This study aimed to determine the physicochemical properties of undulated surf clam (Paphia undulata) hydrolysate as affected by the degree of hydrolysis (DH). Three levels of DH of undulated surf clam hydrolysate were prepared which were DH 36.57% (without any enzymatic hydrolysis), DH 58.25% (0.5% Alcalase®; 5 min; pH 7.5; 60ºC) and DH 91.26% (1% Alcalase®; 30 min; pH 7.5; 60ºC). After protein hydrolysis, the undulated surf clam hydrolysates were centrifuged, and their supernatants were freeze-dried. This study found that the protein hydrolysate with lower DH (DH 36.57%) gave lower protein content and higher ash and fat contents compared to other samples (DH 58.25% and DH 91.26%). However, the carbohydrate content is similar in all samples (16.56-20.04%). This study also found that foaming properties (29.43-67.50%), emulsifying capacity (11.94-110.52%) and peptide solubility (57.61-94.08%) were affected by the DH. As DH increased, the emulsifying capacity decreased, while peptide solubility increased. While the foaming capacity increased with increasing DH until it reached a maximum value and level off afterwards. For colour parameters, although there were differences between L*, a* and b* values for all three samples, a fluctuating pattern was noted with DH. DH also did not affect the water-holding and oil-holding capacity of undulated surf clam hydrolysate. This study shows that certain physicochemical properties of undulated surf clam hydrolysate can be tailored by adjusting the degree of hydrolysis.
Pink Antigonon leptopushave potential to be commercialized as cut flowers for flower arrangement. In order to determine cut inflorescences' vase life, vase solution treatments containing Artificial Tap Water as control, salicyclic acid (SA) at 100, 200, 300 mg/L and combination of 100, 200, 300 mg/L SA with 2% sucrose were conducted. Parameters observed were vase life, relative fresh weight (RFW), vase solution uptake (VSU), flower drop (FD), flower colour, relative water content (RWC) and pH. The results showed that cut inflorescences in vase treatment containing 200 mg/L SA + 2% sucrose and 300 mg/L + 2% sucrose had 1.6 fold longer vase life than the control, showing higher water uptake and reduced flower drop by 28%.
At present, heavy metal pollution is a major environmental concern and the adsorption technique is a potent method for removal of these heavy metals from wastewater. Activated carbon is one of the best adsorbents for metal ionsremoval but it is sometimes restricted due to high cost and problems with regeneration hamper large scale application. Low cost adsorbent is alternatively being introduced to replace activated carbon since it is available in large quantity, renewable and inexpensive. Hence, Pennisetum purpureum(elephant grass) was investigated for its potential in cadmium ions removal. The adsorbent was characterized by Fourier Transforms Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Brunauer–Emmett–Teller (BET) and Barrett–Joyner–Halenda (BJH) analyses.The effects of pH (1 to 5), initial metal ion concentration (5 to 25 mg/L), contact time (10 to 60 minutes) and adsorbent dosage (0.2 to 1.0 g) on cadmium ions removal were conducted by batch adsorption experiments. In this study, the FT-IR results demonstrated that the functional groups for untreated and nitric acid-treated P. purpureum mainly consisted of carbonyl, carboxyl, hydroxyl and amine groups which are able to bind with positively charged cadmium ions. SEM micrographs have proven that nitric acid modification would remove the surface impurities of P. purpureum, which increased the surface roughness, produced deep, open pores and better pore size distribution. From the BET and BJH analyses, the treated P. purpureum was mesoporous, had larger surface area and pore volume compared to untreated P. purpureum. The best pH, adsorbent dosage and contact time were pH 4, 0.6 g and 30 minutes, respectively. The highest removal percentage of cadmium ions for both untreated and treated P. purpureum were 92% and 98% correspondingly. The results shown strengthened the fact that both biosorbents have great potential in cadmium ions removal.
