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Assessment of cross-linking in combined cross-linked soy protein isolate gels by microbial transglutaminase and Maillard reaction

Gan CY, Cheng LH, Easa AM

J Food Sci, 2009 Mar;74(2):C141-6.
PMID: 19323728 DOI: 10.1111/j.1750-3841.2009.01053.x

Soy protein isolate (SPI) gels were produced using single cross-linking agents (SCLA) of microbial transglutaminase (MTG) via incubation for 5 or 24 h (SCLA-MTG). When powdered SCLA-MTG gels were heated for 2 h with ribose (R2) (2 g/100 mL), dark brown gels were formed, and these were designated as combined cross-linking agent (CCLA) gels: MTG5(R2) and MTG24(R2). The results showed that the levels of Maillard-derived browning and cross-links of MTG5(R2) and MTG24(R2) gels were significantly (P < 0.05) lower than a control gel produced without MTG (SCLA-R2) even though the percentage of ribose remaining after heating of these gels was similar, indicating that a similar amount of ribose was consumed during heating. epsilon-(gamma-glutamyl)lysine bonds formed during incubation of SPI with MTG may have reduced the free amino group of SPI to take part in the Maillard reaction; nevertheless, ribose took part in the Maillard reaction and initiated the Maillard cross-linkings within the CCLA gels.

Matched MeSH terms: Amino Acids/analysis*
Aroma precursors and methylpyrazines in underfermented cocoa beans induced by endogenous carboxypeptidase

Jinap S, Ikrawan Y, Bakar J, Saari N, Lioe HN

J Food Sci, 2008 Sep;73(7):H141-7.
PMID: 18803708 DOI: 10.1111/j.1750-3841.2008.00858.x

Cocoa-specific aroma precursors and methylpyrazines in underfermented cocoa beans obtained from fermentation induced by indigenous carboxypeptidase have been investigated. Fermentation conditions and cocoa bean components were analyzed during 0 to 3 d of fermentation. Underfermented cocoa beans were characterized as having hydrophilic peptides and free hydrophobic amino acids much higher than unfermented ones. These 2 key components of cocoa aroma precursors may be produced from the breakdown of proteins and polypeptides by endogenous carboxypeptidase during the fermentation process. The enzyme was activated during fermentation. Polypeptides of 47, 31, and 19 kDa were observed in the samples throughout the 3-d fermentation period; however, only the first 2 polypeptides were remarkably reduced during fermentation. Since the 1st day of fermentation, underfermented cocoa beans contained methylpyrazines, a dominant group of cocoa-specific aroma. This might be due to microbial activities during fermentation, observed through a decrease of pH value and an increase of temperature of cocoa beans. The concentration of tetramethylpyrazines was significantly increased during the 3 d of fermentation. This may increase the cocoa-specific flavor to the beans.

Matched MeSH terms: Amino Acids/analysis
Solvent accessibility in native and isolated domain environments: general features and implications to interface predictability

Raih MF, Ahmad S, Zheng R, Mohamed R

Biophys Chem, 2005 Apr 1;114(1):63-9.
PMID: 15792862

A non-redundant database of 4536 structural domains, comprising more than 790,000 residues, has been used for the calculation of their solvent accessibility in the native protein environment and then in the isolated domain environment. Nearly 140,000 (18%) residues showed a change in accessible surface area in the above two conditions. General features of this change under these two circumstances have been pointed out. Propensities of these interfacing amino acid residues have been calculated and their variation for different secondary structure types has been analyzed. Actual amount of surface area lost by different secondary structures is higher in the case of helix and strands compared to coil and other conformations. Overall change in surface area in hydrophobic and uncharged residues is higher than that in charged residues. An attempt has been made to know the predictability of interface residues from sequence environments. This analysis and prediction results have significant implications towards determining interacting residues in proteins and for the prediction of protein-protein, protein-ligand, protein-DNA and similar interactions.

