Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 11 de 11
Filter
Add more filters










Publication year range
1.
J Food Sci ; 81(2): C341-7, 2016 Feb.
Article in English | MEDLINE | ID: mdl-26720491

ABSTRACT

Palm kernel cake protein was hydrolyzed with different proteases namely papain, bromelain, subtilisin, flavourzyme, trypsin, chymotrypsin, and pepsin to generate different protein hydrolysates. Peptide content and iron-chelating activity of each hydrolysate were evaluated using O-phthaldialdehyde-based spectrophotometric method and ferrozine-based colorimetric assay, respectively. The results revealed a positive correlation between peptide contents and iron-chelating activities of the protein hydrolysates. Protein hydrolysate generated by papain exhibited the highest peptide content of 10.5 mM and highest iron-chelating activity of 64.8% compared with the other hydrolysates. Profiling of the papain-generated hydrolysate by reverse phase high performance liquid chromatography fractionation indicated a direct association between peptide content and iron-chelating activity in most of the fractions. Further fractionation using isoelectric focusing also revealed that protein hydrolysate with basic and neutral isoelectric point (pI) had the highest iron-chelating activity, although a few fractions in the acidic range also exhibited good metal chelating potential. After identification and synthesis of papain-generated peptides, GGIF and YLLLK showed among the highest iron-chelating activities of 56% and 53%, whereas their IC50 were 1.4 and 0.2 µM, respectively.


Subject(s)
Arecaceae/chemistry , Iron Chelating Agents/pharmacology , Iron/metabolism , Papain/metabolism , Peptides/pharmacology , Plant Proteins/chemistry , Protein Hydrolysates/pharmacology , Chemical Fractionation , Chromatography, High Pressure Liquid , Endopeptidases/metabolism , Humans , Hydrolysis , Iron Chelating Agents/chemistry , Isoelectric Point , Pepsin A/metabolism , Peptide Hydrolases/metabolism , Peptides/analysis , Protein Hydrolysates/chemistry , Spectrophotometry , Subtilisins/metabolism , Trypsin/metabolism , o-Phthalaldehyde
2.
Ann Clin Microbiol Antimicrob ; 14: 49, 2015 Nov 11.
Article in English | MEDLINE | ID: mdl-26558683

ABSTRACT

BACKGROUND: This study assessed novel approach of using highly lytic phages against methicillin-susceptible Staphylococcus aureus (MSSA) and methicillin-resistant Staphylococcus aureus (MRSA) biofilms with and without biofilm extracellular matrix- disrupting chemical. METHOD: The resultant phage-based control was assessed in relation to the type of biofilm extracellular matrix namely, polysaccharide intercellular adhesion (PIA) or proteinacious fibronectin-binding protein A (FnBPA). The biofilms were formed in vitro by 24 h incubation of bacteria in 96 wells microtiter plates at room temperature. The formed biofilms were assessed by tissue culture plate (TCP). Moreover, the nature of the biofilm was assessed by scanning electron microscopy (SEM) and PCR assay for detecting PIA genes, ciaA-D and FnBPA genes. RESULTS: this study showed that applied phages with 0.08 % benezenthonium chloride, for PIA biofilms, and 0.06 % ethanol, for proteinacious FnBPA biofilms, exerted 100 % eradication for MSSA biofilms and about 78 % of MRSA biofilms. The phage-based control of biofilms with chemical adjuvant showed significantly higher efficiency than that without adjuvant (P < 0.05). Moreover, FnBPA biofilms were more common in MRSA than in MSSA while PIA biofilms were more common in MSSA than in MRSA. And the most resistant type of biofilms to phage-based control was FnBPA in MRSA where 50 % of biofilms were reduced but not eradicated completely. CONCLUSIONS: It is concluded that PIA-disturbing agent and protein denaturing alcohol can increase the efficiency of attacking phages in accessing host cell walls and lysing them which in turn lead to much more efficient MRSA and MSSA biofilm treatment and prevention.


