Addition Of CaCl2 Research Articles

Pilot-Scale Protease Production by Bacillus sp. C4 for Silk Degumming Processes

ABSTRACT The serine protease of Bacillus sp. C-4 has been reported as candidate proteases in the degumming process of the silk industry. The optimization of protease production by Bacillus sp. C4 was carried out using two-level fractional factorial and central composite designs. The investigation was followed by laboratory and pilot-scale protease production using molasses in batch and fed-batch bioreactors to reduce the production cost. The highest protease activity observed (1546.5 U/mL, equivalent to 34.4 U/mL/h) in a 5-L bioreactor was obtained under fed-batch fermentation compared with batch process. The production of protease was subsequently scaled up to a pilot-scale 300-L fed-batch bioreactor, and a maximum protease activity of 1260 U/mL (28 U/mL/h) was observed. The degumming efficiencies of the protease produced by Bacillus sp. C4 in the CCD and bioreactors were 88.3% and 81.6%, respectively, relative to the alkaline degumming method. Furthermore, the stability test of the protease showed that the addition of CaCl2 prolonged the stability of the protease activity from 4 to 8 weeks at room temperature. Furthermore, the protease can be conveniently preserved at room temperature for 1 month and at 4°C for more than 2 months without the addition of any chemicals/cryoprotectants.

Combined use of CaCl2 roasting and nitric acid leaching for the removal of uranium and radioactivity from uranium tailings

Calcium chloride (CaCl2) roasting and nitric acid (HNO3) leaching were combined to remove uranium and radioactivity from uranium tailings. The results show that the uranium and gross α and β radioactivity removal efficiencies improve with increasing CaCl2 addition and HNO3 leaching time and reach maximum values of 81.5%, 87.9% and 86.5%, respectively, after roasting with 50% CaCl2 for 120 min, followed by 1 mol L−1 HNO3 leaching. The uranium leaching rate is 62.3% higher than with direct acid leaching. The mineralogical characteristics of the roasted clinker show that roasting uranium tailings with CaCl2 changes their mineral phase, and Ca2+ becomes incorporated into the silicate matrix, which is beneficial for removing uranium and other radionuclides by acid leaching.

Use of thermal treatment with CaCl2 and CaO to remove 137Cs in the soil collected from the area near the Fukushima Daiichi Nuclear Power Plant

A massive amount of soils and inflammable materials of plants etc. contaminated by radiocesium are generated from decontamination work in the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident affected area. In present study, the removal experiments of 137Cs in a soil collected from the FDNPP accident affected area were carried out in a lab-scale electrical heating horizontal furnace through thermal treatment with CaCl2 addition over a temperature of 900 – 1300 °C. The results indicated that the average radioactive concentration of 137Cs in the soil was 52.8 Bq/g. The removal ratio of 137Cs in the soil treated at 1300 °C was 96.3 % when 20 % CaCl2 was added. The addition of CaCl2 and CaO mixture exhibited a synergistic effect on the removal of 137Cs, relative to the addition of CaCl2 alone. Accordingly, the addition of CaCl2 or its mixture with CaO during thermal treatment is suggested to remove 137Cs in the soil collected from the FDNPP accident affected area. Additionally, segregation of the soil sample to fine and coarse fraction and then treated individually are also recommended.

Retention of atenolol from single and binary aqueous solutions by thin film composite nanofiltration membrane: Transport modeling and pore radius estimation

The performance of a polyamide-based thin-film composite nanofiltration (NF) membrane (NF33) was investigated for the retention of atenolol, a pharmaceutical pollutant, from the single and binary aqueous solutions. The effect of pH, applied pressure, feed flux, initial atenolol (ATN) concentration, and different co-existing salts with varying concentrations were studied to test the performance of the membrane. The removal efficiency of ATN increased with increasing solution pH giving the highest retention (70.9 ± 3.1) at pH 9, which was slightly decreased with the increasing initial ATN concentration but increased with increasing applied pressure and feed flux. As per the uncharged solutes rejection concept, the average pore radius of NF membrane for slit-like and cylindrical pore geometries were, respectively 0.169 ± 0.003 and 0.264 ± 0.009 nm. The Spiegler-Kedem model could predict the performance of NF membrane by retaining ATN over the investigated range of feed flux. The calculated reflection coefficient (σ) was close to unity, demonstrating the convective transport. Addition of CaCl2 as a co-existing salt into the feed showed promoting effect on ATN retention, and its efficiency was lowered by the addition of NaCl and Na2SO4 salts. As per the cost analysis, the total annualized cost of treatment by the NF was found to be 0.53 $/m3

