Biogenic Amine Synthesis Research Articles

Phenanthridine‐Based Donor/Acceptor Fluorescent Dyes: Synthesis, Photophysical Properties and Fluorometric Sensing of Biogenic Primary Amines

AbstractSynthesis of two new and straight forward phenanthridine based fluorophores (PA1 and PA2) have been described. The molecular structure of PA1 and PA2 was confirmed by spectroscopic studies (1H NMR, 13C NMR and HRMS). The dyes are further characterized by comprehensive photophysical study, and their data are critically analyzed. The fluorescence properties of these D−A chromophores are highly influenced by the position of the hydroxyl substitution and the solvent polarity. These probes exhibited an arsenal of advantageous features such as higher Stokes shift values and appreciable photostability. Compounds PA1 and PA2 are found to be indicating fluorescent ratiometric detection towards primary amines (PAs) with high selectivity and sensitivity. With this background, sensing of PAs was extended to biogenic amines as they have primary amine functionality. As expected, these fluorophores have excellent detection ability towards neurotransmitters, such as dopamine (DA) and serotonin (SN) with a low limit of detection (LOD) such as 1.61 nM and 0.31 nM respectively. The sensing mechanism of the probe PA1 with PAs are based on the nucleophilic addition and confirmed through investigation by 1H NMR titration, mass analysis and theoretical calculations. Moreover, sensor probe PA1 based test paper strip was developed, which could detect DA conveniently when visualized under 365 nm UV lamp.

Biogenic amine neurotransmitters promote eicosanoid production and protein homeostasis.

Metazoans use protein homeostasis (proteostasis) pathways to respond to adverse physiological conditions, changing environment, and aging. The nervous system regulates proteostasis in different tissues, but the mechanism is not understood. Here, we show that Caenorhabditiselegans employs biogenic amine neurotransmitters to regulate ubiquitin proteasome system (UPS) proteostasis in epithelia. Mutants for biogenic amine synthesis show decreased poly-ubiquitination and turnover of a GFP-based UPS substrate. Using RNA-seq and mass spectrometry, we found that biogenic amines promote eicosanoid production from poly-unsaturated fats (PUFAs) by regulating expression of cytochrome P450 monooxygenases. Mutants for one of these P450s share the same UPS phenotype observed in biogenic amine mutants. The production of n-6 eicosanoids is required for UPS substrate turnover, whereas accumulation of n-6 eicosanoids accelerates turnover. Our results suggest that sensory neurons secrete biogenic amines to modulate lipid signaling, which in turn activates stress response pathways to maintain UPS proteostasis.

Evaluation and prediction of the biogenic amines in Chinese traditional broad bean paste.

Biogenic amines (BAs) are a threat to the safety of broad bean paste, and biosynthetic mechanism of BA and its regulation are unknown. This study aimed to assess microbial BA synthesis in Chinese traditional broad bean paste and determine favorable fermentation conditions for BA regulation. The BAs content in 27 pastes was within the safe range. 64 strains with potential decarboxylation were screened in Luria-Bertani Glycerol medium and identified as Bacillus spp. Although Bacillus amyloliquefaciens produced highest levels of BAs (70.14 ± 2.69mg/L) in LBAA, Bacillus subtilis produced 6% more BAs than B. amyloliquefaciens. Meanwhile, temperature was the most remarkable factor affecting BAs production by B. amyloliquefaciens 1-13. Furthermore, the fermented broad bean paste model revealed that BA content increased by 61.2mg/kg every 10days at 45°C, which was approximately threefold of that at 25°C. An ARIMA prediction model of BAs content was constructed, and the total BAs content of 40mg/100g was set as the critical value. This study not only contributed to understanding the BAs formation mechanism, but also provided potential measures to control the BAs in fermented soybean products.

