Degradation Of Biogenic Amines Research Articles

Food-grade expression of multicopper oxidase with improved capability in degrading biogenic amines

Biogenic amines (BAs) are potential amine hazards that are detected in fermented foods and alcoholic beverages. Excessive intake of BAs may lead to allergic symptoms such as difficulty in breathing, nausea, and vomiting. Degradation of BAs by multicopper oxidase (MCO) is a promising method as it has little effect on the fermentation process, food nutrition, and flavor. However, the application of MCO in food industry was restricted due to its poor catalytic properties and low productivity. In this work, food-grade expression of the Bacillus amyloliquefaciens MCO (MCOB) and its three mutants were successfully constructed in Lactococcus lactis NZ3900. The expression level of MCOB in L. lactis NZ3900 was dramatically enhanced by optimizing the cultivation conditions, and the highest expression level reached 4488.1 U/L. This was the highest expression level of food-graded MCO reported so far, to our knowledge. Interestingly, the optimal reaction pH of MCOB expressed in L. lactis NZ3900 switched to 4.5, it would be more suitable for degrading BAs in food as the pH value of most fermented foods was found to be 4.5. Moreover, MCOB expressed in L. lactis NZ3900 was quite stable (with more than 80% residual activity) in the pH range of 4.0–5.5, the catalytic rate constant (kcat) and specific activity of MCOBLS were all dramatically increased compared with that of MCOB expressed in Escherichia coli. Using histamine as the substrate, the degradation of BAs within 24 h by MCOB expressed in L. lactis NZ3900 was 69.7% higher than that expressed in E. coli. The results demonstrated the potential applications of MCOB in food industry for reduction of biogenic amines.

Production and characterization of a new diamine oxidase from Yarrowia lipolytica

A putative diamine oxidase (DAO) from Yarrowia lipolytica PO1f (DAO-1) was homologously recombinantly integrated into the genome of Y. lipolytica PO1f using the CRISPR-Cas9 system for the subsequent DAO production in a bioreactor. Thereby, it was proven that the DAO-1 produced was indeed a functional DAO. The cultivation yielded 2343 ± 98 nkat/Lculture with a specific DAO activity of 1301 ± 54.2 nkat/gprotein, which was a 93-fold increase of specific DAO activity compared to the native Y. lipolytica PO1f DAO-1 production. The DAO-1 showed a broad substrate selectivity with tyramine, histamine, putrescine and cadaverine being the most favored substrates. It was most active at 40 °C, pH 7.2 in Tris-HCl buffer (50 mM) (with histamine as substrate), which is comparable to human and porcine DAOs. The affinity of DAO-1 towards histamine was lower compared to mammalian DAOs (Km = 2.3 ± 0.2 mM). Nevertheless, DAO-1 degraded around 75% of the histamine used in a bioconversion experiment with a food-relevant concentration of 150 mg/L. With its broad selectivity for the most relevant biogenic amines in foods, DAO-1 from Y. lipolytica PO1f is an interesting enzyme for application in the food industry for the degradation of biogenic amines.

HAT/HDAC: The epigenetic regulators of inflammatory gene expression (Review)