Matched MeSH terms: Amino Acids/chemistry*
Individual non-essential amino acids fortification of a low-protein diet for broilers under the hot and humid tropical climate

Awad EA, Zulkifli I, Soleimani AF, Loh TC

Poult Sci, 2015 Nov;94(11):2772-7.
PMID: 26371331 DOI: 10.3382/ps/pev258

A study was conducted to investigate the effects of feeding low-protein diets fortified with individual non-essential amino acids (NEAA) on growth performance, serum metabolites (uric acid, UA; triglycerides, TG; total protein, TP; and albumin, Alb), organ weight, breast yield, and abdominal fat weight in broiler chicks raised under the hot and humid tropical climate. Eight isocaloric (3,017 kcal/kg) experimental diets were formulated and fed to male broiler chicks from d 1-21 as follows: 1) 22.2% crude protein (CP) (positive control; PC); 2) 16.2% CP + mixture essential amino acids (EAA) to meet or exceed the National Research Council (1994) recommendations (negative control; NC); 3) NC + glycine (Gly) to equal the total glycine + serine level in the PC; diets 4 through 7 were obtained by supplementing NC diet with individual glutamic acid, proline, alanine, or aspartic acid (Glu, Pro, Ala, or Asp, respectively); 8) NC + NEAA (Gly + Glu + Pro + Ala + Asp) to equal the total level of these NEAA in the PC. Fortifying NC diet with mixture NEAA resulted in a similar growth performance as PC. However, fortification of low-CP diet with individual NEAA failed to improve body weight (BW) (P < 0.0001), feed intake (FI) (P = 0.0001), and feed conversion ratio (FCR) (P = 0.0001). Serum uric acid (UA) was lower (P = 0.0356) in NC birds and NC diet supplemented with individual NEAA birds, whereas serum triglyceride (TG) (P = 0.007) and relative weight of abdominal fat (P = 0.001) were higher in these birds. In conclusion, no single NEAA fortification may compensate the depressed growth performance attributed to a low-CP diet. However, fortification with Gly may improve FCR. There is a possibility that broilers raised under the hot and humid climate require higher Gly fortification than the level used in this study.

Matched MeSH terms: Amino Acids/metabolism*
Metabolomics - the complementary field in systems biology: a review on obesity and type 2 diabetes

Abu Bakar MH, Sarmidi MR, Cheng KK, Ali Khan A, Suan CL, Zaman Huri H, et al.

Mol Biosyst, 2015 Jul;11(7):1742-74.
PMID: 25919044 DOI: 10.1039/c5mb00158g

Metabolomic studies on obesity and type 2 diabetes mellitus have led to a number of mechanistic insights into biomarker discovery and comprehension of disease progression at metabolic levels. This article reviews a series of metabolomic studies carried out in previous and recent years on obesity and type 2 diabetes, which have shown potential metabolic biomarkers for further evaluation of the diseases. Literature including journals and books from Web of Science, Pubmed and related databases reporting on the metabolomics in these particular disorders are reviewed. We herein discuss the potential of reported metabolic biomarkers for a novel understanding of disease processes. These biomarkers include fatty acids, TCA cycle intermediates, carbohydrates, amino acids, choline and bile acids. The biological activities and aetiological pathways of metabolites of interest in driving these intricate processes are explained. The data from various publications supported metabolomics as an effective strategy in the identification of novel biomarkers for obesity and type 2 diabetes. Accelerating interest in the perspective of metabolomics to complement other fields in systems biology towards the in-depth understanding of the molecular mechanisms underlying the diseases is also well appreciated. In conclusion, metabolomics can be used as one of the alternative approaches in biomarker discovery and the novel understanding of pathophysiological mechanisms in obesity and type 2 diabetes. It can be foreseen that there will be an increasing research interest to combine metabolomics with other omics platforms towards the establishment of detailed mechanistic evidence associated with the disease processes.

