Putrescine Content Research Articles

Changes in Quality and Microbial Succession of Lightly Salted and Sugar-Salted Blunt Snout Bream (Megalobrama amblycephala) Fillets Stored at 4°C

The effect of a low concentration of salt and sugar on the quality and microbial succession in blunt snout bream ( Megalobrama amblycephala) fillets was assessed by sensory analysis, total volatile basic nitrogen, biogenic amines, K value, total viable counts, 16S rRNA gene analysis, and Illumina MiSeq PE300 high-throughput sequencing. Fish samples were left untreated (control), treated with 1.8% salt (T1), or treated with 1.8% salt plus 0.9% sugar (T2). Consequently, salted and sugar-salted treatments extended the shelf life of bream fillets by 2 days, which retarded the increase of total volatile basic nitrogen, putrescine, cadaverine, and total viable counts. The putrescine and cadaverine concentrations of T2 were significantly ( P < 0.05) higher than T1 after day 10. Brachybacterium was the major initial microbiota of bream fillets. As storage time progressed, Pseudomonas and Shewanella were major genera in the spoiled control group. Pseudomonas, Shewanella, and Pseudoalteromonas became the main spoilers in the T1 and T2 groups.

Determination of the effect of polyamines on an oil-degrading strain of Yarrowia lipolytica using an odc minus mutant.

Yarrowia lipolytica is an ascomycetous dimorphic yeast with immense potential for industrial applications, including bioremediation of crude oil-contaminated environments. It has been shown that a dimorphic marine isolate of Y. lipolytica (var. indica) has significant capacity to degrade fatty acids and alkanes, when in its yeast morphology. It has also been demonstrated that polyamines play an important role in the yeast-to-mycelium transition of different strains of Y. lipolytica that are unable to utilize those carbon sources. To determine the role of polyamines on their capacity to utilize oils and hydrocarbons, on the dimorphic transition, and also on other characteristics of the var. indica strain of Y. lipolytica, we proceeded to obtain ornithine decarboxylase minus (odc-) mutants. These mutants behaved as yeasts independently of the concentrations of putrescine added. Further, they conserved the oil-degrading capacity of the parent strain. The odc- mutant can thus be used in fatty acid degradation, and oil spill remediation with distinct advantages.

Salinity influences the interactive effects of cadmium and zinc on ethylene and polyamine synthesis in the halophyte plant species Kosteletzkya pentacarpos

Salt marshes are major sinks for heavy metals where plants are often exposed to polymetallic contamination and high salinity. Seedlings from the wetland halophyte plant species Kosteletzkya pentacarpos were exposed during three weeks to nutrient solution containing 10 μM CdCl2, 100 μM ZnCl2 or a combination of the two metals (Cd + Zn) in the presence or absence of 50 mM NaCl. Synthesis of the senescing hormone ethylene was quantified together with the concentration of protecting polyamines (spermidine and spermine) and their precursor putrescine and analyzed in relation to senescence markers (soluble protein, malondialdehyde, chlorophyll content and assessment of cell membrane stability). Salinity reduced the deleterious impact of heavy metals on plant growth and decreased accumulation of the pollutants in the plants. Heavy metals increased ethylene synthesis but NaCl decreased it in plants exposed to Cd or to the combined treatment (Cd + Zn) but not in plants exposed to Zn alone. Putrescine increased while spermine and spermidine decreased in Cd-treated plants. Zinc had only a marginal impact on polyamine concentration. The highest putrescine and spermine concentrations were observed in plants exposed to the combined treatment. The inhibitor of ethylene synthesis (AVG; aminovynilglycine) partially restored plant growth, reduced putrescine content and increased spermidine and spermine concentration, leading to an attenuation of senescence, mainly in Cd-treated plants. Combined treatment induced a specific physiological status in K. pentacarpos which could not be fully explained by an additive effect of Cd and Zn. Results are discussed in relation to specificities of heavy metals impacts on plant response.