Vinegars are most widely used as preservatives in food industry. Vinegars are known for their health benefits; however, the roles of vinegar-associated microflora in locally produced vinegars are not well established. The objectives of this study are to isolate and identify the lactic acid bacteria (LAB) from black rice vinegar and coconut vinegar, measure their pH and titratable acidity, and determine their antibacterial activity. LAB was isolated using cultural method. Phenotypic characterization of LAB was carried out using Gram-staining, oxidase test, catalase test and API 50 CHL Kit. Results from API 50 CHL Kit confirmed that BRV03M strain from black rice vinegar and CV03M strain from coconut vinegar were Lactobacillus paracaseissp. paracasei. The identified bacteria in both samples were consistent as L. paracaseiusing 16S rDNAgene sequences with 93% and 99% similarity, respectively. The pH and titratable acidity percentage of both vinegars were also determined. The stability of Cell Free Supernatant-Lactic Acid Bacteria (CFS-LAB) strains within 14 days on their inhibition against selected pathogenic bacteria was determined using agar well diffusion method. The CFS-LAB strain isolated from black rice vinegar (BRV03M) was more stable within 14 days than coconut vinegar in inhibiting tested bacteria, suggesting this strain has great potential as natural antibacterial agents.
A preliminary assessment of a simple and rapid electrochemical method was carried out to analyse imidacloprid (IMI) in water samples using cyclic voltammetry (CV) based on modified screen-printed gold electrode (SPGE). Self-assembled monolayer (SAM) was optimized using 11-mercaptoundecanoic acid (11-MUA) with several parameters such as scan rates, type of supporting electrolyte, and pH of the supporting electrolyte. The modified SPGE showed high suppressed current against the potential due to the formation of a monolayer on the electrode surface. Surface morphology of the electrode was analysed using Scanning Electron Microscopy (SEM) confirming that 11-MUA was present on the modified SPGE. The water samples were collected from GM Peladang, Kuala Terengganu and two locations at Universiti Malaysia Terengganu. Method detection limit was expressed as limit of detection (LOD) and limit of quantification (LOQ) for modified SPGE which were calculated at 3.784 and 12.613 mg/L in water samples, respectively. This study showed that the reduction peak current observed on the modified electrode was lower compared with oxidation peak current. Hence, gold is unsuitable for IMI detection.
The distribution of benthic Foraminifera throughout the coastal waters of Taman Negara Pulau Pinang (Penang National Park), Malaysia was studied to assess the impact of various anthropogenic activities, such as fishing, ecotourism and floating cage culture. Samples were obtained at 200 m intervals within the subtidal zone, extending up to 1200 m offshore at Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh. The depth within coastal waters ranged between 1.5 m and 10.0 m, with predominantly muddy substrate at most stations. Water quality analysis showed little variation in micronutrient (nitrite, NO2; nitrate, NO3; ammonia, NH4 and orthophosphate, PO4) concentrations between sampling stations. Temperature (29.6±0.48°C), salinity (29.4±0.28 ppt), dissolved oxygen content (5.4±0.95 mg/l) and pH (8.5± 0.13) also showed little fluctuation between stations. A total of nine genera of foraminifera were identified in the study (i.e., Ammonia, Elphidium, Ammobaculites, Bigenerina, Quinqueloculina, Reopax, Globigerina, Textularia and Nonion). The distribution of benthic foraminifera was dominated by opportunistic groups that have a high tolerance to anthropogenic stressors. Ammonia had the highest frequency of occurrence (84.7%), followed by Bigenerina (50%), Ammobaculites (44.2%) and Elphidium (38.9%). The Ammonia-Elphidium Index (AEI) was used to describe the hypoxic condition of benthic communities at all sites. Teluk Bahang had the highest AEI value. The foraminiferal assemblages and distribution in Teluk Bahang, Teluk Aling, Teluk Ketapang and Pantai Acheh showed no correlation with physical or chemical environmental parameters.
