Which lactic acid bacteria are responsible for histamine production in wine?

Bacteriocins against biogenic amine-accumulating lactic acid bacteria in cheese: Nisin A shows the broadest antimicrobial spectrum and prevents the formation of biofilms

Cheese is a food in which toxic concentrations of biogenic amines (BA) may be reached, mainly as a consequence of the decarboxylation of determined amino acids by certain lactic acid bacteria (LAB). To maintain the food safety of cheese, environmentally friendly strategies are needed that specifically prevent the growth of BA-producing LAB and the accumulation of BA. The bacteriocins produced by LAB are natural compounds with great potential as food biopreservatives. This work examines the antimicrobial potential of 7 bacteriocin-containing, cell-free supernatants (CFS: coagulin A-CFS, enterocin A-CFS, enterocin P-CFS, lacticin 481-CFS, nisin A-CFS, nisin Z-CFS and plantaricin A-CFS) produced by LAB against 48 strains of the LAB species largely responsible for the accumulation of the most important BA in cheese, that is, histamine, tyramine, and putrescine. Susceptibility to the different CFS was strain-dependent. The histamine-producing species with the broadest sensitivity spectrum were Lentilactobacillus parabuchneri (the species mainly responsible for the accumulation of histamine in cheese) and Pediococcus parvulus. The tyramine-producing species with the broadest sensitivity spectrum was Enterococcus faecium, and Enterococcus faecalis and Enterococcus hirae were among the most sensitive putrescine producers. Nisin A-CFS was active against 31 of the 48 BA-producing strains (the broadest antimicrobial spectrum recorded). Moreover, commercial nisin A prevented biofilm formation by 67% of the BA-producing, biofilm-forming LAB strains. These findings underscore the potential of bacteriocins in the control of BA-producing LAB and support the use of nisin A as a food-grade biopreservative for keeping BA-producing LAB in check and reducing BA accumulation in cheese.

Investigation of Biogenic Amine Levels and Microbiological Activity as Quality Markers in Some Dairy and Fish Products in Food Markets in the Kingdom of Saudi Arabia

This study aimed to verify the presence of biogenic amines (BAs) and evaluate the microbiological activity of some food samples collected from retail stores in the Kingdom of Saudi Arabia. A total of thirty-five dairy and fish products were collected and analyzed for BAs, including putrescine (PUT), cadaverine (CAD), spermidine (SPE), histamine (HIS), spermine (SPR), and tyramine (TYR), as well as for total colony count (TCC), lactic acid bacteria (LAB), Enterobacteriaceae, yeast and mold (Y and M), coliforms, and aerobic sporulation count (ASF). The thin layer chromatography (TLC) method was used in the analytical methodology to identify the BAs. The results showed the presence of BAs in all dairy products, but their concentration did not exceed the maximum permissible limit, which in contrast was established by the Food and Drug Administration (FDA) at 10 mg/100 g. The amounts of BAs in fish products varied significantly. All fish product samples contained levels of BAs below the permissible limit. Results of an independent study also indicated potential toxicity at levels of BAs (>10 mg/100 g) in Egyptian herring. Enterobacteriaceae and the coli group were present in higher concentrations in the Egyptian herring samples, whereas other samples (particularly frozen shrimp) showed increased TCC levels with a higher concentration of histamine-producing bacteria. From a consumer safety perspective, this study also indicated that food samples generally contained acceptable levels of BAs. In conclusion, there is a need to improve and standardize food quality and hygiene practices during production and storage to ensure human safety and prevent HIS formation.

A Review on Bio- and Chemosensors for the Detection of Biogenic Amines in Food Safety Applications: The Status in 2022

This article provides an overview on the broad topic of biogenic amines (BAs) that are a persistent concern in the context of food quality and safety. They emerge mainly from the decomposition of amino acids in protein-rich food due to enzymes excreted by pathogenic bacteria that infect food under inappropriate storage conditions. While there are food authority regulations on the maximum allowed amounts of, e.g., histamine in fish, sensitive individuals can still suffer from medical conditions triggered by biogenic amines, and mass outbreaks of scombroid poisoning are reported regularly. We review first the classical techniques used for selective BA detection and quantification in analytical laboratories and focus then on sensor-based solutions aiming at on-site BA detection throughout the food chain. There are receptor-free chemosensors for BA detection and a vastly growing range of bio- and biomimetic sensors that employ receptors to enable selective molecular recognition. Regarding the receptors, we address enzymes, antibodies, molecularly imprinted polymers (MIPs), and aptamers as the most recent class of BA receptors. Furthermore, we address the underlying transducer technologies, including optical, electrochemical, mass-sensitive, and thermal-based sensing principles. The review concludes with an assessment on the persistent limitations of BA sensors, a technological forecast, and thoughts on short-term solutions.

Malolactic Fermentation: New Approaches to Old Problems

Malolactic fermentation (MLF) is the decarboxylation of L-malic acid to L-lactic acid by lactic acid bacteria (LAB). For the majority of wine production, secondary fermentation is crucial. MLF significantly impacts the quality of most red and some white wine. The outcomes of the spontaneously initiated and finished MLF are frequently unpredictable and can even cause the wine to deteriorate. As a result, individuals typically favour inoculating superior starter cultures when performing MLF. The MLF method for wine has, however, faced new difficulties because of the altered wine fermentation substrate environment brought on by global climate change, the growing demands of winemakers for production efficiency, and the rising demand for high-quality wine. To serve as a reference for the study of wine production and MLF in the current situation, this review primarily updates and summarises the research findings on increasing the effectiveness and dependability of MLF in recent years.