Matched MeSH terms: Amino Acids/metabolism
Nutritional quality of germinated cowpea flour (Vigna unguiculata) and its application in home prepared powdered weaning foods

Jirapa P, Normah H, Zamaliah MM, Asmah R, Mohamad K

Plant Foods Hum Nutr, 2001;56(3):203-16.
PMID: 11442221

Amino acid profiles, protein digestibility, corrected amino acid scores (PDCAAS), chemical scores, essential amino acid indexes, and calculated biological values of controlcowpea flour (CCF), germinated cowpea flour (GCF) prepared from cowpeas germinated at 25 degrees C for either 24 h or 48 h and weaning foods prepared from cowpea flours were determined. Locally available rice, cowpea flour, banana-pumpkin slurry, and skim milk powder and sucrose in the ratio 35:35:15:15:5 were used to formulate weaning food containing not less than 15% protein. The ingredients were cooked into a slurry and oven-dried to produce flakes. The nutritional and sensory qualities of the weaning products were evaluated. Germination had little effect on the amino acid profile of cowpeas. In vitro protein quality and starch digestibility were improved in germinated cowpea flour. The PDCAAS of 24 h germinated cowpea flour (GCF) weaning food was higher (55.49%) than CCF-weaning food (46.74%). Vitamin A activity in 24 h GCF weaning food was higher than in CCF-weaning food. In vitro starch digestibilities of 24 h GCF and 48 h GCF-weaning foods were higher than that of CCF weaning food. The 24 h GCF-weaning food which had a higher overall acceptability score by sensory panelist than 48 h GCF and CCF-weaning food is recommended for household consumption.

Matched MeSH terms: Amino Acids/analysis*
Fulltext Serum bone specific alkaline phosphatase and urinary deoxypyridinoline in postmenopausal osteoporosis

Nawawi HM, Yazid TN, Ismail NM, Mohamad AR, Nirwana SI, Khalid BA

Malays J Pathol, 2001 Dec;23(2):79-88.
PMID: 12166596

The objectives of this study were to: (i) evaluate the diagnostic sensitivity and specificity of the biochemical bone markers: serum total alkaline phosphatase (TALP), bone specific alkaline phosphatase (BSALP) and urinary deoxypyridinoline (Dpyr) in postmenopausal osteoporosis, (ii) compare the bone turnover of postmenopausal osteoporotic patients without and with hormone replacement therapy (HRT) against controls and (iii) identify the correlation between these bone markers and bone mineral density (BMD). We examined 42 postmenopausal women with BMD proven osteoporosis and 35 control subjects. Serum TALP, BSALP and urinary Dpyr were measured. All three biochemical bone markers showed comparable moderate diagnostic sensitivity but Dpyr had the highest diagnostic specificity. There were significantly higher serum TALP, BSALP and urinary Dpyr levels in non-HRT treated patients compared to controls (p<0.005, <0.0001 and <0.005 respectively). There were no significant differences in the levels of all three bone markers between HRT treated patients and control subjects. There was no significant correlation between TALP, BSALP or Dpyr and BMD in both controls and patients. In conclusion, the biochemical bone markers are not useful in diagnosis of postmenopausal osteoporosis but may have a role in monitoring progress and response to treatment. HRT treatment reduces bone turnover of postmenopausal osteoporosis.

Matched MeSH terms: Amino Acids/urine*
Purification and properties of the L-amino acid oxidase from monocellate cobra (Naja naja kaouthia) venom

Tan NH, Swaminathan S

Int. J. Biochem., 1992 Jun;24(6):967-73.
PMID: 1612186

1. The L-amino acid oxidase of the monocellate cobra (Naja naja kaouthia) venom was purified to electrophoretic homogeneity. The molecular weight of the enzyme was 112,200 as determined by Sephadex G-200 gel filtration chromatography, and 57,400 as determined by SDS-polyacrylamide gel electrophoresis. 2. The enzyme had an isoelectric point of 8.12 and a pH optimum of 8.5. It showed remarkable thermal stability, and, unlike many venom L-amino acid oxidase, was also stable in alkaline medium. The enzyme was partially inactivated by freezing. 3. The enzyme was very active against L-phenylalanine and L-tyrosine, moderately active against L-tryptophan, L-methionine, L-leucine, L-norleucine, L-arginine and L-norvaline. Other L-amino acids were oxidized slowly or not oxidized. 4. Kinetic studies suggest the presence of a side-chain binding site in the enzyme, and that the binding site comprises of at least four hydrophobic subsites.

