Sugar Amino Acid Research Articles

Screening of Antioxidant Maillard Reaction Products Using HPLC-HRMS and Study of Reaction Conditions for Their Production as Food Preservatives

The Maillard reaction (MR) involves interactions between reducing sugars and amino acids or proteins during heating, producing Maillard reaction products (MRPs) that influence food flavour, aroma, and colour. Some MRPs exhibit antioxidant properties, prompting interest in their potential as natural food preservatives. This study aimed to develop a method for detecting and identifying antioxidant MRPs using high-pressure liquid chromatography (HPLC) coupled with high-resolution mass spectrometry (HRMS). By improving chromatographic conditions, the separation of antioxidant MRPs was optimised using known antioxidant MRPs as reference signals. This work also examined the effects of pH, reaction time, and different sugar–amino acid combinations on the production and composition of antioxidant MRPs. Results indicated that neutral to basic pH facilitated faster reactions, with pH 7 selected as optimal. A library of 50 m/z signals for potential antioxidant MRPs was created, and the best combinations of amino acids and sugars for their production were identified. These findings pave the way for more precise analyses of antioxidant MRPs, with future research focusing on isolating and characterising specific MRPs to understand their structures and mechanisms, ultimately contributing to the development of functional foods with natural antioxidant properties.

Covalent modification of chitosan surfaces with a sugar amino acid and lysine analogues

Covalent modification of chitosan surfaces with a sugar amino acid and lysine analogues

Maillard reaction products of hydrolyzed Copyinds comatus protein with various sugar-amino acid combinations: Focusing on their meaty aroma notes and salt reduction abilities

Maillard reaction products (MRPs) of mushroom protein have been shown to present unique flavor properties, but how additional reducing sugar and amino acids manipulate the generation of meaty flavor and the taste traits of MRPs are still open questions. In this study, the Copyinds comatus protein hydrolysates with different reducing sugars (D-ribose and D-xylose) and amino acids (cysteine, methionine, proline, and glutamic acid) were thermally treated. The flavor properties, volatile compounds and taste profiles of the resulting products were comprehensively evaluated using multi-scale flavor analyses techniques. Though the E-nose and E-tongue revealed enriched volatile profiles and taste traits of MRPs than the original hydrolysate, MRPs derived from various sugar-amino acid combinations cannot be well distinguished according to the PCA score plots. The fingerprints by GC-IMS revealed amino acid-specific compounds, including methylpyrazine, hexanol, and isopropyl acetate for methionine-participated MRPs, and ethyl propanoate, cyclohexanone, and 2-butanone for MRPs derived from cysteine. Quantitative results further demonstrated that the methionine-involved MRPs contained significantly higher amounts of sulfur- and nitrogen-containing VOCs than other MRPs, most of which were associated with meat-like odors. Sensory evaluation confirmed that the species of amino acid and reducing sugars made differences in the taste traits, and MRPs prepared from xylose-glutamic acid and xylose-methionine showed outstanding advantages of saltiness and umami taste enhancement. Overall, Copyinds comatus MRPs with methionine are efficient ingredients for the production of meat flavoring, with capacities to compensate for reduced sensory properties of low-sodium food.

Multidimensional decipherment of interactions in invert sugar–amino acid co-degradation colorants (IACDCs) capture by polyamine co-modified shaddock peel cellulose/graphene oxide aerogel