Role of Marine Bacterial Contaminants in Histamine Formation in Seafood Products: A Review

Histamine is a toxic biogenic amine commonly found in seafood products or their derivatives. This metabolite is produced by histamine-producing bacteria (HPB) such as Proteus vulgaris, P. mirabilis, Enterobacter aerogenes, E. cloacae, Serratia fonticola, S. liquefaciens, Citrobacter freundii, C. braakii, Clostridium spp., Raoultella planticola, R. ornithinolytica, Vibrio alginolyticus, V. parahaemolyticus, V. olivaceus, Acinetobacter lowffi, Plesiomonas shigelloides, Pseudomonas putida, P. fluorescens, Aeromonas spp., Photobacterium damselae, P. phosphoreum, P. leiognathi, P. iliopiscarium, P. kishitanii, and P. aquimaris. In this review, the role of these bacteria in histamine production in fish and seafood products with consequences for human food poisoning following consumption are discussed. In addition, methods to control their activity in countering histamine production are proposed.

Rapid and Wash-Free Time-Gated FRET Histamine Assays Using Antibodies and Aptamers

Histamine (HA) is an indicator of food freshness and quality. However, high concentrations of HA can cause food poisoning. Simple, rapid, sensitive, and specific quantification can enable efficient screening of HA in food and beverages. However, conventional assays are complicated and time-consuming, as they require multiple incubation, washing, and separation steps. Here, we demonstrate that time-gated Förster resonance energy transfer (TG-FRET) between terbium (Tb) complexes and organic dyes can be implemented in both immunosensors and aptasensors for simple HA quantification using a rapid, single-step, mix-and-measure assay format. Both biosensors could quantify HA at concentrations relevant in food poisoning with limits of detection of 0.19 μg/mL and 0.03 μg/mL, respectively. Excellent specificity was documented against the structurally similar food components tryptamine and l-histidine. Direct applicability of the TG-FRET assays was demonstrated by quantifying HA in spiked fish and wine samples with both excellent concentration recovery and agreement with conventional multistep enzyme-linked immunosorbent assays (ELISAs). Our results show that the simplicity and rapidity of TG-FRET assays do not compromise sensitivity, specificity, and reliability, and both immunosensors and aptasensors have a strong potential for their implementation in advanced food safety screening.

Biodiversity of Oenological Lactic Acid Bacteria: Species- and Strain-Dependent Plus/Minus Effects on Wine Quality and Safety

Winemaking depends on several elaborate biochemical processes that see as protagonist either yeasts or lactic acid bacteria (LAB) of oenological interest. In particular, LAB have a fundamental role in determining the quality chemical and aromatic properties of wine. They are essential not only for malic acid conversion, but also for producing several desired by-products due to their important enzymatic activities that can release volatile aromatic compounds during malolactic fermentation (e.g., esters, carbonyl compounds, thiols, monoterpenes). In addition, LAB in oenology can act as bioprotectors and reduce the content of undesired compounds. On the other hand, LAB can affect wine consumers’ health, as they can produce harmful compounds such as biogenic amines and ethyl carbamate under certain conditions during fermentation. Several of these positive and negative properties are species- and strain-dependent characteristics. This review focuses on these aspects, summarising the current state of knowledge on LAB’s oenological diversity, and highlighting their influence on the final product’s quality and safety. All our reported information is of high interest in searching new candidate strains to design starter cultures, microbial resources for traditional/typical products, and green solutions in winemaking. Due to the continuous interest in LAB as oenological bioresources, we also underline the importance of inoculation timing. The considerable variability among LAB species/strains associated with spontaneous consortia and the continuous advances in the characterisation of new species/strains of interest for applications in the wine sector suggest that the exploitation of biodiversity belonging to this heterogeneous group of bacteria is still rising.

Organic Winemaking and Its Subsets; Biodynamic, Natural, and Clean Wine in California

From the ancient times, when wine/oenos was described as "Wine, the benevolent demon" by ancient Greek gastronomist and philosopher Athinaios in "Dipnosofistes", to modern days, the craft has seen significant fruition. The wine industry has evolved over time, and more so recently, to encompass many different subsets, one of which is the organic wine market. The organic wine industry has grown in recent years, especially in California. This rapid gain in interest has resulted in the evolution of several subsets, including biodynamic, natural, and clean wine. While biodynamic and natural wine, function more as a fulfillment of niche markets, clean wine may provide benefits for consumers that otherwise suffer from side effects of wine consumption. Low sulfite levels and lack of histamines in clean wine plausibly decrease headaches and adverse effects some consumers experience when drinking wine. An overview of the organic wine industry and its evolution with potential contributions to consumers, with an emphasis on clean wine, is discussed herein.

Lactic acid bacterial exopolysaccharides strongly bind histamine and can potentially be used to remove histamine contamination in food

The symptoms of foodborne histamine poisoning are similar to those of IgE-mediated food allergies. In this study, we investigated the histamine-binding capacity of lactic acid bacteria (LAB) strains as potential preventive agents against histamine poisoning. Histamine biosorption capacity was determined for 16 LAB strains. Leuconostoc mesenteroides TOKAI 51 m, Lactobacillus paracasei TOKAI 65 m, Lactobacillus plantarum TOKAI 111 m and Pediococcus pentosaceus TOKAI 759 m showed especially high biosorption rates and reached saturation within 30 min. Adsorption isotherms showed better conformance to the Freundlich model than to the Langmuir model. Analyses after heat, periodic acid and guanidine hydrochloride treatments suggested that histamine was bound to the bacterial cell surface. HPLC analysis revealed that exopolysaccharides produced by Lact. paracasei TOKAI 65 m strongly bound to histamine. In the detachment test with 1 mol l^-1 HCl solution, the dissociation rate of histamine for Lact. paracasei TOKAI 65 m was <10 %. This strain is presumably a suitable candidate for use against histamine poisoning.