Inflammation is a condition through which the body responds to infection or tissue injury. It is typically characterized by the expression of a plethora of genes involved in inflammation, that are regulated by transcription factors, transcriptional co‑regulators, and chromatin remodeling events. Differential mitotically heritable patterns of gene expression without changes in the DNA sequence are essentially controlled by epigenetic regulation. Epigenetic mechanisms, such as histone modifications and DNA methylation have a profound effect on inflammatory gene transcription. Histone protein modifications, which include acetylation and the ubiquitination of lysine residues, the methylation of lysine and arginine, and the phosphorylation of serine have been found to modulate chromatin dynamics, thus altering the levels of gene expression. Histone acetyltransferases (HATs) and histone deacetylases (HDACs) regulate the addition and removal of acetyl groups from lysine residues on histones respectively. Nuclear factor <em>(NF)‑κB</em>, tumor necrosis factor <em>(TNF)‑α</em> and interleukin <em>(IL)‑6</em> are the pro‑inflammatory genes known to promote inflammatory responses in cells. By contrast, 15‑lipoxygenase‑1 <em>(15‑LOX‑1)</em> and monoamine oxidase‑A <em>(MAO‑A)</em> are the genes that can act against inflammation in certain specific conditions. 15‑LOX‑1, a lipid peroxidative enzyme, is associated with the development of inflammatory disorders, such as atherosclerosis, rheumatoid arthritis, asthma and renal injury. MAO‑A catalyzes degradation of biogenic amines and has been reported to cause oxidative stress, atherosclerosis and neuroinflammation. 15‑LOX‑1 has been shown to be co‑expressed along with MAO‑A, in both primary human monocytes and A549 lung carcinoma cells upon treatment with Th2 cytokines, such as IL‑4 and IL‑13. The present review aimed to discuss the HAT‑ and HDAC‑mediated epigenetic machinery which governs the expression of pro‑inflammatory genes, such as <em>IL‑6</em>, <em>TNF‑α</em>, etc., as well as the expression of anti‑inflammatory genes, such as <em>15‑LOX‑1</em> and <em>MAO‑A</em>, responsible for modulating the process of inflammation. On the whole, the present review aims to provide deeper insight into the underlying molecular mechanisms involved in the epigenetic regulation of inflammation, which may have novel implications in designing small molecule inhibitors that target the epigenetic machinery for the effective treatment of a variety of inflammation‑related diseases.

Interstrain Variability of Human Vaginal Lactobacillus crispatus for Metabolism of Biogenic Amines and Antimicrobial Activity against Urogenital Pathogens.

Lactobacillus crispatus is the dominant species in the vagina of many women. With the potential for strains of this species to be used as a probiotic to help prevent and treat dysbiosis, we investigated isolates from vaginal swabs with Lactobacillus-dominated and a dysbiotic microbiota. A comparative genome analysis led to the identification of metabolic pathways for synthesis and degradation of three major biogenic amines in most strains. However, targeted metabolomic analysis of the production and degradation of biogenic amines showed that certain strains have either the ability to produce or to degrade these compounds. Notably, six strains produced cadaverine, one produced putrescine, and two produced tyramine. These biogenic amines are known to raise vaginal pH, cause malodour, and make the environment more favourable to vaginal pathogens. In vitro experiments confirmed that strains isolated from women with a dysbiotic vaginal microbiota have higher antimicrobial effects against the common urogenital pathogens Escherichia coli and Enterococcus faecium. The results indicate that not all L. crispatus vaginal strains appear suitable for probiotic application and the basis for selection should not be only the overall composition of the vaginal microbiota of the host from which they came, but specific biochemical and genetic traits.

Monoamine Oxidase Inhibitors: A Review of Their Anti-Inflammatory Therapeutic Potential and Mechanisms of Action.

Chronic inflammatory diseases are debilitating, affect patients’ quality of life, and are a significant financial burden on health care. Inflammation is regulated by pro-inflammatory cytokines and chemokines that are expressed by immune and non-immune cells, and their expression is highly controlled, both spatially and temporally. Their dysregulation is a hallmark of chronic inflammatory and autoimmune diseases. Significant evidence supports that monoamine oxidase (MAO) inhibitor drugs have anti-inflammatory effects. MAO inhibitors are principally prescribed for the management of a variety of central nervous system (CNS)-associated diseases such as depression, Alzheimer’s, and Parkinson’s; however, they also have anti-inflammatory effects in the CNS and a variety of non-CNS tissues. To bolster support for their development as anti-inflammatories, it is critical to elucidate their mechanism(s) of action. MAO inhibitors decrease the generation of end products such as hydrogen peroxide, aldehyde, and ammonium. They also inhibit biogenic amine degradation, and this increases cellular and pericellular catecholamines in a variety of immune and some non-immune cells. This decrease in end product metabolites and increase in catecholamines can play a significant role in the anti-inflammatory effects of MAO inhibitors. This review examines MAO inhibitor effects on inflammation in a variety of in vitro and in vivo CNS and non-CNS disease models, as well as their anti-inflammatory mechanism(s) of action.

