Ammonium Sulfate Precipitation Research Articles

Engineered Alcaligenes sp. by chemical mutagen produces thermostable and acido-alkalophilic endo-1,4-β-mannanases for improved industrial biocatalyst

This study reported physicochemical properties of purified endo-1,4-β-mannanase from the wild type, Alcaligenes sp. and its most promising chemical mutant. The crude enzymes from fermentation of wild and mutant bacteria were purified by ammonium sulfate precipitation, ion exchange and gel-filtration chromatography followed by an investigation of the physicochemical properties of purified wild and mutant enzymes. β-mannanase from wild and mutant Alcaligenes sp. exhibited 1.75 and 1.6 purification-folds with percentage recoveries of 2.6 and 2.5% and molecular weights of 61.6 and 80 kDa respectively. The wild and mutant β-mannanase were most active at 40 and 50 °C with optimum pH 6.0 for both and were thermostable with very high percentage activity but the wild-type β-mannanase showed better stability over a broad pH activity. The β-mannanase activity from the parent strain was stimulated in the presence of Mn2+, Co2+, Zn2+, Mg2+ and Na+. Vmax and Km for the wild type and its mutant were found to be 0.747 U//mL/min and 5.2 × 10−4 mg/mL, and 0.247 U/mL/min and 2.47 × 10−4 mg/mL, respectively. Changes that occurred in the nucleotide sequences of the most improved mutant may be attributed to its thermo-stability, thermo-tolerant and high substrate affinity- desired properties for improved bioprocesses.

Purification and biochemical characterization of a novel ene- reductase from Kazachstania exigua HSC6 for dihydro-β-ionone from β-ionone.

We purified and characterized a novel ene-reductase (KaDBR1) from Kazachstania exigua HSC6 for the synthesis of dihydro-β-ionone from β-ionone. KaDBR1 was purified to homogeneity by ammonium sulfate precipitation and phenyl-Sepharose Fast Flow and Q-Sepharose chromatography. The purified enzyme was characterized by measuring the amount of dihydro-β-ionone from β-ionone with LC-MS analysis method. The molecular mass of KaDBR1 was estimated to be 45kDa by SDS-PAGE. The purified KaDBR1 enzyme had optimal activity at 60°C and pH 6.0. The addition of 5mM Mg2+, Ca2+, Al3+, Na+, and dithiothreitol increased the activity of KaDBR1 by 25%, 18%, 34%, 20%, and 23%, respectively. KaDBR1 favored NADH over NADPH as a cofactor, and its catalytic efficiency (kcat/Km) toward β-ionone using NADH was 8.1-fold greater than when using NADPH. Owing to its unique properties, KaDBR1 is a potential candidate for the enzymatic biotransformation of β-ionone to dihydro-β-ionone in biotechnology applications.

Biochemical and Kinetic Study for the Partial Purified Thioredoxin Reductase from Healthy Human Serum

The research included the separation of thioredoxin reductase (TrxR) from human blood serum using different biochemical techniques. Two proteinous peaks had been isolated by gel filtration using sephadex)G-50) and three proteinous peaks isolated from sephadex (G-100) that produced by ammonium sulphate precipitation (65%). The approximately molecular weight of the isolated protein as a source of enzyme using gel filtration chromatography (G-100) was (118059 + 925) Dalton.
 The results showed two peaks of enzyme when using ion exchange-type DEAE-cellulose and when using electrophoresis technique type SDS-PAGE indicated the presence of two bands from peak of separation column type sephadex G-100 and one band of each peak, resulting from the ion exchange process with molecular weights of 58231 +490 Dalton.
 The results showed that the optimum conditions of purified enzyme from human serum was at (200 µg/ml) of protein as a source of the enzyme using (0.4 mol/l) citric acid-Na2HPO4 buffer solution at pH (7) act for (25) minutes at (40°C). Using Line Weaver-Burk plot, the values of maximum velocity (Vmax) and Michaelis constant (Km) were found to be (0.182 µmol/ min) and (0.013 mol/l) respectively using 5,5-- dithio bis (2-nitrobenzoic acid) (DNTB) as a substrate. Finally, this was, also, involved the study of the effect of some chemicals and drugs on the enzyme activity. The results showed that gundinium - HCl is uncompetitive inhibitor, while bromoacetic acid is noncompetitive inhibitor and zinc sulphate is a competitive inhibitor for the enzyme at different concentrations of inhibitors, but dexathamazone was an activator to the enzyme.

