Nessler Method Research Articles

Nessler Method Verification for Determining Ammonia in Shrimp Pond Wastewater and Its Application in the Ammonia Adsorption Test with Lampung Natural Zeolite

Ammonia levels exceeding 0.50 mg/L can threaten organisms in aquatic environments. The Nessler method is one of the ammonia analysis methods based on the reaction between ammonia in a basic solution and Nessler reagent (K<sub>2</sub>HgI<sub>4</sub>), forming a colloidal dispersion with a brownish-yellow colour. The colour intensity is determined by spectrophotometry. This research aims to verify the Nessler method for determining ammonia levels in shrimp pond wastewater. The research results indicate that the Nessler method shows good linearity in the range of ammonia concentrations from 1 to 5 mg/L, with a correlation coefficient (R<sup>2</sup>) value of 0.9962. The precision value was determined from repeatability, expressed as %RSD (Relative Standard Deviation), i.e., 1.92%, and it meets acceptance criteria, which should be less than 0.5 of the Horwitz RSD. The accuracy obtained from the standard addition method provides a percentage recovery value of 99.25%, meeting the AOAC acceptance criteria. The detection limit and quantification limit of the technique are 0.3883 mg/L and 1.2943 mg/L, respectively. The verified method is then applied to analyze shrimp pond wastewater samples from Sriminosari Village, East Lampung, resulting in an ammonia concentration of 1.52 mg/L. The ammonia levels were then reduced by adsorption with natural zeolite Lampung, decreasing ammonia levels by 20.30%. Meanwhile, adsorption with an activated zeolite reduced the ammonia levels by 45.30%.

The Characteristics of Urease Enzyme of Green Bean Seeds (Vigna radiata L.) and Its Activity as An Antifungal Against Candida albicans

Urease is an enzyme responsible for catalyzing the hydrolysis reaction of urea into CO2 and NH3. The urease isolated in this study came from green bean seeds. The urease enzyme was then tested for its antifungal activity against Candida albicans. The research aims to extract and characterize the urease enzyme from green bean seeds and explore its potential use as an antifungal agent. Green bean seeds were smoothed with a mortar and pestle, followed by homogenization using a stirrer and cold centrifugation. The crude extract of the urease enzyme was assessed for its activity through the Nessler method and measured by employing a UV-Vis spectrophotometer at a wavelength of 500 nm. The well-diffusion method was conducted to determine the antifungal activity of rough enzyme extracts against C. albicans. Positive controls were 100% ketoconazole, and negative controls used a pH buffer of 7. The characterization of the urease enzyme from green bean seeds revealed the optimum urease activity at a concentration of 0.25 M, pH level of 7, and an incubation temperature of 35°C with a value of 32.115 U/mL. Maximum reaction rate (Vmax) and Michaelis-Menten constant value (KM) were obtained at 56.497 U/mL and 0.215 M, respectively. Antifungal tests of C. albicans resulted in strong inhibitory activity at a concentration of 100% crude urease extract of 12 mm inhibition zone. The inhibitory concentration value grows at least 0.5% by 0.25 mm and positive control of 19.802 mm.

Immobilization of Urease from Psophocarpus tetragonolobus L. DC. using Natrium Alginate Supporting Matrix

Urease is an enzyme that has the role to hydrolyzes urea into ammonia and carbon dioxide. Immobilization is one of the most efficient strategies to improve its activity recovery and properties of urease. This research started with the germination of winged beans for 8 days. The winged bean was extracted by grinding using a mortar and pestle and then added with phosphate buffer at pH 7. The solution was homogenized using a stirrer and then centrifuged in cold conditions so that an extract of urease was obtained. Urease extracts were immobilized using a chitosan-supporting matrix. Optimization of the immobilization process of urease extract includes the concentration of chitosan and sodium tripolyphosphate (TPP) and contact time. The obtained was free and immobilized urease activities then tested using the Nessler method and measured using a UV-Vis spectrophotometer with a wavelength of 500 nm. The obtained data were then statistically tested using ANOVA. Urease-chitosan beads were further tested in repeated use and analyzed with SEM-EDX (Scanning Electron Microscopy-Energy Dispersive X-ray). The results showed that the optimum conditions for making urease-chitosan beads were a concentration of 4% (w/v), 2.5% (w/v) TPP, and 60 minutes of contact time, resulting in an activity value of 15.076 U/mL, which can be used 5 times with 46% activity from the initial activity. The EDX analysis results after the addition of the enzyme showed atom composition changes leading to increasing carbon and nitrogen contents. The existence of phosphor showed that TPP was a chitosan cross-link compound.
 