Enhancement of microspore embryogenesis induction and plantlet regeneration of sweet pepper (Capsicum annuum L.) using putrescine and ascorbic acid.

Production of doubled haploid (DH) plants is an efficient tool in genetic and plant breeding programs; however, sweet pepper (Capsicum annuum L.) is recalcitrant to microspore embryogenesis and DH production. Trying to break the barrier of DH production, three independent experiments were conducted on microspore embryogenesis of sweet pepper. In the first experiment, the effect of cold (4°C) and heat (32°C) pretreatments were investigated on microspore embryogenesis of three genotypes of sweet pepper including "Inspiration F1," "Maratus F1," and "Magno F1" cultivars in a factorial design with three replications. Heat shock (32°C for 7days), applied to mannitol-starved anthers of "Inspiration F1," showed higher multinuclear microspore percent, number of multicellular structures, total embryos, cotyledonary embryos, and regenerants. In the second experiment, the effect of different concentrations of putrescine (0, 0.5, 1, 2, and 5mgl-1) was evaluated on microspore embryogenesis of the three aforementioned cultivars of sweet pepper. The highest mean number of multicellular structures, cotyledonary embryos, and regenerants were achieved by applying 0.5-1mgl-1 putrescine during the mannitol starvation and heat shock (32°C) treatments of isolated microspore culture of "Inspiration F1" cultivar. Significant decrease in microspore embryogenesis efficiency was observed when high levels of putrescine (2 and 5mgl-1) were used. Microspore embryogenesis was prevented completely at 5.0mgl-1 putrescine. In the third experiment, the effect of different concentrations of ascorbic acid (0, 20, 50, 100, and 200mgl-1) was investigated and the results showed that the application of ascorbic acid (20 and 50mgl-1) during mannitol starvation and heat shock treatment (32°C) caused remarkable improvement in the number of produced cotyledonary embryos and their regeneration ability compared to control treatment. However, the application of higher levels of ascorbic acid (100 and 200mgl-1) inhibited microspore cell divisions and embryogenesis. In conclusion, the results indicated that both putrescine and ascorbic acid have significant effect on microspore embryogenesis efficiency of sweet pepper when they are used in appropriate concentrations.

Monitoring bacterial communities in ε-Polylysine-treated bighead carp (Aristichthys nobilis) fillets using culture-dependent and culture-independent techniques

The present study investigated the effect of ε-Polylysine on bacterial communities, sensorial, and chemical properties [total volatile basic nitrogen (TVB-N), biogenic amines, and breakdown products of adenosine triphosphate] of bighead carp (Aristichthys nobilis) fillets stored at 4 ± 1 °C. Bacterial communities were explored by the culture-dependent method and the high-throughput sequencing targeting on 16S rRNA genes. The results showed that the major genera in spoiled control samples were Aeromonas, Pseudomonas, Shewanella, and Acinetobacter. ε-Polylysine inhibited the growth of Pseudomonas, Shewanella, and Acinetobacter. Consequently, Aeromonas and Janthinobacterium were dominant in spoiled treated samples. The sensorial shelf-life of the control and treated groups were 8 days and 10 days, respectively. Furthermore, due to the inhibitory effect of ε-Polylysine on bacteria, chemical changes of the treated group were slower, reflecting as lower concentrations of TVB-N, putrescine, cadaverine, and hypoxanthine, and higher contents of inosine 5′-monophosphate and hypoxanthine riboside at the end of storage. In conclusion, ε-Polylysine altered the bacterial communities and delayed quality deterioration of bighead carp fillets during chilled storage.

