Displaying publications 901 - 920 of 1247 in total

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  1. Mechri S, Allala F, Bouacem K, Hasnaoui I, Gwaithan H, Chalbi TB, et al.
    Int J Biol Macromol, 2022 Dec 01;222(Pt A):1326-1342.
    PMID: 36242508 DOI: 10.1016/j.ijbiomac.2022.09.161
    We recently described the production of a detergent-biocompatible crude protease from Streptomyces mutabilis strain TN-X30. Here, we describe the purification, characterization, and immobilization of the serine alkaline protease (named SPSM), as well as the cloning, sequencing, and over-expression of its corresponding gene (spSM). Pure enzyme was obtained after ammonium sulphate precipitation followed by heat-treatment and Sephacryl® S-200 column purification. The sequence of the first 26 NH2-terminal residues of SPSM showed a high sequence identity to subtilisin-like serine proteases produced by actinobacteria. The spSM gene was heterologously expressed in Escherichia coli BL21(DE3)pLysS and E. coli BL21-AI™ strains using pTrc99A (rSPSM) and Gateway™ pDEST™ 17 [(His)6-tagged SPSM] vectors, respectively. Results obtained indicated that the (His)6-tagged SPSM showed the highest stability. The SPSM was immobilized using encapsulation and adsorption-encapsulation approaches and three different carriers. Features of SPSM in soluble and immobilized forms were analyzed by Fourier transform infrared (FTIR) spectroscopy in attenuated total reflection (ATR) mode, X-ray diffraction (XRD), zeta potential measurements, and field emission scanning electron microscopy (FE-SEM). The white clay and kaolin used in this study are eco-friendly binders to alginate-SPSM and show great potential for application of the immobilized SPSM in various industries. Molecular modeling and docking of N-succinyl-l-Phe-l-Ala-l-Ala-l-Phe-p-nitroanilide in the active site of SPSM revealed the involvement of 21 amino acids in substrate binding.
    Matched MeSH terms: Hydrogen-Ion Concentration
  2. Mat Yajit NL, Fazlin Hashim NH, Illias RM, Abdul Murad AM
    Protein Expr Purif, 2024 Jul;219:106486.
    PMID: 38642864 DOI: 10.1016/j.pep.2024.106486
    New thermostable β-1,3-1,4-glucanase (lichenase) designated as Blg29 was expressed and purified from a locally isolated alkaliphilic bacteria Bacillus lehensis G1. The genome sequence of B. lehensis predicted an open reading frame of Blg29 with a deduced of 249 amino acids and a molecular weight of 28.99 kDa. The gene encoding for Blg29 was successfully amplified via PCR and subsequently expressed as a recombinant protein using the E. coli expression system. Recombinant Blg29 was produced as a soluble form and further purified via immobilized metal ion affinity chromatography (IMAC). Based on biochemical characterization, recombinant Blg29 showed optimal activity at pH9 and temperature 60 °C respectively. This enzyme was stable for more than 2 h, incubated at 50 °C, and could withstand ∼50 % of its activity at 70 °C for an hour and a half. No significant effect on Blg29 was observed when incubated with metal ions except for a small increase with ion Ca2+. Blg29 showed high substrate activity towards lichenan where Vm, Km, Kcat, and kcat/Km values were 2040.82 μmolmin‾1mg‾1, 4.69 mg/mL, and 986.39 s‾1 and 210.32 mLs‾1mg‾1 respectively. The high thermostability and activity make this enzyme useable for a broad prospect in industry applications.
    Matched MeSH terms: Hydrogen-Ion Concentration
  3. Al-Qassab AA, Zakaria MR, Yunus R, Salleh MAM, Mokhtar MN
    Int J Biol Macromol, 2024 Sep;276(Pt 2):134030.