Detection and relative quantification of amine oxidase gene (yobN) in Bacillus subtilis: application of real-time quantitative PCR.

Degradation of undesirable biogenic amines (BAs) in foodstuffs by microorganisms is considered one of the most effective ways of eliminating their toxicity. In this study, we design two sets of primers for the detection and quantification of the amine oxidase gene (yobN) and endogenous (housekeeping) gene (gyrB) in Bacillus subtilis. Moreover, these sets can be used for relative quantification of yobN by real-time PCR (qPCR). We also tested the degradation of BAs by three bacterial strains (B. subtilis strains: IB1a, CCM 2216, CCM 2267) in a mineral medium over a two-day period. Their degradation abilities were verified by high performance liquid chromatography with UV detection (HPLC/UV). According to the results, two strains significantly (P < 0.05) reduced histamine, tyramine, putrescine, and cadaverine. Moreover, our results indicate that the degradation ability of B. subtilis strains could be limited by sporulation because the gene encoding amine oxidase (yobN) is no longer expressed in the spores.

Novel starter cultures Virgibacillus spp. selected from grasshopper sub shrimp paste to inhibit biogenic amines accumulation

Controlling the content of biogenic amines (BAs) is critical to guarantee the safety of fermented aquatic products. The degradation characteristics and application potential of amine-negative starter cultures (Virgibacillus halodenitrificans CGMCC 1.18601: G25, Virgibacillus pantothenticus CGMCC 1.18602: G38) screened from grasshopper sub shrimp paste (Gssp) were studied. The enzymes of the two strains G25 and G38 that degrade BAs were amine oxidases (AOs) located on their respective cell membranes. The conditions that promoted the AO activity of Virgibacillus spp. were NaCl concentrations 5–10%, temperature 37 °C, pH 7.0 and ethanol concentrations 0–2%. Safety assessments (antibiotic susceptibility, biofilm activity and hemolytic activity) indicated that Virgibacillus spp. do not present a risk to human health, and this isolate can be confidently recommended as safe starter cultures for the food industry. Then, the two strains were cultured separately as starters and applied to the Gssp to analyze their influence on the flavor and quality of the product. As far as the bad flavors in Gssp such as sulfur-organic and sulf-chlor were concerned, the response values in the starter groups by G25 and G38 were significantly reduced by 39% and 65%, respectively. For the ability of strains to degrade BAs in Gssp, G25 degraded 11.1% of histamine, 11.3% of tyramine, 15.5% of putrescine and 4.1% of cadaverine; G38 significantly degraded 10.1% of histamine, 21.8% of tyramine, 18.1% of putrescine and 5.0% of cadaverine. These results indicated that the selected species could be used as starter cultures for the control of BA accumulation and degradation in Gssp.

Monoamine oxidase A activity in fibroblasts as a functional confirmation of MAOA variants.

AbstractMonoamine oxidase A (MAO‐A) deficiency is a rare inborn error of metabolism with impaired degradation of biogenic amines including 5‐hydroxytryptamine (5‐HT), resulting in borderline intellectual disability and behavioral abnormalities. Genetic variants in MAOA need functional confirmation to enable a definite diagnosis. To this end, we developed an inexpensive, simple and nonradioactive MAO‐A activity assay based on the conversion of 5‐HT into 5‐hydroxyindoleacetic acid (5‐HIAA). Fibroblast cell lysates were incubated with 5‐HT and aldehyde dehydrogenase to allow 5‐HIAA production. 5‐HIAA was quantified using high‐performance liquid chromatography with fluorimetric detection. We optimized reaction mixture components, pH, and substrate concentration and tested linearity and specificity of the assay. We verified the functional validity of the enzyme assay using fibroblasts of controls, female mutation carriers and MAO‐A deficient patients. This included a newly described patient with a novel MAOA variant (c.1336G&gt;A, p.(Glu446Lys)), who represents the fifth MAO‐A deficiency family so far. The optimized enzyme assay showed good linearity and specificity. Application to clinical samples showed a 100% differentiation of affected patients (with negligible MAO‐A enzyme activity) and controls or mutation carriers. In conclusion, the described MAO‐A activity assay is easy to implement and can readily be used to test the pathogenicity of variants in the MAOA gene in a clinical setting. Especially in this era of whole‐exome (and whole‐genome) sequencing, this functional assay fulfills a clinical need for functional confirmation of a suspected diagnosis of MAO‐A deficiency.

