Preferential Synthesis Research Articles

Dynamics of Tryptophan Metabolic Pathways in Human Placenta and Placental-Derived Cells: Effect of Gestation Age and Trophoblast Differentiation.

L-Tryptophan is an essential amino acid and a precursor of several physiologically active metabolites. In the placenta, the serotonin and kynurenine metabolic pathways of tryptophan metabolism have been identified, giving rise to various molecules of neuroactive or immunoprotective properties, such as serotonin, melatonin, kynurenine, kynurenic acid, or quinolinic acid. Current literature suggests that optimal levels of these molecules in the fetoplacental unit are crucial for proper placenta functions, fetal development and programming. Placenta is a unique endocrine organ that, being equipped with a battery of biotransformation enzymes and transporters, precisely orchestrates homeostasis of tryptophan metabolic pathways. However, because pregnancy is a dynamic process and placental/fetal needs are continuously changing throughout gestation, placenta must adapt to these changes and ensure proper communication in the feto-placental unit. Therefore, in this study we investigated alterations of placental tryptophan metabolic pathways throughout gestation. Quantitative polymerase chain reaction (PCR) analysis of 21 selected genes was carried out in first trimester (n = 13) and term (n = 32) placentas. Heatmap analysis with hierarchical clustering revealed differential gene expression of serotonin and kynurenine pathways across gestation. Subsequently, digital droplet PCR, Western blot, and functional analyses of the rate-limiting enzymes suggest preferential serotonin synthesis early in pregnancy with a switch to kynurenine production toward term. Correspondingly, increased function and/or protein expression of serotonin degrading enzyme and transporters at term indicates efficient placental uptake and metabolic degradation of serotonin. Lastly, gene expression analysis in choriocarcinoma-derived cell lines (BeWo, BeWo b30, JEG-3) revealed dissimilar expression patterns and divergent effect of syncytialization compared to primary trophoblast cells isolated from human term placentas; these findings show that the commonly used in vitro placental models are not suitable to study placental handling of tryptophan. Altogether, our data provide the first comprehensive evidence of changes in placental homeostasis of tryptophan and its metabolites as a function of gestational age, which is critical for proper placental function and fetal development.

Selective Stimulation in Laser-Induced Synthesis of Silver Nanoparticles in Nanoporous Glass

Laser-induced synthesis of metal nanoparticles by the method of supercritical deposition provides a wide range of opportunities for implementing various strategies. In the present work, based on the example of silver nanoparticles in the pores of Vycor glass, we demonstrate that irradiation at the plasmon resonance frequency initiates preferential synthesis of a target group. In the present case, the initial ensemble of seeds characterized by a plasmon band at 440 nm was sequentially irradiated at 532 nm and then at 637 nm. This two-stage selective treatment leads to the appearance of a well-defined second peak at $${\sim}600$$ nm, which indicates significant growth of the mass fraction of the corresponding group of the particles that were initially missing. The results we obtained clearly demonstrate that the use of plasmon properties of the nanoparticles allows tuning of the properties of the synthesized ensemble in a targeted manner.

Light quality on growth and phenolic compounds accumulation in Moringa oleifera L. grown in vitro

All plant parts of the Moringa oleifera can contain relevant concentrations of phytochemicals with health benefits. Plants grown in vitro allow pathogen-free plant material production and rapid propagation, and this technique is widely used to obtain secondary metabolites. This study analyzed how light spectrum quality affects growth, chlorophyll, and total phenolic content in M. oleifera plants grown in vitro. M. oleifera seeds were inoculated in MS medium supplemented with 3% sucrose and 0.7% agar and were stored under a controlled temperature, humidity and photoperiod. The light conditions tested were white fluorescent lamps (WFL) and light-emitting diodes (LED: 70% red + 30% blue), both standardized with a photon flux density of 58 μmol m-2s-1. Radiation emitted by WFL and LED did not influence stem germination, height, or diameter. However, WFL provided higher total chlorophyll levels. All plant parts germinated in vitro were analyzed via high-performance liquid chromatography with a diode-array detector (HPLC-DAD), and preliminary analyses revealed preferential synthesis of gallic acid derivatives in the leaves under LED radiation. For the total phenolic content, leaves under the LED and WFL irradiations showed 3.524 ± 0.054 and 3.805 ± 0.304 micrograms, respectively, of gallic acid equivalents per milligram of dry matter (μg GAE mg-1 DM). Light quality did not interfere with phenolic compound accumulation; however, it stimulated the preferential synthesis of gallic acid derivatives in leaves grown under LED radiation, and the evidence indicated that all evaluated organs synthesized nonpolar substances.