Changes in Postfermentation Quality during the Distribution Process of Anchovy (Engraulis japonicus) Fish Sauce

In the present study, we evaluated the changes in quality that can occur during the distribution of nonheated anchovy ( Engraulis japonicus) fish sauce after packaging. The pH values of all samples ranged from 5.5 to 5.8, and there were no significant differences ( P > 0.05) in pH among the samples during storage regardless of storage temperature or salt concentration. The initial total volatile base nitrogen concentration in all samples after bottling was 115 to 121 mg/100 mL, but this concentration increased gradually with storage time. After 1 year of storage, total volatile base nitrogen concentration had increased to approximately 170% of the initial concentration (166 to 194 mg/100 mL). Amino nitrogen increased slightly during storage but was significantly lower than the increase in amino nitrogen during general anchovy fish sauce fermentation with anchovy flesh. Most of the free amino acids increased slightly during the storage period regardless of storage temperature or salt concentration, but tyrosine and histidine increased and then decreased during the storage period. The histamine concentration of the anchovy fish sauce at a salt concentration of 20% was 43.3 mg/100 mL initially, but after 1 year the histamine concentration was 89.7 mg/100 mL in samples stored at 10°C, 102.6 mg/100 mL in samples stored at 25°C, and 116.8 mg/100 mL in samples stored at 35°C . Changes in putrescine and cadaverine concentrations were similar to those in histamine; concentrations increased about twofold from the initial concentrations after 1 year of storage. However, the rate of increase in putrescine from 4 months after storage was very high, and cadaverine slightly decreased by 12 months of storage. High scores for umami and aroma sensory characteristics were given to samples stored at 10°C, but samples stored 35°C were given high scores for rancid. Despite the overall low scores for aroma and umami for samples stored at 35°C, the quality of the anchovy fish sauce as a fermented food was considered acceptable.

Marked Response in Microbial Community and Metabolism in the Ileum and Cecum of Suckling Piglets After Early Antibiotics Exposure.

In modern swine husbandry systems, antibiotics have been used as growth promoters for piglets during suckling or weaning period. However, while early colonization of intestinal microbiota has been regarded crucial for the host’s later life performance and well-being, little is known about the impact of antibiotics on intestinal microbiota in suckling piglets. The present study aimed to investigate the effects of early antibiotics exposure on gut microbiota and microbial metabolism of suckling piglets. Sixteen litters of suckling piglets were fed a creep feed diet with (Antibiotic) or without (Control) antibiotics from postnatal days 7–23 (n = 8). The ileal and cecal digesta were obtained for microbial composition and microbial metabolites analysis. The results showed that the antibiotics significantly altered the bacterial community composition by decreasing (P < 0.05) the diversity and richness in the ileum. The antibiotics significantly reduced the abundance of Lactobacillus in both the ileum and cecum, increased the abundance of Streptococcus, unclassified Enterococcaceae, unclassified Fusobacteriales, and Corynebacterium in the ileum, and the abundance of unclassified Ruminococcaceae and unclassified Erysipelotrichaceae in the cecum. The antibiotics decreased (P < 0.05) ileal lactate concentration and cecal concentration of total short-chain fatty acids (SCFAs). But the antibiotics enhanced protein fermentation (P < 0.05) in the ileum and cecum, as ileal concentrations of putrescine and cadaverine, and cecal concentrations of isobutyrate, isovalerate, putrescine, cadaverine, spermine, and spermidine were significantly increased (P < 0.05). These results indicated that early antibiotics exposure significantly altered the microbial composition of suckling piglets toward a vulnerable and unhealthy gut environment. The findings provide a new insight on the antibiotics impact on neonates and may provide new framework for designing alternatives to the antibiotics toward a healthy practice for suckling piglets.