Removal of biogenic amines from wines by chemisorption on functionalized silica and effects on other wine components

The effectiveness of several functionalized silica materials (cation-exchange materials) for the removal of biogenic amines from wines, and the effects on other wine components and organoleptic characteristics were evaluated. Results have shown that mesoporous silica material bi-functionalized with phosphonic and sulfonic acids allowed the removal of histamine, putrescine, cadaverine, spermine and spermidine from wines, although the dose must be adapted for each wine according to the removal requirements and wine characteristics. A plus of the adsorbent developed is that it can be recovered and re-used for at least 3 treatments. Immediately following the treatments, a decrease in the levels of linear ethyl esters (ethyl hexanoate, ethyl octanoate and ethyl decanoate) was observed, although these levels were re-equilibrated after several days reducing this undesired side effect. A slight, but perceptible, effect on wine color was observed, probably due to the slight decrease in the pH of the wine produced by the treatments. On the basis of the sensory analysis that focused only on the aroma of the wines, the proposed technique would be more adequate for wines aged in barrels than for young wines.

Targeting the microbiota in pharmacology of psychiatric disorders

There is increasing interest in the role of the gut microbiota in health and disease. In particular, gut microbiota influences the Central Nervous System (CNS) development and homeostasis through neural pathways or routes involving the immune and circulatory systems. The CNS, in turn, shapes the intestinal flora through endocrine or stress-mediated responses. These overall bidirectional interactions, known as gut microbiota-brain axis, profoundly affect some brain functions, such as neurogenesis and the production of neurotransmitters, up to influence behavioral aspects of healthy subjects. Consequently, a dysfunction within this axis, as observed in case of dysbiosis, can have an impact on the behavior of a given individual (e.g. anxiety and depression) or on the development of pathologies affecting the CNS, such as autism spectrum disorders and neurodegenerative diseases (e.g. Alzheimer's disease and Parkinson's disease). It should be considered that the whole microbiota has a significant role not only on aspects concerning human physiology, such as harvesting of nutrients and energy from the ingested food or production of a wide range of bioactive compounds, but also has positive effects on the gastrointestinal barrier function and actively contributes to the pharmacokinetics of several compounds including neuropsychiatric drugs. Indeed, the microbiota is able to affect drug absorption and metabolism up to have an impact on drug activity and/or toxicity. On the other hand, drugs are able to shape the human gut microbiota itself, where these changes may contribute to their pharmacologic profile. Therefore, the emerging picture on the complex drug-microbiota bidirectional interplay will have considerable implications in the future not only in terms of clinical practice but also, upstream, on drug development.

Assessment of microbial quality and health risks associated with traditional rice wine starter Xaj-pitha of Assam, India: a step towards defined and controlled fermentation

This study reports the microbial quality of ethnic starter culture Xaj-pitha used for rice wine fermentation in Assam. Here, we collected 60 Xaj-pitha samples belonging to Ahom community of the state and enumerated the microorganisms using spread plate technique. Illumina-based whole genome shotgun sequencing detected the presence of microbial contaminants like Acidovorax, Herbaspirillum, Methylobacterium, Pantoea, Pseudomonas, Stenotrophomonas, Staphylococcus, Micrococcus, Acinetobacter, etc. Presence of major health hazards associated with spontaneous rice wine fermentation necessitated method optimization through the development of a defined mixed starter culture. For this, functionally important α-amylase producers viz., Penicillium sp. ABTSJ23, Rhizopus oryzae ABTSJ63, Mucor guilliermondii ABTSJ72 and Amylomyces rouxii ABTSJ82 and eight yeasts viz., Saccharomyces cerevisiae ABTY1J, ABTY1S, ADJ5 & ADJ1, Wickerhamomyces anomalus ADJ2, Saccharomycopsis malanga ADJ3, Saccharomycopsis fibuligera ADJ4 and Saccharomycopsis malanga ADJ6 were retrieved using appropriate media. All the mould cultures tested negative for aflotoxins production. Among the yeasts, Saccharomyces cerevisiae ABTY1S and ADJ1 decarboxylated lysine HCl and tyramine HCl, respectively, indicating their biogenic amine production ability. For defined mixed starter culture, Amylomyces rouxii ABT82 with α-amylase (5.92 U/ml) and glucoamylase (7.50 U/ml) activities was selected as fungal partner; while Saccharomycopsis fibuligera ADJ4 and Saccharomyces cerevisiae ABT-Y1J with high ethanol production (up to 10.11% and 9.88% v/v, respectively) were selected as yeast partners. The mixed culture was able to produce high amount of glucose, ethanol and liquid (glucose 10.91% w/v; ethanol 7.5% w/v; liquid 51.0% w/v). Therefore, this study demonstrated the efficiency of mixed starter cultures for safe and controlled rice wine production.

Modifications of Phenolic Compounds, Biogenic Amines, and Volatile Compounds in Cabernet Gernishct Wine through Malolactic Fermentation by Lactobacillus plantarum and Oenococcus oeni

Malolactic fermentation is a vital red wine-making process to enhance the sensory quality. The objective of this study is to elucidate the starter cultures’ role in modifying phenolic compounds, biogenic amines, and volatile compounds after red wine malolactic fermentation. We initiated the malolactic fermentation in Cabernet Gernishct wine by using two Oenococcus oeni and two Lactobacillus plantarum strains. Results showed that after malolactic fermentation, wines experienced a content decrease of total flavanols and total flavonols, accompanied by the accumulation of phenolic acids. The Lactobacillus plantarum strains, compared to Oenococcus oeni, exhibited a prevention against the accumulation of biogenic amines. The malolactic fermentation increased the total esters and modified the aromatic features compared to the unfermented wine. The Lactobacillus plantarum strains retained more aromas than the Oenococcus oeni strains did. Principal component analysis revealed that different strains could distinctly alter the wine characteristics being investigated in this study. These indicated that Lactobacillus plantarum could serve as a better alternative starter for conducting red wine malolactic fermentation.