Exploring the Capability of Yeasts Isolated from Colombian Fermented Cocoa Beans to Form and Degrade Biogenic Amines in a Lab-Scale Model System for Cocoa Fermentation

Yeast starters for cocoa fermentation are usually tested according to their enzymatic activities in terms of mucilage degradation and flavor improvement, disregarding their influence on the production or elimination of toxic compounds as biogenic amines (BAs), important for human health. In this work, we tested 145 strains belonging to 12 different yeast species and isolated from the Colombian fermented cocoa beans (CB) for their capability of producing BAs in vitro. Sixty-five strains were able to decarboxylate at least one of the amino acids tested. Pichia kudriavzevii ECA33 (Pk) and Saccharomyces cerevisiae 4 (Sc) were selected to evaluate their potential to modulate BAs, organic acids, and volatile organic compounds (VOCs) accumulation during a simulated cocoa fermentation. The growth of Sc or Pk in the presence of CB caused a significant reduction (p < 0.05) of 2-phenylethylamine (84% and 37%) and cadaverine (58% and 51%), and a significant increase of tryptamine and putrescine with a strong influence of temperature in BA formation and degradation. In addition, our findings pointed out that Pk induced a major production of fatty acid- and amino acid-derived VOCs, while Sc induced more VOCs derived from fatty acids metabolism. Our results suggest the importance of considering BA production in the choice of yeast starters for cocoa fermentation.

Selection of nitrite-degrading and biogenic amine-degrading strains and its involved genes

Abstract Objectives Accumulation of nitrite and biogenic amines (BAs) in fermented meat products is a matter of public health concern. The study aimed to screen nitrite-degrading and BA-degrading strains from sour porridges and sausages and bacon products in China. Materials and Methods After screening out 12 strains, the degradation of nitrite, the degradation of BAs, the activities of nitrite-reducing enzymes, and the detection of genes involved in the BAs were assessed by spectrophotometry method with hydrochloric acid naphthalene ethylenediamine, high-performance liquid chromatography, GENMED kit, and polymerase chain reaction, respectively. Results Pediococcus pentosaceus labelled M SZ1 2 and M GC 2, Lactobacillus plantarum labelled M SZ2 2, and Staphylococcus xylosus labelled Y CC 3 were selected. The activity of nitrite-reducing enzyme in M SZ2 2 was 2.663 units/mg. The degradation rate of total BAs of M SZ2 2 was 93.24%. The degradation rates of nitrite and BAs of M SZ1 2 were 86.49% and 37.87%, respectively. The activity of nitrite-reducing enzyme in M SZ1 2 was up to 1.962 units/mg. M GC 2 showed higher degradation rates of nitrite (89.19%) and Y CC 3 showed higher degradation rates of BAs (36.16%). The genes encoding the multicopper oxidases (suf I/D2EK17) were detected in the four strains, which also did not contain BAs (histidine decarboxylase (hdc), tyrosine decarboxylase (tdc), ornithine decarboxylase (odc), lysine decarboxylase (ldc)) formation encoding genes. Conclusion These four strains (M SZ1 2, M GC 2, M SZ2 2, and Y CC 3) are promising candidates to use as starter cultures for nitrite and BAs in fermented sausages.