Exogenous putrescine changes redox regulations and essential oil constituents in field-grown Thymus vulgaris L. under well-watered and drought stress conditions

Drought stress affects a vast range of morphological, physiological and biochemical characteristics in plants; however, exogenous application of osmotically active materials such as polyamines has been regarded as a good alternative to counter the adverse effects of various environmental stresses on plant functions. The present study investigates the response of Thymus vulgaris L. plants to different concentrations of putrescine (0, 20 and 40 mg L−1) under well-watered and drought stress conditions in a factorial experiment based on randomized complete block design with three replications during 2-year field trial. Drought stress significantly impaired the plant growth and biomass accumulation, and altered leaf water status, photosynthetic pigment contents, hydrogen peroxide (H2O2) and malondialdehyde (MDA) levels, free proline and soluble protein contents, ROS scavenging enzymes such as superoxide dismutase (SOD), peroxidase (POX), catalase (CAT), and ascorbate peroxidase (APX), essential oil content and chemical profiles of the essential oil compared to the respective control values. However, exogenously applied putrescine (particularly at 20 mg L−1) improved leaf water content, accumulated dry matter, reduced cell injury indices and up-regulated antioxidant enzyme activities. Moreover, stressed plants treated with the highest concentration of putrescine increased their essential oil content by 23.07% compared to non-stressed plants without putrescine application. A total of 14 compounds predominantly consisted of monoterpenes such as Thymol, Carvacrol, γ-Terpinene and p-Cymene were identified in the essential oil of the plants in both years. Percentage of the major essential oil constituents substantially enhanced under drought stress, whereas exogenous application of putrescine further improved the content of these specific volatile compounds under well-watered and stressed plants compared to the respective control. A significant negative correlation was observed between essential oil percentage and H2O2 (r0.01 = −0.928) and MDA (r0.01 = −0.947) contents in plants under drought stress. The results of this study indicated that foliar application of putrescine in proper level may act as elicitor to trigger physiological processes and induce valuable metabolites biosynthesis, which may compensate the negative impacts of drought stress on plant biomass and essential oil quality and quantity.

Analysis of bacterial diversity and biogenic amines content during the fermentation processing of stinky tofu

Fermented foods may confer several benefits to human health and play an important role in a healthy and balanced diet. Stinky tofu is an important traditional fermented soy product in Asia. In this study, a comprehensive analysis of bacterial diversity in terms of rarefaction abundance, rank abundance, alpha diversity, and principal coordinates analysis was conducted using next-generation sequencing. The results obtained were further verified by culture-dependent methods. In addition, eight biogenic amines were also quantified to determine their levels in stinky tofu during conventional production. Our study revealed that lactobacillus was the major lactic acid bacteria throughout the fermentation process. Further, some potentially harmful bacterial belonging to the genera Halomonas and Solobacterium, were also found existing in the stinky tofu. In case of biogenic amines, the concentration of putrescine, cadaverine and histamine finally increased to high levels while spermine disappeared after the fermentation was completed. After the soaking step, putrescine, tryptamine and β-phenethylamine increased sharply. This work provided an improved understanding of microbes and biogenic amines content associated with the traditionally consumed fermented food. However, there is a need to understand microbial interactions related to biogenic amines during the fermentation, and the origin and survival strategies of two important pathogens detected in our study

Polyamines and amino acids in triticale plants grown on humic acids enriched nutrient solution and treated with UV-B irradiation

The effects of UV-B irradiation and Biomin (a natural substance extracted from coal with active ingredients of humic acids) on the content of endogenous polyamines spermine, spermidine and putrescine, and free amino acids in shoots and roots of young triticale seedlings were investigated. Biomin was added to the nutrient medium 3 days prior to UV-B irradiation. The seedlings were treated with 7.7 kJ m−2 day−1 UV-B light for 4 days. The exposure to UV-B increased total free amino acids, while Biomin application alone did not affect considerably their content. The treatment with UV-B or Biomin alone provoked augmentation of conjugated and bound polyamine (PA) fractions. Data suggest that Biomin alleviates the negative consequences of UV-B stress, manifested by the normalized amino acid and polyamine amounts in the UV-B + Biomin-treated plants. This study demonstrates the protective effect of Biomin on triticale plants against UV-B irradiation, which could be related to alterations in PAs and amino acids pools.