Subject(s)
Adhesins, Bacterial/metabolism , Biofilms/growth & development , Methicillin-Resistant Staphylococcus aureus/physiology , Methicillin-Resistant Staphylococcus aureus/virology , Microbial Viability , Staphylococcus Phages/growth & development , Methicillin-Resistant Staphylococcus aureus/metabolism , Microscopy, Electron, Scanning
3.
Molecules ; 20(4): 6654-69, 2015 Apr 15.
Article in English | MEDLINE | ID: mdl-25884548

ABSTRACT

Dominant strains of lactic acid bacteria (LAB) isolated from honey bees were evaluated for their γ-aminobutyric acid (GABA)-producing ability. Out of 24 strains, strain Taj-Apis362 showed the highest GABA-producing ability (1.76 mM) in MRS broth containing 50 mM initial glutamic acid cultured for 60 h. Effects of fermentation parameters, including initial glutamic acid level, culture temperature, initial pH and incubation time on GABA production were investigated via a single parameter optimization strategy. The optimal fermentation condition for GABA production was modeled using response surface methodology (RSM). The results showed that the culture temperature was the most significant factor for GABA production. The optimum conditions for maximum GABA production by Lactobacillus plantarum Taj-Apis362 were an initial glutamic acid concentration of 497.97 mM, culture temperature of 36 °C, initial pH of 5.31 and incubation time of 60 h, which produced 7.15 mM of GABA. The value is comparable with the predicted value of 7.21 mM.


Subject(s)
Bees/microbiology , Lactobacillus plantarum/metabolism , gamma-Aminobutyric Acid/biosynthesis , Analysis of Variance , Animals , Fermentation , Glutamic Acid/metabolism , Hydrogen-Ion Concentration , Lactobacillus plantarum/growth & development , Lactobacillus plantarum/isolation & purification , Models, Theoretical , Temperature , gamma-Aminobutyric Acid/chemistry
4.
J Dairy Res ; 80(4): 490-5, 2013 Nov.
Article in English | MEDLINE | ID: mdl-24063299

ABSTRACT

The dairy industry uses lipase extensively for hydrolysis of milk fat. Lipase is used in the modification of the fatty acid chain length, to enhance the flavours of various chesses. Therefore finding the unlimited source of lipase is a concern of dairy industry. Due to the importance of lipase, this study was an attempt to express the lipase from Burkholderia cepacia in Lactococcus lactis. To achieve this, a gene associated with lipase transport was amplified and subcloned in inducible pNZ8148 vector, and subsequently transformed into Lc. lactis NZ9000. The enzyme assay as well as SDS-PAGE and western blotting were carried out to analysis the recombinant lipase expression. Nucleotide sequencing of the DNA insert from the clone revealed that the lipase activity corresponded to an open reading frame consisting of 1092 bp coding for a 37·5-kDa size protein. Blue colour colonies on nile blue sulphate agar and sharp band on 37·5-kD size on SDS-PAGE and western blotting results confirm the successful expression of lipase by Lc. lactis. The protein assay also showed high expression, approximately 152·2 µg/ml.h, of lipase by recombinant Lc. lactis. The results indicate that Lc. lactis has high potential to overproduce the recombinant lipase which can be used commercially for industrially purposes.


Subject(s)
Gene Expression Regulation, Bacterial/physiology , Gene Expression Regulation, Enzymologic/physiology , Lactococcus lactis/enzymology , Lipase/metabolism , Animals , Bacteriological Techniques , Cloning, Molecular , Genetic Engineering , Lactococcus lactis/genetics , Lactococcus lactis/metabolism , Lipase/genetics
5.
BMC Complement Altern Med ; 12: 208, 2012 Nov 05.
Article in English | MEDLINE | ID: mdl-23122182

