different genera. The Lactococcus lactis strain IPLA 655 was selected, and the genes encoding a putative tyrosyl tRNA synthetase, a tyrosine decarboxylase (tdcA), and a tyrosine-tyramine antiporter, found together as a cluster, were sequenced. The disruption of tdcA yielded a strain unable to produce tyramine. Comparison of the L. lactis IPLA 655 tdcA gene with database tdcA sequences led to the design of two primers for use in a PCR method that identified potential tyramine-producing strains. The proposed method can use purified DNA, isolated colonies, milk, curd, and even cheese as a template. Molecular tools for the rapid detection of tyramine-producing bacteria at any time during the fermentation process could help prevent tyramine accumulation in fermented foods. The proposed technique could be of great use to the food industry.

2005 ◽  
Vol 68 (4) ◽  
pp. 874-878 ◽  
Author(s):  
ÁNGELA MARCOBAL ◽  
BLANCA de las RIVAS ◽  
M. VICTORIA MORENO-ARRIBAS ◽  
ROSARIO MUÑOZ

In a screening of primers, we have selected three pairs of primers for a multiplex PCR assay for the simultaneous detection of lactic acid bacteria (LAB) strains, which potentially produce histamine, tyramine, and putrescine on fermented foods. These primers were based on sequences from histidine, tyrosine, and ornithine decarboxylases from LAB. Under the optimized conditions, the assay yielded a 367-bp DNA fragment from histidine decarboxylases, a 924-bp fragment from tyrosine decarboxylases, and a 1,446-bp fragment from ornithine decarboxylases. When the DNAs of several target organisms were included in the same reaction, two or three corresponding amplicons of different sizes were observed. This assay was useful for the detection of amine-producing bacteria in control collection strains and in a LAB collection. No amplification was observed with DNA from nonproducing LAB strains. This article is the first describing a multiplex PCR approach for the simultaneous detection of potentially amine-producing LAB in foods. It can be easily incorporated into the routine screening for the accurate selection of starter LAB and in food control laboratories.


2021 ◽  
Vol 6 (1) ◽  
pp. 15
Author(s):  
Maria Hesty Febriana ◽  
Ekawati Purwijantiningsih ◽  
Pramana Yuda

Gatot is a traditional food from fermented cassava. Lactic acid bacteria (LAB) can be found in fermented cassava food, gatot. Lactic acid bacteria can produce an antimicrobial compound for inhibiting pathogen microorganism. The aim of this research were isolation and identification LAB from gatot and antimicrobial activity test against Bacillus cereus and Aspergillus flavus. Three isolates from raw gatot and three isolates from cooked gatot used in this research. Isolation of LAB was conducted using pour plate method, purification is conducted by streak plate method, the antimicrobial test was conducted by agar well diffusion and molecular identification was conducted by PCR colony method using LABFw and R16RDNA-1492bac primer. Lactic acid bacteria from cooked gatot identified as Enterococcus sp. FTBUAJY04, Enterococcus sp. FTBUAJY05, Enterococcus sp. FTBUAJY06, while LAB from raw gatot identified as Lactococcus lactis strain FTBUAJY01, Lactococcus lactis strain FTBUAJY02 dan Lactococcus lactis strain FTBUAJY03. The results obtained from the inhibition zone test showed that all isolates were able to inhibit the growth of B. cereus and A. flavus.  The greatest inhibition zone against B. cereus was shown by LAB Gt5 supernatant or L. lactis supernatant strain FTBUAJY02 of 1.87 ± 0.67 cm2, while the results of the greatest inhibition zone against A. flavus was LAB Gt6 supernatant or L. lactis supernatant strain FTBUAJY03 of 3.83 ± 0.73 cm2.