 Keywords: Chitosan, immobilization, TPP, urease, winged bean

Implementation of plate reader-based indooxine and Nessler protocols for monitoring L-asparaginase serum activity in childhood acute lymphoblastic leukaemia.

Monitoring the blood serum activity of L-asparaginase in children with acute lymphoblastic leukaemia (ALL) has been highly recommended to detect enzyme inactivation that can cause relapse and to avoid unwanted toxicity. Nevertheless, perhaps at least partially due to the lack of clinically approved commercially available kits or standardized and independently reproduced and validated in-house protocols, laboratory assay-based determination of the optimal doses of L-asparaginase is not carried out routinely. In this study, we adapted previously published protocols for two plate reader-based colorimetric methods, indooxine and Nessler, to measure asparaginase activity. Mock samples with dilutions of the enzyme for initial optimization steps, and patient samples were used as a proof of principle and to compare the two protocols. For the first time the indooxine and the Nessler methods are adapted for a plate reader and L-asparaginase serum activity levels are compared by both protocols. Passing-Bablok and Bland-Altman's statistical analyses found very little difference, strong correlation (r = 0.852), and bias of only 6% between the data from the two methods when used for fresh patient samples. Furthermore, we demonstrate that the Nessler method could also be applied for frozen sera as the results, compared to fresh samples, showed little difference, strong correlation (r = 0.817), and small bias (9%). We successfully adapted and validated two methods for measuring L-asparaginase activity in cALL and provided the most detailed description to date on how to reproduce and implement them in other clinical laboratories.

Synthesis and development of Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/CaCO<sub>3</sub> nanocomposite adsorbents for ammonia adsorption in the shrimp pond waste

<p>We developed a Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/CaCO<sub>3</sub> magnetic nanocomposite adsorbent, with SiO<sub>2</sub> synthesized from sea sand and CaCO<sub>3</sub> derived from coral skeletons. The Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/CaCO<sub>3</sub> nanocomposite was characterized and employed as an adsorbent to reduce ammonia levels in shrimp pond wastewater where ammonia concentrations ranged from 11.9 to 38.8 mg/L. We further explored the effects of various parameters on the removal efficiency, adsorption capacity, thermodynamics, isoterm, and kinetics of the adsorption process. Specifically, we examined the influence of pH (3–8), adsorbent mass (0.025–0.25 g), temperature (27–60 ℃), and contact time (10–120 min). Ammonia concentrations in the filtrate were measured using the Nessler method. The synthesis of CaCO<sub>3</sub> from coral skeleton, SiO<sub>2</sub> from sand, and Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/CaCO<sub>3</sub> adsorbent was successfully achieved, as confirmed by XRF, FTIR, and XRD characterizations. The adsorption process adhered to the second-order kinetics model, exhibited spontaneous behavior with a negative ΔG value, and followed the Langmuir isotherm model (R<sup>2</sup> = 0.9267). The results indicated an optimal adsorbent mass of 0.025 g, achieving 89.3% adsorption at 60 minutes of contact time, a temperature of 27 ℃, and an optimal pH of 5. When applied to shrimp pond wastewater, the Fe<sub>3</sub>O<sub>4</sub>/SiO<sub>2</sub>/CaCO<sub>3</sub> adsorbent demonstrated an adsorption efficiency ranging from 52.1% to 86.8% and an adsorption capacity between 6.2 and 30.9 mg/g.</p>