Pencirian enzim ekstraselular protease daripada bakteria Alkalophilic Bacillus lehensis G1 dari Malaysia telah dikaji. Enzim protease yang dirembeskan diuji pada agar susu skim 2%. Keputusan menunjukkan protease ekstraselular mampu mengekalkan aktiviti sehingga suhu 60°C di dalam julat pH yang luas iaitu 3 hingga 11 dengan suhu optimum pada 40°C dan pH optimum pada 7.0. Aktiviti enzim juga diperhatikan akan meningkat dengan penambahan beberapa ion iaitu Mn2+, Fe2+, Cu2+, Mg2+ dan Co2+. Manakala aktiviti protease didapati sedikit direncat dengan kehadiran ion Ca2+, K+ dan Ni2+ dengan baki aktiviti sebanyak 85%, 81% dan 75%. Protease ekstraselular juga didapati serasi dengan beberapa cecair detergen komersial dari Malaysia, yang menunjukkan protease ini boleh dimanfaatkan sebagai pembersih kotoran pada pakaian. Selain itu, potensi kegunaan protease yang dihasilkan oleh B. lehensis G1 ke atas penguraian gelatin dari filem X-ray yang telah digunakan juga telah dilakukan di dalam kajian ini.
An investigation study was conducted in Bukit Merah Reservoir (BMR) for the assessment of arsenic concentration in the surface sediment in 23 sampling stations. The sediment samples were digested and analysed for arsenic using Inductively Coupled Plasma-Optical Emission Spectrometry (ICP-OES). Sediment parameters such as pH (4.42 ± 0.71), redox potential (121.77 ± 42.45 mV), conductivity (205.7 ± 64.07 μS cm-1) and organic matter (25.35 ± 9.34%) were also examined. The main objectives of this study are to determine the arsenic distribution and concentration and at the same time to assess the enrichment of arsenic using the geoaccumulation index (I geo ) and enrichment factor (EF). This study shows the total arsenic concentration in the surface sediment of BMR is 4.302 ± 2.43 mg kg-1 and found to be below the threshold value of Canadian Interim Sediment Quality Guidelines (ISQG). High arsenic concentration is recorded near the southern part of the lake where anthropogenic activities are prevalent. Based on I geo , 13% of sampling stations are categorised as moderately polluted, 52.2% as unpolluted to moderately polluted and the rest is categorised as unpolluted. EF shows 78.3% stations are classified as extremely high enrichment and the rest as very high enrichment. This finding provides important information on the status of arsenic contamination in BMR and creating awareness concerning the conservation and management of the reservoir in the future.
Clitoria ternatea is a herbaceous plant with many health benefits. Extraction is crucial to obtain its bioactive components which contribute to its antioxidant properties. Therefore, this study was conducted to find an optimum extraction condition of C. ternatea flower on total phenolic content (TPC) and antioxidant activity (2,2-diphenyl-1-picrylhydrazyl (DPPH) free radical-scavenging activity) as well as to determine its total flavonoid content (TFC) and anthocyanin content based on the optimum extraction condition generated by Response Surface Methodology (RSM)-Design Expert 7.1.5. TPC, TFC and total anthocyanin of C. ternatea were conducted by Folin Ciocalteu (FC), calorimetric assay and pH differential method, respectively. The ranges of selected independent variables were ethanol concentration (30°C-90% v/v), time (60-120 min) and temperature (30°C-70°C). The optimum extraction condition was obtained at 39.62% v/v ethanol concentration, 90 min and 44.24°C. However, these values were slightly adjusted according to the convenience of equipment to operate in which ethanol concentration was adjusted to 37% v/v, time remain at 90 min and temperature at 45°C. The predicted values of TPC and DPPH radical scavenging activity were 41.60 mg GAE/g dry samples and 68.12% inhibition and were experimentally verified to be 41.17 ± 0.5 mg GAE/g dry samples and 63.53 ± 0.95% inhibition of TPC and DPPH radical scavenging activity respectively. This result has showed RSM can optimise TPC and radical scavenging activity of C. ternatea. Upon the optimum condition, the TFC determined was 187.05 ± 3.18 mg quercetin/g dried sample which was higher than TPC and the total anthocyanin content was 28.60 ± 0.04 mg/L. Hence, the extractable phenolic, flavonoid and anthocyanin compounds indicated that C. ternatea is a good source of natural antioxidant.