ABSTRACT

BACKGROUND: The anticancer and immunomodulatory activity of mung bean sprouts (MBS) and the underlying mechanisms against human cervical and hepatocarcinoma cancer cells were explored. METHODS: MBS cytotoxicity and MBS-induced anticancer cytokines, TNF-α and IFN-ß from cancer cells, and immunological cytokines, IL-4, IFN-γ, and IL-10 from peripheral mononuclear cells (PMNC) were assessed by MTS and ELISA assays. Apoptotic cells were investigated by flow cytometry. The expression level of apoptotic genes (Bax, BCL-2, Capsases 7-9) and cell cycle regulatory genes (cyclin D, E, and A) and tumor suppressor proteins (p27, p21, and p53) was assessed by real-time qPCR in the cancer cells treated with extract IC50. RESULTS: The cytotoxicity on normal human cells was significantly different from HeLa and HepG2 cells, 163.97 ± 5.73, 13.3 ± 0.89, and 14.04 ± 1.5 mg/ml, respectively. The selectivity index (SI) was 12.44 ± 0.83 for HeLa and 11.94 ± 1.2 for HepG2 cells. Increased levels of TNF-α and IFN-ß were observed in the treated HeLa and HepG2 culture supernatants when compared with untreated cells. MBS extract was shown to be an immunopolarizing agent by inducing IFNγ and inhibiting IL-4 production by PBMC; this leads to triggering of CMI and cellular cytotoxicity. The extract induced apoptosis, in a dose and time dependent manner, in treated HeLa and HepG2, but not in untreated, cells (P < 0.05). The treatment significantly induced cell cycle arrest in G0/G1 in HeLa cells. The percentage of cells in G0/G1 phase of the treated HeLa cells increased from 62.87 ± 2.1%, in untreated cells, to 80.48 ± 2.97%. Interestingly, MBS IC50 induced the expression of apoptosis and tumor suppressor related genes in both HeLa and HepG2 cells. MBS extract succeeded in inducing cdk-inhibitors, p21, p53, and p27 in HeLa cells while it induced only p53 in HepG2 cells (P < 0.05). This is a clue for the cell type- specific interaction of the studied extract. These proteins inhibit the cyclin-cdk complexes apart from the presence of some other components that might stimulate some cyclins such as cyclin E, A, and D. CONCLUSION: MBS extract was shown to be a potent anticancer agent granting new prospects of anticancer therapy using natural products.


Subject(s)
Antineoplastic Agents, Phytogenic/therapeutic use , Fabaceae , Immunologic Factors/therapeutic use , Liver Neoplasms/drug therapy , Phytotherapy , Plant Extracts/therapeutic use , Uterine Cervical Neoplasms/drug therapy , Antineoplastic Agents, Phytogenic/pharmacology , Apoptosis/drug effects , Apoptosis/genetics , Cell Cycle Checkpoints/drug effects , Cell Cycle Checkpoints/genetics , Cyclin-Dependent Kinase Inhibitor Proteins/genetics , Cyclin-Dependent Kinase Inhibitor Proteins/metabolism , Cyclin-Dependent Kinases/antagonists & inhibitors , Cyclins/antagonists & inhibitors , Cytokines/metabolism , Dose-Response Relationship, Drug , Female , Gene Expression/drug effects , HeLa Cells , Hep G2 Cells , Humans , Immunity, Cellular/drug effects , Immunologic Factors/pharmacology , Inhibitory Concentration 50 , Leukocytes, Mononuclear , Liver Neoplasms/genetics , Liver Neoplasms/metabolism , Plant Extracts/pharmacology , Seeds , Tumor Suppressor Proteins/genetics , Tumor Suppressor Proteins/metabolism , Uterine Cervical Neoplasms/genetics , Uterine Cervical Neoplasms/metabolism
6.
Int J Mol Sci ; 13(5): 5482-5497, 2012.
Article in English | MEDLINE | ID: mdl-22754309