Study of Ammonia-Nitrogen and Phosphorus in Parit Rasipan Canal During the Wet Season

The Parit Rasipan Canal's deteriorating water quality and eutrophication are both blamed on ammonia-nitrogen and phosphorus. In order to conserve freshwater resources, it is crucial to understand the relationship between land use and water quality. It is also crucial to evaluate how land use affects the pollutants load. In this study, eutrophication along the Parit Rasipan drainage system will be identified, water quality will be investigated in terms of phosphorus and ammonia nitrogen concentration and classified according to land use type during the wet season, and ammonia-nitrogen and phosphorus concentrations will be compared with Normalized Difference Vegetation Index (NDVI) using unmanned aerial vehicles (UAV). At a specific location along the Parit Rasipan drainage system, samples were taken. The USEPA PhosVer 3 (Method 8190) and Nessler's Method (Method 8038) were used, respectively, to measure phosphorus and ammonia nitrogen. Ammonia nitrogen and phosphorus final effluent concentrations ranged from 3.21 mg/L to 5.96 mg/L and 0.36 mg/L to 1.55 mg/L, respectively. The residential area's water, on the other hand, had significant concentrations of ammonia, nitrogen, and phosphorus, which contributed to eutrophication in the wake of industrial, agricultural, and farming activities.

Production, Characterization, and Toxicity Test of L-asparaginase from Vibrio alginolyticus Bacterial Symbiont of Green Algae Caulerpa lentillifera

L-asparaginase is an enzyme that can be used as an anticancer therapeutic agent. This study aimed to optimize fermentation time for production, optimization, and to test the toxicity of L-asparaginase from Vibrio alginolyticus (V. alginolyticus) bacterial symbiont of green algae Caulerpa lentillifera (C. lentillifera). The activity of L-asparaginase enzyme assay and the toxicity test were done by using the Nessler method and the Brine Shrimp Lethality Test (BSLT) method respectively. The results show L-asparaginase with 66 hours of fermentation time indicates the highest enzyme activity. L-asparaginase mentioned has an optimum enzyme activity of 17.99 U/mL for 30 minutes of incubation time at 37 °C, and pH 7.5. The BSLT results show LC50 value of 17.83 μg/mL indicating the enzyme is bio-toxic with high-level toxicity, which can continue for cytotoxicity tests on cancer cells.

A new miniaturized microextraction HS-LPME-OIP procedure for ammonium determination based on Nessler's method

A recently proposed combination of headspace liquid-phase microextraction with an optical immersion probe (HS-LPME-OIP) was adapted for the spectrophotometric determination of ammonium. The developed method is based on the conversion of ammonium ions to ammonia in a 0.15 M sodium hydroxide solution, followed by the absorption of ammonia by 200 µL of Nessler's reagent solution preliminary diluted with distilled water (1:16.7). The extracting phase, in which OIP was immersed, was placed into vial fixed in the headspace above the sample solution in a hermetically sealed vessel. The analytical signal was monitored for 30 min at 400 nm. The duration of the analysis can be flexibly adjusted and, if necessary, reduced to 5 min. The level of permissible concentrations of some interfering substances, including calcium, magnesium, iron and some organic compounds, was significantly reduced. The LOD was equal to 0.20 mg L−1, and the linear calibration range was from 0.70 to 15 mg L−1. The RSD ranged from 2.5 to 5.2%. The developed method was successfully applied to the analysis of natural waters, fertilizers and CRM samples.Graphical abstract

Immobilization of urease from Phaseolus vulgaris L. seeds using calcium alginate as a support matrix