Painful interactions: Microbial compounds and visceral pain

Visceral pain, characterized by abdominal discomfort, originates from organs in the abdominal cavity and is a characteristic symptom in patients suffering from irritable bowel syndrome, vulvodynia or interstitial cystitis. Most organs in which visceral pain originates are in contact with the external milieu and continuously exposed to microbes. In order to maintain homeostasis and prevent infections, the immune- and nervous system in these organs cooperate to sense and eliminate (harmful) microbes. Recognition of microbial components or products by receptors expressed on cells from the immune and nervous system can activate immune responses but may also cause pain. We review the microbial compounds and their receptors that could be involved in visceral pain development.

Isolation and molecular identification for autochthonous starter Saccharomyces cerevisiae with low biogenic amine synthesis for black raspberry (Rubus coreanus Miquel) wine fermentation

Biogenic amines (BAs) are widely present in nearly all fermented foods and beverages, and excess consumption can cause adverse health effects. To prepare BA-free Korean black raspberry wine (BRW), four autochthonous starter yeast strains without hazardous BA synthesis activity were selected and their physiological and biochemical properties were examined. The selected strains were identified as Saccharomyces cerevisiae based on 26S rDNA sequencing and microsatellite analysis. Molecular fingerprinting revealed that isolates were quite different from commercial wine yeast S. cerevisiae (52.4% similarity), but genetically relevant to commercial beer yeasts. The four S. cerevisiae strains produced over 10% ethanol during BRW fermentation. In addition, the fermented BRW with these strains showed higher levels of total flavonoids and similar antioxidant activity compared to the control sample. Potentially hazardous BAs that commonly occur in black raspberry extract (BRE) such as cadaverine, histamine, and spermidine were also not detected in the fermented BRW. Thus, we suggest that our strains are promising fermentation tools to ensure high quality and enhanced functionality in the production of BA-free BRW.

Magnetic immunochromatographic test for histamine detection in wine

Histamine, a biogenic amine, is abundant in fermented foods and beverages, notably wine. A high intake of this monoamine may produce adverse reactions in humans, which may be severe in individuals with a reduced capacity to catabolise extrinsic histamine. Thus, control of histamine concentration during wine production and before distribution is advisable. Simple, rapid, point-of-use bioanalytical platforms are needed because traditional methods for the detection and quantification of histamine are expensive and time-consuming. This work applies the lateral flow immunoassay technique to histamine detection. Superparamagnetic particle labels, and an inductive sensor designed to read the test line in the immunoassay, enable magnetic quantification of the molecule. The system is calibrated with histamine standards in the interval of interest for wine production. A commercial optical strip reader is used for comparison measurements. The lateral flow system has a limit of detection of 1.2 and 1.5 mg/L for the inductive and optical readers, respectively. The capability of the inductive system for histamine quantification is demonstrated for wine samples at different processing points (at the end of alcoholic fermentation, at the end of malolactic fermentation, in freshly bottled wine, and in reserve wine). The results are validated by ultra-high-performance liquid chromatography. Graphical abstract.

Neurotransmitter modulation by the gut microbiota

The gut microbiota - the trillions of bacteria that reside within the gastrointestinal tract - has been found to not only be an essential component immune and metabolic health, but also seems to influence development and diseases of the enteric and central nervous system, including motility disorders, behavioral disorders, neurodegenerative disease, cerebrovascular accidents, and neuroimmune-mediated disorders. By leveraging animal models, several different pathways of communication have been identified along the "gut-brain-axis" including those driven by the immune system, the vagus nerve, or by modulation of neuroactive compounds by the microbiota. Of the latter, bacteria have been shown to produce and/or consume a wide range of mammalian neurotransmitters, including dopamine, norepinephrine, serotonin, or gamma-aminobutyric acid (GABA). Accumulating evidence in animals suggests that manipulation of these neurotransmitters by bacteria may have an impact in host physiology, and preliminary human studies are showing that microbiota-based interventions can also alter neurotransmitter levels. Nonetheless, substantially more work is required to determine whether microbiota-mediated manipulation of human neurotransmission has any physiological implications, and if so, how it may be leveraged therapeutically. In this review this exciting route of communication along the gut-brain-axis, and accompanying data, are discussed.

Diversity and Functional Properties of Lactic Acid Bacteria Isolated From Wild Fruits and Flowers Present in Northern Argentina

Lactic acid bacteria (LAB) are capable of converting carbohydrate substrates into organic acids (mainly lactic acid) and producing a wide range of metabolites. Due to their interesting beneficial properties, LAB are widely used as starter cultures, as probiotics, and as microbial cell factories. Exploring LAB present in unknown niches may lead to the isolation of unique species or strains with relevant technological properties. Autochthonous rather than allochthonous starter cultures are preferred in the current industry of fermented food products, due to better adaptation and performance of autochthonous strains to the matrix they originate from. In this work, the lactic microbiota of eight different wild tropical types of fruits and four types of flowers were studied. The ability of the isolated strains to produce metabolites of interest to the food industry was evaluated. The presence of 21 species belonging to the genera Enterococcus, Fructobacillus, Lactobacillus, Lactococcus, Leuconostoc, and Weissella was evidenced by using culture-dependent techniques. The isolated LAB corresponded to 95 genotypically differentiated strains by applying rep-PCR and sequencing of the 16S rRNA gene; subsequently, representative strains of the different isolated species were studied for technological properties, such as fast growth rate and acidifying capacity; pectinolytic and cinnamoyl esterase activities, and absence of biogenic amine biosynthesis. Additionally, the strains' capacity to produce ethyl esters as well as mannitol was evaluated. The isolated fruit- and flower-origin LAB displayed functional properties that validate their potential use in the manufacture of fermented fruit-based products setting the background for the design of novel functional foods.