Matched MeSH terms: Amino Acids/metabolism
Isolation and characterization of an acidic lethal phospholipase Az from Malayan cobra (Naja naja sputatrix) venom

Tan NH, Arunmozhiarasi A

Biochem. Int., 1989 Apr;18(4):785-92.
PMID: 2764979

An acidic, lethal phospholipase Az was purified to electrophoretic homogeneity from the venom of the Malayan cobra (Naja naja sputatrix). The enzyme has an isoelectric point of 5.58, a molecular weight of 12000, and a medium lethal dose (LD50) of 0.86 micrograms/g in mice by intravenous injection. The enzyme also exhibited weak anticoagulant and edema-forming activities. The amino acid composition of the enzyme is similar to those of other cobra venom phospholipases Az.

Matched MeSH terms: Amino Acids/analysis
Nutritional evaluation on Lignosus cameronensis C. S. Tan, a medicinal Polyporaceae

Fung SY, Cheong PCH, Tan NH, Ng ST, Tan CS

IUBMB Life, 2019 07;71(7):821-826.
PMID: 30629799 DOI: 10.1002/iub.2006

Sclerotial powder of a cultivated species of the Tiger Milk Mushroom, Lignosus cameronensis was analysed for its nutritional components and compared against species of the same genus, Lignosus rhinocerus and Lignosus tigris. All three species have been used by indigenous tribes in Peninsular Malaysia as medicinal mushrooms. Content of carbohydrate, fibre, mineral, amino acid, palatable index, fat, ash and moisture were determined. L. cameronensis sclerotial material consists of carbohydrate (79.7%), protein (12.4%) and dietary fibre (5.4%) with low fat (1.7%) and no free sugar. It has the highest content of total carbohydrate (791 g kg-1 ), energy value (3,700 kcal kg-1 ) and calcium (0.85 g kg-1 ). The crude protein content (123 g kg-1 ) is comparable to that of L. rhinocerus with its main amino acids consisting of glutamic acid, aspartic acid and leucine. The umami index is determined to be 0.27. The total essential amino acid (45 g kg-1 ) is comparable to that of L. tigris. The main mineral is potassium (1.51 g kg-1 ) and the Na/K ratio was <0.6. Heavy metals such as mercury, cadmium, lead and arsenic were absent. L. cameronensis has the highest amount of food energy, total carbohydrate and calcium compared to those of both L. rhinocerus and L. tigris. The essential amino acids comprised almost 40% of the total amino acid content, slightly more than that reported from sclerotial powder of the L. tigris. © 2019 IUBMB Life, 9999(9999):1-6, 2019.

Matched MeSH terms: Amino Acids/analysis*
Circulating branched-chain amino acids and incident heart failure in type 2 diabetes: The Hong Kong Diabetes Register

Lim LL, Lau ESH, Fung E, Lee HM, Ma RCW, Tam CHT, et al.

Diabetes Metab Res Rev, 2020 03;36(3):e3253.
PMID: 31957226 DOI: 10.1002/dmrr.3253

AIM: Levels of branched-chain amino acids (BCAAs, namely, isoleucine, leucine, and valine) are modulated by dietary intake and metabolic/genetic factors. BCAAs are associated with insulin resistance and increased risk of type 2 diabetes (T2D). Although insulin resistance predicts heart failure (HF), the relationship between BCAAs and HF in T2D remains unknown.
METHODS: In this prospective observational study, we measured BCAAs in fasting serum samples collected at inception from 2139 T2D patients free of cardiovascular-renal diseases. The study outcome was the first hospitalization for HF.
RESULTS: During 29 103 person-years of follow-up, 115 primary events occurred (age: 54.8 ± 11.2 years, 48.2% men, median [interquartile range] diabetes duration: 5 years [1-10]). Patients with incident HF had 5.6% higher serum BCAAs than those without HF (median 639.3 [561.3-756.3] vs 605.2 [524.8-708.7] μmol/L; P = .01). Serum BCAAs had a positive linear association with incident HF (per-SD increase in logarithmically transformed BCAAs: hazard ratio [HR] 1.22 [95% CI 1.07-1.39]), adjusting for age, sex, and diabetes duration. The HR remained significant after sequential adjustment of risk factors including incident coronary heart disease (1.24, 1.09-1.41); blood pressure, low-density lipoprotein cholesterol, and baseline use of related medications (1.31, 1.14-1.50); HbA1c , waist circumference, triglyceride, and baseline use of related medications (1.28, 1.11-1.48); albuminuria and estimated glomerular filtration rate (1.28, 1.11-1.48). The competing risk of death analyses showed similar results.
CONCLUSIONS: Circulating levels of BCAAs are independently associated with incident HF in patients with T2D. Prospective cohort analysis and randomized trials are needed to evaluate the long-term safety and efficacy of using different interventions to optimize BCAAs levels in these patients.