LEGUME INDIAN BEAN (PHASEOLUS VULGARIS) PARTIALLY PURIFIED ANTI-NUTRITIONAL PROTEIN FACTOR EXHIBIT ANTI-OXIDANT, IMMUNOMODULATORY AND ANTI-CANCER PROPERTIES

Objective: This study was aimed to access one of the hidden ANF in Indian bean and assessment of its antioxidant, immunomodulatory, antiangiogenic, and anti-cancer properties. Methods: Indian beans were processed and evaluated for the presence of ANF through HA activity. Bean-ANF was partially purified by ammonium sulfate precipitation (ASP) and dialysis. Obtained Partially Purified bean-ANF (PPb-ANF) resolved on 12% SDS-PAGE, analyzed protease digestibility. The immunogenicity of PPb-ANF was characterized by producing polyclonal antibodies and checked for the presence of natural antibodies in healthy human sera. Pharmacological studies of PPb-ANF were assessed through anti-oxidant, immunogenic, anti-angiogenic and anti-cancer assays. Results: Partially purified Bean-ANF (PPb-ANF) showed significant specific HA activity up to 150 Units/mg compared to crude extract 9.3 of Units/mg. The PPb-ANF was identified to have more than 90% homogeneity in purity with an observed M W of 30-32 kDa. PPb-ANF showed significant pepsin digestive stability up to 2 h at 37 ᵒC and appears digestive resistant. Rabbit produced anti-PPb-ANF IgG polyclonal antibody on immunization and exhibited immunogenic properties. Natural human IgG and IgE antibodies were found in the non-atopic human sera against PPb-ANF, indicative of its immunogenicity. Pharmacological studies of PPb-ANF confirmed its potent antioxidant activity. At 400 µg of PPb-ANF showed the highest around 90% DPPH activity and at 150 µg of PPb-ANF showed 89% inhibitory lipid peroxidation activity. The PPb-ANF showed 70% (3 μg) and 40% (1.5 μg) inhibitory in blood vessel density compared to control and exhibited significant anti-angiogenic activity. The PPb-ANF showed a significant (*p<0.05.) reduction in solid tumor weight upon dose-2 treatment (50 mg/kg body weight) and also increased lifespan up to 70 d compared with the control tumor model. Conclusion: PPb-ANF was identified as digestive-resistant, hemagglutinin with a molecular weight of 30-32 kDa. The protein is immunogenic and has potential antioxidant, antiangiogenic and anti-cancer properties. Further purification and mechanistic-based pharmacological characterization might explore this protein as a potential anti-cancer molecule.

Purification and enzymatic properties of a new thermostable endoglucanase from Aspergillus oryzae HML366.

Aspergillus oryzae HML366 is a newly screened cellulase-producing strain. The endoglucanase HML ED1 from A. oryzae HML366 was quickly purified by a two-step method that combines ammonium sulfate precipitation and strong anion exchange column. SDS-PAGE electrophoresis indicated that the molecular weight of the enzyme was 68kDa. The optimum temperature of the purified endoglucanase was 60 ℃ and the enzyme activity was stable below 70 ℃. The optimum pH was 6.5, and the enzyme activity was stable at pH between 4.5 and 9.0. The analysis indicated that additional Na+, K+, Ca2+, and Zn2+ reduced the catalytic ability of enzyme to the substrate, but Mn2+ enhanced its catalytic ability to the substrate.The Km and Vmax of the purified endoglucanase were 8.75mg/mL and 60.24μmol/min·mg, respectively. In this study, we report for the first time that A. oryzae HML366 can produce a heat-resistant and wide pH tolerant endoglucanase HML ED1, which has potential industrial application value in bioethanol, paper, food, textile, detergent, and pharmaceutical industries.