Application of a cascade membrane filtration process to standardise serum protein depleted cheese milk for cheddar cheese manufacture

A cascade membrane filtration process including microfiltration (MF), ultrafiltration (UF) and reverse osmosis (RO) was used to fractionate skim milk into different streams. Significant quantities of lactose and minerals were removed to permeate after MF at 0.14 μm. Cheese milk, of similar casein content to the raw milk, was standardised simultaneously for casein, lactose, ash and total calcium from the membrane streams without requiring CaCl2 and lactose addition. Serum protein depleted cheese milk of typical casein content had similar rennet coagulability, cheese composition, texture and yield to the control; milk of 1.5 × casein content had a faster coagulation rate and resulted in cheese of lower moisture content. On a dry matter basis, the serum protein content of MF permeate concentrated by UF was significantly higher than that in cheese whey (51.54% versus 5.63–9.45%), with significantly lower contents of ash (0.95% versus 7.11–7.53%) and lactose (9.50% versus 61.98–70.35%).

Mineralized Polyamide66/Calcium Chloride Nanofibers for Bone Tissue Engineering.

This study aimed at designing a novel electrospun scaffolding material that structurally and chemically resembles native extracellular matrix for bone tissue engineering. Calcium chloride-complexed polyamide66 (PA66/CaCl2) and pure PA66 electrospun nanofibers were fabricated by the electrospinning method. Scanning electron microscopy, X-ray diffraction, and Fourier transform infrared (FTIR) spectroscopy were used to investigate the effect of the presence of ionized salt in the polymer solution on the mechanical properties and other properties of the electrospun scaffolds. The results show that addition of CaCl2 to PA66 solution can achieve an internal modification and improve the tensile strength and modulus of the polymeric electrospun nanofiber. Ca2+ uploaded through electrospun fibers could provide nucleation sites for the formation of hydroxylapatite (HA) coating. After mineralization, the tensile strength and modulus of HA/PA66/CaCl2 scaffolds reach up to 41.33 ± 16.17 MPa and 168.59 ± 42.20 MPa, respectively. LIVE/DEAD assay shows that compared with pure PA66 scaffolds, a greater density of viable MC3T3-E1 cells were seen on the HA/PA66/CaCl2 scaffolds. Cell Counting Kit-8 results indicate that HA/PA66/CaCl2 scaffolds displays a more favorable ability to promote MC3T3-E1 cell proliferation and growth than that of the other groups with the prolongation of culture time. These results demonstrate that HA/PA66/CaCl2 scaffolds that structurally and chemically resemble native bone have a good cytocompatibility, and might be a potential candidate for bone tissue engineering. [Figure: see text] Impact statement In this work, the calcium chloride-complexed polyamide66 (PA66/CaCl2) hybrid nanofibers were prepared by adding CaCl2 to the PA66 formic acid solution before electrospinning, and then mineralized by saturated calcium phosphate solution. The findings of this study show that the addition of CaCl2 could achieve an internal modification, improve the tensile strength and modulus of the polymeric electrospun nanofiber, and provide nucleation sites for biomimetic mineralization. This research provides insight and foundation of application of mineralized PA66/CaCl2 electrospun scaffolding material that structurally and chemically resembles native extracellular matrix for bone tissue engineering.