Highly selective colorimetric detection of putrescine in fish products using o-phthalaldehyde derivatization reaction

A highly selective colorimetric detection method for putrescine on the basis of an optimized derivatization reaction was established. With the aids of o-phthalaldehyde (OPA) and thioglycolic acid (TGA), putrescine was derived to become red derivatives (PUT-RD), the form that can be detected qualitatively and quantitatively by visual inspection and UV-vis spectrophotometer at λmax of 490 nm, respectively. Key parameters affecting the experiment were investigated by one-factor-at-a-time and response surface analysis. At the optimal condition, this colorimetric method achieved good linearity at putrescine concentrations ranging from 0.8 to 200 μM with detection limit of 0.44 µM. The method also has good selectivity when common amino acids and inorganic ions, as well as ethylenediamine, 1,3-propanediamine, 1,5-pentanediamine, and 1,6-hexanediamine were used as interferences. The established colorimetric method was successfully employed for the detection of putrescine in 10 commercial fish products.

Modulation of the nutritional value of lupine wholemeal and protein isolates using submerged and solid‐state fermentation with Pediococcus pentosaceus strains

SummaryThe influence of different factors (submerged and/or solid‐state fermentation, pediococci strain, lupine variety and protein isolation process) on the protein digestibility, total phenolic compounds (TPC) content and radical scavenging activity of Lupinus luteus and angustifolius wholemeal and protein isolates was evaluated. As safety factor, biogenic amines (Bas) formation was analysed. The Pediococcus pentosaceus strains No. 8, No. 9 and No. 10 are suitable starters for lupine wholemeal fermentation and both applied processes (fermentation and protein isolation) increase protein digestibility (by 10%). Higher TPC content in fermented wholemeal can be obtained, compare to isolates. In SMF isolates by 58.3%, 68.2%, 95.6%, 76.6%, lower content of phenylethylamine, putrescine, cadaverine and histamine, respectively was found. The highest protein digestibility and the lowest BAs content using submerged fermentation with pediococcus No. 8 in lupine variety Vilnius protein isolates can be obtained and this technology for high‐quality lupine proteins preparation can be recommended.

NH4+ facilitates iron reutilization in the cell walls of rice (Oryza sativa) roots under iron-deficiency conditions

NH4+ and NO3− are two major nitrogen sources that differentially affect the uptake and transfer of other nutrients in rice (Oryza sativa), although their effects on Fe remobilization under Fe-starvation conditions are largely unknown. Here, by investigating the rice cultivar ‘Kasalath’ (Kas), which is tolerant of nutrient-deficient soil, we found that NH4+ negatively regulates the hemicellulose 1 content in root cell walls and stimulates the secretion of phenolic compounds from roots under −Fe conditions, thus facilitating the release of cell wall Fe and increasing soluble Fe levels in roots. NH4+ significantly increased the translocation of Fe from root to shoot by upregulating the expression of OsFRDL1 in roots and increasing the Fe content in the xylem. We further found that the higher putrescine content in rice roots under NH4+ conditions led to a higher nitric oxide (NO) content compared with NO3− conditions, and that NO is involved in the NH4+-stimulated cell wall Fe reutilization. The addition of the NO donor sodium nitroprusside significantly reduced the hemicellulose 1 content in cell walls and increased Fe release from cell walls, ultimately increasing the soluble Fe content in rice and alleviating chlorosis under −Fe conditions. Taken together, our findings demonstrate that NH4+ promotes Fe remobilization from the cell wall in rice.

Cholesterol accumulation by suppression of SMT1 leads to dwarfism and improved drought tolerance in herbaceous plants.