Characterization of Catalase Enzyme from Leaf Tissue of Aronia (Aronia melanocarpa) Plant

Aronia is among the most antioxidant containing plants which is found commonly around the world. Aronia cultivation started in Turkey for the first time in 2012 at the Atatürk Central Research Institute of Garden Cultures, and a plantation was constructed in the experimental area. Since antioxidants help to preserve food by blocking oxidation processes and contributing to the health promotion provided by numerous dietary supplements, nutraceutical and functional food additives, antioxidant capacity of these plants should be well characterized. To assess and evaluate the antioxidant content of foods and plant products, many approaches are utilized. In this study, catalase (CAT) enzyme was partially purified from aronia plant leaf tissue and characterization was carried out. Purification process consisted of homogenate preparation, ammonium sulfate precipitation and dialysis. The optimal ionic strength, pH, substrate concentration and enzyme quantity were examined. These values were found to be 300 mM Tris, pH:8.0, 12 mM H2O2 and 75 μl, respectively, for the catalase enzyme of the Aronia plant leaf tissue. This study is the first in the literature dealing with the characterization of antioxidant enzyme from Aronia plant.

Purification, Characterization and Bactericidal Action of Lysozyme, Isolated from Bacillus subtillis BSN314: A Disintegrating Effect of Lysozyme on Gram-Positive and Gram-Negative Bacteria.

In the present study, lysozyme was purified by the following multi-step methodology: salt (ammonium sulfate) precipitation, dialysis, and ultrafiltration. The lysozyme potential was measured by enzymatic activity after each purification step. However, after ultrafiltration, the resulting material was considered extra purified. It was concentrated in an ultrafiltration centrifuge tube, and the resulting protein/lysozyme was used to determine its bactericidal potential against five bacterial strains, including three gram-positive (Bacillus subtilis 168, Micrococcus luteus, and Bacillus cereus) and two gram-negative (Salmonella typhimurium and Pseudomonas aeruginosa) strains. The results of ZOI and MIC/MBC showed that lysozyme had a higher antimicrobial activity against gram-positive than gram-negative bacterial strains. The results of the antibacterial activity of lysozyme were compared with those of ciprofloxacin (antibiotic). For this purpose, two indices were applied in the present study: antimicrobial index (AMI) and percent activity index (PAI). It was found that the purified lysozyme had a higher antibacterial activity against Bacillus cereus (AMI/PAI; 1.01/101) and Bacillus subtilis 168 (AMI/PAI; 1.03/103), compared to the antibiotic (ciprofloxacin) used in this study. Atomic force microscopy (AFM) was used to determine the bactericidal action of the lysozyme on the bacterial cell. The purified protein was further processed by gel column chromatography and the eluate was collected, its enzymatic activity was 21.93 U/mL, while the eluate was processed by native-PAGE. By this analysis, the un-denatured protein with enzymatic activity of 40.9 U/mL was obtained. This step shows that the protein (lysozyme) has an even higher enzymatic potential. To determine the specific peptides (in lysozyme) that may cause the bactericidal potential and cell lytic/enzymatic activity, the isolated protein (lysozyme) was further processed by the SDS-PAGE technique. SDS-PAGE analysis revealed different bands with sizes of 34 kDa, 24 kDa, and 10 kDa, respectively. To determine the chemical composition of the peptides, the bands (from SDS-PAGE) were cut, enzymatically digested, desalted, and analyzed by LC-MS (liquid chromatography-mass spectrometry). LC-MS analysis showed that the purified lysozyme had the following composition: the number of proteins in the sample was 56, the number of peptides was 124, and the number of PSMs (peptide spectrum matches) was 309. Among them, two peptides related to lysozyme and bactericidal activities were identified as: A0A1Q9G213 (N-acetylmuramoyl-L-alanine amidase) and A0A1Q9FRD3 (D-alanyl-D-alanine carboxypeptidase). The corresponding protein sequence and nucleic acid sequence were determined by comparison with the database.