The development of an environmentally friendly scavenger with an outstanding ability to eliminate IACDCs from molasses-based distillery wastewater is essential for the safety of aquatic ecosystems and organisms. By combining polyamine co-modified shaddock peel cellulose (SPC) and graphene oxide (GO), a multistage porous aerogel (i.e., CP-GO/SPA) was constructed for the highly effective capture of IACDCs. CP-GO/SPA exhibited a surprisingly high IACDC adsorption capacity (1157 mg/g, which was 1.5–100 times that of previously reported ones). It also had an ultrafast adsorption mass transfer (AMT) rate. Advanced AMT-resistance models reveal that the capture on active site is the main AMT resistance, whereas liquid-film and pore diffusion are quite fast. CP-GO/SPA exhibited excellent reusability (>90% IACDC removal efficiency after six cycles) and considerable potential for industrial applications (i.e., treatment of actual wastewater by fixed-bed adsorption). The polyamine co-modified SPC and GO endowed CP-GO/SPA with substantial amine groups and high affinity for water, as validated by advanced molecular dynamics simulations. These features are extremely conducive for capturing electronegative and water-soluble IACDCs. A series of characterizations and multiple quantum chemical theory calculations (including ETP, ALIE, FMOs, IGM, and HIS analyses) further revealed the adsorption mechanisms from a molecular perspective. The IACDC capture by CP-GO/SPA resulted from charge, electron sharing, and van der Waals interactions. However, charge interactions played a dominant role. The optimal capture configurations were visualized at the molecular level, and the H-bond donor–acceptor relationship was determined. The IACDCs act as H-bond acceptors in a diverse range of capture configurations.

Insights into the catalytic mechanism of a bacterial deglycase essential for utilization of fructose-lysine.

Amadori rearrangement products are stable sugar-amino acid conjugates that are formed nonenzymatically during preparation, dehydration, and storage of foods. Because Amadori compounds such as fructose-lysine (F-Lys), an abundant constituent in processed foods, shape the animal gut microbiome, it is important to understand bacterial utilization of these fructosamines. In bacteria, F-Lys is first phosphorylated, either during or after uptake to the cytoplasm, to form 6-phosphofructose-lysine (6-P-F-Lys). FrlB, a deglycase, then converts 6-P-F-Lys to L-lysine and glucose-6-phosphate. Here, to elucidate the catalytic mechanism of this deglycase, we first obtained a 1.8-Å crystal structure of Salmonella FrlB (without substrate) and then used computational approaches to dock 6-P-F-Lys on this structure. We also took advantage of the structural similarity between FrlB and the sugar isomerase domain of Escherichia coli glucosamine-6-phosphate synthase (GlmS), a related enzyme for which a structure with substrate has been determined. An overlay of FrlB-6-P-F-Lys on GlmS-fructose-6-phosphatestructures revealed parallels in their active-site arrangement and guided our selection of seven putative active-site residues in FrlB for site-directed mutagenesis. Activity assays with eight recombinant single-substitution mutants identified residues postulated to serve as the general acid and general base in the FrlB active site and indicated unexpectedly significant contributions from their proximal residues. By exploiting native mass spectrometry (MS) coupled to surface-induced dissociation, we distinguished mutations that impaired substrate binding versus cleavage. As demonstrated with FrlB, an integrated approach involving x-ray crystallography, in silico approaches, biochemical assays, and native MS can synergistically aid structure-function and mechanistic studies of enzymes.

Design and synthesis of novel carbohydrate-amino acid hybrids and their antioxidant and anti-β-amyloid aggregation activity

Herein we report the synthesis of new furanoid sugar amino acids and thioureas, prepared by coupling aromatic amino acids and dipeptides with isothiocyanato- functionalized ribofuranose ring. Since carbohydrate-derived structures possess many biological activities, synthesized compounds were evaluated as anti-amyloid and antioxidant agents. The anti-amyloid activity of the studied compounds was evaluated based on their potential to destroy amyloid fibrils of intrinsically disordered Aβ40 peptide and globular hen egg-white (HEW) lysozyme. The destructive efficiency of the compounds differed between the studied peptides. While the destruction activity of the compounds on the HEW lysozyme amyloid fibrils was negligible, the effect on Aβ40 amyloid fibrils was significantly higher. Furanoid sugar α-amino acid 1 and its dipeptide derivatives 8 (Trp-Trp) and 11 (Trp-Tyr) were the most potent anti-Aβ fibrils compounds. The antioxidant properties of synthesized compounds were estimated by three complementary in vitro assays (DPPH, ABTS, and FRAP). The ABTS assay was the most sensitive for assessing the radical scavenging activity of all tested compounds compared to the DPPH test. Significant antioxidant activity was detected for compounds in the group of aromatic amino acids depending on the present amino acid, with the highest activity in the case of dipeptides 11 and 12 containing the Tyr and Trp moiety. Regarding the FRAP assay, the best reducing antioxidant potential revealed Trp-containing compounds 5, 10, and 12.