Dwarfism and drought tolerance are 2 valuable traits in breeding of many crops. In this study, we report the novel physiological roles of cholesterol in regulation of plant growth and drought tolerance. Compared with the wild type, sterol-C24-methyltransferase 1 (SMT1) gene transcript was greatly reduced in a bermudagrass mutant with dwarfism and enhanced drought tolerance, accompanied with cholesterol accumulation, elevated transcript levels of a small group of genes including SAMDC, and increased concentrations of putrescine (Put), spermidine (Spd), and spermine (Spm). Knock-down of OsSMT1 expression by RNA interference resulted in similar phenotypic changes in transgenic rice. Moreover, exogenously applied cholesterol also led to elevated transcripts of a similar set of genes, higher levels of Put, Spd, and Spm, improved drought tolerance, and reduced plant height in both bermudagrass and rice. We revealed that it is Spm, but not Spd, that is responsible for the height reduction in bermudagrass and rice. In conclusion, we suggest that cholesterol induces expression of SAMDC and leads to dwarfism and elevated drought tolerance in plants as a result of the promoted Spd and Spm synthesis.

Improved in vitro Vitis vinifera L. embryo development of F1 progeny of ‘Delight’ × ‘Ruby seedless’ using putrescine and marker-assisted selection

Production of seedless V. vinifera L. cultivars is one of the major goals of table grape breeding. Traditional methods result in only a low percentage of seedless progeny. Modern techniques, such as embryo rescue, are used to improve production efficiency of seedless cultivars. In this study, the effects of various putrescine concentrations (0, 1, 2, 3, 4, and 5 mmol L−1) and different stages of embryo development (globular-, heart-, torpedo-, and cotyledon-shaped embryo) on the success rate of embryo rescue were assessed in three lines of the F1 Vitis vinifera L., cross ‘Delight’ × ‘Ruby Seedless,’ ‘DR2,’ ‘DR3,’ and ‘DR6’ (with small seed traces). The plant development rates of ‘DR2,’ ‘DR3,’ and ‘DR6’, which contain small seed traces, as female parents, were significantly higher than those of seedless varieties. The rates of embryo development on woody plant medium (WPM) of ‘DR2’ × ‘Thompson Seedless,’ ‘DR3’ × ‘Thompson Seedless,’ and ‘DR6’ × ‘Monukka’ were highest with 2, 2, and 4 mmol L−1 putrescine, respectively. The germination rates of torpedo- and cotyledon-shaped embryos were significantly higher than those of globular- and heart-shaped embryos. Characteristics of the embryo germination progress of ‘DR2’ × ‘Thompson Seedless’ at different developmental stages were recorded. The Grape Seedless gene Probe 1 (GSLP1) marker was used to help identify the seedless descendants; 14 plantlets showed a corresponding electrophoresis band at 569 bp and were preliminarily defined as seedless.

Metabolic characterization of Hyoscyamus niger root-specific putrescine N-methyltransferase

N-methylputrescine is the precursor of nicotine and pharmaceutical tropane alkaloids such as hyoscyamine. Putrescine N-methyltransferase (PMT) catalyzes the N-methylation of putrescine to form N-methylputrescine. While the role of PMT in nicotine biosynthesis is clear, knowledge of PMT in the biosynthesis of tropane alkaloids (TAs) and the regulation of polyamines remains limited. We characterized a PMT gene from Hyoscyamus niger, designated HnPMT that was specifically expressed in roots, especially in the secondary roots and dramatically induced by methyl jasmonate (MeJA). The GUS gene was specifically expressed in Arabidopsis roots or in the vascular tissues, including pericycles and endodermis, of the H. niger hairy root cultures, when it was driven by the 5′-flanking promoter region of HnPMT. The recombinant HnPMT was purified for enzymatic assays. HnPMT converted putrescine to form N-methylputrescine, as confirmed by LC-MS. The kinetics analysis revealed that HnPMT had high affinity with putrescine but low catalytic activity, suggesting that it was a rate-limiting enzyme. When HnPMT was suppressed in the H. niger plants by using the VIGS approach, the contents of N-methylputrescine and hyoscyamine were markedly decreased, but the contents of putrescine, spermidine and a mixture of spermine and thermospermine were significantly increased; this suggested that HnPMT was involved in the biosynthesis of tropane alkaloids and played a competent role in regulating the biosynthesis of polyamines. Functional identification of HnPMT facilitated the understanding of TA biosynthesis and thus implied that the HnPMT-catalyzed step might be a target for metabolic engineering of the TA production in H. niger.