Honey proteins regulate oxidative stress, inflammation and ameliorates hyperglycemia in streptozotocin induced diabetic rats

BackgroundDiabetes Mellitus (DM) poses a serious health problem worldwide and several inflammatory mediators are involved in the pathogenesis of this disease. Honey composed of various constituents which have been proven to have immunomodulatory and anti-inflammatory properties. The aim of this study is to investigate the in vitro and in vivo effects of Ziziphus honey and its isolated crude proteins in modulation of immune system and inflammation involved in the pathogenesis of diabetes.MethodologyThe proteins from Ziziphus honey were isolated by ammonium sulfate precipitation and estimated by Bradford method. In vitro anti-inflammatory activities were evaluated by inhibition of reactive oxygen species (ROS) from phagocytes via chemiluminescence immunoassay and nitric oxide (NO) by Griess method. Cytotoxicity was evaluated by MTT Assay. The comparative effect of oral and IP routes of honey and isolated proteins was observed in streptozotocin (STZ) induced diabetic male Wistar rats. qRT-PCR technique was utilized for gene expression studies.ResultsThe honey proteins suppressed phagocyte oxidative burst and nitric oxide (NO) at significantly lower concentrations as compared to crude honey. The isolated proteins showed promising anti-inflammatory and hypoglycemic effects along with maintenance of body weight of rodents via both oral and IP routes, with significant down-regulation of inflammatory markers TNF-α, IL-1β, IFN-γ, iNOS, caspase 1, Calgranulin A (S100A8) and NF-κB expression in diabetic rats.ConclusionThe isolated honey proteins showed better immunomodulatory and therapeutic potential at significantly lower doses as compared to crude honey.

Ochratoxin A degrading enzymes of Stenotrophomonassp. 043-1a.

Ochratoxin A is a secondary metabolite that acts as a mycotoxin and is produced by Aspergillus, Penicillium, and other fungal species. It is a threat to animal and human health due to nephrotoxic, carcinogenic, and genotoxic properties and its widespread incidence in agricultural products. To reduce this threat, biological remediation processes are of growing interest. The aerobic gram-negative bacterium Stenotrophomonassp. 043-1a, isolated from soil, was previously shown to degrade ochratoxin A into the non-toxic ochratoxin α and l-phenylalanine (Schatzmayr et al. 2002). However, the enzyme or enzymes catalyzing this reaction in this strain remained elusive. Here, we report the targeted purification of Stenotrophomonassp. 043-1a lysate via ammonium sulfate precipitation, size-exclusion chromatography, and hydrophobic interaction chromatography to identify the ochratoxin A degrading enzymes by subsequent peptide fragment fingerprinting. The metallo-dependent hydrolase Chr1_3858681_3267 and a member of the peptidase S9 family, Chr1_3858681_771, were shown to degrade ochratoxin A. This was, to our knowledge, the first report of an ochratoxin A degrading enzyme from the peptidase S9 family.

An alkaline protease from Bacillus cereus NJSZ-13 can act as a pathogenicity factor in infection of pinewood nematode

Endophytic bacteria are an important biological control for nematodes. We isolated the nematicidal Bacillus cereus NJSZ-13 from healthy Pinus elliottii trunks. Bioassay experiments showed killing of all tested nematodes by proteins from the NJSZ-13 culture filtrate within 72 h. Degradation of the nematode cuticles was observed, suggesting the action of extracellular bacterial enzymes. The responsible protease was purified by ammonium sulfate precipitation, hydrophobic interaction chromatography, ion-exchange chromatography, and SDS-PAGE. The protease had a molecular weight of 28 kDa and optimal activity at 55 °C and pH 9, indicating an alkaline protease. The study suggests the potential for using this B. cereus NJSZ-13 strain protease to prevent pinewood nematode infection.

Purification and biochemical characterization of two laccase isoenzymes isolated from Trichoderma harzianum S7113 and its application for bisphenol A degradation

Two laccase isoenzymes (LacA and LacB) were isolated from a novel Trichoderma harzianum S7113 isolate employing ammonium sulfate precipitation, Sephadex G100, and DEAE Sepharose ion exchange chromatography. The molecular weights of the purified LacA and LacB laccases were estimated to be 63 and 48 kDa, respectively. The two isoenzymes had their optimum activities at the same temperature (50 °C), but at slightly different pH values (pH 3.0 for LacA and pH 2.5 for LacB). LacA and LacB had the same thermal stability at 40 °C and pH stability at pH 9.0. The two isoenzymes also showed a high level of specific activity toward ABTS, where the Km values of LacA and LacB were 0.100 and 0.065 mM, whereas their Vmax values were 0.603 and 0.182 µmol min−1, respectively. LacA and LacB catalytic activity was stimulated by Mg2+, Zn2+, K+, and Ni2+, whereas it was inhibited by Hg2+ and Pb2+, β-mercaptoethanol, EDTA, and SDS, and completely inhibited by sodium azide. Our findings indicate that purified laccase has a promising capacity for bisphenol A (BPA) bioremediation across a broad pH range. This finding opens up new opportunities for the commercialization of this technique in a variety of biotechnology-based applications, particularly for removing endocrine chemicals from the environment.