Nitrogen Sources Added to Must: Effect on the Fermentations and on the Tempranillo Red Wine Quality

Nitrogen supplementation in musts or during the alcoholic fermentation is a common practice to promote fermentations. In this study, the impact of the supplementation of two different sources of nitrogen during Tempranillo red wine elaboration was studied. Mineral and organic nitrogen was added after the exponential yeast growth phase and during winemaking, examining its impact on the alcoholic and malolactic fermentation development, on the aromatic wine composition and on the nitrogenous wine composition. The nitrogen supplementation did not provide neither significant advantages in kinetics and fermentations time, nor differences in the chemical wine composition. The aromatic composition of the wines improved with the addition of inorganic nitrogen, although its organoleptic evaluation was not favored. Moreover, the concentration of amino acids in wines increased slightly after the malolactic fermentation and significantly during the stabilization time, especially with organic nitrogen addition. However, the synthesis of biogenic amines did not increase in wines neither after the malolactic fermentation, nor after the storage period.

Investigation of the synthesis of biogenic amines and quality during high-salt liquid-state soy sauce fermentation

Soy sauce is a traditional fermented food in Asia. In this study, we determined the contents of biogenic amines (BAs) in commercial high-salt liquid-state fermented (HLF) soy sauce. Using high performance liquid chromatography (HPLC), we evaluated the effects of salinity on the synthesis of BAs during soy sauce fermentation. According to the results, various grades of HLF soy sauce demonstrated significant differences (p < 0.05) in the contents of BAs. The major BAs in laboratory-made soy sauce include spermidine (SPD), histamine (HIS), and tyramine (TYR). After fermentation, the contents of SPD, HIS, and TYR in the 20% salinity group were significantly (p < 0.05) reduced than those in the 16% and 18% salinity groups, suggesting that the salinity might be a crucial factor for reducing the biogenic amines during HLF soy sauce fermentation. We also found a positive correlation between the contents of amino nitrogen and biogenic amines.

Isolation, Identification, and Screening of Lactic Acid Bacteria with Probiotic Potential in Silage of Different Species of Forage Plants, Cocoa Beans, and Artisanal Salami.

The objective of this study was to isolate and characterize lactic acid bacteria with probiotic potential in silages of different species of forage plants, cocoa beans, and artisanal salami. The obtained isolates were submitted to the following evaluations: (i) screening for tolerance to pH2 and bile salts, (ii) genotypic identification of isolates, (iii) survival in simulated gastric and pancreatic conditions, (iv) antimicrobial activity, (v) antibiotic susceptibility and safety, and (vi) properties associated with adhesion capacity. A total of 82 isolates were obtained and were screened for pH2.0 tolerance and capacity to growth in the presence of bile salts (1.0 and 2.0%). Only 19 strains simultaneously presented tolerance to pH2.0 and bile salts. These 19 strains were evaluated for genetic profile by Box-PCR. Subsequently, the selected strains were subjected to partial sequencing of the 16S rRNA gene. The species Lactobacillus plantarum was prevalent. The identified strains were evaluated for survival under simulated gastric and pancreatic conditions. Some strains have shown tolerance in both conditions. Different strains showed variations in antimicrobial activity, susceptibility to antibiotics, and properties associated with adhesion (hydrophobicity, autoaggregation, coaggregation, and adhesion to CaCo2 cells). All strains were negative for hemolysis, DNase, gelatinase, and biogenic amine synthesis activity. The L. plantarum SBR64.7 strain can be considered the most promising for it presented the lowest viability reduction when exposed to gastric and pancreatic juices.

Long-term clinical outcome of 6-pyruvoyl-tetrahydropterin synthase-deficient patients

Introduction6-Pyruvoyl-tetrahydropterin synthase deficiency (PTPSd) is a rare autosomal recessive disorder of synthesis of biogenic amines, which is characterized by variable neurological impairment and hyperphenylalaninemia. We aimed to assess the long-term clinical outcome of this disorder and the factors affecting it. MethodsAt total of 28 PTPSd patients (aged 19.9 ± 10.9 years) underwent clinical (neurological and psychiatric) and neuropsychological assessment (BRIEF, VABS-II, and IQ). Based on CSF homovanillic (HVA) and 5-hydroxyindolacetic acid (5-HIAA) and pterin concentrations at diagnosis, patients were classified as having either a severe [SF; low level of CSF, HVA, and 5-HIAA with altered neopterin/biopterin (Neo/Bio)] or mild form (MF; normal HVA and 5-HIAA with altered Neo/Bio) of PTPSd. ResultsApproximately 36% of patients had MF PTPSd. At the last examination, 43% of patients had movement disorders (2 MF, 10 SF), 43% of patients had variable degrees of intellectual disability (SF only), 39% met the criteria for a psychiatric disorder (3 MF, 9 SF). Applying a linear regression model, we found that HVA and phenylalanine levels at birth had a significant influence on IQ, BRIEF, and VABS-II variability. Lastly, 5-HIAA further contributed to VABS-II variability. The disease showed a self-limiting clinical course and its treatment, although delayed, is effective in improving the neurological status. ConclusionsNeurodevelopmental impairment due to PTPSd shows a self-limiting course. A continuous improvement in the neurological condition has been observed in patients receiving treatment, even when delayed. The severity of brain biogenic amine depletion at diagnosis predicts neurological and psychiatric outcomes.