Biogenic Amine Production by Lactic Acid Bacteria: A Review

Lactic acid bacteria (LAB) are considered as the main biogenic amine (BA) producers in fermented foods. These compounds derive from amino acid decarboxylation through microbial activities and can cause toxic effects on humans, with symptoms (headache, heart palpitations, vomiting, diarrhea) depending also on individual sensitivity. Many studies have focused on the aminobiogenic potential of LAB associated with fermented foods, taking into consideration the conditions affecting BA accumulation and enzymes/genes involved in the biosynthetic mechanisms. This review describes in detail the different LAB (used as starter cultures to improve technological and sensorial properties, as well as those naturally occurring during ripening or in spontaneous fermentations) able to produce BAs in model or in real systems. The groups considered were enterococci, lactobacilli, streptococci, lactococci, pediococci, oenococci and, as minor producers, LAB belonging to Leuconostoc and Weissella genus. A deeper knowledge of this issue is important because decarboxylase activities are often related to strains rather than to species or genera. Moreover, this information can help to improve the selection of strains for further applications as starter or bioprotective cultures, in order to obtain high quality foods with reduced BA content.

Mixed Starter Culture Regulates Biogenic Amines Formation via Decarboxylation and Transamination during Chinese Rice Wine Fermentation

The utilization of amine-negative starter based on an understanding of nitrogen metabolism is a useful method for controlling biogenic amine (BA) in Chinese rice wine (CRW) fermentation. The contribution of brewing materials to protein degradation was analyzed; wheat Qu protein had no effect, and yeast autolysis generated 10% amino nitrogen. Milling degree of rice was strongly correlated with BAs formation ( R² = 0.99). Subsequently, Lactobacillus plantarum and Staphylococcus xylosus were coinoculated as amine-negative starter at an optimized ratio of 1:2. Coinoculation induced a significant reduction in total BAs (43.7%, 44.5 mg L^-1), putrescine (43.0%, 20.4 mg L^-1), tyramine (42.8%, 14.3 mg L^-1), and histamine (42.6%, 3.5 mg L^-1) content. Notably, BAs degradation ability of Staphylococcus xylosus was stronger than the suppression effect of Lactobacillus plantarum, and higher lactic acid bacteria (LAB) amount has a positive correlation with lower BAs content. Overall, mixed strains exerted a synergistic effect in lowering BAs accumulation via decarboxylation and transamination.

Development of Tyrosine Decarboxylase-Negative Strains of Lactobacillus curvatus by Classical Strain Improvement

Biogenic amines have been widely studied because of their potential toxicity in fermented foods. Several lactic acid bacteria have the potential to decarboxylate the amino acid tyrosine to tyramine. In this work, we identified two strains of Lactobacillus curvatus, Lbc1 and Lbc2, endowed with the ability to produce tyramine, a metabolic feature that limits their application in starter cultures for fermented meat. To overcome this limitation, we set out to eliminate tyramine production from L. curvatus strains by using classical strain improvement. About 4,000 mutant isolates of both strains were screened using a colorimetric method, and then potential tyrosine decarboxylase-negative mutants were selected. Firm identification of loss-of-function mutants was performed by analytical determination of tyrosine and tyramine in cultivation medium. Of the 8,000 mutants screened, only one mutant of Lbc1 and two mutants of Lbc2 had completely lost the potential to produce tyramine. Subsequently, one tyrosine decarboxylase-negative mutant of both Lbc1 and Lbc2 was characterized in more detail. DNA sequencing of the Lbc1 mutant tdcA gene disclosed two missense mutations in the promoter distal part of the coding sequence. These two mutations result in two amino acid changes in the encoded tyrosine decarboxylase, Pro87Thr and Ser130Leu, presumably inactivating the enzyme activity. The DNA sequence of the other characterized mutant, derived from strain Lbc2, showed that insertion of a 6-bp fragment at nucleotide position 1348 in the tdc gene is presumably the factor leading to loss of activity. With the successful elimination of the undesirable tyramine-producing phenotype without the use of recombinant DNA technology, these developed L. curvatus mutant strains can be safely used in the dairy industry or in the manufacture of various food products.

Scientific Opinion on the update of the list of QPS-recommended biological agents intentionally added to food or feed as notified to EFSA

EFSA is requested to assess the safety of a broad range of biological agents in the context of notification for market authorisation as sources of food and feed additives, food enzymes and plant protection products. The qualified presumption of safety (QPS) assessment was developed to provide a harmonised generic pre-assessment to support safety risk assessments performed by EFSA's scientific Panels. The safety of unambiguously defined biological agents (at the highest taxonomic unit appropriate for the purpose for which an application is intended), and the completeness of the body of knowledge are assessed. Identified safety concerns for a taxonomic unit are, where possible and reasonable in number, reflected as 'qualifications' in connection with a recommendation for a QPS status. The list of QPS recommended biological agents was reviewed and updated in the current opinion and therefore becomes the valid list. The 2016 update reviews previously assessed microorganisms including bacteria, yeasts and viruses used for plant protection purposes following an Extensive Literature Search strategy. The taxonomic units related to the new notifications received since the 2013 QPS opinion, were periodically evaluated for a QPS status and the results published as Statements of the BIOHAZ Panel. Carnobacterium divergens, Lactobacillus diolivorans, Microbacterium imperiale, Pasteuria nishizawae, Pediococcus parvulus, Bacillus flexus, Bacillus smithii, Xanthomonas campestris and Candida cylindracea were recommended for the QPS list. All taxonomic units previously recommended for the 2013 QPS list had their status reconfirmed as well their qualifications with the exception of Pasteuria nishizawae for which the qualification was removed. The exclusion of filamentous fungi and enterococci from the QPS evaluations was reconsidered but monitoring will be maintained and the status will be re-evaluated in the next QPS Opinion update. Evaluation of bacteriophages should remain as a case-by-case procedure and should not be considered for QPS status.