Involvement of Photoprotective Compounds of a Phenolic Nature in the Response of Arabidopsis Thaliana Leaf Tissues to Low-Intensity Laser Radiation.

The influence of low-intensity laser radiation (LILR) on the changes in the content of anthocyanins, kaempferol, quercetin and their glycosides in the leaves of 5-week-old plants of Arabidopsis thaliana L. was studied by means of methods of high-performance liquid chromatography and gas chromatography mass spectrometry (GC-MS). It was found that in the leaves subjected to a stimulating He-Ne laser radiation dose (3.6Jcm-2 , continuous wave radiation, wavelength-632.8nm, exposure time-5min), the radiation induced an increase in the content of such compounds, the most significant one being in the case of anthocyanins (9 times). The present study also revealed an increase in the antioxidant potential of kaempferol, quercetin and their glycosides as a result of laser exposure. This increase was due to the preferential synthesis of compounds with a larger number of OH-groups on the phenyl ring. Thus, the content of quercetin, which has five OH-groups in its structure, increased almost by three times as compared to the control.

Combined choline and DHA supplementation: a randomized controlled trial.

Choline and docosahexaenoic acid (DHA) are essential nutrients for preterm infant development. They are metabolically linked via phosphatidylcholine (PC), a constitutive plasma membrane lipid and the major transport form of DHA in plasma. Plasma choline and DHA-PC concentrations rapidly decline after preterm birth. To improve preterm infant nutrition, we evaluated combined compared to exclusive choline and DHA supplementation, and standard feeding. Randomized partially blinded single-center trial. Neonatal tertiary referral center in Tübingen, Germany. 24 inborn preterm infants < 32 week postmenstrual age. Standard nutrition (control) or, additionally, enteral choline (30mg/kg/day), DHA (60mg/kg/day), or both for 10days. Single enteral administration of 3.6mg/kg [methyl-D9-] choline chloride as a tracer at 7.5days. Primary outcome variable was plasma choline following 7 days of supplementation. Deuterated and unlabeled choline metabolites, DHA-PC, and other PC species were secondary outcome variables. Choline supplementation increased plasma choline to near-fetal concentrations [35.4 (32.8-41.7)µmol/L vs. 17.8 (16.1-22.4) µmol/L, p < 0.01] and decreased D9-choline enrichment of PC. Single DHA treatment decreased DHA in PC relative to total lipid [66 (60-68)% vs. 78 (74-80)%; p < 0.01], which was prevented by choline. DHA alone increased DHA-PC only by 35 (26-45)%, but combined treatment by 63 (49-74)% (p < 0.001). D9-choline enrichment showed preferential synthesis of PC containing linoleic acid. PC synthesis via phosphatidylethanolamine methylation resulted in preferential synthesis of DHA-containing D3-PC, which was increased by choline supplementation. 30mg/kg/day additional choline supplementation increases plasma choline to near-fetal concentrations, dilutes the D9-choline tracer via increased precursor concentrations and improves DHA homeostasis in preterm infants. clinicaltrials.gov. Identifier: NCT02509728.

Preferential synthesis of ethanol from syngas via dimethyl oxalate hydrogenation over an integrated catalyst.