    PMID: 39038578 DOI: 10.1016/j.ijbiomac.2024.134030
    This study investigates the synthesis of (hemi)cellulolytic enzymes, including endoglucanase (CMCase), xylanase, and β-glucosidase, employing Trichoderma reesei RUT-C30 and deoiled oil palm mesocarp fiber (OPMF) through solid-state fermentation (SSF). The objective was to determine the optimal process conditions for achieving high enzyme activities through a one-factor-at-a-time approach. The study primarily focused on the impact of the solid-to-liquid ratio, incubation period, initial pH, and temperature on enzyme activity. The effects of OPMF pretreatment, particularly deoiling and fortification, were explored. This approach significantly improved enzyme activity levels compared to the initial conditions, with CMCase increasing by 111.6 %, xylanase by 665.2 %, and β-Glucosidase by 1678.1 %. Xylanase and β-glucosidase activities, peaking at 1346.75 and 9.89 IU per gram dry substrate (GDS), respectively, under optimized conditions (1:4 ratio, pH 7.5, 20 °C, 9-day incubation). With lower moisture levels, CMCase reached its maximum activity of 227.84 IU/GDS. The study highlights how important it is for agro-industrial byproducts to support environmentally sustainable practices in the palm oil industry. It also emphasizes how differently each enzyme reacts to changes in process parameters.
    Matched MeSH terms: Hydrogen-Ion Concentration
  4. Hasan NWM, Baharin B, Mohd N, Rahman MA, Hassan N
    BMC Oral Health, 2024 Jul 29;24(1):861.
    PMID: 39069628 DOI: 10.1186/s12903-024-04650-7
    BACKGROUND: The nicotine in e-cigarette liquid can negatively impact periodontal tissues by altering the salivary pH and elevating cotinine levels. Thus, the study aimed to determine the periodontal parameters, salivary pH, and cotinine levels among cigarette, e-cigarette, and never-smokers.

    METHODS: A total of 144 participants were recruited (48 cigarette smokers, 48 e-cigarette smokers, and 48 never-smokers). Clinical periodontal parameters, including plaque index (PI), gingival index (GI), periodontal probing pocket depth (PPD), and clinical attachment loss (CAL) were recorded, excluding third molars. The level of unstimulated whole salivary pH was measured using a portable pH meter and the levels of salivary cotinine were measured using Enzyme-Linked Immunosorbent Assay (ELISA).

    RESULTS: Data were analysed statistically using analysis of variance. Mean scores of PPD, percentage of pocket depth ≥ 4 mm, and CAL (p 

    Matched MeSH terms: Hydrogen-Ion Concentration
  5. Zohora FT, Pathmanathan R, Chowdhury EH
    ACS Appl Bio Mater, 2025 Jan 20;8(1):348-367.
    PMID: 39723844 DOI: 10.1021/acsabm.4c01319
    Naked siRNAs are sensitive to enzymatic degradation, phagocytic entrapment, quick renal excretion, membrane impermeability, endosomal escape, and off-target effects. Designing a safe and efficient nanocarrier for siRNA delivery to the target site without toxicity remains a significant hurdle in gene therapy. CA is a unique derivative of hydroxyapatite and a highly pH-sensitive nanocarrier with strong particle aggregation and a high polydispersity index. Strontium (Sr2+), a group two divalent metal in the periodic table, has been reported for substituting calcium (Ca2+) ions from the apatite lattice and limiting particle growth/aggregation. This study used strontium chloride hexahydrate (SrCl2·6H2O) salt to develop a Sr-substituted CA (Sr-CA) nanocarrier with ∼30 nm size, spherical shape, less aggregation, homodispersity, and a fair anionic charge. Sr-CA demonstrated a large surface area-to-volume ratio, an improved cargo loading efficiency, and enhanced cellular uptake in HEK-293 cells. Moreover, Sr-CA is a pH-responsive nanocarrier responsible for its long physiological stability, efficient endosomal escape, and optimal cargo delivery within cells. These NPs have differential effects on MAPK1, MAP2K4, PIK3Ca, CAMK4, and p53 gene expression in HEK-293 cells without showing any significant cytotoxicity in cell growth properties. Gene silencing by Sr-CA-mediated siRNA delivery against MAPK1, MAP2K4, PIK3Ca, and CAMK4 genes significantly decreased the level of target gene expression and cell survival, demonstrating successful intracellular siRNA delivery in HEK-293 cells. Additionally, biocompatibility testing confirmed the biological safety of the Sr-CA nanocarrier in mice. These findings suggest that Sr-CA nanocarriers are a promising siRNA delivery system, combining high efficiency with pH-sensitive release and excellent biocompatibility, making them a viable option for future therapeutic applications.
    Matched MeSH terms: Hydrogen-Ion Concentration
  6. Ahmed SZ, Khan AS, Nasser WW, Alrushaid MA, Alfaraj ZM, Aljeshi MM, et al.
    Microsc Res Tech, 2025 Feb;88(2):595-610.