Biogenic Amines in Alcohol-Free Beverages

Biogenic amines are ubiquitous bioactive compounds that are synthesized by living organisms and perform essential functions for their metabolism. In the human diet, their excessive intake can cause food poisoning. In food, especially in alcohol-free beverages, biogenic amines can be synthesized by enzymes, naturally present in raw materials, or by microorganisms, which may be naturally present in the matrix or be added during beverage transformation processes. For this reason, in alcohol-free beverages, biogenic amine amount can be considered, above a certain level, as undesired microorganism activity. Therefore, it is important to evaluate the biogenic amine profile of non-alcoholic beverages in order to monitor food quality and safety. Moreover, biogenic amines can be taken into account by industries in order to monitor production processes and products. This review article provides an overview on the biogenic amine profile of alcohol-free beverages (plant milk, nervine drinks, soft drinks, and fruit juices). Furthermore, the clinical and toxicological effects, the biogenic amines legislation, and biogenic amine synthesis have been evaluated in non-alcoholic beverages.

Effects of Soaking and Fermentation Time on Biogenic Amines Content of Maesil (Prunus Mume) Extract.

Maesil extract, a fruit-juice concentrate derived from Prunus mume prepared by fermenting with sugar, is widely used with increasing popularity in Korea. Biogenic amines in maesil extract were extracted with 0.4 M perchloric acid, derivatized with dansyl chloride, and detected using high-performance liquid chromatography. Among 18 home-made maesil extracts collected from different regions, total biogenic amine content varied from 2.53 to 241.73 mg/L. To elucidate the effects of soaking and fermentation time on biogenic amine content in maesil extract, maesil was soaked in brown sugar for 90 days and the liquid obtained was further fermented for 180 days at 15 and 25 °C, respectively. The main biogenic amines extracted were putrescine and spermidine and the total biogenic amine content was higher at 25 °C than at 15 °C. Soaking at 15 and 25 °C increased the total biogenic amines content from 14.14 to 34.98 mg/L and 37.33 to 69.05 mg/L, respectively, whereas a 180 day fermentation decreased the content from 31.66 to 13.59 mg/L and 116.82 to 57.05 mg/L, respectively. Biogenic amine content was correlated with total amino acid content (particularly, arginine content). Based on these results, we have considered that biogenic amine synthesis can be reduced during maesil extract production by controlling temperature and fermentation time.

Biosafety assessment of Bifidobacterium animalis subsp. lactis AD011 used for human consumption as a probiotic microorganism

In this work, the previously identified Bifidobacterium strain, Bifidobacterium animalis subsp. lactis AD011 (obtained from an infant fecal sample), intended as a potential probiotic microorganism, is assessed for its safety using multiple in vitro virulence assays (ammonia and biogenic amine synthesis, hemolytic and mucin degradation activities, antimicrobial susceptibility and conjugal transferability of antibiotic resistance genes to other microorganisms) and comparative genomic analysis. The genome data of B. lactis AD011 was compared with genome sequences of two commercially available probiotic microorganisms (Bifidobacterium lactis BB-12 and Bifidobacterium lactis Bl-04) which are designated as generally recognized as safe by the U.S. Food and Drug Administration. The results of these experiments showed no significant potential vulnerabilities and no side effects. B. lactis AD011 showed higher resistance to tetracycline than the European Food Safety Authority cut-off. However, the measured susceptibility is similar to or lower than that of other previously certified GRAS Bifidobacterium strains. Tetracycline resistance of B. lactis AD011 was not conveyed via conjugation with L. fermentum AGBG1, which is susceptible to tetracycline. Complete DNA sequencing of B. lactis AD011 showed the absence of transferable drug resistance plasmids. The three B. lactis strains (AD011, BB12 and Bl-14) compared in this study were found to share very close genomic sequence homology (>99.8%). Therefore, based on this study, B. lactis AD011 appears to be a safe, bioactive, bifidobacterial food ingredient, starter culture, and/or probiotic microorganism for human health.