Carbon dots-assisted degradation of some common biogenic amines: An in vitro study

In this work, the reduction/degradation capability of carbon dots (CDs) on biogenic amines (BAs) produced by Enterococcus faecalis and Escherichia coli was investigated in vitro conditions. In this work, the response surface methodology (RSM) and the central composite design (CCD) was applied in order to find the optimized CDs concentration and incubation time on the reduction of BAs. CDs represented a quite high degradation percentage on cadaverine, followed by histamine, tyramine and putrescine. Cadaverine produced by E. coli was completely degraded, while CDs degraded only 55% of putrescine produced by E. faecalis. Based on RSM outputs, both independent variables (concentration of CDs and the incubation time), affected the reduction/degradation of BAs in the two investigated pathogens. The results revealed that the concentration of CDs had the major influence on BAs degradation. The antimicrobial and FTIR investigations implied that CDs degraded only BAs of E. faecalis and have no activity on the production of BAs by the bacterium, In the case of BAs of E. coli, CDs not only inhibited the E. coli growth and reduced BA accumulation but also degraded the as-formed BAs. These data serve to reinforce a conclusion that CDs represent a potential material for BAs degradation.

묵은지로부터 바이오제닉 아민을 분해하는 프로바이오틱 유산균의 분리 및 동정

The aim of this study was to evaluate biogenic amines (BA)-forming and -degrading abilities of lactic acid bacteria (LAB) and yeasts isolated from over-ripened kimchi and to investigate probiotic characteristics of the BA-degrading and -degrading microorganism. There were significantly more BA-forming LAB and yeasts in over-ripened kimchi prepared with fish sauce or salted fish than sun-dried salt. The BA-forming ability of the microorganisms was highly strain-dependent. Among the isolated microorganisms, the BA degradation ability was found in LAB including Leuconostoc mesenteroides subsp. mesenteroides CML01, Enterococcus faecium KML12, Lactobacillus fermentum MML21, Lactobacillus sakei MML23, Enterococcus faecalis MML26, and Pediococcus pentosaceus SML34. However, all yeast tested did not show the BA degradtion ability. In addition, L. sakei MML23 and P. pentosaceus SML34 exhibited probiotic characteristics including tolerance to gastric acid and bile salt, adhesion capacity to intestinal epithelial cells, and antibiotic susceptibility. Furthermore, the bacteriocin produced by L. sakei MML23 and P. pentosaceus SML34 showed antibacterial activity against E. faecium KML15, Saccharomyces cerevisiae MMY28, and Lactobacillus brevis MML24. Consequently, the bacteriocin produced by probiotic L. sakei MML23 and P. pentosaceus SML34 seemed to be effective in reducing the risk of BA toxicity by inhibiting the growth of histamine, cadaverine, and putrescine-forming bacteria.

Control of Biogenic Amines in Peanut Butter by Incorporation of Some Probiotic Bacteria

Biogenic amines have been reported to present in different foods. The formation of biogenic amines is influenced by many factors, such as raw materials, microorganisms, and storage conditions. The study aimed to investigate the possibility of incorporation of probiotic bacteria (B. infantis 35624 and L. plantarum 299v) to control biogenic amines formation in peanut butter under the conditions prevailing in this product. The data showed that peanut butter might be a suitable matrix to protect probiotics during storage, and B. infantis had the highest survivability in all samples during incubation at different pH. The values of biogenic amines were decreased continuously in liquid medium relevant to the activity of probiotic bacteria cells. All liquid medium samples had high histamine decreasing ratio; 77.2% for B. infantis and 76.16% for L. plantarum compared with other amines at pH 6.8. The data showed that the incorporation of probiotic bacteria in peanut butter, reduced biogenic amines, especially tyramine and cadaverine, during storage at different temperatures. Degradation of biogenic amines was less at 37° C comparing to 4° C and 25° C. All organoleptic properties were significant when compared to the control sample after 12 weeks of storage at 4, 25 and 37°C, respectively.

Heterologous Expression and Application of Multicopper Oxidases from Enterococcus spp. for Degradation of Biogenic Amines.