1995 ◽  
Vol 58 (11) ◽  
pp. 1275-1280 ◽  
Author(s):  
HASSAN GOURAMA ◽  
LLOYD B. BULLERMAN

Lactic acid bacteria are extensively used in the fermentation of a wide variety of food products and are known for their preservative and therapeutic effects. Many lactic acid bacteria species have been reported to inactivate bacterial pathogens, and numerous antibacterial substances have been isolated. However, the antimycotic and antimycotoxigenic potential of lactic acid bacteria has still not been fully investigated. Fermented foods such as cheese can be contaminated by molds and mycotoxins. Mold causes spoilage and renders the product unusable for consumption, and the presence of mycotoxins presents a potential health hazard. A limited number of reports have shown that lactic acid bacteria affect mold growth and aflatoxin production. Although numerous lactic acid bacteria such as Lactobacillus spp. were found to inhibit aflatoxin biosynthesis, other lactic bacteria such as Lactococcus lactis were found to stimulate aflatoxin production. The morphology of lactic acid bacteria cells has also been found to be affected by the presence of fungal mycelia and aflatoxin. Lactococcus lactis cells became larger and formed long chains in the presence of Aspergillus flavus and aflatoxins. Numerous investigations reported that low pH, depletion of nutrients, and microbial competition do not explain the reason for aflatoxin inhibition. Some investigators suggested that the inhibition of aflatoxin is due to lactic acid and/or lactic acid bacteria metabolites. These metabolites have been reported to be heat-stable low-molecular-weight compounds.


2008 ◽  
Vol 71 (10) ◽  
pp. 2024-2029 ◽  
Author(s):  
PONGSAK RATTANACHAIKUNSOPON ◽  
PARICHAT PHUMKHACHORN

Lactic acid bacteria isolated from various Thai fermented foods were screened for the presence of nisin gene by using PCR with primers specific to nisin A structural gene. Only one strain, Lactococcus lactis subsp. lactis TFF 221, isolated from kung jom, a traditional shrimp paste, was found to carry a nisin gene. The TFF 221 nisin had antimicrobial activity against not only closely related lactic acid bacteria but also some foodborne pathogens. It was heat stable and inactivated by α-chymotrypsin and proteinase K. Some characteristics of TFF 221 nisin were found to be very similar to those of nisin A produced by Lactococcus lactis subsp. lactis NCDO 2111. Both of them had the same antimicrobial spectrum and MICs against all indicator bacteria. However, when assayed with indicator organisms, in all cases the TFF 221 nisin produced larger zones of inhibition in agar diffusion assays than the nisin A did. Sequencing of the TFF 221 nisin gene showed that it was the natural nisin variant, nisin Z, as indicated by the substitution of asparagine residue instead of histidine at position 27. The nisin determinant in strain TFF 221 was found to be located on a conjugative transposon residing in the chromosome. The ability of the nisin produced by L. lactis subsp. lactis TFF 221 to inhibit a wide range of foodborne pathogens may be useful in improving the food safety of the fermented product, especially in the Thai environment, which suffers from perennial problems of poor food hygiene.


Foods ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 1435
Author(s):  
Hee Seo ◽  
Jae-Han Bae ◽  
Gayun Kim ◽  
Seul-Ah Kim ◽  
Byung Hee Ryu ◽  
...  

The use of probiotic starters can improve the sensory and health-promoting properties of fermented foods. This study aimed to evaluate the suitability of probiotic lactic acid bacteria (LAB) as a starter for kimchi fermentation. Seventeen probiotic type strains were tested for their growth rates, volatile aroma compounds, metabolites, and sensory characteristics of kimchi, and their characteristics were compared to those of Leuconostoc (Le.) mesenteroides DRC 1506, a commercial kimchi starter. Among the tested strains, Limosilactobacillus fermentum, Limosilactobacillus reuteri, Lacticaseibacillus rhamnosus, Lacticaseibacillus paracasei, and Ligilactobacillus salivarius exhibited high or moderate growth rates in simulated kimchi juice (SKJ) at 37 °C and 15 °C. When these five strains were inoculated in kimchi and metabolite profiles were analyzed during fermentation using GC/MS and 1H-NMR, data from the principal component analysis (PCA) showed that L. fermentum and L. reuteri were highly correlated with Le. mesenteroides in concentrations of sugar, mannitol, lactate, acetate, and total volatile compounds. Sensory test results also indicated that these three strains showed similar sensory preferences. In conclusion, L. fermentum and L. reuteri can be considered potential candidates as probiotic starters or cocultures to develop health-promoting kimchi products.