Matched MeSH terms: Amino Acids, Branched-Chain/blood*
Fulltext Complementary Analytical Platforms of NMR Spectroscopy and LCMS Analysis in the Metabolite Profiling of Isochrysis galbana

Bustamam MSA, Pantami HA, Azizan A, Shaari K, Min CC, Abas F, et al.

Mar Drugs, 2021 Mar 02;19(3).
PMID: 33801258 DOI: 10.3390/md19030139

This study was designed to profile the metabolites of Isochrysis galbana, an indigenous and less explored microalgae species. 1H Nuclear Magnetic Resonance (NMR) spectroscopy and Liquid Chromatography-Mass Spectrometry (LCMS) were used to establish the metabolite profiles of five different extracts of this microalga, which are hexane (Hex), ethyl acetate (EtOAc), absolute ethanol (EtOH), EtOH:water 1:1 (AqE), and 100% water (Aq). Partial least square discriminant analysis (PLS-DA) of the generated profiles revealed that EtOAc and Aq extracts contain a diverse range of metabolites as compared to the other extracts with a total of twenty-one metabolites, comprising carotenoids, polyunsaturated fatty acids, and amino acids, that were putatively identified from the NMR spectra. Meanwhile, thirty-two metabolites were successfully annotated from the LCMS/MS data, ten of which (palmitic acid, oleic acid, α-linolenic acid, arachidic acid, cholesterol, DHA, DPA, fucoxanthin, astaxanthin, and pheophytin) were similar to those present in the NMR profile. Another eleven glycerophospholipids were discovered using MS/MS-based molecular network (MN) platform. The results of this study, besides providing a better understanding of I.galbana's chemical make-up, will be of importance in exploring this species potential as a feed ingredient in the aquaculture industry.

Matched MeSH terms: Amino Acids/isolation & purification
Genome Mining Reveals the Biosynthetic Pathways of Polyhydroxyalkanoate and Ectoines of the Halophilic Strain Salinivibrio proteolyticus M318 Isolated from Fermented Shrimp Paste

Van Thuoc D, Loan TT, Trung TA, Van Quyen N, Tung QN, Tien PQ, et al.

Mar Biotechnol (NY), 2020 Oct;22(5):651-660.
PMID: 32827070 DOI: 10.1007/s10126-020-09986-z

Salinivibrio proteolyticus M318, a halophilic bacterium isolated from fermented shrimp paste, is able to produce polyhydroxyalkanoate (PHA) from different carbon sources. In this study, we report the whole-genome sequence of strain M138, which comprises 2 separated chromosomes and 2 plasmids, and the complete genome contains 3,605,935 bp with an average GC content of 49.9%. The genome of strain M318 contains 3341 genes, 98 tRNA genes, and 28 rRNA genes. The 16S rRNA gene sequence and average nucleotide identity analysis associated with morphological and biochemical tests showed that this strain has high homology to the reference strain Salinivibrio proteolyticus DSM 8285. The genes encoding key enzymes for PHA and ectoine synthesis were identified from the bacterial genome. In addition, the TeaABC transporter responsible for ectoine uptake from the environment and the operon doeABXCD responsible for the degradation of ectoine were also detected. Strain M318 was able to produce poly(3-hydroxybutyrate) [P(3HB)] from different carbon sources such as glycerol, maltose, glucose, fructose, and starch. The ability to produce ectoines at different NaCl concentrations was investigated. High ectoine content of 26.2% of cell dry weight was obtained by this strain at 18% NaCl. This report provides genetic information regarding adaptive mechanisms of strain M318 to stress conditions, as well as new knowledge to facilitate the application of this strain as a bacterial cell factory for the production of PHA and ectoine.