S-13-3: AN APPROACH TO IDENTIFY THE UNDETERMINED ADIPOCYTE-DERIVED FACTOR(S) THAT STIMULATE ALDOSTERONE SYNTHASE GENE (CYP11B2) EXPRESSION

Objectives: Hypertension is a frequently observed complication among obese patients. Recently, undetermined adipocyte-derived factor(s) have been recognized as one of the causes of the obesity-related hypertension independent of angiotensin (A) II. In this study, we aim to identify the undetermined adipocyte-derived factor(s) that stimulate aldosterone synthase gene (CYP11B2) expression aldosterone secretion that may induce hypertension. Methods: We first differentiated mouse fibroblast 3T3-L1 cells into adipocytes and collected their supernatants. The supernatants were incubated with human adrenocortical carcinoma H295R cells, and their CYP11B2 mRNA expression was measured by quantitative PCR with reverse transcription (qRT-PCR). Thereafter, the supernatants were fractionated by ammonium sulfate precipitation to purify adipocyte-derived factor(s) that stimulate CYP11B2 expression. The precipitates were collected in 30%, 60% and 90% saturated concentration of ammonium sulfate. Each of precipitates was concentrated using 100 kDa ultrafiltration membrane and incubated with H295R cells. CYP11B2 mRNA expression in H295R cells was measured by qRT-PCR. Then, we purified the precipitation of the supernatants that obtained in 60% ammonium sulfate by anion-exchange chromatography. Each of the fractions was incubated with human adrenocortical carcinoma H295R cells, and their CYP11B2 mRNA expression was measured by qRT-PCR. Results: The supernatants obtained from 3T3-L1 adipocytes were demonstrated to stimulate CYP11B2 expression. Fractionation of the supernatants by ammonium sulfate precipitation demonstrated that the ability to stimulate CYP11B2 expression was detected in fractions precipitated in 60% saturated concentration. Fractionation of the supernatants by anion-exchange chromatography demonstrated that the ability to stimulate CYP11B2 expression was detected in two specific fractions. Specific fractions were analyzed by mass spectrometry, resulting in the identification of 39 specific proteins. We are now investigating that the relationship between CYP11B2 gene expression and 39 proteins.

Characterization of the immunomodulatory protein isolated from guduchi (Tinospora cordifolia) churna, an ayurvedic rejuvenator

Objective: Guduchi [Tinospora cordifolia (Willd.) f. and Thoms.], a rasayana (rejuvenator) in the traditional system of Indian medicine (Ayurveda), is known for its diverse bioactivities. The aim of this study was to isolate the immunomodulatory protein (ImP) from commercial guduchi churna (stem powder) and characterize it. Methods: Guduchi churna extract following 80% ammonium sulfate precipitation was chromatographed on Q-Sepharose. Purified guduchi ImP was evaluated for its lymphoproliferative and macrophage activation properties, structural relatedness to certain plant lectins, amino acid composition, stability to trypsin, and N-terminal sequencing. Results: The purified protein, obtained in a yield of 140[Formula: see text]mg/100[Formula: see text]g guduchi churna, showed a molecular mass of [Formula: see text] kDa by SDS-PAGE. Guduchi ImP (10 [Formula: see text]g) showed seven-fold increase over control in mitogenic activity of murine splenocytes, and a four-fold increase over control in nitric oxide (NO) release from murine peritoneal exudates cells (PECs). These activities were abolished in pronase-treated guduchi ImP. Guduchi ImP does not agglutinate rabbit erythrocytes. Rabbit antiserum to guduchi stem ImP strongly reacted with purified guduchi ImP, and did not recognize common plant lectins (concanavalin A (Con A), poke weed mitogen (PWM) and garlic lectin). Amino acid composition of guduchi ImP shows high content of acidic amino acids, serine (12.4%) and cysteine (10.2%); guduchi ImP is highly stable to trypsin and has a blocked N-terminus. Conclusion: Guduchi ImP is an acidic, non-lectin ImP with a high content of serine and cysteine, and appears to have an immense potential for future structural, immunological, and therapeutic studies.