Aroma precursor enhancing in dried cocoa beans fermentation using enzyme and heat addition

<abstract> <p>Changes in amino acids and reducing sugars in cocoa beans during fermentation were investigated using a 3 × 3 full complete factorial design using different enzyme additions (cellulase, papain and control–no enzyme) and water bath temperatures (40, 45 and 50 ℃) as variables over three days of fermentation. Aroma precursors (reducing sugars and free amino acids) developed inside the bean by enzymatic mechanisms during fermentation are converted into volatile compounds such as pyrazines and aldehydes during roasting. This study aimed to improve the fermentation process of dried beans by adding acetic acid, heat and enzymes, because there is insufficient pulp for the ideal spontaneous fermentation process. Samples were analyzed for fermentation index, cut bean, reducing sugar amino acid composition and volatile aroma composition profile using headspace solid phase microextraction (HS-SPME) and gas chromatography mass spectrometry (GC-MS). The results showed that the fermentation index was significantly affected by the addition of enzymes and water temperature. Although amino acids rose to 200%–300%, the composition contained several acidic amino acids because the pH utilized less than 4. Adding cellulase enzymes increases the amount of reducing sugars and amino acids but does not result in the formation of various amino acids.</p> </abstract>

The role of integrin α4 in the anti-liver fibrosis effect of the sticky sugar amino acid extract of Periplaneta americana

The role of integrin α4 in the anti-liver fibrosis effect of the sticky sugar amino acid extract of Periplaneta americana

Elucidating the catalytic mechanism of a bacterial deglycase essential for utilization of fructose‐lysine, an Amadori product

Amadori products are stable sugar‐amino acid conjugates that are formed non‐enzymatically via the Maillard reaction that takes place during preparation of foods by heating, roasting, and drying. Fructose‐lysine (F‐Lys, ε‐conjugated) is one of the most abundant Amadori compounds in processed foods and is a key intermediate in the formation of advanced glycation end products, which in turn are implicated in inflammation and disease. The variation among humans in their ability to metabolize F‐Lys has motivated an examination of the inter‐individual differences in gut microbial taxa and the enzymes that help convert F‐Lys into short‐chain fatty acids or cellular energy. Results from such studies are also expected to yield insights into whether F‐Lys utilization by bacterial pathogens (e.g., Escherichia coli, Salmonella enterica serovar Typhimurium) might offer them a competitive edge. Either during or after bacterial uptake, F‐Lys is phosphorylated to form 6‐phosphofructose‐lysine (6‐P‐F‐Lys). FrlB, a deglycase, converts 6‐P‐F‐Lys to L‐lysine and glucose 6‐phosphate, with the latter feeding into glycolysis. Since the catalytic mechanism of FrlB has not been studied, we sought to obtain a high‐resolution structure of Salmonella FrlB ± 6‐P‐F‐Lys and identify the active‐site residues essential for catalysis.After overexpression and purification of recombinant Salmonella FrlB, we obtained its 1.9 Å crystal structure. FrlB exists as a dimer with two identifiable inter‐subunit active sites. In the absence of a co‐crystal structure of FrlB with 6‐P‐F‐Lys, we took two different strategies to delineate its catalytic pocket. First, we observed that the phosphosugar‐binding module–called the sugar isomerase (SIS) domain in FrlB–shared sequence similarity with the eponymous domain in E. coli glucosamine 6‐phosphate synthase (GlmS), which generates glucosamine 6‐phosphate from fructose 6‐phosphate (F‐6‐P) and glutamine. Overlaying the tertiary structures of Salmonella FrlB with E. coli GlmS, which had previously been co‐crystallized with F‐6‐P, helped identify FrlB residues that could be involved in 6‐P‐F‐Lys binding and cleavage. Second, sequence alignment of Salmonella FrlB with FraB, a related and biochemically characterized deglycase required for metabolism of fructose‐asparagine (an Amadori compound) pinpointed residues that could act as a general acid and a general base during deglycation. From these comparative analyses, six candidate residues in FrlB were individually mutated to alanine or another conservative substitution, and the mutant derivatives were purified using affinity chromatography. Our differential scanning fluorimetry studies revealed that all the mutants exhibit thermal stability nearly identical to wild‐type FrlB; importantly, our native mass spectrometry (nMS) studies confirmed that the mutations did not impair the ability of these mutants to form a stable dimer. A spectrophotometric coupled assay was employed to measure the activity of FrlB and the panel of mutants. When a mutation dampened or eliminated deglycase activity, nMS was leveraged to distinguish between a defect in substrate binding versus cleavage. Collectively, our results provide a platform for defining the active site and catalytic mechanism of FrlB even while highlighting the value of exploiting structures of distant homologs to advance structure‐function relationship studies.