In the present study, pectinase was produced by local fungal isolate, Aspergillus niger LFP-1 grown on pomelo peels as a sole carbon source under solid-state fermentation (SSF). The purification process begins with the concentration of crude enzyme using ammonium sulfate precipitation and followed by purification using anion-exchange column chromatography (DEAE-Sephadex) and subsequently using gel filtration column chromatography (Sephadex G-100). On the other hand, the molecular weight of the purified enzyme was determined through SDS-PAGE. The findings revealed the crude enzyme was purified up to 75.89 folds with a specific activity of 61.54 U/mg and the final yield obtained was 0.01%. The molecular mass of the purified pectinase was 48 kDa. The optimum pH and temperature were 3.5 and 50°C, respectively. This enzyme was stable at a range of pH 3.5 to 4.5 and a relatively high temperature (40°C-50°C) for 100 min. The Km and Vmax were found to be 3.89 mg/mL and 1701 U/mg, respectively. Meanwhile, pectin from citrus fruit and the metal ion (Co2+) were the best substrate and inducer to enhance pectinase yield, respectively.
Studies show that the pH of the malaria parasite's digestive vacuole (DV) plays a key role in the physiological functions of this organelle and antimalarial drug accumulation, and yet is technically difficult to measure. In this study, a flow cytometry-based technique was developed to measure the DV pH using a ratiometric pH indicator, FITC-dextran loaded into the DV of saponin-permeabilized parasites. To calculate the DV pH, a standard pH calibration curve was generated by incubating the saponin-permeabilized cells in buffers with different pH in the presence of an ionophore, CCCP. The measured average pH of the DV was 5.27 ± 0.03 that is approximately the same in the parasites observed microscopically by Hayward et al. (2006) (5.50 ± 0.14) using the same probe. The removal of glucose from the medium, causing a rapid depletion of parasite ATP, resulted in an alkalization of the DV. The DV was reacidified upon restoration of glucose to the medium. This technique provides a rapid, simple and quantitative measurement of the DV pH on a large number of cells. It will also be useful in future attempts to evaluate the effect of antimalarial drugs (i.e. chloroquine and artemisinin-based drugs) in pH changes of the DV.
The use of ice cubes in beverages is common among patrons of food outlets in Malaysia although its safety for human consumption remains unclear. Hence, this study was designed to determine the presence of faecal coliforms and several useful water physicochemical parameters viz. free residual chlorine concentration, turbidity and pH in ice cubes from 30 randomly selected food outlets in Kubang Kerian, Kelantan. Faecal coliforms were found in ice cubes in 16 (53%) food outlets ranging between 1 CFU/100mL to >50 CFU/ 100mL, while in the remaining 14 (47%) food outlets, in samples of tap water as well as in commercially bottled drinking water, faecal coliforms were not detected. The highest faecal coliform counts of >50 CFU/100mL were observed in 3 (10%) food outlets followed by 11-50 CFU/100mL and 1-10 CFU/100mL in 7 (23%) and 6 (20%) food outlets, respectively. All samples recorded low free residual chlorine concentration (<0.10mg/L) with the pH ranging between 5.5 and 7.3 and turbidity between 0.14-1.76 NTU. Since contamination by faecal coliforms was not detected in 47% of the samples, tap water and commercially bottled drinking water, it was concluded that (1) contamination by faecal coliforms may occur due to improper handling of ice cubes at the food outlets or (2) they may not be the water sources used for making ice cubes. Since low free residual chlorine concentrations were observed (<0.10mg/ L) in all samples as well as in both tap water and commercially bottled drinking water, with the pH ranged between 5.5-7.3, ineffective disinfection of water source as a contributing factor to such high counts of faecal coliforms in ice cubes also could not be ruled out. Therefore, a periodical, yet comprehensive check on the food outlets, including that of ice cube is crucial in ensuring better food and water for human consumption.