    PMID: 39501540 DOI: 10.1002/jemt.24725
    This study aimed to investigate the efficacy and durability of bioactive glass-based dental resin infiltrants. Resin infiltrants were formulated by combining photoinitiated dimethacrylate monomers with three variations of bioactive glass: 45S5 Bioglass (RIS), boron-substituted (RIB), fluoride-substituted (RIF), and pure resins (PR), whereby TOOTH group (TH) and ICON (CN) served as commercial control groups. Teeth samples were prepared, and experimental and control infiltrants were applied on demineralized human-extracted teeth. All the samples were subjected to immersion in artificial saliva and pH cycling for 30 days. The samples from another group underwent tooth brushing simulation for 9600 cycles. Following artificial saliva immersion, the samples' hardness values showed that RIB had the highest values (318.44 ± 3.83) while PR (212.52 ± 9.02) had the lowest values. After immersing into the pH cycling solution, the RIF showed the highest hardness (286.86 ± 5.11), while the lowest values for the CN (143.76 ± 3.50). After the tooth brushing simulation, the teeth samples with RIB showed maximum microhardness values (312.06 ± 16.30) and the weakest for the TH (189.60 ± 6.43). The commercial and experimental enamel resin infiltrants showed almost similar results overall, with RIB demonstrating better microhardness and comparable surface roughness. In contrast, RIF proved more resistant to pH cycling, exhibited higher microhardness, and performed better in surface roughness analysis. These findings suggest that resin infiltrant materials, especially RIF, have promising potential for effectively and esthetically managing white spot lesions.
    Matched MeSH terms: Hydrogen-Ion Concentration
  7. Jawad AH, Maharani RA, Hapiz A, ALOthman ZA, Wilson LD
    Int J Biol Macromol, 2025 Mar;292:139165.
    PMID: 39732267 DOI: 10.1016/j.ijbiomac.2024.139165
    Chitosan salicylaldehyde/calcium oxide nanoparticle (CS-SL/CaO) was synthesized by hydrothermal process and isolated via different drying processes, namely, air-drying (AD) and freeze-drying (FD). The physicochemical properties of freeze-dried CS-SL/CaO nanoparticle (CS-SL/CaO-FD) and air-dried CS-SL/CaO nanoparticle (CS-SL/CaO-AD) were compared. In particular, the adsorption properties reveal that the specific surface area of CS-SL/CaO-FD increased by ca. 6 times (BET SA = 7.28 m2/g) greater than CS-SL/CaO-FD (BET SA = 1.26 m2/g). Also, the adsorptive removal of acid red 88 dye (AR88) from aqueous media was optimized by employing the Box-Behnken design (BBD). The optimal adsorption conditions obtained from desirability functions test for the removal of AR88 dye employed a dosage of 0.09 g/100 mL of adsorbent dosage at a solution pH of 5.6 and 25 °C. The best AR88 dye removal was found for the adsorbents CS-SL/CaO-AD (38.2 %) and CS-SL/CaO-FD (86.1 %), which concur with differences in the adsorbent surface areas. Moreover, the adsorption kinetics and isotherm profiles for CS-SL/CaO-FD were described by the pseudo second order (PSO) and Temkin models, where the maximum adsorption capacity of AR88 by CS-SL/CaO-FD 175.4 was mg/g. These findings reveal the potential application of the CS-SL/CaO-FD towards removal of toxic cationic dye (AR88) from an aqueous environment.
    Matched MeSH terms: Hydrogen-Ion Concentration
  8. Elsayed N, How CW, Foo JB
    Eur J Pharm Biopharm, 2025 Feb;207:114599.