An integrated catalyst that contains Fe5C2 and CuZnO-SiO2 with a dual-bed configuration was designed for the preferential synthesis of ethanol via dimethyl oxalate hydrogenation. The cooperation of the two catalyst components remarkably inhibited the formation of various byproducts, resulting in a significantly high ethanol yield of about 98%.

Metabolism of a synthetic compared with a natural therapeutic pulmonary surfactant in adult mice

Secreted pulmonary surfactant phosphatidylcholine (PC) has a complex intra-alveolar metabolism that involves uptake and recycling by alveolar type II epithelial cells, catabolism by alveolar macrophages, and loss up the bronchial tree. We compared the in vivo metabolism of animal-derived poractant alfa (Curosurf) and a synthetic surfactant (CHF5633) in adult male C57BL/6 mice. The mice were dosed intranasally with either surfactant (80 mg/kg body weight) containing universally 13C-labeled dipalmitoyl PC (DPPC) as a tracer. The loss of [U13C]DPPC from bronchoalveolar lavage and lung parenchyma, together with the incorporation of 13C-hydrolysis fragments into new PC molecular species, was monitored by electrospray ionization tandem mass spectrometry. The catabolism of CHF5633 was considerably delayed compared with poractant alfa, the hydrolysis products of which were cleared more rapidly. There was no selective resynthesis of DPPC and, strikingly, acyl remodeling resulted in preferential synthesis of polyunsaturated PC species. In conclusion, both surfactants were metabolized by similar pathways, but the slower catabolism of CHF5633 resulted in longer residence time in the airways and enhanced recycling of its hydrolysis products into new PC species.

Lipid biosynthesis of Nitrosopumilus maritimus dissected by lipid specific radioisotope probing (lipid-RIP) under contrasting ammonium supply

Ammonia-oxidizing archaea (AOA) are among the most abundant microbes in the oceans and are one of the major sources of glycerol dibiphytanyl glycerol tetraethers (GDGTs) in the water column and underlying sediments. However, little is known about the mechanistic steps during biosynthesis of GDGTs that form the basis of the TEX86 paleothermometer. Recent results showed that, apart from temperature, physiological factors such as growth stage and variations of the ammonium oxidation rate may affect the TEX86 temperature proxy. We performed a short term incubation experiment with radiolabeled 14C-bicarbonate to accurately trace the effect of high and low ammonium (NH4+) supply, on the production of individual membrane lipids by the AOA model organism Nitrosopumilus maritimus. The 14C incorporation during growth was monitored at five time intervals by liquid chromatography coupled to flow-through scintillation counting of the hydrolyzed membrane lipid extract, allowing a straight forward and sensitive on-line detection of 14C incorporation into archaeal lipids on time-scales lower than a single cell cycle. The experiments showed that low NH4+ supply results in higher cyclization of GDGTs with a preferential synthesis of crenarchaeol, whereas excess NH4+ led to predominant production of GDGT-0. Consequently, the cultures with a high NH4+ supply resulted in up to 10 °C lower estimated incubation temperatures than the cultures with low quantities of available NH4+ using the TEX86L calibration. Interestingly, a high relative production of archaeol was observed at the beginning of all experiments (up to 27%), independent of the NH4+ supply; likewise the degree of cyclization was initially lowest indicating delayed production of cycloalkylated derivatives. This pattern is consistent with N. maritimus synthesizing GDGTs by head-to-head condensation of two archaeol molecules and subsequent cyclization of the resulting acyclic tetraether. This study provides robust information on the biosynthesis of GDGTs in N. maritimus and advances our understanding of the influence of NH4+ supply on the TEX86 proxy.

Inhibiting the integrated stress response pathway prevents aberrant chondrocyte differentiation thereby alleviating chondrodysplasia.