Urease is an enzyme that functions as a catalyst in the hydrolysis of urea into ammonia and carbon dioxide. The industrial sector has made extensive use of urease. To date, enzymes are used in free form, deemed less effective. Therefore, enzymes are used in immobilized form because they can be utilized repeatedly. This research aimed to isolate urease from kidney bean (Phaseolus vulgaris L.) seed and immobilize it using a Ca-alginate support matrix and a trapping technique. Eight days were devoted to germinating kidney bean seeds to begin the investigation. Isolation of crude urease extract from kidney beans was carried out using phosphate buffer pH 7. It was then immobilized with Ca-alginate at different concentrations of Na-alginate and contact times The crude free and immobilized urease extract was further characterized including pH, temperature and stability of repeated use. The urease activity was determined using the Nessler method using a spectrophotometer. The results demonstrated that urease immobilization from kidney bean seeds with a Ca-alginate matrix was most effective at a concentration of 5% Na-alginate and a contact period of 60 minutes, yielding a value of 5.92 U/mL. The optimal pH of free and immobilized urease was 7 and 8, respectively, and temperatures of 35 and 40 °C, respectively. The immobilization of urease from kidney bean seeds using a Ca-alginate support matrix increased the stability of recurrent use by fivefold, while the relative urease activity remained at 52%.

Study On Utilization of Active Natural Zeolite As Ammonia Absorbent In Aquarium As A Medium Fresh Fish Cultivation

A study of the use of natural zeolite active as ammonia absorbent in an aquarium as the cultivation of medium fresh fish has been conducted. The water sample was taken from the surface water of Toba Lake, Pangururan, Samosir Regency. Natural zeolite was refined until measured at 200 mesh and activated by physics. Determination of ammonia was performed using spectrophotometrically with the Nessler method at the maximum wavelength of 410 nm. The result of the analysis of this study obtained that decrease in water pH and ammonia content in the water after feeding the fish was caused by the absorption of active natural zeolite active to the tenth day which concentration of ammonia on the first and tenth day was 1.2723 mg/L and 2.4171 mg/L with the largest absorption percent on the day to ten was 38.04%.

Actual questions of standardization of water-salt extracts of house dust mites mixed allergens intended for medicinal forms of sublingual immunotherapy

Background: Standardization of medical forms of allergens is the process of establishing and applying a unified system of quality indicators and control methods. Quality control of therapeutic forms of allergens is an essential condition for guaranteeing the clinical efficacy and safety of allergen-specific immunotherapy (ASIT). The technology for obtaining the granular form of the mixed allergen from house dust mites Dermatophagoides pteronyssinus (Der p) and Dermatophagoides farinae (Der f) for oral use was developed in the laboratory of allergens Mechnikov Research Institute of Vaccines and Sera.
 Aims: to determine the authenticity of the anphenolic water-salt extract of the mixed allergen from mites Der p and Der f, intended for the therapeutic form of the drug.
 Materials and methods: Standardization of the obtained allergen extract was carried out by protein nitrogen unit by the Nessler method. The protein concentration was determined by the Bradford method. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) was used to study the presence of protein composition in mixed allergen. The pH value was determined potentiometrically. The comparison of the specific activity of the standard allergen and the experimental mixed allergen was carried out by the method of reverse immunoassay (REAST).
 Results: SDS-PAGE showed the preservation of the protein profile of the water-salt extract of the mixed allergen Der p and Der f, corresponding to the protein profile of allergens of house dust mites. There were no statistically significant differences in the optical density of the studied allergen (four drug series) and the standard allergen with reference serums containing specific IgE to Der p or Der f when reacting with a Class 3 reference serum in REAST(р0,05).
 Conclusions: The above in accordance with the State Pharmacopoeia of the Russian Federation XIV edition is a confirmation of the authenticity of the drug. Not phenolic extraction did not affect the main allergenic components of the mixed allergen Der p and Der f and allowed it to maintain a high degree of specificity.