Matched MeSH terms: Amino Acids, Diamino/biosynthesis*
Fulltext Amino acid compounds released by the giant freshwater prawn Macrobrachium rosenbergii during ecdysis: a factor attracting cannibalistic behaviour?

Juneta-Nor AS, Noordin NM, Azra MN, Ma HY, Husin NM, Ikhwanuddin M

J Zhejiang Univ Sci B, 2020 10 13;21(10):823-834.
PMID: 33043647 DOI: 10.1631/jzus.B2000126

Ecdysis is a common phenomenon that happens throughout the life phase of the giant freshwater prawn Macrobrachium rosenbergii. It is vital to better understand the correlation between cannibalism and biochemical compound that exists during the moulting process. The objective of the present study was to determine the amino acid profile released by M. rosenbergii during the ecdysis process that promotes cannibalism. To accomplish this, changes in amino acid levels (total amino acid (TAA) and free amino acid (FAA)) of tissue muscle, exoskeleton, and sample water of culture medium from the moulting (E-stage) and non-moulting (C-stage) prawns were analysed using high-performance liquid chromatography (HPLC). Comparison study revealed that among the TAA compounds, proline and sarcosine of tissues from moulting prawn were found at the highest levels. The level of FAA from water that contains moulting prawns (E-stage) was dominated by tryptophan and proline. Significant values obtained in the present study suggested that these amino acid compounds act as a chemical cue to promote cannibalism in M. rosenbergii during ecdysis. The knowledge of compositions and compounds that were released during the moulting process should be helpful for better understanding of the mechanism and chemical cues that play roles on triggering cannibalism, and also for future dietary manipulation to improve feeding efficiencies and feeding management, which indirectly impacts productivity and profitability.

Matched MeSH terms: Amino Acids/chemistry*
Fulltext Urinary amino acids profile of vegetarians and non-vegetarians

Chia, Yoke Yin, Ton, So Ha

Malays J Nutr, 2006;12(1):67-78.
MyJurnal

The objective of the study was to quantify and to profile the amino acids content in urine samples. The amino acids content in urine was determined in 162 individuals (62 young non-vegetarians aged 15-45 years, 24 elderly non-vegetarians aged 46-70 years, 40 young vegetarians and 36 elderly vegetarians) by high performance liquid chromatography (HPLC). The most common amino acids detected in the young and elderly individuals on vegetarian and non-vegetarian diets were phenylalanine, threonine, arginine and asparagine, while leucine, aspartic acid and alanine were not found in any urine samples in both groups. Isoleucine was not detected in the urine of vegetarians. The concentrations of the majority of essential amino acids were between 0.10 - 2.00 mgl24hrs except for histidine which had a range of 4.1 - 5.0 mgl24hrs. The concentrations of non-essential amino acids varied. Proline, glycine and tyrosine concentrations were between 0.10 - 1.00 mg/24hrs, while cysteine, glutamine, glutamic acid and cystine concentrations were between 11.0 - 21.0 mg124hrs. Asparagine and hydroxy-proline had a range of 0.10 - 5.00 mg/24hrs, while serine and arginine ranged between 31.0 - 50.0 mg124hrs. Isoleucine and serine were not detected in elderly vegetarians while histidine, glycine, glutamic acid and hydroxy-proline were not detected in elderly non-vegetarians. Isoleucine, glycine and hydroxy proline were detected in young non-vegetarians but not in young vegetarians. The levels of amino acids showed no significant statistical differences between young vegetarians and non-vegetarians as well as between elderly vegetarians and non-vegetarians. Phenylalanine, threonine and trypthophan were commonly detected in the lacto-ovo and lacto vegetarians, while valine, cysteine, arginine and asparagine were commonly detected in vegans. In conclusion, except for isoleucine, general differences were seen in urinary amino acid excretions between vegetarians and non-vegetarians even though the differences were statistically not significant. Therefore lacto-ovo diets could be nutritionally adequate as the nutrients were substituted by dairy or plant products.