The integrated stress response (ISR) is activated by diverse forms of cellular stress, including endoplasmic reticulum (ER) stress, and is associated with diseases. However, the molecular mechanism(s) whereby the ISR impacts on differentiation is incompletely understood. Here, we exploited a mouse model of Metaphyseal Chondrodysplasia type Schmid (MCDS) to provide insight into the impact of the ISR on cell fate. We show the protein kinase RNA-like ER kinase (PERK) pathway that mediates preferential synthesis of ATF4 and CHOP, dominates in causing dysplasia by reverting chondrocyte differentiation via ATF4-directed transactivation of Sox9. Chondrocyte survival is enabled, cell autonomously, by CHOP and dual CHOP-ATF4 transactivation of Fgf21. Treatment of mutant mice with a chemical inhibitor of PERK signaling prevents the differentiation defects and ameliorates chondrodysplasia. By preventing aberrant differentiation, titrated inhibition of the ISR emerges as a rationale therapeutic strategy for stress-induced skeletal disorders.

High temperature growth of single-walled carbon nanotubes with a narrow chirality distribution by tip-growth mode

An MgO supported Co catalyst prepared by atomic layer deposition was applied for the growth of single-walled carbon nanotubes (SWNTs). Different from other catalysts, which generally nucleate SWNTs by base-growth mode, the Co-MgO catalyst uniquely generates SWNTs by tip-growth mode, indicating a weak metal-support interaction. During chemical vapor deposition process, the lift-off of Co nanoparticles from support inhibits the aggregation of Co nanoparticles and favors the synthesis of small-diameter SWNTs with a narrow chirality distribution, even at a high reaction temperature. Particularly, product grown at 800 °C maintains a preferential synthesis of small-diameter (6, 5) SWNTs. The enrichment of (6, 5) SWNT arises from the combination of SWNT-catalyst interface thermodynamics with growth kinetic. The growth dynamics of SWNTs was further investigated by in situ Raman spectroscopy, which revealed that SWNTs with smaller diameters appeared prior to the growth of large-diameter counterparts.

Protopanaxadiol derivative DDPU improves behavior and cognitive deficit in AD mice involving regulation of both ER stress and autophagy

Alzheimer's disease (AD) is a progressively neurodegenerative disease with typical hallmarks of amyloid β (Aβ) plaque accumulation, neurofibrillary tangle (NFT) formation and neuronal death extension. Aggressive Aβ accumulation promotes senile plaque formation and perturbs endoplasmic reticulum (ER) function to trigger the unfolded protein response (UPR) leading to neuronal apoptosis. The stress-dependent activation of protein kinase RNA-like endoplasmic reticulum kinase (PERK) increases the phosphorylation of eukaryotic translation initiation factor-2α (eIF2α) to promote the preferential synthesis of β-site APP cleavage enzyme 1 (BACE1) and Aβ generation in turn. Additionally, dysfunction in autophagy has been reported to contribute to several neurodegenerative diseases including AD, and impairment in autophagy-mediated pathway may constitutively stimulate the generation of Aβ in AD. Here we discovered that protopanaxadiol derivative 1-(3,4-dimethoxyphenethyl)-3-(3-dehydroxyl-20(s)-protopanaxadiol-3β-yl)-urea (DDPU) effectively improved the activity of daily living (ADL) and cognitive deficits in APP/PS1 transgenic mice. The crosstalk between Aβ and ER stress has been intensively investigated by using DDPU as a probe. DDPU reduced Aβ production mainly by inhibiting the PERK/eIF2α signaling-mediated BACE1 translation and stimulated Aβ clearance by promoting autophagy as a PI3K inhibitor through PI3K/AKT/mTOR signaling pathway, while exhibited neuroprotective effect involving attenuation of ER stress. DDPU might be the first reported ginsenoside derivative with dual effects on both autophagy promotion and ER stress amelioration. Our results have highlighted the potential of DDPU in the treatment of AD.

Selective intrathecal enrichment of G1m1-positive B cells in multiple sclerosis.