Dietary Supplementation of Dried Grape Pomace Increases the Amount of Linoleic Acid in Beef, Reduces the Lipid Oxidation and Modifies the Volatile Profile.

Simple SummaryThe grape pomace is the main solid by-product of the oenological industry, and represents a rich source of potent bioactive compounds. In this study we demonstrated that its inclusion in bovine diet resulted in a significant increase of linoleic acid concentration in meat, a condition which led to a positive increase in the polyunsaturated fatty acid:saturated fatty acids (PUFA:SFA) ratio. Despite the greater predisposition of PUFA to oxidation, an interesting improvement in the oxidative stability of meat was evidenced, presumably as an effect of the antioxidant activity performed by the bioactive compounds of which the grape pomace is rich in. This finding was also confirmed by the analysis of volatile compounds which highlighted a reduction of hexanal in meat samples obtained from animals fed the dietary grape pomace supplementation. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry.The aim of this study was to evaluate the effect of dietary supplementation with dried grape pomace on beef quality. Ten Friesian calves were divided into two groups, a control group that received a standard diet, and an experimental group that was administered the dietary supplementation. At the end of the 75 days of the trial, animals were slaughtered, and meat samples analyzed for physical and chemical properties, fatty acids composition, lipid oxidation, volatile compounds, and biogenic amines. The fatty acid profile resulted affected by dietary supplementation, since an increase in concentration of linoleic acid was observed. Furthermore, a reduction of lipid oxidation was found in the same samples. With reference to volatile compounds a reduction of hexanal and an increase of 2-3 octanedione was evidenced, while no effects were induced by diets on the synthesis of biogenic amines. The grape pomace exploitation as a dietary supplement in bovine diet did not have negative effects on the quality of beef and showed the potential to extend shelf life due to marked improvement in oxidative stability. Overall, the present study showed a viable way for the recovery and the valorization of the main by-product of the oenological industry.

Cerebrospinal fluid biogenic amines depletion and brain atrophy in adult patients with phenylketonuria.

Biogenic amines synthesis in phenylketonuria (PKU) patients with high phenylalanine (Phe) concentration is thought to be impaired due to inhibition of tyrosine and tryptophan hydroxylases and competition with amino acids at the blood-brain barrier. Dopamine and serotonin deficits might explain brain damage and progressive neuropsychiatric impairment in adult PKU patients. Ten early treated adult PKU patients (mean age 38.2 years) and 15 age-matched controls entered the study. Plasma and cerebrospinal fluid (CSF) Phe, 5-hydroxyindoleacetic acid (5-HIAA), 5-hydroxytryptophan (5-HTP), 3,4-dihydroxy-l-phenylalanine (l-DOPA) and homovanillic acid (HVA) were analyzed. Voxel-based morphometry statistical nonparametric mapping was used to test the age-corrected correlation between gray matter atrophy and CSF biogenic amines levels. 5-HIAA and 5-HTP were significantly reduced in PKU patients compared to controls. Significant negative correlations were found between CSF 5-HIAA, HVA, and 5-HTP and Phe levels. A decrease in 5-HIAA and 5-HTP concentrations correlated with precuneus and frontal atrophy, respectively. Lower HVA levels correlated with occipital atrophy. Biogenic amines deficits correlate with specific brain atrophy patterns in adult PKU patients, in line with serotonin and dopamine projections. These findings may support a more rigorous Phe control in adult PKU to prevent neurotransmitter depletion and accelerated brain damage due to aging.

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.