Matched MeSH terms: Amino Acids; Amino Acids, Essential
Fulltext Screening method for detection of immediate amino acid decarboxylases--producing bacteria implicated in food poisoning

Hussain H, Mohd Fuat AR, Vimala B, Ghazali HM

Trop Biomed, 2011 Aug;28(2):351-61.
PMID: 22041756

Assessment of amino acid decarboxylase activity can be conducted using tubed broth or plated agar. In this study, the test was carried out in microtitre plates containing lysine, ornithine, arginine, tyrosine, tryptophan, phenylalanine or histidine as biogenic amine precursors. Møller decarboxylase base broth (MDB) with or without 1% of a known amino acid were added to wells of a 96 well-microtitre plate. The wells were inoculated with Escherichia coli, Klebsiella pneumoniae, Acinetobacter anitratus or Staphylococcus aureus to the final concentration of 6.0 x 10(7) cfu/ml and incubated at 35ºC. The absorbance of the culture broth was read at 570 nm at 0, 1.0, 2.0, 3.0, 4.0, 5.5, 6.5 and 7.5 hour. Comparison of means of A'(570) between 0 hour and a specified incubation time was determined statistically. Positive decarboxylase activities were detected in the media inoculated with E. coli and K. pneumoniae in less than 6 hours. The current method is suitable for immediate producers of amino acid decarboxylase enzymes. It costs less as it uses less amino acid and it has the potential to be used for screening aliquots of food materials for amino acid decarboxylase activities.

Matched MeSH terms: Amino Acids/metabolism*
Chemical composition and physicochemical properties of tropical red seaweed, Gracilaria changii

Chan PT, Matanjun P

Food Chem, 2017 Apr 15;221:302-310.
PMID: 27979207 DOI: 10.1016/j.foodchem.2016.10.066

A study on the proximate composition, minerals, vitamins, carotenoids, amino acids, fatty acids profiles and some physicochemical properties of freeze dried Gracilaria changii was conducted. It was discovered that this seaweed was high in dietary fibre (64.74±0.82%), low in fat (0.30±0.02%) and Na/K ratio (0.12±0.02). The total amino acid content was 91.90±7.70% mainly essential amino acids (55.87±2.15mgg(-1)) which were comparable to FAO/WHO requirements. The fatty acid profiles were dominated by the polyunsaturated fatty acids particularly docosahexaenoic (48.36±6.76%) which led to low ω6/ω3, atherogenic, and thrombogenic index. The physicochemical properties of this seaweed namely the water holding and the swelling capacity were comparable to some commercial fibre rich products. This study suggested that G. changii could be potentially used as ingredients to improve nutritive value and texture of functional foods for human consumption.

Matched MeSH terms: Amino Acids/analysis*
Fulltext Metabolite Profiling of the Microalgal Diatom Chaetoceros Calcitrans and Correlation with Antioxidant and Nitric Oxide Inhibitory Activities via ¹H NMR-Based Metabolomics

Azizan A, Ahamad Bustamam MS, Maulidiani M, Shaari K, Ismail IS, Nagao N, et al.

Mar Drugs, 2018 May 07;16(5).
PMID: 29735927 DOI: 10.3390/md16050154

Microalgae are promising candidate resources from marine ecology for health-improving effects. Metabolite profiling of the microalgal diatom, Chaetoceros calcitrans was conducted by using robust metabolomics tools, namely ¹H nuclear magnetic resonance (NMR) spectroscopy coupled with multivariate data analysis (MVDA). The unsupervised data analysis, using principal component analysis (PCA), resolved the five types of extracts made by solvents ranging from polar to non-polar into five different clusters. Collectively, with various extraction solvents, 11 amino acids, cholesterol, 6 fatty acids, 2 sugars, 1 osmolyte, 6 carotenoids and 2 chlorophyll pigments were identified. The fatty acids and both carotenoid pigments as well as chlorophyll, were observed in the extracts made from medium polar (acetone, chloroform) and non-polar (hexane) solvents. It is suggested that the compounds were the characteristic markers that influenced the separation between the clusters. Based on partial least square (PLS) analysis, fucoxanthin, astaxanthin, violaxanthin, zeaxanthin, canthaxanthin, and lutein displayed strong correlation to 2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging and nitric oxide (NO) inhibitory activity. This metabolomics study showed that solvent extractions are one of the main bottlenecks for the maximum recovery of bioactive microalgal compounds and could be a better source of natural antioxidants due to a high value of metabolites.