Immunoglobulin gamma (IgG) heavy chain genes are associated with susceptibility to multiple sclerosis (MS) and IgG levels in the cerebrospinal fluid (CSF). However, how these variants are implicated in disease mechanisms remains unknown. Here, we show that proliferating plasmablasts expressing the G1m1 allotype of IgG1 are selectively enriched in CSF of G1m1/G1m3 heterozygous MS patients, whereas plasmablasts expressing either G1m1 or G1m3 are evenly distributed in blood. Moreover, there was a preferential intrathecal synthesis of oligoclonal IgG1 of the G1m1 allotype in heterozygous patients, whereas controls with Lyme neuroborreliosis displayed oligoclonal IgG1 of both allotypes. This points to a disease‐specific mechanism involved in B‐cell establishment within the central nervous system in MS.

Preferential synthesis of (6,4) single-walled carbon nanotubes by controlling oxidation degree of Co catalyst

Chirality-selective synthesis of single-walled carbon nanotubes (SWNTs) has been a research goal for the last two decades and is still challenging due to the difficulty in controlling the atomic structure in the one-dimensional material. Here, we develop an optimized approach for controlling the chirality of species by tuning the oxidation degree of Co catalyst. Predominant synthesis of (6,4) SWNTs is realized for the first time. The detailed mechanism is investigated through a systematic experimental study combined with first-principles calculations, revealing that the independent control of tube diameter and chiral angle achieved by changing the binding energy between SWNTs (cap and tube edge) and catalyst causes a drastic transition of chirality of SWNTs from (6,5) to (6,4). Since our approach of independently controlling the diameter and chiral angle can be applied to other chirality species, our results can be useful in achieving the on-demand synthesis of specific-chirality SWNTs.

Allosteric modulation of the substrate specificity of acyl-CoA wax alcohol acyltransferase 2

The esterification of alcohols with fatty acids is a universal mechanism to form inert storage forms of sterols, di- and triacylglycerols, and retinoids. In ocular tissues, formation of retinyl esters is an essential step in the enzymatic regeneration of the visual chromophore (11-cis-retinal). Acyl-CoA wax alcohol acyltransferase 2 (AWAT2), also known as multifunctional O-acyltransferase (MFAT), is an integral membrane enzyme with a broad substrate specificity that has been shown to preferentially esterify 11-cis-retinol and thus contribute to formation of a readily available pool of cis retinoids in the eye. However, the mechanism by which this promiscuous enzyme can gain substrate specificity is unknown. Here, we provide evidence for an allosteric modulation of the enzymatic activity by 11-cis retinoids. This regulation is independent from cellular retinaldehyde-binding protein (CRALBP), the major cis-retinoid binding protein. This positive-feedback regulation leads to decreased esterification rates for 9-cis, 13-cis, or all-trans retinols and thus enables preferential synthesis of 11-cis-retinyl esters. Finally, electron microscopy analyses of the purified enzyme indicate that this allosteric effect does not result from formation of functional oligomers. Altogether, these data provide the experimental basis for understanding regulation of AWAT2 substrate specificity.

Paradoxes of Symmetry: Homochirality; Cryptochiral Reactions; Chiral Field, Memory, and Induction; Chiral and Racemic Environment