Characterization of alkaline metalloprotease isolated from halophilic bacterium Bacillus cereus and its applications in various industrial processes.

Microbial proteases are one of the most demanding enzymes for various industries with diverse applications in food, pharmaceutics, and textile industries to name the few. An extracellular alkaline metalloprotease was produced and purified from moderate halophilic bacterial strain, Bacillus cereus TS2, with some unique characteristics required for various industrial applications. The protease was produced in basal medium supplemented with casein and was partially purified by ion exchange chromatography followed by ammonium sulphate precipitation. The alkaline metalloprotease has molecular weight of 35 kDa with specific activity of 535.4 µM/min/mg. It can work at wide range of pH from 3 to 12, while showing optimum activity at pH 10. Similarly, the alkaline metalloprotease is stable till the temperature of 80 °C and works at wide range of temperature from 20 to 90 °C with optimum activity at 60 °C. The turnover rate increases in the presence of NaCl and Co+2 with k cat/KM of 1.42 × 103 and 1.27 × 103 s-1.M-1 respectively, while without NaCl and Co+2 it has a value of 7.58× 102. The alkaline metalloprotease was relatively resistant to thermal and solvent mediated denaturation. Applications revealed that the metalloprotease was efficient to remove hair from goat skin, remove blood stains and degrade milk, thus can be a potential candidate for leather, detergent, and food industry.

Catalytic properties of purified alpha amylase from Aspergillus flavus cultivated on low-cost agricultural substrate

Aspergillus flavus isolated from fermented millet flour produced a crude enzyme, which was purified via ammonium sulphate precipitation and subsequent chromatographic techniques. The biochemical characteristics of the purified amylase were thereafter investigated showing activity in a wide range of pH and temperature, with optimal conditions of pH 6.0 and 50 °C. The enzyme retained even 89% of its activity after 1 h at 50 °C and 2 h at pH 6.0. The purified enzyme was stimulated by Ca2+, Zn2+ and Co2+, while Hg2+ and EDTA caused mild inhibition of α-amylase activity. The kinetic indices (Km and Vmax) and molecular weight of the enzyme were estimated in 1.71 mg mL-1, 2.133 μmol min-1 mL-1 and 45 kDa respectively. The catalytic properties of α-amylase from A. flavus makes it a promising candidate for use in various starch processing industries.

Purification and characterization of moderately thermostable raw-starch digesting α-amylase from endophytic Streptomyces mobaraensis DB13 associated with Costus speciosus.

Endophytic actinobacteria are known to produce various enzymes with potential industrial applications. Alpha-amylase is an important class of industrial enzyme with a multi-dimensional utility. The present experiment was designed to characterize a moderately thermostable α-amylase producing endophytic Streptomyces mobaraensis DB13 isolated from Costus speciosus (J. Koenig) Sm. The enzyme was purified using 60% ammonium sulphate precipitation, dialysis, and Sephadex G-100 column chromatography. Based on 12% SDS-PAGE, the molecular weight of the purified α-amylase was estimated to be 55 kDa. The maximum α-amylase activity was achieved at pH 7.0, 50°C and it retained 80% of its activity at both pH 7.0 and 8.0 after incubation for 2 h. The α-mylase activity is strongly enhanced by Ca2+, Mg2+, and inhibited by Ba2+. The activity remains stable in the presence of Tween-80, SDS, PMSF, and Triton X-100; however, β-mercaptoethanol, EDTA, and H2O2 reduced the activity. The kinetic parameters Km and Vmax values for this α-amylase were calculated as 2.53 mM and 29.42 U/mL respectively. The α-amylase had the ability to digest various raw starches at a concentration of 10 mg/mL at pH 7.0, 50°C, where maize and rice are the preferred substrates. The digestion starts after 4 h of incubation, which reaches maximum after 48 h of incubation. These results suggest that S. mobaraensis DB13 is a potential source of moderately thermostable α-amylase enzyme, that effciently hydrolyzes raw starch. It suggesting that this α-amylase is a promising candidate to be use for industrial purposes.