EFFECT OF SUBSTRATE CONCENTRATION AND FeCl2 ADDITION ON L-ASPARAGINASE ACTIVITIES OF BACTERIA SYMBIONTS BROWN ALGAE Sargassum sp. AND ITS POTENTIAL AS A NEW ANTI-DENGUE AGENTS

The disintegration of the amide link, causing L-Asparaginase catalyzes the hydrolysis process of L-Asparagine into ammonia and aspartic acid. The purposes of this study were to determine the optimal conditions for enzyme production and enzymatic activity, including their potential as a new anti-dengue of L-asparaginase from Klebsiella sp. The Nessler method used a UV-Visible spectrophotometer to determine the L-asparaginase activity by measuring ammonia levels produced by L-asparaginase catalysis. The ideal fermentation period was at the 48th hour, and the optimal substrate concentration was 10 g/L with an activity value of 49.572 U/mL, and the optimal FeCl2 concentration was 0.5 g/L with an activity value of 60.1183 U/mL, and protein content of 0.1878 mg/mL. The optimum conditions for L-asparaginase, which has an activity value of 61.1182 U/mL, were observed at pH 8 and 37 °C. The optimum cofactor concentration of FeCl2 was 0.5 mM, which resulted in an activity value of 106.5046 U/mL. Both the inhibition percentage and CC50 value were 80% and 167.15 μg/mL respectively, showing that the L-asparaginase has a high antidengue potential.

Immobilization of Urease onto Modified Egg Shell Membrane through Cross Linking

Background:Immobilization is an approach in industry to improve stability and reusability of urease. The efficiency of this technique depends on the type of membrane and the method of stabilization. Methods:The PEI-modified egg shell membrane was used to immobilize urease by absorption and glutaraldehyde cross-linking methods. The membranes were characterized by FTIR and AFM, and Nessler method was applied to measure the kinetic of the immobilized enzymes. Finally, the storage stability (6 °C for 21 days) and reusability (until enzyme activity reached to zero) of the immobilized enzymes were investigated. Results:Based on FTIR, three new peaks were observed in both the absorption- (at 1389.7, 1230.8, and 1074.2 cm-1) and the cross-linking (at 1615-1690, 1392.7, 1450 cm-1) immobilized enzymes. The surface roughness of the native membrane was altered after PEI treatment and enzyme immobilization. The optimal pH of cross-linking immobilized enzymes was shifted to a more neutral pH, while it was alkaline in adsorption-immobilized and free enzymes. The reaction time decreased in all immobilized enzymes (100 min for free enzyme vs. 60 and 30 min after immobilizing by adsorption and cross-linking methods, respectively). The optimal temperature for all enzymes was 70 °C and they had a higher Km and a lower Vmax than free enzyme. The stability and reusability of urease were improved by both methods. Conclusion:Our findings propose these approaches as promising ways to enhance the urease efficiency for its applications in industries and medicines.

Extraction and Characterization of Urease from Durio zibethinus L

Urease is a biocatalyst that serves to hydrolyze urea into ammonia and carbon dioxide. Since it is an imported product, the price of urea is still high. Urease can be found in grains. One of the grains that has not been explored for its urease content is durian (Durio zibethinus L.) seeds. This study aims to determine the effect of germination time on the activity of urease from durian seeds and its characteristics including the effect of pH, incubation temperature, enzymatic reaction time, addition of EDTA and metals, and storage time on the activity of urease from durian seeds. The first step of this study was seed germination which was carried out in the dark for 0, 3, 5, 7, and 9 days. Durian seed sprouts were extracted by mashing them using a mortar and pestle. They were then homogenized using a stirrer and centrifuged in a cold state. The crude urease extract obtained was then tested for its activity using the Nessler method. The acquired data was tested statistically using ANOVA. The results showed that the activity of urease from durian seeds was optimum at 3-day germination time, pH 7, incubation temperature at 30 °C, and 15-minute enzymatic reaction time with an activity of 163.6 U/mL. Urease is a metalloenzyme with its inhibitor being the Cu2+ and Na+ metal ions and its activator being Ba2+ metal ion. Tukey's test analysis showed that the effect of urease storage time at 4 °C resulted in a stable urease activity for 8 days while at room temperature it decreased its activity significantly to 72.8%.