Role ofPediococcusin winemaking

The genus Pediococcus comprises a group of nutritionally fastidious bacteria, several of which have been isolated from wines worldwide, for example P. damnosus, P. inopinatus, P. parvulus and P. pentosaceus. The growth of these bacteria is generally considered undesirable because of their ability to produce off‐odours and flavours. As examples, Pediococcus spp. have been associated with the synthesis of excessive diacetyl, exopolysaccharides, and/or biogenic amines, all of which have a detrimental impact on wine quality. Historically, oenological factors, such as low pH, high ethanol and nutrient depletion following malolactic fermentation, have often been considered sufficient to limit growth. Recent research, however, has supported the contention that Pediococcus spp. can grow in wines considered to be microbiologically stable. Furthermore, the presence of Pediococcus spp. in wines does not always lead to spoilage. New findings have suggested potential uses for Pediococcus spp. in winemaking, but have also highlighted a lack of understanding of those factors that influence growth and spoilage potential. The present work reviews the current knowledge of pediococci isolated during vinification as well as focuses on areas for future research.

Evaluation of Serotonin and Hystamine Exchange in Women with Premature Birth in Different Terms of Gestation

In modern obstetrics and gynecology, the problem of preterm labor is considered one of the most urgent.A significant number of factors affects on the run of pregnancy and it`s result, it`s activity is realized through numerical metabolic interactions, where an important role is given to biogenic monoamines, in particular serotonin and histamine.The aim of the study - to study the features of serotonin and histamine exchange in women`s body with different periods of abortion by determining in the blood the content of biogenic amines level of excretion with daily urine of serotonin 5-oxyindoloacetic acid and activity in the blood serum of the enzyme inactivation of histamine - histaminase.Material and methods of research – there were examined 227 pregnant women, 190 of these had clinical signs of the threat of preterm delivery in the gestation period of 23-36 weeks in the form of premature and timely childbirth.Women with early premature pregnancy, which ended with childbirth in the period from 23 to 27 weeks have a depletion of the functional activity of the serotonergic system.In women with late onset of pregnancy, there is an increasing of the serotoninergic system`s functional state, is probably with inhibition purpose of excessive excitement of stress-implementing systems. In women with a physiological course of pregnancy indicating an increasing of the histamine-histamine system activity with signs of a balance between the synthesis of biogenic amine and its inactivation. In women with early onset of pregnancy the inferiority of the blood system "histamine-histamine" develops, which is confirmed by a significant increasing of biogenic monoamine and reduction in the activity of the enzyme inactivation. In women with onset of pregnancy, there is a probable increasing of the histamine concentration in the blood indicating some exhaustion of "histamine-histaminase" systems with predominance signs of biogenic amine synthesis over its inactivation.Revealed changes in the state of serotonin and histamine in pregnant women indicate the violation of the adaptation mechanisms and the promoting possibility of the preterm labor development.

Water-soluble naphthalene diimides: synthesis, optical properties, and colorimetric detection of biogenic amines

Biocompatible water-soluble naphthalene diimides (NDIs) were synthesized and a core-dichlorinated NDI was shown to detect primary amines and biogenic diamines.

Transcriptome profiling of ontogeny in the acridid grasshopper Chorthippus biguttulus.

Acridid grasshoppers (Orthoptera:Acrididae) are widely used model organisms for developmental, evolutionary, and neurobiological research. Although there has been recent influx of orthopteran transcriptomic resources, many use pooled ontogenetic stages obscuring information about changes in gene expression during development. Here we developed a de novo transcriptome spanning 7 stages in the life cycle of the acridid grasshopper Chorthippus biguttulus. Samples from different stages encompassing embryonic development through adults were used for transcriptomic profiling, revealing patterns of differential gene expression that highlight processes in the different life stages. These patterns were validated with semi-quantitative RT-PCR. Embryonic development showed a strongly differentiated expression pattern compared to all of the other stages and genes upregulated in this stage were involved in signaling, cellular differentiation, and organ development. Our study is one of the first to examine gene expression during post-embryonic development in a hemimetabolous insect and we found that only the fourth and fifth instars had clusters of genes upregulated during these stages. These genes are involved in various processes ranging from synthesis of biogenic amines to chitin binding. These observations indicate that post-embryonic ontogeny is not a continuous process and that some instars are differentiated. Finally, genes upregulated in the imago were generally involved in aging and immunity. Our study highlights the importance of looking at ontogeny as a whole and indicates promising directions for future research in orthopteran development.