    PMID: 39617356 DOI: 10.1016/j.ejpb.2024.114599
    Zerumbone (ZER), a compound derived from the rhizome of Zingiber Zerumbet (L.) Smith, has demonstrated anti-inflammatory properties but suffers from poor water solubility, limiting its clinical application. While ZER's effects on lung inflammation are known, its role in lung fibrosis remains unexplored. Herein, ZER was encapsulated in pH-sensitive liposomes formulated with oleic acid, dipalmitoylphosphatidylcholine, and cholesterol to enhance ZER solubility and delivery to the acidic environment of lung fibrosis. The liposomes were optimized using Box-Behnken design, resulting in an average diameter of 87.8 ± 3.5 nm, a polydispersity index of 0.16 ± 0.2, and a zeta potential of -24 ± 0.32 mV. ZER release from the carrier followed zero-order kinetics and showed higher release in acidic settings. Cascade impactor and HPLC analyses confirmed that ZER liposome powder produced by freeze-drying reached stage 7, indicating effective delivery to deep lung regions. The uptake of ZER liposomes was concentration and pH-dependent, being higher in acidic conditions and greater in MRC-5 cells compared to A549 cells. Notably, ZER liposomes reduced cell migration and downregulated fibrotic markers such as fibronectin, MMP-2, and α-SMA in MRC-5 and A549 cells. This study suggests that ZER liposomes hold promise for treating lung fibrosis and merit further investigation.
    Matched MeSH terms: Hydrogen-Ion Concentration
  9. Bijle MN, Sharaf D, Bahdar MAM, Daood U, Yiu C
    J Dent, 2025 Feb;153:105500.
    PMID: 39626842 DOI: 10.1016/j.jdent.2024.105500
    OBJECTIVE(S): The aim of the study was to examine the potential of arginine (Arg)-enriched fancy waters in preventing erosive tooth wear.

    METHODS: L-arginine (2 % w/v.) was added to five commercial fancy waters: Oasis-Lemon, Oasis-Lemon Mint, Perrier-Lemon, Perrier-Grapefruit, Pellegrino-Lemon; and deionized water served as a negative control. The pH, buffer capacity of added Arg, and F- concentrations were measured. Tooth specimens were prepared and baseline volumetric assessment (T0) was conducted using micro-CT. Subsequently, the specimens were immersed in fancy waters for 72 h, kept in an incubator (37 ℃) and solutions were changed every 24 h. After the experimental cycle (T1), 3D volumetric analysis was performed, and 3D structural images were reconstructed for qualitative assessment.

    RESULTS: The pH and F- concentrations of fancy waters with Arg were significantly higher than the control (p < 0.001). The buffer capacity of added Arg with Perrier-Grapefruit was significantly higher than Oasis-Lemon, Oasis-Lemon Mint & Pellegrino-Lemon (p < 0.05), except for Perrier-Lemon (p > 0.05). At T1, the specimen volume in Oasis-Lemon Mint (+/- Arg) and Pellegrino-Lemon (control) was significantly lower than T0 (p < 0.05). At T1, the specimen volume of Oasis-Lemon Mint and Pellegrino-Lemon (control) was significantly lower than Arg-containing fancy waters (p < 0.05). Surface contrast indicating wear was evident from T0 to T1 in specimens from the Oasis-Lemon Mint (+/- Arg) and Pellegrino-Lemon (- Arg).

    CONCLUSION: Incorporating Arg in fancy waters reduces the potential of erosive tooth wear associated with these beverages.

    CLINICAL SIGNIFICANCE: Consuming fancy water beverages (flavoured sparkling/carbonated) can lead to erosive tooth wear in young people. Incorporating Arg in fancy water beverages can prevent the erosive wear potential of these beverages while alleviating the burden of oral care on individuals at risk to erosive wear.

    Matched MeSH terms: Hydrogen-Ion Concentration
  10. Li X, Tiang MF, Cui X, Li Y, Wang Z, Zhao L, et al.
    Int J Biol Macromol, 2024 Dec;283(Pt 4):137989.
    PMID: 39581417 DOI: 10.1016/j.ijbiomac.2024.137989
    In this pioneering study, electrostatic spraying (ES) technology with high voltages is proposed to reduce the size of hydrogel microbeads further, aiming to enhance the adsorption rate of cationic methylene blue (MB) dye. The increased voltages, ranging from 0.0 to 13.0 kV, further decreased the size of electrostatically sprayed hydrogel microbeads crosslinked by hydrogen bonds between sodium alginate (SA) and carboxymethyl chitosan (CMCS) in hydrochloric acid. The size of SA/CMCS hydrogel microbeads was successfully reduced from 2000 ± 121 μm (SC-2000) to 400 ± 15 μm (SC-400). Notably, SC-400 exhibits the highest maximum adsorption capacity (qm) and rate constant (k2) at 840.3 mg/g and 0.0598 g/mg/min, respectively, at pH 9.0 and a temperature of 25 °C in the absence of ionic compounds, which is three times higher than that of SC-2000, due to their high specific surface area and pore volume. Through a series of adsorption studies and characterization analyses, SA/CMCS hydrogel microbeads displayed heterogeneous adsorption behaviors towards MB dye through electrostatic interactions between the deprotonated carboxylic groups and cationic MB molecules, where MB adsorption efficiency could be significantly influenced by pH and ionic strength. These findings suggest that ES technology is effective in synthesizing smaller SA/CMCS hydrogel microbeads with enhanced MB removal rates and stable adsorption capacities and their applications could be further explored for removing other organic dyes and toxic metals in subsequent research studies.