Determination of Cu and Pb concentrations based on urease activity inhibition of Durio zibethinus L. seeds

The determination of heavy metal concentrations has been carried out using sophisticated instruments, and therefore a simple and reliable alternative method is needed as a comparison. The study aimed to determine Cu and Pb concentration of standard solution using the urease activity inhibition method of Durio zibethinus L. seeds. The research started with urease extraction from Durio D. zibethinus L. seeds. The activity of the obtained extract was determined using the Nessler method. The optimum substrate concentration was also determined. Urease activity inhibition was carried out using various metal solution concentrations, which continued by plotting a log graph of urea concentration vs. %inhibition. The obtained graph would then determine the metal concentration in a synthetic water sample. The data was then compared to the measurement, determined by the Atomic Absorption Spectrophotometry (AAS) method. Results of the study showed that the urease activity of D. zibethinus L.seeds was 296.774 U/mL. Urease activity was optimum at a urea concentration of 0.3 M. The comparison Cu, and Pb concentration determination using the urease inhibitory activity and AAS methods showed no significant difference at 95% confidence level. This research showed that urease of D. zibethinus L. seed could be used to determine Cu and Pb's concentration based on its inhibiting activity.

Bacteria producing L-asparaginase isolated from Peruvian saline environments

L-asparaginase (EC 3.5.1.1) hydrolyzes L-asparagine in L-aspartic acid and ammonia. Its efficiency is subject to its kinetics and specificity on the substrate, characteristics that vary from one source to another. Thus, microorganisms from saline environments constitute a phylogenetic and metabolically heterogeneous group for the search of new enzymes. Therefore, the objective of this study was the phenotypic and genotypic characterization of bacteria with L-asparaginase activity isolated from Maras, Pilluana and Chilca salterns. The 24 evaluated bacteria were classified as 38% Gram-negative bacilli and 54% positive; and 8% Gram-positive cocci. The majority grew in 5% salt water, pH 7.0 and 37 °C, all assimilated glucose. Of the 24 bacteria that produced L-asparaginase in solid medium, enzymatic activity was determined in submerged cultures by the Nessler method in 14 of them. The CH11, M62, M64, M68, and P19 strains identified as Bacillus sp., by partial sequencing of the 16S ribosomal gene, presented higher L-asparaginase activity and instability due to the presence of proteases. Saline environments bacteria are potential sources for the prospective production of L-asparaginase to use them as a therapeutic agent and in the food industry.

Occurrence dynamics of nitrogen compounds in faecal sludge stabilisation ponds in the Tamale Metropolis, Ghana

Faecal sludge, with richness in soil nutrients represents an important resource for enhancing soil productivity. In this study, the occurrence dynamics of nitrogen compounds NH3, NO2- and NO3- in engineered waste stabilisation ponds in the Tamale metropolis was monitored for 5 months in the dry season. Four treatment ponds were divided into three units: Influent point, midpoint and effluent point for sampling purposes. Faecal sludge sampling was simultaneously carried out for each of the ponds at marked points and approximate depth of 30 to 50 cm using 500 ml sample collection bottles. Using the Nessler method and Powder Pillows NH3, NO3- and NO2- levels were determined through direct reading with a DR 2800 Spectrophotometer. Mean concentrations of NH3, NO3-, and NO2- were determined to be 42.65, 57.99 and 0.15 mg/l, respectively. The anaerobic pond on average, recorded the maximum concentration levels of all three compounds. The primary facultative pond recorded the average minimum concentration of NO2- while the maturation pond recorded the minimum for both NH3 and NO3. Variation in concentration of nitrogen compounds was statistically highly insignificant by ANOVA at 5% significance level, except NH3. Average NH3 concentrations in stabilisation ponds were observed to be higher than the allowable limit of EPA Ghana for effluent discharge or reuse for agriculture while NO3- was lower aside concentration in the anaerobic pond. The effluent should further be treated to reduce NH3 concentration using different treatment options such as the filter beds or constructed wetland prior to reuse for agriculture. Key words: Faecal sludge, stabilisation pond, nitrogen compounds, nitrification, denitrification.