Functional roles of ornithine decarboxylase and arginine decarboxylase during the peri-implantation period of pregnancy in sheep

BackgroundPolyamines stimulate DNA transcription and mRNA translation for protein synthesis in trophectoderm cells, as well as proliferation and migration of cells; therefore, they are essential for development and survival of conceptuses (embryo/fetus and placenta). The ovine conceptus produces polyamines via classical and non-classical pathways. In the classical pathway, arginine (Arg) is transformed into ornithine, which is then decarboxylated by ornithine decarboxylase (ODC1) to produce putrescine which is the substrate for the production of spermidine and spermine. In the non-classical pathway, Arg is converted to agmatine (Agm) by arginine decarboxylase (ADC), and Agm is converted to putrescine by agmatinase (AGMAT).MethodsMorpholino antisense oligonucleotides (MAOs) were designed and synthesized to inhibit translational initiation of the mRNAs for ODC1 and ADC, in ovine conceptuses.ResultsThe morphologies of MAO control, MAO-ODC1, and MAO-ADC conceptuses were normal. Double knockdown of ODC1 and ADC (MAO-ODC1:ADC) resulted in two phenotypes of conceptuses; 33% of conceptuses appeared to be morphologically and functionally normal (phenotype a) and 67% of the conceptuses presented an abnormal morphology and functionality (phenotype b). Furthermore, MAO-ODC1:ADC (a) conceptuses had greater tissue concentrations of Agm, putrescine, and spermidine than MAO control conceptuses, while MAO-ODC1:ADC (b) conceptuses only had greater tissue concentrations of Agm . Uterine flushes from ewes with MAO-ODC1:ADC (a) had greater amounts of arginine, aspartate, tyrosine, citrulline, lysine, phenylalanine, isoleucine, leucine, and glutamine, while uterine flushes of ewes with MAO-ODC1:ADC (b) conceptuses had lower amount of putrescine, spermidine, spermine, alanine, aspartate, glutamine, tyrosine, phenylalanine, isoleucine, leucine, and lysine.ConclusionsThe double-knockdown of translation of ODC1 and ADC mRNAs was most detrimental to conceptus development and their production of interferon tau (IFNT). Agm, polyamines, amino acids, and adequate secretion of IFNT are critical for establishment and maintenance of pregnancy during the peri-implantation period of gestation in sheep.

Impact of production season on the chemical composition and health properties of goat milk and rennet cheese

This study compared selected parameters of milk and rennet cheese produced from milk obtained from alpine goats during winter and summer feeding under climatic conditions of the Warmia and Mazury region. Milk from the winter season contained more protein, less vitamin A and over seven times less vitamin E than milk obtained in summer. In cheese from the winter season, the content of dry matter, fat, protein and vitamin A was lower when compared with cheese from the summer period. The content of total biogenic amines in cheese was almost twice as high in winter than in summer (1056.4 vs 567.6 mg/kg). Winter cheese contained more cadaverines and histamine than summer cheese. The content of tyramine and putrescine was comparable in cheese from both seasons and was higher than the level of histamine. Milk fat from milk obtained in winter contained more long-chained SFA and MUFA in comparison with the summer period. Fat from cheese produced in summer had a higher content of SFA, CLA and ALA, whereas cheese from the period of winter feeding contained more C16:0izo and C18:1. The content of hyper- and hypocholesterolemnic acids was comparable in milk and in cheese with a slightly smaller proportion of hyper-acids and a slightly higher proportion of hypocholesterolemnic acids during summer feeding of goats. In conclusion, it was found that the feeding season had a minor impact on the chemical composition of milk, although it significantly differentiated the chemical composition of rennet cheese produced from that milk and the health quality parameters of both products. Milk from winter feeding had a higher content of protein, whereas the chemical composition of cheese was more beneficial in winter as the content of dry matter, fat and protein was higher. The health properties of both products were more beneficial in summer, which was determined by the profile of fatty acids and the content of vitamin A.

