Let me thank for being here today.I would like to introduce my self. My name is Wilawan Jaimaroeng.I’m study Industrial fermentation technology.My Adviser is Dr.Aphacha Jindaprasert.Today I’m going to give presentation on the topic of Biogenic amine formation by lactic acid bacteria isolated from dairy's product
First of all,I’d like to talk about biogenic amine.Biogenic amine are organic and nitrogenous compounds with biological activity, mainly formed by the decarboxylation of amino acids. The consumption of foods containing large amounts of these amines can have toxicological affect healt.and The most important biogenic amines in dairy foods are histamine, tyramine, cadaverine and putrescine
Futhermore, Lactic acid bacteria (LAB) play an essential role in the production of fermented dairy products, with Lactococcus lactis and Streptococcus thermophiles being the species most commonly used as primary fermentation starters .Their major function is the rapid production of lactic acid from lactose.
This slide present biosynthesis pathway of biogenic amine.Histamine decarboxylate by histidine decarboxylase.Tyramine decarboxylate by tyrosine.Cadaverine decarboxylate by lysine and arginine is decarboxylated by arginine decarboxylase(ADC) to produce agmatine. Agmatine can be converted to putrescine.and Putrescine can be formed from ornithine by ornithine decarboxylase (ODC)
In this slide they are found that biogenic amine in different dairy product from raw milk have a large amount of biogenic amine as opposed to pasteurized milk
BA in home made natural yogurt and In this research objective of the study were to investigate
biogenic amines formation by S. thermophilus isolated from home-made natural yogurt, and in lysine and histidine decarboxylase broth.
Material and method
Culture media and bacterial extraction
- They are used home made yogurt sample
- and propagation of S.thermophilus cultures used SM17 broth
- then S. thermophilus strains were incubated at 37 oC for 72 h.
- and Take these bacterial cultures (1011cfu/ml) removed and put into the LDB and HDB
- In order to identify the S. thermophilus strains showing the ability to decarboxylate, of the LDB and HDB containing.
- then centrifuged at 3000 g for 10 min and then filtered a filter paper Ø125 mm
- After that, bacterial supernatant were taken for derivatisation in order to be analysed by HPLC.
Analytical method
High Performance Liquid Chromatography (HPLC)
-they are used bacterial supernatant
-Analysis by HPLC method with Reversed phase colume(Pre-column derivatization method) by using gardient elution program.
- Total separation time was less than 20 min. and the injection volume was 10 µL
- Detection was monitored at 254 nm.
- A standard curve for ammonia and each of the twelve amines in the range of 0– - 50 mg/mL was prepared.
this picture show High Performance Liquid Chromatography (HPLC) apparatus
Polymerase Chain Reaction (PCR)
-they are used DNA Extraction of S.thermophilus
- then Make PCR thermal cycler machine conain 3 step 1. Denaturation,2. Annealing ,3. Extension
- after that Amplified PCR products were run on 1.5% electrophoresis gel and analysed under UV light.
this picture show PCR thermal cycler machine and Electrophoresis gel.
In this result of research HPLC show that the number of S. thermophilus isolates produced biogenic amines in histidine decarboxylase (HDB) and lysine decarboxylase broth (LDB).They are found that S. thermophiles isolated produce not only histamine also other amiine and biogenic amine production generally below 100 mg/L
Fig.1 show histamine production by S. thermophilus isolates in histidine decarboxylase broth. Most of the S. thermophilus isolates formed low amounts of histamine (1–50 mg/L) from histidine whilst one isolate was a prolific amine producer, with amine production above 36.33 mg/L.
Fig.2 show Histamine production by S. thermophilus isolates in lysine decarboxylase broth. histamine amounts produced by most isolates ranged from 1.29 to 45.2 mg/L.
Fig. 3. Show PCR amplification with primers designed to amplify histidine decarboxylase (hdca) gene in isolates.and designed for amplification of a 435 bp length part of hdc gene.they are found that
only 13 isolates tested positive for hdcA gene, while PCR bands were not detected for some isolates producing histamine. So histamine production was not controlled by only hdcA gene. Some other gene(s) could take part in histamine production.
BA in artisanal cheese and In this research objective of the study capacity to produce BA can be tested by either chromatographic or molecular methods
Material and method
BA Production capacity
-they used artisanal cheeses sample
-and culture supernatants of the LAB strains grown for 24 h in 10 ml M17 or MRS broth supplemented with 1 mM tyrosine ,1 mM histidine ,1 mM ornithine or 1 mM agmatine
-then centrifugation of the cultures (2000 X g for 15 min) and filtering of the supernatant through a 0.2 µm pore diameter membrane.
-After that Derivatized samples were analyzed by (U)HPLC
Polymerase Chain Reaction (PCR)
-they are used DNA Extraction of LAB
-then Performed in a MyCycler™ thermal cycler using DreamTaq polymerase
-and PCR products were separated in 0.8 % (w/v) agarose gels in 1XTAE buffer and visualized after staining with ethidium bromide using a GelDoc 2000 system
In this result of research from total 137 strains they found that 7 strain produce tyramine ,2 strain produce histamine and 17 strain produce putrecine via AGDI.All strain that positive PCR result for the presence of gene involved in production able to systhesize the corresponding BA, except for two strains of S. thermophilus.
Fig1.show Results of PCR tests for the presence of genes involved in BA production.They are found that Lactobacillus brevis and Lactobacillus curvatus presence both TDC+( tyramine-producing cluster) and AGDI+ (putrescine-producing cluster via the agmatine deiminase pathway) and Lactococcus lactis subsp. Lactis and Lactococcus lactis subsp. Cremoris presence both AGDI+, AGDI-
Table2. show classification of tyramine- and putrescine-producing strains.they are found that Lactobacillus brevis and Lactobacillus curvatus classification as strong tyramine producer strains and Variation in the efficiency of putrescine production was observed among the producing strains of L. lactis; this allowed their classification as ‘strong’ or ‘medium putrescine producer’s
In conclusion capability biogenic amines production of 58 S. thermophilus isolates in yogurt showed that most of the S. thermophilus isolates have an ability to form biogenic amines, especially histamine and tyramine, which are the most toxic amines for human health.And seconds research of lactic acid bacteria 137 strains isolated from different artisanal cheese show that Lactobacillus brevis. and Lactobacillus curvatus. can produce tyramine and putrescine (via the agmatine deiminase pathway).And in this work presence L. lactis; this allowed their classification as ‘strong’ or ‘medium putrescine producers’
So it is important to select suitable strains as starter cultures for dairy product.If not seselect
strain microorganisim can accumulate BA in high concentration and consumption food containing large
amounts of these amines can have toxicological consequences. Although there is no specific legislation
regarding the BA content in dairy products, it is generally assumed that they should not be allowed to
accumulate. thus ,In the future should have available methods for detecting the presence of BA or BA
producing microorganisms in dairy products and the factors affecting BA accumulation are analyzed in order to suggest possible means of reducing their presence, and establish safety limits for their concentration in dairy product including other foods.