2020 ◽  
Vol 9 (1) ◽  
pp. 33
Author(s):  
Jirapat Kanklai ◽  
Tasneem Chemama Somwong ◽  
Patthanasak Rungsirivanich ◽  
Narumol Thongwai

Gamma-aminobutyric acid (GABA), the inhibitory neurotransmitter, can be naturally synthesized by a group of lactic acid bacteria (LAB) which is commonly found in rich carbohydrate materials such as fruits and fermented foods. Thirty-six isolates of GABA-producing LAB were obtained from Thai fermented foods. Among these, Levilactobacillus brevis F064A isolated from Thai fermented sausage displayed high GABA content, 2.85 ± 0.10 mg/mL and could tolerate acidic pH and bile salts indicating a promising probiotic. Mulberry (Morus sp.) is widely grown in Thailand. Many mulberry fruits are left to deteriorate during the high season. To increase its value, mulberry juice was prepared and added to monosodium glutamate (MSG), 2% (w/v) prior to inoculation with 5% (v/v) of L. brevis F064A and incubated at 37 °C for 48 h to obtain the GABA-fermented mulberry juice (GABA-FMJ). The GABA-FMJ obtained had 3.31 ± 0.06 mg/mL of GABA content, 5.58 ± 0.52 mg gallic acid equivalent/mL of antioxidant activity, 234.68 ± 15.53 mg cyanidin-3-glucoside/mL of anthocyanin, an ability to inhibit growth of Bacillus cereus TISTR 687, Salmonella Typhi DMST 22842 and Shigella dysenteriae DMST 1511, and 10.54 ± 0.5 log10 colony-forming units (CFU)/mL of viable L. brevis F064A cell count. This GABA-FMJ was considered as a potential naturally functional food for human of all ages.


2004 ◽  
Vol 70 (10) ◽  
pp. 5769-5777 ◽  
Author(s):  
Catherine Burgess ◽  
Mary O'Connell-Motherway ◽  
Wilbert Sybesma ◽  
Jeroen Hugenholtz ◽  
Douwe van Sinderen

ABSTRACT This study describes the genetic analysis of the riboflavin (vitamin B2) biosynthetic (rib) operon in the lactic acid bacterium Lactococcus lactis subsp. cremoris strain NZ9000. Functional analysis of the genes of the L. lactis rib operon was performed by using complementation studies, as well as by deletion analysis. In addition, gene-specific genetic engineering was used to examine which genes of the rib operon need to be overexpressed in order to effect riboflavin overproduction. Transcriptional regulation of the L. lactis riboflavin biosynthetic process was investigated by using Northern hybridization and primer extension, as well as the analysis of roseoflavin-induced riboflavin-overproducing L. lactis isolates. The latter analysis revealed the presence of both nucleotide replacements and deletions in the regulatory region of the rib operon. The results presented here are an important step toward the development of fermented foods containing increased levels of riboflavin, produced in situ, thus negating the need for vitamin fortification.


1999 ◽  
Vol 62 (12) ◽  
pp. 1416-1429 ◽  
Author(s):  
J. MIGUEL ROCHA ◽  
F. XAVIER MALCATA

Traditional manufacture of bread from maize has been noted to play important roles from both economic and social standpoints; however, enforcement of increasingly strict hygiene standards requires thorough knowledge of the adventitious microbiota of the departing dough. To this goal, sourdough as well as maize and rye flours from several geographic locations and in two different periods within the agricultural year were assayed for their microbiota in sequential steps of quantification and identification. More than 400 strains were isolated and taxonomic differentiation between them was via Biomerieux API galleries (375 of which were successfully identified) following preliminary biochemical and morphological screening. The dominant groups were yeasts and lactic acid bacteria (LAB). The most frequently isolated yeasts were Saccharomyces cerevisiae and Candida pelliculosa. The most frequently isolated LAB were (heterofermentative) Leuconostoc spp. and (homo-fermentative) Lactobacillus spp.; L. brevis, L. curvatus, and L. lactis ssp. lactis were the dominant species for the Lactobacillus genera; Lactococcus lactis ssp. lactis for lactococci; Enterococcus casseliflavus, E. durans, and E. faecium for enterococci; and Streptococcus constellantus and S. equinus for streptococci.


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