ABSTRACT

l-glutamaic acid is the principal excitatory neurotransmitter in the brain and an important intermediate in metabolism. In the present study, lactic acid bacteria (218) were isolated from six different fermented foods as potent sources of glutamic acid producers. The presumptive bacteria were tested for their ability to synthesize glutamic acid. Out of the 35 strains showing this capability, strain MNZ was determined as the highest glutamic-acid producer. Identification tests including 16S rRNA gene sequencing and sugar assimilation ability identified the strain MNZ as Lactobacillus plantarum. The characteristics of this microorganism related to its glutamic acid-producing ability, growth rate, glucose consumption and pH profile were studied. Results revealed that glutamic acid was formed inside the cell and excreted into the extracellular medium. Glutamic acid production was found to be growth-associated and glucose significantly enhanced glutamic acid production (1.032 mmol/L) compared to other carbon sources. A concentration of 0.7% ammonium nitrate as a nitrogen source effectively enhanced glutamic acid production. To the best of our knowledge this is the first report of glutamic acid production by lactic acid bacteria. The results of this study can be further applied for developing functional foods enriched in glutamic acid and subsequently γ-amino butyric acid (GABA) as a bioactive compound.


Subject(s)
Food Microbiology , Glutamic Acid/metabolism , Lactic Acid/metabolism , Lactobacillus plantarum/metabolism , Fermentation , Glutamic Acid/isolation & purification , Lactic Acid/isolation & purification , Lactobacillus plantarum/genetics , Lactobacillus plantarum/growth & development , Malaysia , RNA, Ribosomal, 16S/genetics
7.
Sensors (Basel) ; 11(8): 7302-13, 2011.
Article in English | MEDLINE | ID: mdl-22164018

ABSTRACT

Fabrication of a test strip for detection of benzoic acid was successfully implemented by immobilizing tyrosinase, phenol and 3-methyl-2-benzothiazolinone hydrazone (MBTH) onto filter paper using polystyrene as polymeric support. The sensing scheme was based on the decreasing intensity of the maroon colour of the test strip when introduced into benzoic acid solution. The test strip was characterized using optical fiber reflectance and has maximum reflectance at 375 nm. It has shown a highly reproducible measurement of benzoic acid with a calculated RSD of 0.47% (n = 10). The detection was optimized at pH 7. A linear response of the biosensor was obtained in 100 to 700 ppm of benzoic acid with a detection limit (LOD) of 73.6 ppm. At 1:1 ratio of benzoic acid to interfering substances, the main interfering substance is boric acid. The kinetic analyses show that, the inhibition of benzoic is competitive inhibitor and the inhibition constant (K(i)) is 52.9 ppm. The activity of immobilized tyrosinase, phenol, and MBTH in the test strip was fairly sustained during 20 days when stored at 3 °C. The developed test strip was used for detection of benzoic acid in food samples and was observed to have comparable results to the HPLC method, hence the developed test strip can be used as an alternative to HPLC in detecting benzoic acid in food products.


Subject(s)
Benzoic Acid/analysis , Biosensing Techniques/methods , Food Contamination/analysis , Algorithms , Catechol Oxidase/chemistry , Equipment Design , Hydrogen-Ion Concentration , Kinetics , Monophenol Monooxygenase/chemistry , Optics and Photonics , Polystyrenes/chemistry , Reproducibility of Results , Spectrophotometry/methods
8.
N Biotechnol ; 28(6): 738-45, 2011 Oct.
Article in English | MEDLINE | ID: mdl-21238617