Impact of flocculant addition in oil recovery from multiphasic fermentations

Emulsion formation is a major concern when dealing with multiphasic fermentations. Flocculants can be used together with other demulsification techniques to improve oil recovery in multiphasic fermentations. In this paper, the impact of adding flocculants during a multiphasic fermentation with 10wt% dodecane, to destabilize the broth emulsion, improve creaming formation and enhance oil recovery is studied. Flocculants, CaCl2 and (NH4)2SO4 were shown to be the most promising flocculants. Flocculant addition, their time of addition, and its impact on multiphasic fermentations has been evaluated by comparing fermentation performance against reference fermentations and three oil recovery methods: gravity settling, gas enhanced oil recovery and centrifugation. When adding 75mM of (NH4)2SO4 during fermentation, the creaming rate during gravity settling increased 3-fold and the oil recovery by gas enhanced oil recovery was 35%, without altering fermentation performance. Addition of CaCl2 during fermentation resulted in 88% and 67% oil recovery for early and late addition, which is a 4 and 3-fold increase in comparison with the reference. Yet, CaCl2 deviated from standard fermentation performance when added immediately after second phase addition. In conclusion, flocculant addition during multiphasic fermentation can be used to destabilize microbial emulsions and potentially improve in situ oil recovery.

Chemical and Microstructural Characterization of pH and [Ca2+] Dependent Sol-Gel Transitions in Mucin Biopolymer

Mucus is responsible for controlling transport and barrier function in biological systems, and its properties can be significantly affected by compositional and environmental changes. In this study, the impacts of pH and CaCl2 were examined on the solution-to-gel transition of mucin, the primary structural component of mucus. Microscale structural changes were correlated with macroscale viscoelastic behavior as a function of pH and calcium addition using rheology, dynamic light scattering, zeta potential, surface tension, and FTIR spectroscopic characterization. Mucin solutions transitioned from solution to gel behavior between pH 4–5 and correspondingly displayed a more than ten-fold increase in viscoelastic moduli. Addition of CaCl2 increased the sol-gel transition pH value to ca. 6, with a twofold increase in loss moduli at low frequencies and ten-fold increase in storage modulus. Changing the ionic conditions—specifically [H+] and [Ca2+] —modulated the sol-gel transition pH, isoelectric point, and viscoelastic properties due to reversible conformational changes with mucin forming a network structure via non-covalent cross-links between mucin chains.

The effects of water hardness on the growth, metabolic indicators and stress resistance of largemouth bass Micropterus salmoides

Water hardness varies regionally and optimal levels for fish are often species specific. It is generally assumed that largemouth bass, Micropterus salmoides, require elevated water hardness, but this has not yet been investigated. In this two-part study, M. salmoides juveniles were subjected to 100, 200, 400 and 600 mg/l CaCO3 (by CaCl2 additions) and the survival, growth, ammonia-N excretion/oxygen consumption rates, biochemical composition and ion-regulatory enzymes were measured after one month. Afterwards, fish were subjected to a sudden salinity shock test (SSST) at 10 ppt. In experiment 2, M. salmoides juveniles were subjected to 50 or 400 mg/l CaCO3 for one month and measured for the above-mentioned parameters. In experiments 1 and 2, both feed intake and feed conversion ratio (FCR) significantly decreased at 400 mg/l CaCO3, compared to 50 or 100 mg/l CaCO3, however, hardness had no significant effect on survival or growth. There was no significant effect to gill Na+/K+-ATPase or H+-ATPase activities; however, survival to SSST was significantly less at 50 or 100 mg/l than the other treatments. At 400 mg/l CaCO3, ammonia-N excretion/oxygen consumption rates were significantly less compared at 50 mg/l CaCO3, indicating greater energy expenditure at lower water hardness. These results demonstrate that while high water hardness substantially improves stress resistance in M. salmoides juveniles, they do not require high water hardness for optimal growth.

Oxalic Acid from Corn Stalk for Photocatalytic Reduction of Cr(VI)