Lowering histamine formation in a red Ribera del Duero wine (Spain) by using an indigenous O. oeni strain as a malolactic starter

This study demonstrates for the first time that a non-commercial selected autochthonous O. oeni strain has been used to conduct malolactic fermentation (MLF) while lowering histamine formation in the same winery. Lactic acid bacteria (LAB) were isolated from 13 vats before and after spontaneous MLF at the Pago de Carraovejas winery from the Ribera del Duero region (Spain). Only O. oeni were present, typed and characterized, and both histamine producer and non-producers existed. From the non-producers, one strain was selected to become a starter according to its genetic profile, prevalence in the different wines in the winery, resistance to alcoholic degree, resistance to high polyphenolic content, inability to synthesise histamine, growth kinetics and malolactic activity. This starter was produced at semi-industrial levels to inoculate 20,000L of Tempranillo red wine. The inoculated vat showed 5-fold less histamine than the non-inoculated control vat. After 1year, the barrel-ageing histamine concentrations were 3-fold lower in the inoculated vat than in the non-inoculated vat.

Technological Factors Affecting Biogenic Amine Content in Foods: A Review

Biogenic amines (BAs) are molecules, which can be present in foods and, due to their toxicity, can cause adverse effects on the consumers. BAs are generally produced by microbial decarboxylation of amino acids in food products. The most significant BAs occurring in foods are histamine, tyramine, putrescine, cadaverine, tryptamine, 2-phenylethylamine, spermine, spermidine, and agmatine. The importance of preventing the excessive accumulation of BAs in foods is related to their impact on human health and food quality. Quality criteria in connection with the presence of BAs in food and food products are necessary from a toxicological point of view. This is particularly important in fermented foods in which the massive microbial proliferation required for obtaining specific products is often relater with BAs accumulation. In this review, up-to-date information and recent discoveries about technological factors affecting BA content in foods are reviewed. Specifically, BA forming-microorganism and decarboxylation activity, genetic and metabolic organization of decarboxylases, risk associated to BAs (histamine, tyramine toxicity, and other BAs), environmental factors influencing BA formation (temperature, salt concentration, and pH). In addition, the technological factors for controlling BA production (use of starter culture, technological additives, effects of packaging, other non-thermal treatments, metabolizing BA by microorganisms, effects of pressure treatments on BA formation and antimicrobial substances) are addressed.

The use of core-shell high-performance liquid chromatography column technology to improve biogenic amine quantification in wine

BACKGROUND

HPLC column technology has been improved, providing better resolution of closely eluting compounds, better analyte sensitivity, and shorter analysis times. The core-shell technology columns offer a faster analysis through the use of shorter columns without compromising resolution. The aim of this work was to improve the methods for determination of biogenic amines (BAs) in wine using the new HPLC PFP core-shell column technology.

RESULTS

Two different elution programs were designed to quantify BAs with the core-shell PFP column. Program I flow rate was 2 mL min(-1). The total elution time was 10 min. In elution program II, the flow rate was 0.8 mL min(-1) and the total elution time was 25 min. The two elution programs used with the core-shell PFP HPLC column showed differences related mainly to the histamine peak. The chromatograms showed that when a temporary isocratic elution was added in the gradient (program II), the histamine peak was eluted later, causing its isolation, and therefore its quantification was easier.

CONCLUSIONS

Compared to the previous C18 HPLC column for the BAs determination in wine, the main advantage of the presented technique is the reduction of the run times and solvent volumes, and has a better sensitivity and selectivity as peaks are higher and sharper.

New Trends and Perspectives in the Evolution of Neurotransmitters in Microbial, Plant, and Animal Cells

The evolutionary perspective on the universal roles of compounds known as neurotransmitters may help in the analysis of relations between all organisms in biocenosis-from microorganisms to plant and animals. This phenomenon, significant for chemosignaling and cellular endocrinology, has been important in human health and the ability to cause disease or immunity, because the "living environment" influences every organism in a biocenosis relationship (microorganism-microorganism, microorganism-plant, microorganism-animal, plant-animal, plant-plant and animal-animal). Non-nervous functions of neurotransmitters (rather "biomediators" on a cellular level) are considered in this review and ample consideration is given to similarities and differences that unite, as well as distinguish, taxonomical kingdoms.

Bacteria isolated from Korean black raspberry vinegar with low biogenic amine production in wine

A high concentration of histamine, one of the biogenic amines (BAs) usually found in fermented foods, can cause undesirable physiological side effects in sensitive humans. The objective of this study is to isolate indigenous Acetobacter strains from naturally fermented Bokbunja vinegar in Korea with reduced histamine production during starter fermentation. Further, we examined its physiological and biochemical properties, including BA synthesis. The obtained strain MBA-77, identified as Acetobacter aceti by 16S rDNA homology and biochemical analysis and named A. aceti MBA-77. A. aceti MBA-77 showed optimal acidity % production at pH 5; the optimal temperature was 25 °C. When we prepared and examined the BAs synthesis spectrum during the fermentation process, Bokbunja wine fermented with Saccharomyces cerevisiae showed that the histamine concentration increased from 2.72 of Bokbunja extract to 5.29 mg/L and cadaverine and dopamine was decreased to 2.6 and 10.12 mg/L, respectively. Bokbunja vinegar prepared by A. aceti MBA-77 as the starter, the histamine concentration of the vinegar preparation step was decreased up to 3.66 mg/L from 5.29 mg/L in the wine preparation step. To our knowledge, this is the first report to demonstrate acetic acid bacteria isolated from Bokbunja seed vinegar with low spectrum BA and would be useful for wellbeing vinegar preparation.