EFFICACY OF AQUEOUS AND METHANOLIC EXTRACTS OF PLANT BRASSICA RAPA LEAVES POTENTIAL ANTI-PSEUDOMONAL ACTIVITY

Objective: Efficacy of Aqueous and Methanolic Extracts of Plant Brassica Rapa Leaves Potential Anti-Pseudomanal Activity
 Methods: Phytochemical analysis of Brassica rapa belonging to the family was examined using Aqueous and Methanolic extracts. Methanolic and aqueous extracts of leaves part of the plant were investigated individually for Anti-pseudomanal activity by agar well diffusion method. The susceptibility of three gram-negative bacteria to the aqueous and Methanolic extracts of this plant was measured and the results compared with standard antibiotic Gentamycin. Both the extracts were tested against selected species of Pseudomonas aeruginosa MTCC2295 (G-ve), Pseudomonas fluorescens MTCC2421 (G-ve), and Pseudomonas alcaligenes MTCC7095 (G-ve), to find the inhibitory activities of microbes at the dose level of 50 and 100 µg/ml.
 Results: The phytochemical analysis of Aqueous and Methanolic extracts confirmed the presence of Carbohydrates, Fat, proteins, Vitamins, Minerals, Electrolytes, sugar, soluble and insoluble fiber and amino acids. Methanolic extract of Brassica rapa showed considerably high Anti-pseudomonal activities against all bacteria than Aqueous extract.
 Conclusion: The leaves of Brassica Rapa were found to be rich in sulphur and nitrogen-containing compounds. Brassicarapamethanolic extract has anti-pseudomonal effects against bacteria.
 The current study's range of activity can provide a new plant source for safe anti-pseudomanal drugs.

Role of Exogenous Application of Alpha-Tocopherol in Reducing Low Temperature Stress in Bell Pepper

Changing climatic conditions have an impact on the commercial harvest and production of Capsicum annuum L. across the world. It is a summer crop that grows best at 21°C (low) to 37 °C (high) temperature. Changes in normal growth, poor shoot and root length, increased antioxidant activity, low sugar content, high proline content, and poor yield were observed in bell pepper at low temperature stress. A research trial was conducted on bell peppers in the Department of Plant Pathology at University of Agriculture, Faisalabad. Bell peppers were cultivated hydroponically and alpha-tocopherol control (0ppm), 25ppm, 50ppm, and 100ppm were applied in foliar application. At the reproductive period, a low temperature stress of 18 °C day and 15 °C night was used given. After seven days of foliar spray, plants were exposed to cold temperatures during the day and night. After seven days of stress, the plants were harvested and morphological, physiological, and biochemical data were examined. Plant growth, leaf area, number of leaves, buds, and flowers, photosynthetic pigments, relative water content, cell membrane permeability, total soluble sugar, total reducing sugar, protein contents, and total free amino acid levels were all reduced when exposed to high temperatures. When the stress of low temperature was applied, there was a rise in proline, phenolic, flavonoid, H2O2, MDA, enzymatic antioxidants SOD, CAT, POD, and in APX. Under temperature stress, foliar application of alpha-tocopherol significantly improved CAT, POD, APX activity, decreased MDA, H2O2, and improved proline content. Exogenously administered alpha-tocopherol was found to be effective in boosting capsicum growth and antioxidant capability under low temperature stress.

Antioxidant and Functional Activities of MRPs Derived from Different Sugar-Amino Acid Combinations and Reaction Conditions.