A new concept is proposed on the basis of chemical, biological and physical data, according to which stable chiral factors on the prebiotic Earth are likely to contribute to homochirality arising (configurational homogeneity of important compounds of life). The axial rotation of the Earth near Moon (and Sun) and orbital movement of the Earth-Moon double planet around the Sun produces the simplest and most stable chiral effect in the terrestrial conditions. This right-handed helix motion is considered as the basis for Nature’s selection of L amino acids and D sugars for the synthesis of right-handed helices of essential macromolecules of living matter. This stage may be a rate-determining step of life origin. Lunar tides could be a possible “intermediate link” of the environment chiral influence on the molecular level. The surf occurring at an angle to the plane of spin rotation of the Eath leads to the predominant formation of right-handed helix-shaped water associates. Biological evidence of their existence is discussed. These chiral water associates could contribute to the preferential synthesis of homochiral molecules of amino acids and sugars. Their inclusion to the right-handed helical structure protects these molecules from racemization. Only a very small energy barrier exists between enantiomers, therefore the chiral field of the environment can affect asymmetric reactions and chiral processes in terrestrial conditions. The problem of chiral effects in polymerization, catalytic reactions with chirality amplification (chiral autcatalysis), cryptochiral and dissolution-recrystallization reactions are discussed. The chiral field, memory, and asymmetric induction phenomena are also considered. Because physical properties of racemic compounds change significantly in comparison with enantiomeres, it would be difficult, if not impossible, to explain the distinctions between racemates and enatiomers in the crystalline or dissolved forms only by dissimilar hydrogen bonding. This issue is discussed in the light of the possible influence of the external chiral field. The consideration of this effect may be beneficial for the understading of the mechanism of nonlinear chiral catalytic reactions. The concept of the external chiral field can be useful also for the explanation of other biological artifacts. Aspects of a possible chiral or racemic external influence on these reactions, effects, and processes are discussed. It is likely that this influence is more significant than believed. Keywords: Homochirality, macromolecular helices, chiral amplification, chiral and racemic fields.

A Fe5C2 nanocatalyst for the preferential synthesis of ethanol via dimethyl oxalate hydrogenation.

A Fe-based catalyst exhibits extremely high selectivity (89.6%) besides excellent catalytic activity in gas-phase dimethyl oxalate hydrogenation. The ethanol formation occurs via hydrogenation of methyl acetate instead of ethylene glycol over the active species Fe5C2.

MRNA quality control is bypassed for immediate export of stress-responsive transcripts.

Cells grow well only in a narrow range of physiological conditions. Surviving extreme conditions requires the instantaneous expression of chaperones that help to overcome stressful situations. To ensure the preferential synthesis of these heat-shock proteins, cells inhibit transcription, pre-mRNA processing and nuclear export of non-heat-shock transcripts, while stress-specific mRNAs are exclusively exported and translated. How cells manage the selective retention of regular transcripts and the simultaneous rapid export of heat-shock mRNAs is largely unknown. In Saccharomyces cerevisiae, the shuttling RNA adaptor proteins Npl3, Gbp2, Hrb1 and Nab2 are loaded co-transcriptionally onto growing pre-mRNAs. For nuclear export, they recruit the export-receptor heterodimer Mex67-Mtr2 (TAP-p15 in humans). Here we show that cellular stress induces the dissociation of Mex67 and its adaptor proteins from regular mRNAs to prevent general mRNA export. At the same time, heat-shock mRNAs are rapidly exported in association with Mex67, without the need for adapters. The immediate co-transcriptional loading of Mex67 onto heat-shock mRNAs involves Hsf1, a heat-shock transcription factor that binds to heat-shock-promoter elements in stress-responsive genes. An important difference between the export modes is that adaptor-protein-bound mRNAs undergo quality control, whereas stress-specific transcripts do not. In fact, regular mRNAs are converted into uncontrolled stress-responsive transcripts if expressed under the control of a heat-shock promoter, suggesting that whether an mRNA undergoes quality control is encrypted therein. Under normal conditions, Mex67 adaptor proteins are recruited for RNA surveillance, with only quality-controlled mRNAs allowed to associate with Mex67 and leave the nucleus. Thus, at the cost of error-free mRNA formation, heat-shock mRNAs are exported and translated without delay, allowing cells to survive extreme situations.

DNA-Based Nanotemplate Directed In Situ Synthesis of Silver Nanoclusters with Specific Fluorescent Emission: Surface-Guided Chemical Reactions

DNA-hosted silver nanoclusters (AgNCs) are a set of metallic fluorescent nanodots that possess high quantum yields and photostability. Here, we show the in situ hosted synthesis of AgNCs by single-stranded DNA preorganized on the self-assembled DNA nanostructure templates, which results in the site-specific formation of AgNCs with the specific fluorescence wavelengths. The excitation/emission properties of AgNCs were tuned by adjusting the distance between nucleation site and the template, the template configuration, and the location of the nucleation site on the template. Mass spectra analysis of AgNC products was performed to study the cluster sizes. The 5′ and 3′ ends of freely diffusing and template-supported host strands were labeled with a donor and an acceptor, and the FRET efficiency was evaluated to reveal the conformations of the host strands and their complexes with Ag+. It is indicated that the rigid template guided the synthetic pathway toward the preferential synthesis of AgNCs with a specif...