Genetic and technological characterisation of vineyard- and winery-associated lactic acid bacteria

Vineyard- and winery-associated lactic acid bacteria (LAB) from two major PDO regions in Greece, Peza and Nemea, were surveyed. LAB were isolated from grapes, fermenting musts, and winery tanks performing spontaneous malolactic fermentations (MLF). Higher population density and species richness were detected in Nemea than in Peza vineyards and on grapes than in fermenting musts. Pediococcus pentosaceus and Lactobacillus graminis were the most abundant LAB on grapes, while Lactobacillus plantarum dominated in fermenting musts from both regions. No particular structure of Lactobacillus plantarum populations according to the region of origin was observed, and strain distribution seems random. LAB species diversity in winery tanks differed significantly from that in vineyard samples, consisting principally of Oenococcus oeni. Different strains were analysed as per their enological characteristics and the ability to produce biogenic amines (BAs). Winery-associated species showed higher resistance to low pH, ethanol, SO₂, and CuSO₄ than vineyard-associated isolates. The frequency of BA-producing strains was relatively low but not negligible, considering that certain winery-associated Lactobacillus hilgardii strains were able to produce BAs. Present results show the necessity of controlling the MLF by selected starters in order to avoid BA accumulation in wine.

Evaluation of microbial diversity in sulfite-added and sulfite-free wine by culture-dependent and -independent methods

The difference in microbiota including non-lactic acid bacteria, non-acetic acid bacteria, and wild yeast during winemaking and in the end-products between sulfite-added and sulfite-free wine, was investigated using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE) and a culture-dependent method. There were differences between the microorganisms detected by PCR-DGGE and those detected by the culture-dependent method, probably because of the selectivity of culture medium and the characteristics of PCR-based method. In both the red wine and white wine, the microbial diversity of the sulfite-added wine was lower than that of the sulfite-free wine during fermentation. Tatumella terrea was detected from the fermenting must by PCR-DGGE and by the culture-dependent method, even though sulfite inhibited its growth to some extent. We confirmed that the addition of sulfite plays an important role in winemaking by inhibiting the growth of unexpected microorganisms, but on the other hand, it was revealed that some microorganisms can survive and grow in sulfite-added fermenting must. We also analyzed 15 samples of commercial wines by the PCR-DGGE method and detected various microorganisms. Among them, Sphingomonas sp., Pseudozyma sp., Ochromonas sp. and Methylophilus sp. were found for the first time in wine as far as we know. We did not identify a specific microorganism that was detected only from wines without sulfite addition. Thus, the microbiota of end-products seemed to be influenced by other factors, such as filtration before bottling, the production equipment and the storage environment.

The influences of fish infusion broth on the biogenic amines formation by lactic acid bacteria

The influences of fish infusion decarboxylase broth (IDB) on biogenic amines (BA) formation by lactic acid bacteria (LAB) were investigated. BA productions by single LAB strains were tested in five different fish (anchovy, mackerel, white shark, sardine and gilthead seabream) IDB. The result of the study showed that significant differences in ammonia (AMN) and BA production were observed among the LAB strains in fish IDB (p < 0.05). The highest AMN and TMA production by LAB strains were observed for white shark IDB. The all tested bacteria had decarboxylation activity in fish IDB. The uppermost accumulated amines by LAB strains were tyramine (TYM), dopamine, serotonin and spermidine. The maximum histamine production was observed in sardine (101.69 mg/L) and mackerel (100.84 mg/L) IDB by Leuconostoc mesenteroides subsp. cremoris and Pediococcus acidophilus, respectively. Lactobacillus delbrueckii subsp. lactis and Pediococcus acidophilus had a high TYM producing capability (2943 mg/L and 1157 mg/L) in sardine IDB.

Biodiversity and safety aspects of yeast strains characterized from vineyards and spontaneous fermentations in the Apulia Region, Italy

This work is the first large-scale study on vineyard-associated yeast strains from Apulia (Southern Italy). Yeasts were identified by Internal Transcribed Spacer (ITS) ribotyping and bioinformatic analysis. The polymorphism of interdelta elements was used to differentiate Saccharomyces cerevisiae strains. Twenty different species belonging to 9 genera were identified. Predominant on the grape surface were Metschnikowia pulcherrima, Hanseniaspora uvarum and Aureobasidium pullulans, whereas M. pulcherrima and H. uvarum were dominant in the early fermentation stage. A total of 692 S. cerevisiae isolates were identified and a number of S. cerevisiae strains, ranging from 26 to 55, was detected in each of the eight fermentations. The strains were tested for biogenic amines (BAs) production, either in synthetic media or grape must. Two Pichia manshurica, an Issatchenkia terricola and a M. pulcherrima strains were able to produce histamine and cadaverine, during must fermentation. The production of BAs in wine must was different than that observed in the synthetic medium. This feature indicate the importance of an "in grape must" assessment of BAs producing yeast. Overall, our results suggest the importance of microbiological control during wine-making to reduce the potential health risk for consumer represented by these spoilage yeasts.