    Matched MeSH terms: Hydrogen-Ion Concentration
  11. Cheng Y, Zheng Y, Cai X, Wang L, Zhou C, Cao J, et al.
    Food Res Int, 2024 Dec;197(Pt 1):115166.
    PMID: 39593377 DOI: 10.1016/j.foodres.2024.115166
    This study examined the impact of pre-acidification induction on the quality attributes and flavor retention of ready-to-cook (RTC) goose meat products. The results demonstrated that pre-acidification could influence the eating qualities of RTC goose meat by effectively regulating the physicochemical properties of goose myofibrillar proteins (MP) including solubility and water-holding capacity. Elevated carbonyl contents indicated an enhanced gel-forming capacity in RTC goose meat during storage, accompanied with reduced total sulfhydryl contents from enhanced protonation pretreatment and augmented lipid oxidation. Structural characterization of MP via sodium dodecyl sulfate-polyacrylamide gel electrophoresis, circular dichroism spectroscopy, and intrinsic fluorescence revealed the formation of a dense protein matrix under highly acidic conditions. Furthermore, the headspace concentration of aldehydes increased by 3.23 times upon enhancing the pre-acidification intensity, resulting in the production of esters and acidic flavor compounds with favorable aromas. Correlation analysis demonstrated the dependence of headspace concentrations of volatile constituents on the acidification-enhanced surface hydrophobicity of MP, attributed to the modified binding sites of proteins after pre-acidification. Current results have indicated both the positive and negative influence of pre-acidulation induction on the eating quality of goose meat products, suggesting the necessity of introducing extra processes to modulate the quality of prefabricated products.
    Matched MeSH terms: Hydrogen-Ion Concentration
  12. Jawad AH, Maharani RA, Hapiz A, Khadiran T, Jani NA, ALOthman ZA, et al.
    Int J Biol Macromol, 2025 Jan;286:138373.
    PMID: 39643197 DOI: 10.1016/j.ijbiomac.2024.138373
    Herein, a mesoporous magnetic chitosan-salicylaldehyde/calcium oxide nanoparticle (CS-SL/CaO/Fe3O4) biocomposite adsorbent that was prepared via freeze-drying. The CS-SL/CaO/Fe3O4 was utilized for the adsorption of ramazol brilliant blue (RBB) dye from aqueous solution. The physicochemical properties of the CS-SL/CaO/Fe3O4 were evaluated using diverse characterization techniques, including BET, XRD, FTIR, FESEM-EDX, CHNS, and pHpzc. The three main factors for adsorption included the following A: CS-SL/CaO/Fe3O4 dosage (0.02-0.1 g/100 mL), B: pH (4-10), and C: Time (60-540 min). These factors were improved using statistical methods, specifically the Box-Behnken design (BBD). The optimal conditions for achieving maximum RBB removal (62.5 %) are listed: CS-SL/CaO/Fe3O4 dosage of 0.1 g/100 mL, a solution pH of 7, and a contact time of 540 min. The adsorption kinetics and equilibrium isotherms were well described by the pseudo first order (PFO) kinetic and Langmuir isotherm models, respectively. Thus, the CS-SL/CaO/Fe3O4 material has a maximum adsorption capacity (qmax) of 63.3 mg/g for RBB at 25 °C. The adsorption mechanism of RBB onto the CS-SL/CaO/Fe3O4 surface was attributed to electrostatic forces, n-π stacking, H-bonding, and Pi-Pi interactions. Thus, CS-SL/CaO/Fe3O4 represents a recoverable magnetic adsorbent with potential for capture of organic dyes from wastewater.