Preferential synthesis of highly conducting Tl(TCNQ) phase II nanorod networks via electrochemically driven TCNQ/Tl(TCNQ) solid-solid phase transformation

Facile synthesis and characterization of the highly conducting, thermodynamically favored, Tl(TCNQ) phase II microrods/nanorods onto conducting (glassy carbon (GC)) and semiconducting (indium tin oxide (ITO)) surfaces have been accomplished via redox-based transformation of 7,7,8,8-tetracynoquinodimethane (TCNQ) microcrystals. This electrochemically irreversible process involves the one-electron reduction of surface-confined solid TCNQ into TCNQ·− with concomitant incorporation of the Tl+ (aq) cation, from the bulk solution, at the triple-phase boundary, GC or ITO│(TCNQ(s)/TCNQ·− (s))│Tl+ (aq), through a nucleation/growth mechanism. Consistent with the conceptually related M(TCNQ) systems (M+ = Li+, Na+, K+, Ag+, and Cu+), the TCNQ/Tl(TCNQ) interconversion is strongly dependent upon scan rate, Tl+ (aq) electrolyte concentration, and the method of attaching solid TCNQ onto the electrode surface. Spectroscopic (infrared (IR) and Raman), microscopic (scanning electron microscopy (SEM)), and surface science (X-ray photoelectron spectroscopy (XPS), energy-dispersive X-ray (EDX), and X-ray diffraction (XRD)) characterization of the electrochemically synthesized material revealed formation of pure Tl(TCNQ) phase II. Importantly, the generic solid-state electrochemical approach used in this study not only offers facile protocol for controllable and preferential synthesis of Tl(TCNQ) phase II but also provides access to fabricate and tune the morphology to yield microrod/nanorod networks.

Study amino acid activity lacto-, bifidobacteria during fermentation

The paper evaluated the role of lactobacilli and bifidobacteria, as a source of amino acids, are the building blocks of a number of biologically active substances produced by the indigenous microflora of the human body and involved in various metabolic processes of the host organism. Research Consortium bifidobacteria amino activity consisting of Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium adolescentis, Bifidobacterium bifidum Y-4 or Lactobacillus casei rhamnosus carried Lactobacillus after fermentation of milk with initial acidity titrated 19 °T at 38-40 °C for 12-16 hours until the titratable acidity 85-100 °T, dense gel formation and accumulation of biomass of bifidobacteria and lactobacilli to a concentration of not less than 109 cfu/g. The mass proportion of protein was determined by the Kjeldahl method, the amino acid composition – by ion exchange chromatography using the liquid chromatography Shimadzu LC-20 Prominence. As a result of fermentation was investigated systems installed increasing mass fraction of protein in the product, indicating that the accumulation of bacterial proteins – for bifidobacteria consortium - in an amount of 1%, in an amount of lactobacilli to – 0.2%. Fermentation Bifidobacterium bifidum, Bifidobacterium longum, Bifidobacterium adolescentis, Bifidobacterium bifidum Y-4 installed next row preferential synthesis of amino acids: alanine, glutamic acid, methionine, glycine, histidine, serine, threonine, tyrosine, valine, proline. Fermentation Lactobacillus casei rhamnosus installed advantageous synthesis of methionine, alanine, glutamic acid, arginine, serine, histidine, threonine, valine, isoleucine, leucine, tyrosine, tryptophan. The data needed to assess the nutritional status of correction, when introduced into the diet of probiotic products with this consortium of bifidobacteria or lactobacilli Lactobacillus casei rhamnosus in the organization of children, gerontology, and preventive diet.