Decarboxylase activity test of the genus Enterococcus isolated from goat milk and cheese

Biogenic amines are aliphatic, aromatic or heterocyclic alkalic substances with a biological impact on live organisms. They may cause serious problems to sensitive persons in combination with some medicaments or in case of higher intake. They are present in non-fermented food, usually coming from contaminating microflora, and especially in fermented food where biogenic amines might be produced by microbiota used for procedure. The genus Enterococcus spp. can occur in cheese because their resistance to pasteurizing temperatures is much higher compared to other mesophilic microorganisms. Previous studies have targeted the occurrence and problems of enterococci isolated from cow and sheep milk. The aim of this study was to detect decarboxylase activity of enterococci isolated from goat milk and cheese and to see how the particular temperatures involve decarboxylase activity using a rapid and inexpensive screening method. In this study, bacteria Enterococcus faecium, E. mundtii, E. durans were isolated from 9 samples of goat milk and cheeses. Colonies of bacteria were inoculated on diagnostic medium fortified with amino acids (lysine, arginine, phenylalanine, histidine, tyrosine and tryptophan) and acidity indicator. Changes in colour detected decarboxylase activity of enterococci. The only positive reactions were determined in samples containing arginine and tyrosine. Cultivation of bacteria was confirmed by PCR. All of the tested microorganisms showed significant activity of tyrosindecarboxylase and arginindecarboxylase which was regulated by temperature and influenced by duration of cultivation. The test of decarboxylase activity using colour changes is suitable for a relatively rapid and inexpensive detection of microorganisms that are able to produce biogenic amines.

Evaluation of biogenic amines content in chilean reserve varietal wines

Biogenic amines play important roles in many physiological functions, but when they are ingested in high concentrations may produce severe adverse effects. The aim of this research was to evaluate the biogenic amine content in Chilean reserve varietal wines. A high performance liquid chromatography method was optimized and validated to quantify histamine, tyramine, spermine, spermidine, putrescine, cadaverine and phenylethylamine in Chilean wines. Derivatization and chromatographic conditions were optimized using a central composite design. Sixty reserve wines of the most important Chilean grape varieties were analyzed, i.e. Cabernet Sauvignon (n=11), Merlot (n=11), Carménère (n=11), Syrah (n=10) and Sauvignon Blanc (n=10), as well as organic wines (n=7). Biogenic amines content ranged from 2.19 to 65.09 mg L(-1), no significant difference (P>0.05) was observed between Cabernet Sauvignon, Merlot and Carménère but all showed statistically higher (P<0.05) concentrations than Sauvignon Blanc. Syrah wines showed no difference (P>0.05) with Cabernet Sauvignon, higher concentrations (P<0.05) than Sauvignon Blanc and lower than Merlot and Carménère. Regarding biogenic amines profile, putrescine showed the highest concentration in all grape varieties.

Does Oenococcus oeni produce histamine?

The presence of histamine in wine and other fermented foods may pose a toxicological risk for consumers. Production of histamine by Oenococcus oeni, which is the main agent of malolactic fermentation in wine and thus very important for the wine industry, has been extensively analyzed with contradictory results. If histamine production by O. oeni strains is a widespread trait, enological practices will be affected and the use of non-producing commercial O. oeni starters should be strongly recommended to avoid histamine production during winemaking. However, a review of published data showed that most evidence strongly supports the view that O. oeni is not responsible for histamine production in wine. We therefore propose the adoption of common analytical methods and the introduction of publicly-available validated histamine-producing O. oeni reference strains as a common positive control in assays to resolve this important issue.

Biogenic amines and ethyl carbamate in primitivo wine: survey of their concentrations in commercial products and relationship with the use of malolactic starter

This research was conducted to determine the biogenic amine (BA) and ethyl carbamate (EC) concentrations in commercial Primitivo wine samples and the influence of the use of malolactic starter culture on concentrations of these potentially hazardous compounds in this wine. One hundred sixty bottles of wine from eight producers in the Apulia region of southern Italy were purchased at retail and analyzed. The most common BAs were histamine, 2-phenylethylamine, tyramine, cadaverine, putrescine, spermine, and spermidine. Putrescine (derived from ornithine) was the most abundant BA in all commercial Primitivo wines (5.41 to 9.51 mg/liter), 2-phenylethylamine was detected in only two commercial wines (at less than 2.12 mg/liter), and histamine was found at concentrations of 1.49 to 16.34 mg/liter. The concentration of EC in commercial Primitivo wine was 6.81 to 15.62 ppb, which is not considered dangerous for human health. Malolactic fermentation (MLF) affected the concentrations of BAs and EC differently. For EC, no significant differences were detected between samples of wine produced by spontaneous fermentation and wine that was inoculated malolactic starter. Mean EC concentrations were 12 and 14 ppb in two batches tested (always 18 ppb or less), regardless of whether the malolactic starter was added. Although present at trace levels in wine before the MLF, histamine accumulated during the MLF process, regardless of whether the malolactic starter was added. However, the increase in histamine was higher in wines without the malolactic starter. The concentrations of putrescine and cadaverine increased after MLF, especially in the wine that spontaneously fermented. The use of a selected malolactic starter resulted in reductions in BA concentrations in wine produced by this guided MLF compared with wine produced by spontaneous MLF.

Wine features related to safety and consumer health: an integrated perspective

This review presents a global view of the current situation of the scientific knowledge about aspects of wine with possible repercussions (positive or negative) on consumer health and wine safety. The presence in wine of some potential harmful compounds such as phytosanitary products, trace metal compounds, sulfites, and some toxics of microbial origin, such as ochratoxin A, ethyl carbamate, and biogenic amines, is discussed. The different strategies and alternative methodologies that are being carried out to reduce or to avoid the presence of these substances in wines are also discussed. In recent years much work has focused on establishing the scientific explanations for the positive biological effects of some wine compounds. In this review, we also examine the latest knowledge regarding wine and health, focusing on two types of compounds that have been related to the positive effects of moderate wine consumption, such as phenolic compounds and bioactive peptides.