    Matched MeSH terms: Hydrogen-Ion Concentration
  13. Yasin NM, Polanska M, Verbeken K, Van Impe JFM, Akkermans S
    Bioresour Technol, 2025 Mar;420:132114.
    PMID: 39870143 DOI: 10.1016/j.biortech.2025.132114
    Environmental pollution from packaging, has led to a need for sustainable alternatives. This study investigates the biodegradation of polylactic acid (PLA) by Amycolatopsis orientalis and Amycolatopsis thailandensis after thermal and thermal-alkaline pretreatments. The biodegradation was assessed based on weight loss, CO2 evolution, carbon balance analysis and scanning electron microscopy (SEM). The analysis showed that pretreatment at 37 °C for 8 h provided effective enhancement of the biodegradation performance. Combining thermal pretreatment with alkaline conditions led to chemical degradation of PLA, but is less suitable as a pretreatment for biodegradation. It was also demonstrated that the mineralization rate over a two-week period was higher following thermal than thermal-alkaline pretreatment. SEM confirmed improved biodegradation as illustrated by increased surface roughness. These findings suggest that thermal pretreatment at 37 °C for 8 h is the most effective strategy for enhancing PLA biodegradation by Amycolatopsis spp., promoting a sustainable approach to plastic waste management.
    Matched MeSH terms: Hydrogen-Ion Concentration
  14. Ismail N, Myint K, Khaing SL, Giribabu N, Salleh N
    Mol Biol Rep, 2023 Aug;50(8):6729-6737.
    PMID: 37382776 DOI: 10.1007/s11033-023-08555-6
    BACKGROUND: Unexplained infertility could arise from a defect in the cervix. However, the contribution of abnormal cervical fluid microenvironment to this problem still needs to be identified. Therefore, this study identifies the changes in the cervical fluid microenvironment, i.e., pH, electrolytes and osmolarity as well as expression of ion transporters in the cervix including ENaC, CFTR and AQP in fertile women and in women suffering from primary unexplained infertility.

    METHODS: Fertile women and women with unexplained infertility but having regular 28-day menstrual cycles were chosen in this study, Day-22 serum progesterone levels were determined. In the meantime, serum FSH and LH levels were determined on day 2 while, cervical flushing was performed at day 14 to analyse changes in the cervical fluid pH, osmolarity, Na+ and Cl- levels. Meanwhile, cells retrieved from cervical fluid were subjected to mRNA expression and protein distribution analysis for CFTR, AQP and ENaC by qPCR and immunofluorescence, respectively.

    RESULTS: No significant changes in serum progesterone, FSH and LH levels were observed between the two groups. However, cervical fluid pH, osmolarity, Na+ and Cl- levels were significantly lower in primary unexplained infertile group when compared to fertile group. Expression of CFTR and AQP (AQP 1, AQP 2, AQP 5 and AQP 7) in endocervical cells was lower and expression of β-ENaC was higher in primary unexplained infertile women (p ion transporter expression in the cervix might contribute towards the unfavourable condition that accounts for unexplained infertility in women.

    Matched MeSH terms: Hydrogen-Ion Concentration
  15. Khalil M, Hanif MA, Rashid U, Ahmad J, Alsalme A, Tsubota T
    Environ Sci Pollut Res Int, 2023 Jul;30(34):81333-81351.
    PMID: 35710971 DOI: 10.1007/s11356-022-21367-8
    The hazardous dyes on mixing with water resources are affecting many life forms. Granite stone is popular worldwide for decorating floors, making other forms of decorative materials and items. Granite stone powder waste can be obtained free of cost from marble factories as factories spend on the disposal of this waste. In the present study, novel granite stone powder waste composite has been prepared and utilized for the effective removal of Terasil dye. Two types of granite including gray granite and white granite were used in pure, calcinized, and chemically modified forms. Freundlich adsorption isotherm model best explained the adsorption mechanism of dye removal using granite composites as compared to other adsorption isothermal models. Characterization techniques like scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) spectroscopy were used for the determination of morphological features and functional groups of granite composites. The obtained results were statistically analyzed using analysis of variance (ANOVA) along with the post hoc Tukey test. An extraordinarily high Terasil dye uptake capacity (more than 400 mg/g) was exhibited by granite composites prepared using sodium metasilicate. The synthesized novel nano-constructed composites provided a viable strategy as compared to the pure granite stone for dye removal from wastewater water.