Surface antigens are the most abundant proteins found on the surface of the parasite Toxoplasma gondii. Surface antigen 1 (SAG1) and Surface antigen 2 (SAG2) remain the most important and extensively studied surface proteins. These antigens have been identified to play a role in host cell invasion, immune modulation, virulence attenuation. Recombinant SAG1/2 was cloned and expressed in yeast Pichia pastoris. We describe here optimization of critical parameters involved in high yield expression of the recombinant SAG1/2. Our results suggest that recombinant SAG1/2 were best expressed at 30ºC, pH 6 and 1% methanol as the carbon source by X33 Pichia cells. Additional optimizations included the downstream process such as ammonium sulphate precipitation and dialysis. The fusion protein was purified using Ni-NTA purification system with 80% recovery. The purified protein was 100% specific and sensitive in detection of toxoplasmosis.
The reduced efficacy of the mainstay antimalarial drugs due to the widespread of drugresistant Plasmodium falciparum has necessitated efforts to discover new antimalarial drugs with new targets. Quercus infectoria (Olivier) has long been used to treat various ailments including fever. The acetone extract of the plant galls has recently been reported to have a promising antimalarial activity in vitro. This study was aimed to determine the effect of the Q. infectoria gall acetone crude extract on pH of the digestive vacuole of Plasmodium falciparum. A ratiometric fluorescent probe, fluorescein isothiocyanate-dextran (FITC-dextran) was used to facilitate a quantitative measurement of the digestive vacuole pH by flow cytometry. Mid trophozoite stage malaria parasites grown in resealed erythrocytes containing FITC-dextran were treated with different concentrations of the acetone extract based on the 50% inhibitory concentration (IC50). Saponin-permeabilized parasites were analyzed to obtain the ratio of green/yellow fluorescence intensity (Rgy) plotted as a function of pH in a pH calibration curve of FITC-dextran. Based on the pH calibration curve, the pH of the digestive vacuole of the acetone extract-treated parasites was significantly altered (pH values ranged from 6.35- 6.71) in a concentration-dependent manner compared to the untreated parasites (pH = 5.32) (p < 0.001). This study provides a valuable insight into the potential of the Q. infectoria galls as a promising antimalarial candidate with a novel mechanism of action.
Outbreak of SARS-CoV-2 has been declared a pandemic, which is a serious threat to human health. The disease was named coronavirus disease 2019 (COVID-19). Until now, several vaccines and a few drugs have been approved for the prevention and treatment for COVID-19. Recently, the effect of some macrolides including clarithromycin (CAM) on COVID-19 has attracted attention. CAM is known to have diverse effects including immunomodulatory and immunosuppressive effects, autophagy inhibition, steroid sparing effect, reversibility of drug resistance, antineoplastic effect, antiviral effect as well as bacteriostatic/bactericidal effect. Many patients with COVID-19 died due to an overwhelming response of their own immune system characterized by the uncontrolled release of circulating inflammatory cytokines (cytokine release syndrome [CRS]). This CRS plays a major role in progressing pneumonia to acute respiratory distress syndrome (ARDS) in COVID-19 patients. It is noteworthy that CAM can suppress inflammatory cytokines responsible for CRS and also has anti-SARS-CoV-2 effect. Considering the rapidly progressive global disease burden of COVID 19, the application of CAM for treating COVID-19 needs to be urgently evaluated. Recently, an open-labeled non-randomized trial using CAM for treating COVID-19 (ACHIEVE) was initiated in Greece in May, 2020. Its results, though preprint, indicated that CAM treatment of patients with moderate COVID-19 was associated with early clinical improvement and containment of viral load. Thus, treatment with CAM as a single agent or combined with other anti-SARS CoV-2 drugs should be tried for treating COVID-19. In this article, we discussed the significance and usefulness of CAM in treating COVID-19.