Cr(VI) is toxic species of chromium in the aquatic environment. The reduced species, Cr (III), has lower toxicity than Cr(VI). The change of Cr(VI) species to Cr(III) can be conducted by photocatalytic reduction using oxalic acid as an oxidant with the aid of Fe(III) as a catalyst. Oxalic acid can be isolated from the biomass waste of corn stalk. This research aimed to isolate oxalic acid from corn stalk biomass as an oxidator for Cr(VI) photocatalytic reduction. The oxalic acid was isolated from corn stalks powder using NaOH, precipitated with the addition of CaCl2, acidified with H2SO4, and then crystalized to form the oxalic acid crystals. The photocatalytic reduction was carried out in a closed reactor equipped with two of 30-watt UV lights. About 30 mg of oxalic acid was used to reduce 300 mg/L Cr(VI) with the presence of 4 ml Fe(III) 100 mg/L as a catalyst. The process was conducted for 120 minutes while stirring. The reduction efficiency was calculated from the differentiation of the initial Cr(VI) concentration to the final ones. Cr(VI) concentrations were measured as Cr(VI)-diphenylcarbazide complex compound at pH 2 that could be detected at 540 nm. The results showed that the isolated oxalic acid has hydroxyl and carbonyl groups at 3441 cm−1 and 1627 cm−1 respectively identical with the oxalic acid standard. The crystals have melting point at 103°C. It could be used effectively to reduced Cr(VI) up to 45.9 %.

Perubahan Karakteristik Fisik Model Minuman Biji Chia Akibat Proses Pemanasan, Perubahan pH, Penambahan Gula dan Garam

Chia seed is rich in protein, lipid, and carbohydrates as well as bioactive compounds such as phenol. The outer layer of chia seed is made of insoluble polysaccharide (mucilage) which is able to absorb water. For this reason, chia seed is potentially used as a functional ingredient in beverages. This study aimed to evaluate the changes of physical characteristics of chia seeds in beverage models (water absorption capacity or WAC and capsule thickness of chia seeds, and viscosity of beverage model) as the effect of heating temperatures (70, 90oC) and heating times (1, 2 hours), pH changes (3, 5, 7), the addition of sugar (0, 15%) and salts (1% KCl and 1% CaCl2) at 3% and 5% chia seeds. The results showed that the pH of the beverage models affected the WAC, viscosity and capsule thickness. The higher the pH, the greater the WAC, viscosity, and capsule thickness. Sugar concentration and heating time did not affect the physical charac-teristics of chia seeds, whereas the heating temperature only showed a significant effect at pH 3. Addition of CaCl2 1% caused the increase of WAC for approximately twice compared to that of KCl 1%.

Reduction of the P5A-ATPase Spf1p phosphoenzyme by a Ca2+-dependent phosphatase.

P5 ATPases are eukaryotic pumps important for cellular metal ion, lipid and protein homeostasis; however, their transported substrate, if any, remains to be identified. Ca2+ was proposed to act as a ligand of P5 ATPases because it decreases the level of phosphoenzyme of the Spf1p P5A ATPase from Saccharomyces cerevisiae. Repeating previous purification protocols, we obtained a purified preparation of Spf1p that was close to homogeneity and exhibited ATP hydrolytic activity that was stimulated by the addition of CaCl2. Strikingly, a preparation of a catalytically dead mutant Spf1p (D487N) also exhibited Ca2+-dependent ATP hydrolytic activity. These results indicated that the Spf1p preparation contained a co-purifying protein capable of hydrolyzing ATP at a high rate. The activity was likely due to a phosphatase, since the protein i) was highly active when pNPP was used as substrate, ii) required Ca2+ or Zn2+ for activity, and iii) was strongly inhibited by molybdate, beryllium and other phosphatase substrates. Mass spectrometry identified the phosphatase Pho8p as a contaminant of the Spf1p preparation. Modification of the purification procedure led to a contaminant-free Spf1p preparation that was neither stimulated by Ca2+ nor inhibited by EGTA or molybdate. The phosphoenzyme levels of a contaminant-free Spf1p preparation were not affected by Ca2+. These results indicate that the reported effects of Ca2+ on Spf1p do not reflect the intrinsic properties of Spf1p but are mediated by the activity of the accompanying phosphatase.

Thermal and Mineral Sensitivity of Oil-in-Water Emulsions Stabilised using Lentil Proteins.