The Maillard reaction (MR), or non-enzymatic browning, involves reducing sugars reacting with amino acids, peptides, or proteins when heated to produce an abundance of products that contribute to sensory, nutritional, and functional qualities of the food system. One example of an important functional quality of MR relates to antioxidant capacity, which has relevance to preserve food quality and also to extend a potential role that may promote gastrointestinal health. The addition of Alphacel (10%), a non-reactive polysaccharide, to MR reactants produced small significant (p < 0.05) reductions in yield of soluble Maillard reaction products (MRPs), sugar loss, and color change of products formed respectively, for reducing sugars. A similar effect was also noticed for different free-radical scavenging capacity (p < 0.05), using chemical (e.g., 2,2-diphenyl-1-picrylhydrazyl (DPPH)), Trolox equivalent antioxidant capacity (TEAC), and oxygen radical absorbance capacity (ORAC) assays. An inflamed Caco-2 cell model revealed nitric oxide (NO) inhibitory activity for Glu-amino acid MRPs, which contrasted the NO stimulatory activity obtained with Fru-amino acid MRPs, especially when glycine was used as the amino acid. Pre-treating Caco-2 cells with Fru-glycine MRPs protected against loss in trans-epithelial resistance (TEER) (p < 0.05) and reduced (p < 0.05) disruption of Caco-2 intestinal epithelial tight-junction (TJ) protein cells when exposed to 7.5% ethanol. A low molecular weight Fru-glycine (e.g., <1 kDa) fraction contributed to the protective effect, not observed with the corresponding high molecular weight MRP fraction. The presence of Alphacel had minimal effect on generating MRPs with relative modified protection against intestinal dysfunction in cultured Caco-2 cells. Rather, different types of sugar–amino acid combinations used to generate MRPs contributed more to mitigate injury in stress-induced Caco-2 cells. With the growing evidence that MRPs have a wide range of bioactive activities, this study concludes that specificity of substrate precursors that produce MRPs in heated foods is a critical factor for antioxidant and related cellular functions that represent a healthy gut.

Variations of soil organic nitrogen fractions during degradation succession in the Gahai Wetland, Northwest China.

This study amined to explore the variation of soil organic nitrogen components across the degradation succession of Gahai Wetland. By combining field sampling and laboratory analysis, the content and distribution characteristics of soil organic nitrogen components, i.e., hydrolytic total nitrogen (HTN), unidentified acidolytic nitrogen (HUN), ammonium nitrogen (AMN), amino acid nitrogen (AAN) and acid amino sugar nitrogen (ASN) were investigated in undegraded (UD), lightly degraded (LD), moderately degraded (MD), and heavy degraded (HD) Gahai Wetland. The results showed that, in the 0-10 cm layer, the contents of total nitrogen (TN), HUN, AMN, and AAN in LD decreased by 17.3%, 19.4%, 8.6%, and -5.6%, 28.0%, 19.4%, 17.1% and 0 in MD, and 35.8%, 28.8%, 28.6% and 55.6% in HD, respectively. In the 10-20 cm layer, the four components decreased by 4.0%, 10.3%, 2.9% and 9.1% in LD, 21.0%, 18.3%, -2.9% and -9.1% in MD, and 9.9%, 38.9%, 21.2% and 51.4% in HD, respectively. The corresponding contents in the 20-40 cm soil layer did not change. The proportion of soil acid-hydrolyzed nitrogen components to TN under four degradation stages was HUN (25.9%-32.5%) &gt; AMN (6.7%-11.1%) &gt; AAN (4.8%-11.1%) &gt; ASN (1.2%-4.4%). Soil water content was the main driving factor for variations of soil organic nitrogen components as indicated by the results of redundancy analysis. Degradation of the Gahai Wetland significantly reduced the content of soil TN and the components of acid-hydrolyzed nitrogen in 0-10 cm soil layer, and weakened the nitrogen "sink" function of soils. The AAN and ASN were sensitive to wetland degradation.