Matched MeSH terms: Amino Acids/metabolism
Fulltext Metabolomics approach for multibiomarkers determination to investigate dengue virus infection in human patients

Shahfiza N, Osman H, Hock TT, Abdel-Hamid AZ

Acta Biochim. Pol., 2017;64(2):215-219.
PMID: 28350402 DOI: 10.18388/abp.2015_1224

BACKGROUND: Dengue is one of the major public health problems in the world, affecting more than fifty million cases in tropical and subtropical region every year. The metabolome, as pathophysiological end-points, provide significant understanding of the mechanism and progression of dengue pathogenesis via changes in the metabolite profile of infected patients. Recent developments in diagnostic technologies provide metabolomics for the early detection of infectious diseases.
METHODS: The mid-stream urine was collected from 96 patients diagnosed with dengue fever at Penang General Hospital (PGH) and 50 healthy volunteers. Urine samples were analyzed with proton nuclear magnetic resonance (1H NMR) spectroscopy, followed by chemometric multivariate analysis. NMR signals highlighted in the orthogonal partial least square-discriminant analysis (OPLS-DA) S-plots were selected and identified using Human Metabolome Database (HMDB) and Chenomx Profiler. A highly predictive model was constructed from urine profile of dengue infected patients versus healthy individuals with the total R2Y (cum) value 0.935, and the total Q2Y (cum) value 0.832.
RESULTS: Data showed that dengue infection is related to amino acid metabolism, tricarboxylic acid intermediates cycle and β-oxidation of fatty acids. Distinct variations in certain metabolites were recorded in infected patients including amino acids, various organic acids, betaine, valerylglycine, myo-inositol and glycine.
CONCLUSION: Metabolomics approach provides essential insight into host metabolic disturbances following dengue infection.

Matched MeSH terms: Amino Acids/metabolism
Influence of amino acids and vitamins on the growth of gdhA derivative Pasteurella multocida B:2 for use as an animal vaccine

Oslan SNH, Tan JS, Saad MZ, Halim M, Mohamed MS, Ariff AB

Bioprocess Biosyst Eng, 2019 Mar;42(3):355-365.
PMID: 30483888 DOI: 10.1007/s00449-018-2040-y

Pasteurella multocida serotype B:2 is the causative agent of haemorrhagic septicaemia, a fatal disease in cattle and buffaloes. For use as a vaccine in the treatment of HS disease, an efficient cultivation of attenuated gdhA derivative P. multocida B:2 (mutant) for mass production of viable cells is required. In this study, the role of amino acids and vitamins on the growth of this particular bacterium was investigated. Initially, three basal media (Brain-heart infusion, Terrific broth, and defined medium YDB) were assessed in terms of growth performance of P. multocida B:2. YDB medium was selected and redesigned to take into account the effects of amino acids (glutamic acid, cysteine, glycine, methionine, lysine, tyrosine, and histidine) and vitamins (vitamin B1, nicotinic acid, riboflavin, pyridoxine, pantothenic acid, and biotin). High viable cell number was largely affected by the availability of micronutrient components and macronutrients. Histidine was essential for the growth whereby a traceable amount (20 mM) was found to greatly enhance the growth of gdhA derivative P. multocida B:2 mutant (6.6 × 109 cfu/mL) by about 19 times as compared to control culture (3.5 × 108 cfu/mL). In addition, amongst the vitamins added, riboflavin exhibited the highest impact on the viability of gdhA derivative P. multocida B:2 mutant (5.3 × 109 cfu/mL). Though the combined histidine and riboflavin in the culture eventually did not promote the stacking impact on cell growth and cell viability, nonetheless, they were still essential and important in either growth medium or production medium.

Matched MeSH terms: Amino Acids/pharmacology*

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