    Matched MeSH terms: Hydrogen-Ion Concentration
  16. Lim IKJ, Looi PZY, Chong EZH, Chong CS, Lam MQ, Ee KY
    World J Microbiol Biotechnol, 2025 Oct 17;41(10):396.
    PMID: 41105288 DOI: 10.1007/s11274-025-04534-0
    Soy sauce cake (SSC), a protein-rich by-product from soy sauce production, remains underutilized despite its potential for valorization into bioactive peptides. Halophilic bacteria, known for their robust enzymes, offer a sustainable solution for SSC biodegradation under high-salt conditions. This study investigates Mesobacillus sp. strain LC4, a protease-producing halophilic bacterium isolated from mangrove sediment. Phylogenetic and whole genome analyses confirmed strain LC4 as a novel Mesobacillus species, with ANIb and dDDH values below species delineation thresholds. Genome mining identified 25 extracellular protease-encoding genes, comprising serine and metalloproteases with physicochemical properties indicating thermotolerance and halophilicity. Crude protease assays demonstrated broad activity across temperatures (27-70 °C), pH levels (6-11), and salinities (0-15% w/v NaCl), with optimal activity at 40-60 °C, pH 8 and 4-8% NaCl. Enzymatic stability was retained in the presence of Ca2+ and Al3+ ions. Submerged fermentation of SSC by strain LC4 demonstrated significant protein hydrolysis (5.16 ± 0.18 mg/g dry sample) at 24 h, and peptide production (0.63 ± 0.03 mg/g dry sample) at 72 h. These findings have highlighted the potential of strain LC4 for upcycling proteinaceous high-salt food waste, providing a basis for future applications in sustainable food waste valorization and bioactive peptides production.
    Matched MeSH terms: Hydrogen-Ion Concentration
  17. Ramli NS, Eng Guan C, Nathan S, Vadivelu J
    PLoS One, 2012;7(9):e44104.
    PMID: 22970167 DOI: 10.1371/journal.pone.0044104
    Burkholderia pseudomallei, a Gram-negative saprophytic bacterium, is the causative agent of the potentially fatal melioidosis disease in humans. In this study, environmental parameters including temperature, nutrient content, pH and the presence of glucose were shown to play a role in in vitro biofilm formation by 28 B. pseudomallei clinical isolates, including four isolates with large colony variants (LCVs) and small colony variants (SCVs) morphotypes. Enhanced biofilm formation was observed when the isolates were tested in LB medium, at 30 °C, at pH 7.2, and in the presence of as little as 2 mM glucose respectively. It was also shown that all SVCs displayed significantly greater capacity to form biofilms than the corresponding LCVs when cultured in LB at 37 °C. In addition, octanoyl-homoserine lactone (C(8)-HSL), a quorum sensing molecule, was identified by mass spectrometry analysis in bacterial isolates referred to as LCV CTH, LCV VIT, SCV TOM, SCV CTH, 1 and 3, and the presence of other AHL's with higher masses; decanoyl-homoserine lactone (C(10)-HSL) and dodecanoyl-homoserine lactone (C(12)-HSL) were also found in all tested strain in this study. Last but not least, we had successfully acquired two Bacillus sp. soil isolates, termed KW and SA respectively, which possessed strong AHLs degradation activity. Biofilm formation of B. pseudomallei isolates was significantly decreased after treated with culture supernatants of KW and SA strains, demonstrating that AHLs may play a role in B. pseudomallei biofilm formation.
    Matched MeSH terms: Hydrogen-Ion Concentration/drug effects
  18. Jahromi MF, Liang JB, Ho YW, Mohamad R, Goh YM, Shokryazdan P
    J Biomed Biotechnol, 2012;2012:196264.