Synthetic development of sugar amino acid oligomers towards novel podophyllotoxin analogues

In this work, we have developed an approach for the synthesis of sugar amino acid oligomers based on the glucosamine scaffold. We found that the solid-phase approach was unsuccessful for the preparation of sugar amino acid oligomers and the limitation of the liquid-phase approach revolved around the low solubility of larger oligomers. Nevertheless, this strategy allowed the coupling of alkynylated carbohydrate amino acids with podophyllotoxin-bearing an azide functional group yielding novel podophyllotoxin analogues. Due to their low solubility, the antiproliferative study revealed no anticancer activity of these newly synthesized analogues.

Changes in Reserve Mobilization Caused by Salinity Could Interfere in the Initial Growth of Jatropha curcas

Salinity in soil can affect Jatropha seedling metabolism, interfering with plant establishment. In this study, the effect of salinity on the mobilization of reserves during the development of Jatropha seedlings was tested. Two genotypes of Jatropha were used and three concentrations of NaCl were applied between the 4th and 8th days after germination. The effects of salinity on seedling growth, in terms of fresh and dry phytomass, ionic partition, and sugar quantification, starch, proteins, amino acids, and lipids were evaluated in cotyledon leaves, hypocotyls, and roots. There was an increase in the content of all classes of macromolecules analyzed in at least one of the organs. It is hypothesized that the hypocotyls acted as an accumulating organ of Na+. The accumulations of amino acids and protein in roots suggest that metabolic responses occurred in response to the ionic and osmotic effects of NaCl, although this accumulation did not appear to prevent biomass losses in seedlings. Furthermore, the findings of this study demonstrate that salinity inhibits the mobilization of lipids and carbon stocks from cotyledon leaves to the rest of the plant, and together with the synthesis of proteins and amino acids that occurred primarily in roots, contributed to response of these plants to salinity.

Synthesis of novel sugar derived aziridines, as starting materials giving access to sugar amino acid derivatives.

D-Erythrosyl aziridines were obtained from D-erythrosyl triazoles either by photolysis or through diazirine intermediates. These were found to undergo rich, high yielding chemistry by reaction with protic acids (HCl, BiI3/H2O and trifluoroacetic acid) leading to two types of furanoid sugar α-amino acids, and polyhydroxylprolines. Based on experimental evidence, reaction mechanisms have been proposed for the syntheses.

The interaction of intestinal bacteria and feed: a case study of intensive-duck husbandry in Central Java

This study was aimed to compare sugars and amino acid content in duck’s feed and the intestinal bacteria's effects to improve ducks' quality. This research was an observational exploration involving five duck husbandries from Semarang, Temanggung, Magelang, Pati, and Salatiga District, Central Java. A total of 5 g of intestinal contents were collected from each of the five ducks randomly selected from each husbandry. The feed and intestinal contents were then analyzed using high-performance liquid chromatography (HPLC). The highest amino acid types were glutamate, aspartate, lysine, valine, and isoleucine, while the lowest was asparagine found in all sample farms. Intestinal contents freshly extracted then placed in dark bottles sterile for microbiome analysis with primers 6S rRNA V3-V4 genome identification. The concentration of glucose, fructose, and galactose in the intestine has increased significantly caused by digested polysaccharides. The composition of bacteria plays a vital role in digesting polysaccharides, makes them quickly absorbed by duck’s intestine cells. The abundance of bacteria in all sample locations was dominated by the phylum Firmicutes, especially Lactobacilalles, Bacilalles, and Clostridialles. Over feeding may not effective in sugar and essential amino acid absorption, however, it may play an essential role in the diversity of gut bacteria to produce necessary component for duck’s physiology.