Biogenic amines are harmful to human health at a certain extent. As a kind of biogenic amine oxidase, multicopper oxidase can be used to degrade them. Currently, the literature about enzyme from Enterococcus spp. are limited, and recombinant multicopper oxidase might be an effective way to degrade biogenic amines. (i) Select and identify strains that can degrade biogenic amines, (ii) overexpress enzyme from Enterococcus spp., (iii) measure gene expression and probe amine-degradation differences among strains (native, E. coli DH5α, and L. delbruckii), and (iv) examine the biochemical properties of recombinant multicopper oxidase, (v) apply the recombinant enzyme into smoked horsemeat sausage. Reverse transcription PCR and high-performance liquid chromatography were performed to examine gene expression and amine degradation rate. The results demonstrated that target enzymes were successfully overexpressed, accompanied by increased amine-degrading activity (P <0.05). Gene from E. faecalis M5B was expressed in L. delbrueckii resulted in degradation rates for phenylethylamine, putrescine, histamine and tyramine of 54%, 52%, 70% and 40%, respectively, significantly higher than achieved by other recombinant strains. In this work, gene expression levels were higher in recombinant M5B than recombinant M2B, regardless of host. E. coli is more stable to express multicopper oxidase. Besides, the amine-degrading ability was markedly increased in the two recombinant strains. After prolonged incubation, the recombinant enzyme could degrade three amines, and it displayed high alkali resistance and thermostability.

Combined approaches for evaluation of xenoestrogen neural toxicity and thyroid dysfunction: Screening of oxido-nitrosative markers, DNA fragmentation, and biogenic amine degradation.

Anthropogenic chemicals such as parabens and triclosan are used in personal care products. Duetotheir ability to decrease or prevent bacterial contamination and act as preservatives, these chemicals are used in cosmetic manufacturing processes to increase the shelf life of products. In this study, we assessed the side effects of environmental estrogens (such as the xenoestrogen butylparaben and the antimicrobial agent and preservative triclosan) on thyroid function, brain monoamine levels, and DNA aberration. Forty-two male albino rats were divided into seven groups with six members each: the first group served as control; the second and the third groups were treated with butylparaben 10 and 50 mg/kg body weight, respectively; the fourth and fifth groups were treated with triclosan 10 and 50 mg/kg body weight, respectively; and the sixth and seventh groups were treated with butylparaben plus triclosan 10 and 50 mg/kg body weight, respectively. After 60 days, blood samples were collected and brain specimens were divided into striatum, midbrain, cortex, and thalamus. Thyroid function and levels of monoamines and monoamine metabolites were determined for each brain area. Comet assay was used for brain tissue analysis. The results showed that butylparaben and triclosan and their combinations induced hypothyroidism and disrupted monoamine levels, leading to a decrease in catecholamine and serotonin levels, and accelerated production of 5-hydroxyindoleacetic acid. The obtained data indicate that anthropogenic chemicals such as butylparaben and triclosan have harmful effects on thyroid and brain function and accelerate cell destruction and mutation, as evidenced by single-stranded DNA breaks in the comet assay.

Degradation of biogenic amines and in vitro evaluation of ruminal parameters of the ruminal fluid of Charolais sheep

In this study, we reported the evaluation of ruminal parameters and the rate and degree of degradation of biogenic amines (BA) in vitro, using ruminal fluid from sheep fed two different diets (meadow hay and silage of Medicago sativa L.). Herein, the Charolais sheep breed with a ruminal cannula was used to gather samples. Multiple rumen parameters were evaluated after 10 days of the feeding period. Samples were processed using fermenters inoculated by BA (histamine, tyramine, putrescine, cadaverine, spermine, [...]