ABSTRACT

Thermostable lipase produced by a genotypically identified extremophilic Bacillus subtilis NS 8 was purified 500-fold to homogeneity with a recovery of 16% by ultrafiltration, DEAE-Toyopearl 650M and Sephadex G-75 column. The purified enzyme showed a prominent single band with a molecular weight of 45 kDa. The optimum pH and temperature for activity of lipase were 7.0 and 60°C, respectively. The enzyme was stable in the pH range between 7.0 and 9.0 and temperature range between 40 and 70°C. It showed high stability with half-lives of 273.38 min at 60°C, 51.04 min at 70°C and 41.58 min at 80°C. The D-values at 60, 70 and 80°C were 788.70, 169.59 and 138.15 min, respectively. The enzyme's enthalpy, entropy and Gibb's free energy were in the range of 70.07-70.40 kJ mol(-1), -83.58 to -77.32 kJ mol(-1)K(-1) and 95.60-98.96 kJ mol(-1), respectively. Lipase activity was slightly enhanced when treated with Mg(2+) but there was no significant enhancement or inhibition of the activity with Ca(2+). However, other metal ions markedly inhibited its activity. Of all the natural vegetable oils tested, it had slightly higher hydrolytic activity on soybean oil compared to other oils. On TLC plate, the enzyme showed non-regioselective activity for triolein hydrolysis.


Subject(s)
Bacillus subtilis/enzymology , Bacterial Proteins/chemistry , Bacterial Proteins/isolation & purification , Lipase/chemistry , Lipase/isolation & purification , Soybean Oil/chemistry , Triolein/chemistry , Bacillus subtilis/growth & development , Bacterial Proteins/biosynthesis , Entropy , Enzyme Stability , Hot Temperature , Hydrogen-Ion Concentration , Hydrolysis , Kinetics , Lipase/biosynthesis , Substrate Specificity
9.
Mol Cancer ; 9: 249, 2010 Sep 17.
Article in English | MEDLINE | ID: mdl-20846456

ABSTRACT

BACKGROUND: Colorectal cancer (CRC) has long been associated with bacteremia and/or endocarditis by Streptococcus gallolyticus member bacteria (SGMB) but the direct colonization of SGMB along with its molecular carcinogenic role, if any, has not been investigated. We assessed the colonization of SGMB in CRC patients with history of bacteremia (CRC-w/bac) and without history of bacteremia (CRC-wo/bac) by isolating SGMB from feces, mucosal surfaces of colorectum, and colorectal tissues and detecting SGMB DNA, via PCR and in situ hybridization (ISH) assays targeting SodA gene in colorectal tissues. Moreover, mRNA of IL1, IL-8, COX-2, IFN-γ, c-Myc, and Bcl-2 in colorectal tissues of studied groups was assessed via ISH and RT-PCR. RESULTS: SGMB were found to be remarkably isolated in tumorous (TU) and non-tumorous (NTU) tissues of CRC-w/bac, 20.5% and 17.3%, and CRC-wo/bac, 12.8% and 11.5%, respectively while only 2% of control tissues revealed SGMB (P < 0.05); such contrast was not found in mucosal and fecal isolation of SGMB. The positive detection of SGMB DNA in TU and NTU of CRC-w/bac and CRC-wo/bac via PCR, 48.7%, 35.9%, 32.7%, and 23%, respectively, and ISH, 46.1%, 30.7%, 28.8%, and 17.3%, respectively, was higher than in control tissues, 4 and 2%, respectively (P < 0.05). SGMB count measured via quantitative PCR of SGMB DNA in terms of copy number (CN), in TU and NTU of CRC-w/bac and CRC-wo/bac, 2.96-4.72, 1.29-2.81, 2.16-2.92, and 0.67-2.07 log10 CN/g respectively, showed higher colonization in TU than in NTU and in CRC-w/bac than in CRC-wo/bac (P < 0.05). The PCR-based mRNA ratio and ISH-based percentage of positively stained cells of IL-1, 1.77 and 70.3%, COX-2, 1.63 and 44.8%, and IL-8, 1.73 and 70.3%, respectively, rather than IFN-γ, c-Myc, and Bcl-2, were higher in SGMB positive patients than in control or SGMB negative patients (P < 0.05). CONCLUSIONS: The current study indicated that colorectal cancer is remarkably associated with SGMB; moreover, molecular detection of SGMB in CRC was superior to link SGMB with CRC tumors highlighting a possible direct and active role of SGMB in CRC development through most probably inflammation-based sequel of tumor development or propagation via, but not limited to, IL-1, COX-2, and IL-8.