    PMID: 23118499 DOI: 10.1155/2012/196264
    Ability of two strains of Aspergillus terreus (ATCC 74135 and ATCC 20542) for production of lovastatin in solid state fermentation (SSF) using rice straw (RS) and oil palm frond (OPF) was investigated. Results showed that RS is a better substrate for production of lovastatin in SSF. Maximum production of lovastatin has been obtained using A. terreus ATCC 74135 and RS as substrate without additional nitrogen source (157.07 mg/kg dry matter (DM)). Although additional nitrogen source has no benefit effect on enhancing the lovastatin production using RS substrate, it improved the lovastatin production using OPF with maximum production of 70.17 and 63.76 mg/kg DM for A. terreus ATCC 20542 and A. terreus ATCC 74135, respectively (soybean meal as nitrogen source). Incubation temperature, moisture content, and particle size had shown significant effect on lovastatin production (P < 0.01) and inoculums size and pH had no significant effect on lovastatin production (P > 0.05). Results also have shown that pH 6, 25°C incubation temperature, 1.4 to 2 mm particle size, 50% initial moisture content, and 8 days fermentation time are the best conditions for lovastatin production in SSF. Maximum production of lovastatin using optimized condition was 175.85 and 260.85 mg/kg DM for A. terreus ATCC 20542 and ATCC 74135, respectively, using RS as substrate.
    Matched MeSH terms: Hydrogen-Ion Concentration/drug effects
  19. Ebrahimpour A, Rahman RN, Basri M, Salleh AB
    Bioresour Technol, 2011 Jul;102(13):6972-81.
    PMID: 21531550 DOI: 10.1016/j.biortech.2011.03.083
    The mature ARM lipase gene was cloned into the pTrcHis expression vector and over-expressed in Escherichia coli TOP10 host. The optimum lipase expression was obtained after 18 h post induction incubation with 1.0mM IPTG, where the lipase activity was approximately 1623-fold higher than wild type. A rapid, high efficient, one-step purification of the His-tagged recombinant lipase was achieved using immobilized metal affinity chromatography with 63.2% recovery and purification factor of 14.6. The purified lipase was characterized as a high active (7092 U mg(-1)), serine-hydrolase, thermostable, organic solvent tolerant, 1,3-specific lipase with a molecular weight of about 44 kDa. The enzyme was a monomer with disulfide bond(s) in its structure, but was not a metalloenzyme. ARM lipase was active in a broad range of temperature and pH with optimum lipolytic activity at pH 8.0 and 65°C. The enzyme retained 50% residual activity at pH 6.0-7.0, 50°C for more than 150 min.
    Matched MeSH terms: Hydrogen-Ion Concentration/drug effects
  20. Bashir S, Teo YY, Naeem S, Ramesh S, Ramesh K
    PLoS One, 2017;12(7):e0179250.
    PMID: 28678803 DOI: 10.1371/journal.pone.0179250
    There has been significant progress in the last few decades in addressing the biomedical applications of polymer hydrogels. Particularly, stimuli responsive hydrogels have been inspected as elegant drug delivery systems capable to deliver at the appropriate site of action within the specific time. The present work describes the synthesis of pH responsive semi-interpenetrating network (semi-IPN) hydrogels of N-succinyl-chitosan (NSC) via Schiff base mechanism using glutaraldehyde as a crosslinking agent and Poly (acrylamide-co-acrylic acid)(Poly (AAm-co-AA)) was embedded within the N-succinyl chitosan network. The physico-chemical interactions were characterized by Fourier transform infrared (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA), and field emission scanning electron microscope (FESEM). The synthesized hydrogels constitute porous structure. The swelling ability was analyzed in physiological mediums of pH 7.4 and pH 1.2 at 37°C. Swelling properties of formulations with various amounts of NSC/ Poly (AAm-co-AA) and crosslinking agent at pH 7.4 and pH 1.2 were investigated. Hydrogels showed higher swelling ratios at pH 7.4 while lower at pH 1.2. Swelling kinetics and diffusion parameters were also determined. Drug loading, encapsulation efficiency, and in vitro release of 5-fluorouracil (5-FU) from the synthesized hydrogels were observed. In vitro release profile revealed the significant influence of pH, amount of NSC, Poly (AAm-co-AA), and crosslinking agent on the release of 5-FU. Accordingly, rapid and large release of drug was observed at pH 7.4 than at pH 1.2. The maximum encapsulation efficiency and release of 5-FU from SP2 were found to be 72.45% and 85.99%, respectively. Kinetics of drug release suggested controlled release mechanism of 5-FU is according to trend of non-Fickian. From the above results, it can be concluded that the synthesized hydrogels have capability to adapt their potential exploitation as targeted oral drug delivery carriers.
    Matched MeSH terms: Hydrogen-Ion Concentration
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