Application of qPCR for multicopper oxidase gene (MCO) in biogenic amines degradation by Lactobacillus casei

Degradation of undesirable biogenic amines (BAs) in foodstuffs by microorganisms is considered one of the most effective ways of eliminating their toxicity. In this study, we designed two sets of primers for the detection and quantification of the multicopper oxidase gene (MCO), which encodes an enzyme involved in BAs degradation, and endogenous (glyceraldehyde-3-phosphate dehydrogenase) gene (GAPDH) in Lactobacillus casei group by real-time PCR (qPCR). We tested 15 Lactobacillus strains in the screening assays (thus, MCO gene possessing assay (PCR) and monitoring of BAs degradation by HPLC-UV), in which Lactobacillus casei CCDM 198 exhibited the best degradation abilities. For this strain, we monitored the expression of the target gene (MCO) in time (qPCR), the effect of redox treatments (cysteine, ascorbic acid) on the expression of the gene, and the ability to degrade BAs not only in a modified MRS medium (MRS/2) but also in a real food sample (milk). Moreover, decarboxylase activity (ability to form BAs) of this strain was excluded. According to the results, CCDM 198 significantly (P < 0.05) reduced BAs (putrescine, histamine, tyramine, cadaverine), up to 25% decline in 48 h. The highest level of relative expression of MCO (5.21 ± 0.14) was achieved in MRS/2 media with cysteine.

Selection of a versatile Lactobacillus plantarum for wine production and identification and preliminary characterisation of a novel histamine‐degrading enzyme

SummaryIn this study, a desirable and versatile Lactobacillus plantarum strain possessing great ability of L‐malic acid consumption, biogenic amine degradation and resistance to wine harsh environment was obtained through successive screenings. Malolactic fermentation (MLF) in contaminated grape wine and cherry wine (supplemented with histamine, tyramine and cadaverine) conducted by this strain was finished within 24 and 18 days, respectively, and the concentration of histamine, tyramine and cadaverine was decreased by over 57% following MLF. The enzyme from L. plantarum responsible for the amine degradation was purified to homogeneity by four steps including cell disruption, ammonium sulphate fractionation, an anion chromatography and a gel filtration chromatography. Such enzyme was identified as glyceraldehyde‐3‐phosphate dehydrogenase (GAPDH) after N‐terminal sequence analysis and protein Blast, a tetramer enzyme with a subunit molecular weight of 36 kDa. The optimum values of pH and temperature of this enzyme were at pH 7.5 and 40 °C, and stable between pH 5.5–8.5 and 30–50 °C.

Isolation, characterization, and application of biogenic amines‐degrading strains from fermented food

AbstractThe aim of the present study was to screen a type of microorganism for degradation of bioamines in fermented food, investigate their characteristics in growth and degrading bioamines, and also assess the effects of inoculating strain starter cultures on biogenic amines (BAs) accumulation in soy sauces. The screening for no‐BAs‐producing strains was carried out using a double color method and an oxidase test. The degradation rates were determined by high‐performance liquid chromatography with fluorescence detection (HPLC‐FLD). In this study, strains (J2 and J3) with high ability were isolated from some naturally fermented food samples. They were identified as Wickerhamomyces anomalus and Millerozyma farinosa, respectively, by partial amplification of the 16S rRNA gene. The strains exhibited high multiple BAs degradation activity over a range of pH values (5–8), temperatures (28–35°C), salt (NaCl) concentrations (0–10%), and ethanol concentrations (0–10%). One of the isolated strains, W. anomalus, has the highest biodegradability for putrescine, cadaverine, histamine, and tyramine with degradation rates of 61, 66, 67, and 59% in an experimental model, and 39.3, 33.6, 39.9, and 43.1% in fermented soy sauce containing 10% of NaCl, respectively. Additionally, the study of mechanism demonstrated that the removal ability of BAs was mainly due to biodegradation.

Innovative Approaches for the Degradation of Biogenic Amines in Foods

Biogenic Amines (BA) are low molecular weight organic bases that have biological activity, they can be formed and degraded as a result of normal metabolic activity in animals, plants and microorganisms, and are usually produced by the decarboxylation of amino acids. The most common biogenic amines which can be found in foods are aliphatic (putrescine, cadaverine, spermine, spermidine), aromatic (tyramine, phenylethyl amine) or heterocyclic (histamine, tryptamine) structures.