Effects of nitrogen form on accumulation of alkaloids and expression of relative genes in Atropa belladonna

Hyoscyamine and scopolamine are two main alkaloids in Atropa belladonna with great medicinal value. In this paper, the contents of hyoscyamine and scopolamine, the upstream products in alkaloid synthesis, and the expression levels of key enzyme genes PMT, TRⅠ and H6H in secondary metabolism of A. belladonna seedlings were measured to clarify the mechanism of nitrogen forms regulating alkaloids synthesis.The results showed that the 50/50 (NH⁺₄/NO⁻₃) treatment was more favorable for the accumulation of alkaloids and the conversion of hyoscyamine to scopolamine. The content of putrescine was almost consistent with the change of key enzymes activities in the synthesis of putrescine, they both increased with the rise of ammonium ratio, reaching the highest at 75/25 (NH⁺₄/NO⁻₃). The detection of signaling molecule nitric oxide (NO) showed that the NO concentration decreased with the decrease of nitrate proportion. Further detection of gene expression levels of PMT, TRⅠ and H6H in TAs synthesis pathway showed that a certain amount of ammonium promoted the expression of PMT and H6H in roots. When the ratio of ammonium to nitrate was 50/50, PMT, TRⅠ and H6H in leaves and roots had higher expression levels. It can be speculated that the regulation of the formation of hyoscyamine to scopolamine by nitrogen forms mainly through affecting the expression of key enzyme genes. 50/50 (NH⁺₄/NO⁻₃) treatment increased the gene expression of TRⅠ in both leaves and roots as well as PMT and H6H in roots, promoting the synthesis of putrescine to hyoscyamine and the conversion of hyoscyamine to scopolamine.

Detection of ten biogenic amines in Chinese commercial soybean paste by HPLC

ABSTRACTThis paper aimed to develop a high-performance liquid chromatography (HPLC) method that can simultaneously detect ten biogenic amines (BAs) in commercially available soybean paste and to determine the contents of BAs in these products. Heptylamine (Hep) was used as the internal standard reagent and benzoyl chloride as the sample derivatization reagent; Inertsil ODS-3 chromatographic column was set as the stationary phase while the acetonitrile and 5 mmol/L ammonium acetate solution as the mobile phases; the samples were treated with gradient elution and detected at 254 nm (UV). Perchloric acid solution (0.4 mol/L) was employed as the sample extraction solvent to determine the contents of ten BAs in soybean paste products. All BAs were separated within 20 min. The methodological validation suggested good linearity, whereas the linear correlation coefficient of all standards was greater than 0.99 with the linear range of 0.1–80 μg/g, detection limits of 0.01–0.03 μg/g, and quantitation limits of 0.03–0.10 μg/g. For 17 commercially available soybean paste products involved in our study, different samples were distinguished from each other not only by the dramatic differences in the contents of BAs but also by the variance in BA types. Of these BAs, tyramine (Tyr) and agmatine (Agm) were found to be the highest contents in soybean paste products; the contents of histamine (His), 2-phenylethylamine (Phe), serotonin (Ser), spermidine (Spd), and putrescine (Put) were lower, followed by cadaverine (Cad), tryptamine (Try), and spermine (Spm). This method proved to be highly sensitive and effective in determining the contents of BAs in soybean paste products; there was a dramatic difference in the contents of ten BAs among different soybean paste products.