Oil-in-water emulsion systems formulated with plant proteins are of increasing interest to food researchers and industry due to benefits associated with cost-effectiveness, sustainability and animal well-being. The aim of this study was to understand how the stability of complex model emulsions formulated using lentil proteins are influenced by calcium fortification (0 to 10 mM CaCl2) and thermal processing (95 or 140 °C). A valve homogeniser, operating at first and second stage pressures of 15 and 3 MPa, was used to prepare emulsions. On heating at 140 °C, the heat coagulation time (pH 6.8) for the emulsions was successively reduced from 4.80 to 0.40 min with increasing CaCl2 concentration from 0 to 10 mM, respectively. Correspondingly, the sample with the highest CaCl2 addition level developed the highest viscosity during heating (95 °C × 30 s), reaching a final value of 163 mPa·s. This was attributed to calcium-mediated interactions of lentil proteins, as confirmed by the increase in the mean particle diameter (D[4,3]) to 36.5 µm for the sample with 6 mM CaCl2, compared to the unheated and heated control with D[4,3] values of 0.75 and 0.68 µm, respectively. This study demonstrated that the combination of calcium and heat promoted the aggregation of lentil proteins in concentrated emulsions.

A novel method for the preparation and prolonged storage of growth factors and cytokines obtained from platelet rich plasma

Purpose: Platelet Rich Plasma (PRP) therapy is employed for the treatment of damaged and/or injured connective tissues and/or chronic degenerative joint conditions (osteoarthritis). PRP fractions are typically collected in the presence of a blood anticoagulant to avoid a premature activation of the platelets resulting in the uncontrolled growth factors and the cytokines releasing. Platelet activation can be achieved through addition of CaCl, thrombin, freezing and thawing of platelets and ultrasonic waves, however each of these activation methods has regulatory or cost drawbacks.

Stability assay of antagonistic activity of Serratia plymuthica strain UBCR_12 under various environmental factors

Serratia plymuthica strain UBCR_12 exhibited promising antifungal activity against Colletotrichum gloeosporioides. The development of this strain for field use requires a certain level of stability towards various environmental exposures that might occur in the natural condition. This study was aimed to evaluate the stability level of antifungal activity produced by the culture supernatants of S. plymuthica strain UBCR_12 under several environmental factors. Antifungal assay of this strain was performed through the application of culture supernatants under several parameters and was performed in five technical replications. Data were confirmed statistically using one-way and two-way ANOVA and significance among treatments were verified through DNMRT with a p<0.05. The antagonistic effect of this strain varied in each environmental parameter tested. The highest suppression was recorded at pH 8.0 [30.32%] after eight days of application indicating that the alkaline condition might trigger its defense mechanism. Other parameters showed quite similar inhibition efficacy, such as 24.06% [100 C for 45 minutes] and 21.15% [CaCl2 addition]. Compared to control, this strain could suppress anthracnose-causing fungi up to 24.06% suggesting that its antifungal activity was considered as quite stable over the presence of heat and calcium.

Assessment of Ion Affinity for the Lipid Bilayer Interface

Calcium ions play a key role in cell signaling processes, yet the molecular nature of their interaction with heterogenous membranes is difficult to study with traditional techniques. Parameters were developed for sodium, calcium and chloride ions for use with the CgProt force field for molecular dynamics simulations of membrane‐protein systems. Similar to atomistic simulations, highly attractive behavior was observed for calcium with zwitterionic POPC/POPE membrane interfaces. Both sodium and calcium preferentially bound to the phosphate region of anionic POPG bilayers. The addition of CaCl2 to implicit solvent simulations had the effect of stabilizing the lipid bilayer. Sub‐molar concentrations of calcium adsorb onto POPE and POPG membranes and enable low or zero tension simulations. Close agreement in the area per lipid was obtained compared to results from atomistic simulations, indicating the utility of the model for large scale membrane simulations.Support or Funding InformationNational Science Foundation, grant MCB 1516826

Preparation and digestive characteristics of a novel soybean lipophilic protein-hydroxypropyl methylcellulose-calcium chloride thermosensitive emulsion gel

This study describes the preparation, physicochemical characterization, and nutrient release behavior analysis during the in vitro digestion of a soybean lipophilic protein-hydroxypropyl methylcellulose-calcium chloride (LHC-Ca) thermosensitive emulsion gel. Infrared spectroscopy, X-ray diffraction (XRD), and 1H NMR spectra showed that CaCl2 addition changed the crystallinity of HPMC and reduced its hydrogen content, thereby lowering its emulsion gel temperature significantly. Microstructure and rheology showed that CaCl2 addition effectively altered LHC-Ca's fundamental structure and interface characteristics. The ideal LHC-Ca performances were achieved using 0.3 M CaCl2. Simulated in vitro digestion experiments replicated the targeted release of vitamin E in the intestine and higher bioaccessibility. These findings may help develop a functional thermosensitive emulsion gel carrier based on a lipophilic-hydroxypropyl methylcellulose (LP-HPMC) emulsion for targeted and sustained release of nutrients.