Ammonia Liquid Waste Processing using Electrolysis Method

Abstract This study uses an ammonia wastewater treatment system using 6 lanes and uses a batch-continuous system with electrolysis. Ammonia liquid waste content before and after electrolysis was analyzed using the Nessler method and analyzed using the Spectrophotometry method at a wavelength of 460 nm. Ammonia liquid waste with ammonia content can be used between 18,000-22,000 ppm used as a test sample. The results of this study indicate that the decrease in ammonia concentration every time is directly proportional to the amount of strong current and the number of electrode cells applied. The difference in number, by using 1 pair of cells can reduce 49.19%, 3 pairs of cells by 67.89%, and 5 pairs of cells by 85.08%. In the variation of electric current, 1; 5; 10; and 15 amperes produce 34.03%, respectively; 55.99%; 67.68% and 83.28%. On variations in the influence of the flow rate of 250; 500; 750; 1,000; and 1,250 mL/min resulting from a decrease in the concentration of ammonia is relatively the same, ie concentrations between 82% to 84%. The rate of decrease in ammonia concentration at the liquid level reaches 85.08% by using a variation of 5 pairs of electrode cells with a strong current of 15 amperes. The flow rate used is 250 mL/minute, the electrolysis process is carried out for 8 hours. The modification of the wastewater treatment system by using this electrolysis method is feasible for ammonia liquid waste treatment. Keywords : Electrolysis, modification, batch-continuous, Nessler, Spectrophotometry, ammonia liquid waste, electrode cells, current strength, flow rate, stainless steel.

Isolation, characterization and anticancer potential test of crude extract of L-asparaginase enzyme from siam weed leaf (Chromolaena odorata Linn): a novel source

L-asparaginase enzyme is potentially isolated from Siam weed (C. odorata L.) and also used as anticancer treatment. The point of this study is to isolate crude extract of L-asparaginase as well as its characteristics for anticancer. The activity of the enzyme was observed by Nessler Method and its potential for anticancer was tested by Brine Shrimp Lethality Test (BSLT) method. The results showed the specific activity by 4.8234 UI/mg. The enzyme worked maximally at pH of 8, 37 °C for 30 minutes with Na+ and K+ being activator and Ca2+, Zn+2, Mg+2, Cu+2, Co+2, Mn+2 as inhibitor. Base on BSLT revealed an LC50 value of 5.8063 μg/mL and proved that the enzyme has biotoxicity in high level. The results of this study denoted that C. odorata L. leaves able to be isolated and characterized by L-asparaginase enzyme and these reveals the potential to be developed as an anticancer in the future.

Interferences that impact measuring optimal L-asparaginase activity and consequent errors interpreting these data.

L-asparaginase is an enzyme produced by microorganisms, plants, and animals, which is used clinically for the treatment for acute lymphoblastic leukemia (ALL) and, in the food industry, to control acrylamide formation in baked foods. The purpose of this review was to evaluate the available literature regarding microbial sources of L-asparaginase, culture media used to achieve maximum enzyme expression in microbial fermentations, and assay methods employed to assess L-asparaginase activity. Studies were gathered by searching PubMed, and Web of Science databases before January 22, 2018, with no time restrictions. The articles were evaluated according to the source of L-asparaginase being studied, the nitrogen source in the culture medium, the type of sample, and the method employed to evaluate L-asparaginase activity. Bacterial L-asparaginase appeared to be the most commonly studied source of the enzyme and, most often, the enzyme activity was assayed from crude protein extracts using the Nessler method, which is an indirect measurement of asparaginase activity that determines the concentration of ammonia generated after the action of the enzyme on the substrate, L-asparagine. However, ammonia is also generated throughout microbial fermentations and this endogenous ammonia will also reduce the Nessler reagent if crude microbial extracts are used to determine total L-asparaginase activity. We suggest that current estimates of L-asparaginase activity reported in the literature may be overestimated when Nessler reagent is used, since we were unable to find a single study that made reference to the possible inference of fermentation derived ammonia.