Content of biogenic amines in Lemna minor (common duckweed) growing in medium contaminated with tetracycline

Aquatic plants are continuously exposed to a variety of stress factors. No data on the impact of antibiotics on the biogenic amines in duckweed (Lemna minor) have been available so far, and such data could be significant, considering the ecological role of this plant in animal food chains. In the tissues of control (non-stressed) nine-day-old duckweed, the following biogenic amines were identified: tyramine, putrescine, cadaverine, spermidine and spermine.Based on the tetracycline contents and the computed EC values, the predicted toxicity units have been calculated. The obtained results demonstrated phytoxicity caused by tetracycline in relation to duckweed growth rate, yield and the contents of chlorophylls a and b. The carotenoid content was not modified by tetracycline. It was found that tetracycline as a water pollutant was a stress factor triggering an increase in the synthesis of amines. Tetracycline at 19, 39 and 78μM concentrations increased biogenic amine synthesis by 3.5 times. Although the content of tyramine increased fourteen times with the highest concentration of the drug (and of spermidine − only three-fold) the increase of spermidine was numerically the highest. Among the biogenic amines the most responsive to tetracycline were spermine and tyramine, while the least affected were putrescine and spermidine. Despite putrescine and spermidine being the least sensitive, their sum of contents increased five-fold compared to the control. These studies suggest that tetracycline in water reservoirs is taken up by L. minor as the antibiotic clearly modifies the metabolism of this plant and it may likely pose a risk.

Abstract 899: Cancer protection associated with dietary methyl donor deficiency is characterized by persistent changes to epithelial proliferation and metabolism

Abstract The role of folate one-carbon metabolism in colorectal cancer development is incompletely understood, and nutritional intervention studies have produced conflicting results. We previously demonstrated that a diet deficient in the methyl donors folic acid, methionine, choline and vitamin B12, and supplemented with homocysteine, reduces intestinal tumor incidence by greater than 95% in ApcMin/+ mice. Here we extend these findings to a second mouse tumor model, ApcÄ14, and further show that the cancer protection afforded by even short-term dietary methyl donor deficiency (MDD) is long-lasting. Eleven weeks of MDD followed by methyl donor repletion was sufficient to maintain tumor suppression for at least 7 additional weeks (22.2 ± 3.5 vs 70.2 ± 4.6 intestinal tumors; p &amp;lt; 0.001). Sustained tumor protection was associated with altered intestinal crypt homeostasis. MDD increased the proportion of intestinal epithelial cells undergoing apoptosis in normal crypts and in tumors (4.9- and 3.2-fold, respectively), while reducing cell proliferation (Ki-67) and mitosis (PHH3). In addition, metabolomic profiling and metabolite set enrichment analysis (MSEA) revealed that tumor protection is associated with persistent alterations to metabolic pathways related to cellular proliferation, including glutamine metabolism, biogenic amine synthesis, nucleotide salvage and glutathione synthesis. Taken together, these results indicate that even a temporary dietary methyl donor restriction in cancer-prone mice can induce persistent changes to the intestinal epithelium that provide long-lasting protection in adult mice. Citation Format: Matthew P. Hanley, Daniel W. Rosenberg. Cancer protection associated with dietary methyl donor deficiency is characterized by persistent changes to epithelial proliferation and metabolism. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 899.

Selection and characterization of Oenococcus oeni strains for use as new malolactic fermentation starter cultures

Oenococcus oeni (O. oeni) strains are critically important for winemaking. They bring microbial stabilization, de-acidification and sensory improvement through malolactic fermentation (MLF) to almost all red wines and some white wines. In this study, 23 strains of O. oeni isolated from China were evaluated for use as MLF starter cultures. Strains were characterized and screened in wine-like media with increasing selective pressure, such as low pH and high ethanol concentration. Their abilities to conduct MLF were affected significantly by ethanol concentration and pH. Eight strains were selected and subsequently evaluated by detecting the enzyme-encoding genes involved in biogenic amines synthesis and wine aroma modification. Seven well-performing strains were further assessed in newly alcohol-fermented Cabernet Sauvignon wine. The results show that strains O. oeni CS-4b and O. oeni ME-5b exhibited better performance than the commercial starter O. oeni 31MBR in wine. Therefore, they were selected as potential MLF starters suitable for wine with high ethanol concentration and low pH.