Enhancement of desorption amount of carbon dioxide gas from monoethanolamine solution using ultrasound and calcium chloride

Ultrasound can desorb CO2 from dissolved CO2 gas [CO2(aq)] in a low-concentration monoethanolamine (MEA) solution (0.2 M) at a low temperature (25 °C). However, it is difficult to desorb CO2 using ultrasound at pH >8.2 because CO2 mainly exists as HCO3− and not as CO2(aq). We investigated the increment of the CO2 gas desorption ratio on the synthesis reaction of CaCO3 by the shift in the CO2 equilibrium in the direction of the increase of CO2(aq) by the decrease of pH from 8.2 with an increase in the H+ concentration in the MEA solution. Results indicated that a high Ca recovery ratio of 93.1% was observed by CaCl2 addition and ultrasound irradiation. Compared with the desorption ratio of CO2 gas using ultrasound irradiation without the addition of CaCl2, the CO2 gas desorption ratio increases from 2.2% to 9.8% using ultrasound with a low concentration of CaCl2 (Ca/MEA molar ratio 0.026).

Effect of CaCl2 on the stability and rheological properties of foams and high-sugar aerated systems produced by preheated egg white protein

This study aimed to evaluate foams and meringues produced from preheated egg white protein (PH-EWP) in the presence of CaCl2 as compared to those from native egg white protein (native EWP). EWP solution was heated at alkaline condition (pH 11.3) to form a solution of denatured protein. While both the native and PH-EWP solutions showed similar foaming capacity, liquid drainage was significantly lower for the latter foams than the former ones. Furthermore, while CaCl2 had no significant effect on drainage of native EWP based foams, the addition of CaCl2 significantly decreased the drainage of the PH-EWP foams probably by forming a viscoelastic network at the bubble surface. As a proof-of-concept for the application of the PH-EWP in an actual food product, stability and rheological properties of French meringues produced by native EWP and PH-EWP were investigated. While French meringues prepared from native EWP showed an undesirable runny texture, French meringues made with PH-EWP, particularly those supplemented with CaCl2, had a stronger viscoelastic network with a higher zero-shear viscosity, yield stress, and elastic modulus so that the meringues could support its weight under gravity, rather like a dollop of whipped dairy cream. This research has developed a new method to stabilize food foam systems by using PH-EWP as a dual function ingredient, not only facilitating foam formation but also as the thickening and structuring agents to stabilized them in the presence of Ca2+.

Effect of calcium chloride on the protein encapsulation and stability of proliposomal granules

The purpose of this study was to develop oral proliposomal granules incorporating CaCl2 in order to enhance the encapsulation efficiency (EE) of protein model drug after reconstitution. Proliposomal granules were prepared by a granulation process with a solid carrier, protein model drug, and lipid solution. The proliposomal granules were characterized in terms of particle size, EE, and loading capacity. Protein structure analysis and cellular viability were also examined. CaCl2, ranged 0.125–6.0% w/w, was successfully incorporated into the dried granules during the wet binding process of granulation. Reconstituted proliposomes with 1% w/w CaCl2 showed the highest EE among those examined. Different reconstituted diluents did not alter the EE, but had an impact on particle size and charge. The α-helical content (%), calculated from the mean molar ellipticity, was similar between protein drug alone and that with addition of CaCl2, indicating the preservation of structural integrity, as also confirmed by electrophoresis. CaCl2–incorporated proliposomes were non-toxic to cells at the dose used. In conclusion, inclusion of CaCl2 into proliposomal granules enhanced the EE of protein drug showing optimal effects at 1% w/w with good preservation of protein integrity and cellular viability.