Subject(s)
Colorectal Neoplasms/genetics , Colorectal Neoplasms/microbiology , Cyclooxygenase 2/genetics , Interleukin-1/genetics , Interleukin-8/genetics , Streptococcus/isolation & purification , DNA, Bacterial/genetics , Female , Humans , In Situ Hybridization , Interferon-gamma/genetics , Male , Middle Aged , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-myc/genetics , Reverse Transcriptase Polymerase Chain Reaction , Streptococcus/genetics
10.
J Food Prot ; 73(3): 541-6, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20202342

ABSTRACT

The objective of this study was to determine the level of preservatives and microbiological loads in various brands of commercially available chili bo (paste). Fifteen different brands of chili bo obtained from the local market and hypermarkets were analyzed for pH, moisture and benzoic acid content, microbiological loads (aerobic, anaerobic, aerobic spores, and fungi), and thermophilic microorganisms. Results showed that both moisture content and pH vary among samples. The concentrations of benzoic acid detected in chili bo were found to be in the range of 537 to 5,435 mg/kg. Nine of fifteen brands were found to exceed the maximum level permitted by the Malaysian Food Law in accordance with the Codex Alimentarius (1,000 mg/kg for benzoic acid). An apparent correlation between benzoic acid concentration and microbiological loads present in the chili bo was observed. The microbiological loads were found to be relatively low in the end products containing high amounts of benzoic acid. The heat-resistant (70 to 80 degrees C) microorganisms present in chili bo were identified as Ochrobacterum tritici, Stenotrophomonas rhizophila, Microbacterium maritypicum, Roseomonas spp., CDC group II-E subgroup A, Flavimonas oryzihabitans, and Pseudomonas aeruginosa, with M. maritypicum being the most frequently found (in 9 of 15 samples) microorganism. Most of these identified microorganisms were not known to cause foodborne illnesses.


Subject(s)
Bacteria/isolation & purification , Capsicum/chemistry , Capsicum/microbiology , Consumer Product Safety , Food Contamination/analysis , Bacteria/growth & development , Benzoic Acid/analysis , Food Microbiology , Fungi/growth & development , Fungi/isolation & purification , Humans , Hydrogen-Ion Concentration , Malaysia , Water/metabolism
11.
Int J Food Microbiol ; 117(1): 106-11, 2007 Jun 10.
Article in English | MEDLINE | ID: mdl-17399832

ABSTRACT

The main aim of this study was to combine the techniques of most probable number (MPN) and polymerase chain reaction (PCR) for quantifying the prevalence and numbers of Campylobacter spp. in ulam, a popular Malaysian salad dish, from a traditional wet market and two modern supermarkets in Selangor, Malaysia. A total of 309 samples of raw vegetables which are used in ulam were examined in the study. The prevalences of campylobacters in raw vegetables were, for supermarket I, Campylobacter spp., 51.9%; Campylobacter jejuni, 40.7%; and Campylobacter coli, 35.2%: for supermarket II, Campylobacter spp., 67.7%; C. jejuni, 67.7%; and C. coli, 65.7%: and for the wet market, Campylobacter spp., 29.4%; C. jejuni, 25.5%; and C. coli, 22.6%. In addition Campylobacter fetus was detected in 1.9% of raw vegetables from supermarket I. The maximum numbers of Campylobacter spp. in raw vegetables from supermarkets and the wet market were >2400 and 460 MPN/g, respectively.


Subject(s)
Campylobacter/isolation & purification , Consumer Product Safety , Food Contamination/analysis , Vegetables/microbiology , Colony Count, Microbial , Food Microbiology , Humans , Malaysia , Polymerase Chain Reaction/methods , Prevalence
SELECTION OF CITATIONS
SEARCH DETAIL
...