An appropriate pH maintenance within a membrane-enclosed organelle is vital for the occurrence of biological processes. Artemisinin (ART), a potent antimalarial drug has been reported to target the digestive vacuole (DV) of Plasmodium falciparum, which might alter the pH of the organelle, thereby impairing the hemoglobin degradation and subsequent heme detoxification. Hence, a flow cytometry-based technique using fluorescein isothiocyanate-dextran (FITC-dextran) as a ratiometric pH probe was employed to measure the pH of the DV of the malaria parasite treated with ART. Based on the pH calibration curve generated, the steady-state pH of the acidic DV of the non-treated parasites was 5.42 ± 0.11, indicating that FITC-dextran is suitable for detection of physiological pH of the organelle. The alteration of the DV pH occurred when the parasites were treated with ART even at the sub-lethal concentrations (15 and 30 nM) used. The similar effect was shown by the parasites treated with a standard proton pump inhibitor, concanamycin A. This suggests that ART might have altered the DV pH at lower levels than the level needed to kill the parasite. This study has important implications in designing new ART treatment strategies and in generating new endoperoxide-based antimalarial drugs pertaining to the interruption of the pH regulation of the malaria parasite's DV.
A study was carried out to investigate the effects of feeding liquid metabolite combinations produced by Lactobacillus plantarum strains on growth performance, diarrhoea incidence, faecal pH, microfloral counts, short-chain fatty acids (SCFA) and intestinal villus height and crypt depth of postweaning piglets. A total of 120 piglets (26 days old) were randomly assigned evenly into five treatment groups treated with same basal diet: (1) -ve control (free antibiotic); (2) + ve control (0.03% of chlortetracycline); (3) Com 1 (0.3% metabolite of TL1, RG11 and RI11 strains); (4) Com 2 (0.3% metabolite of TL1, RG14 and RS5 strains); (5) Com 3 (0.3% metabolite of RG11, RG14 and RI11 strains). After 5 weeks, the average daily feed intake was not significantly different (P > 0.05) among the treatments and feed conversion ratio was the highest (P
This study investigated the effect of different levels of corn supplementation as energy source into palm kernel cake-urea-treated rice straw basal diet on urinary excretion of purine derivatives, nitrogen utilization, rumen fermentation, and rumen microorganism populations. Twenty-seven Dorper lambs were randomly assigned to three treatment groups and kept in individual pens for a 120-day period. The animals were subjected to the dietary treatments as follows: T1: 75.3% PKC + 0% corn, T2: 70.3% PKC + 5% corn, and T3: 65.3% PKC + 10% corn. Hypoxanthine and uric acid excretion level were recorded similarly in lambs supplemented with corn. The microbial N yield and butyrate level was higher in corn-supplemented group, but fecal N excretion, T3 has the lowest level than other groups. Lambs fed T3 had a greater rumen protozoa population while the number of R. flavefaciens was recorded highest in T2. No significant differences were observed for total bacteria, F. succinogenes, R. albus, and methanogen population among all treatment. Based on these results, T3 could be fed to lambs without deleterious effect on the VFA and N balance.
Helicobacter pylori colonizes the gastric epithelial cells of at least half of the world's population, and it is the strongest risk factor for developing gastric complications like chronic gastritis, ulcer diseases, and gastric cancer. To successfully colonize and establish a persistent infection, the bacteria must overcome harsh gastric conditions. H. pylori has a well-developed mechanism by which it can survive in a very acidic niche. Despite bacterial factors, gastric environmental factors and host genetic constituents together play a co-operative role for gastric pathogenicity. The virulence factors include bacterial colonization factors BabA, SabA, OipA, and HopQ, and the virulence factors necessary for gastric pathogenicity include the effector proteins like CagA, VacA, HtrA, and the outer membrane vesicles. Bacterial factors are considered more important. Here, we summarize the recent information to better understand several bacterial virulence factors and their role in the pathogenic mechanism.