Utilization of Maillard reaction in moist-dry-heating system to enhance physicochemical and antioxidative properties of dried whole longan fruit

This research aimed to enhance the physicochemical and antioxidant properties of dried whole longan fruit using Maillard reaction or non-enzymatic glycosylation (glycation) in a moist-dry-heating system at 60 °C with approximately 75% relative humidity for 5–50 days. During Maillard reaction, the browning index (BI) of the fruits increased significantly while lightless, redness and yellowness decreased. Interestingly, the rare sugars especially D-psicose and D-allose gradually increased by 2–3 folds when compared to the initial Maillard reaction. The development of D-mannose was additionally established through the glycation. The degree of glycation increased with the decrease of free amino acid, suggesting that conjugation of sugar with amino acids was involved. SDS-PAGE confirmed that the high molecular weight (HMW) of conjugated sugar-amino acid was the Maillard reaction product. The antioxidative properties including DPPH and ABTS radical scavenging activities, also ferric reducing antioxidant power (FRAP) were also increased as Maillard reaction progressed, which showed the activities in the range of 43.2–94.1 mg GAE/100 g dry basis, 0.23–3.09 g TE/100 g dry basis, and 0.35–5.95 g FeSO4/100 g dry basis, respectively. This study demonstrated a practical approach of Maillard reaction for the development of dried longan fruit with high antioxidative properties.

Effects of cadmium stress on physiological indexes and fruiting body nutritions of Agaricus brasiliensis

In this study, 0, 0.5, 1, 1.5, 2, 4, 6 and 8 mg·kg−1 of cadmium were added to the cultivation materials. In order to study the effects of different concentrations of Cd stress on J1 and J77, the contents of antioxidant enzymes, proline and malondialdehyde, Cd content, agronomic traits and yield of fruiting bodies of Agaricus brasiliensis were determined, and the nutritional components such as polysaccharide, triterpene, protein, total sugar and total amino acid were determined. The results showed that the physiological indexes of strain J1 and J77 changed regularly under different concentrations of Cd stress. J1 was a high absorption and low tolerance variety, while J77 was a low absorption and high tolerance variety. Low concentration of Cd promoted the growth of strain J1, and higher concentration of Cd promoted the growth of strain J77. The contents of protein and total amino acids in the two strains changed greatly, followed by polysaccharides, which indicated that Cd stress had the greatest impact on the three nutrients, and other nutrients were not sensitive to Cd stress.

Carbon utilization phenome of Leptospira interrogans serovar Manilae strain K64

Background: Leptospirosis, an acute febrile disease caused by the pathogenic species of genus Leptospira, is one of the neglected emerging zoonoses that is of global public health concern. The recent genus-wide sequencing of Leptospira isolates led to the need for better understanding of the complex metabolic mechanisms of this organism. However, majority of the published studies on Leptospira metabolism were still the pioneering works of Baseman and Cox in the 60’s and their contemporaries. Knowledge on the carbon sources that supports the growth of a Leptospira species will not only contribute to the limited metabolic studies but will further support the reported genes and metabolic pathways of this organism. Objective: Thus, this study aimed to describe the carbon utilization phenome of Leptospira interrogans serovar Manilae strain K64, one of the dominantly circulating pathogenic Leptospira in the Philippines. Methods: A previously optimized BiologTM Gen III sole carbon utilization phenotype microarray assay protocol for leptospires was adapted. Results: L. interrogans serovar Manilae strain K64 showed utilization of 29 carbon sources belonging to sugars and sugar derivatives, amino acids, methyl ester, carboxylic acid and fatty acids. These were N-acetyl-β-D-mannosamine, N-acetyl-D-galactosamine, N-acetyl neuraminic acid, D-fructose, D-galactose, 3-methyl glucose, D-fucose, L-fucose, L-rhamnose, inosine, D-fructose-6-phosphate, D-gluconic, D-glucuronic acid, glucuronamide, D-saccharic acid, D-aspartic acid, D-serine, L-alanine, L-arginine, L-histidine, L-pyroglutamic acid, L-serine, D-lactic acid methyl ester, citric acid, D-malic acid, L-malic acid, alpha ketoglutaric acid, alpha ketobutyric acid, and acetoacetic acid. Discussion and Conclusion: The carbon sources utilized by L. interrogans serovar Manilae strain K64 agreed well with the identified genes and metabolic pathways among Leptospira species. Moreover, these 29 carbon sources have been previously reported to be associated in the biosynthesis of peptidoglycan, lipopolysaccharide, histidine, sulfur, amino acids, and isoleucine and in other metabolic pathways such as glycolysis, pentose-phosphate, pyruvate and fatty acid in Leptospira spp.