LIPASE PRODUCTION FROM WASTE FRUIT PEELS FOR BIODIESEL PRODUCTION

Waste pineapple and passion fruit peels have potency as lipase enzyme sources. The combination of both peels with a ratio of 6:4 has the highest enzyme lipase activity after 3 days of fermentation and it has increased to 28.33 ± 0.0 U/ml after purification using the ammonium sulfate precipitation method. The response surface method design experiment was applied to determine the effect of the ratio of molar oil to methanol (1:3 – 1:9), reaction time (1 – 24 hours), and temperature (30 - 60C). The maximum biodiesel conversion of 82.7% could be achieved using the reaction condition of a ratio molar of 1:9, 13.65 hours reaction time, and a temperature of 46.5C for enzymatic transesterification of PO. Further, for bio-catalysis biodiesel production from WCO, the maximum conversion of 88% was achieved under reaction conditions of a ratio molar of 1:9, 14 hours reaction time, and a temperature of 48C.

Modified method for obtaining phycocyanine concentrate of Arthrospira platensis biomass

The biomass of Arthrospira platensis cyanobacteria is a source of bioactive compounds such as chlorophylls, carotenoids, and, particularly, phycobiliproteins: C-phycocyanin and allophycocyanin. The wide range of biological activity shown by extracts with a high content of phycocyanins determines the prospects for their use as dietary supplements and ingredients of special foods. For food purposes, the degree of purity of phycocyanin concentrates, determined by the ratio of optical densities of their aqueous solutions at two wavelengths, namely D620/D280, must be greater than 0.7. Most methods for obtaining phycocyanin concentrates include laborious steps of fractional ammonium sulphate precipitation of protein from A. platensis biomass extracts followed by removal of salts solution. The use of membrane technology, specifically microfiltration, makes it possible to significantly intensify and simplify the process of obtaining phycocyanin concentrates. The aim of this research was to modify the method for obtaining a high-purity A. platensis phycocyanin concentrate by replacing the stage of ammonium sulfate precipitation of the protein by ultrafiltration of the extract followed by microfiltration. Material and methods. A sample of dry A. platensis biomass was used as a feedstock. Extraction of A. platensis biomass was carried out at a temperature of +40 °C for 3 h, the resulting suspension was centrifuged, and the supernatant was separated from the sediment. The obtained extract was subjected to ultrafiltration (membrane with a pore diameter of 30 kDa) followed by removal of the permeate containing low molecular weight impurities. The retentate was subjected to microfiltration (membrane with a pore size of 0.2 μm), concentrated by reverse osmosis and freeze-dried. Results. The content of C-phycocyanin and allophycocyanin in the dry concentrate was 42.0±1.3 and 7.0±0.3%, respectively, the degree of purity was 1.98. Conclusion. The scheme for obtaining A. platensis phycocyanin concentrate has been modified. A concentrate was obtained with a high degree of purity, allowing its use in food.

Extraction, Partial Purification and Utilization of Milk Coagulating Enzyme from Kiwifruit (Actinidia Deliciosa) in Fresh Cheesemaking

The study aimed to determine the potential of kiwifruit milk clotting enzyme in cheesemaking. The kiwifruit crude enzyme, extracted with sodium phosphate buffer (pH 7.0), was partially purified by 30-80% ammonium sulfate precipitation. 50% ammonium sulfate saturation exhibited maximum milk clotting activity (MCA), along with 1.56 purification fold, and 78.84% activity recovery. From SDS-PAGE analysis, the partially purified protease showed two bands with a molecular mass of 24 kDa and 23 kDa respectively. The optimum conditions (temperature and pH of milk) for a minimum time of coagulation (TOC) and maximum MCA were determined by response surface methodology (RSM). From the numerical optimization study, the optimum conditions for cheesemaking were pH 6.5 and temperature 55oC, having 0.94 desirability. The cheese prepared by kiwifruit protease had significantly (p<0.05) higher moisture, ash, calcium content, and yield than rennet cheese, while significantly (p<0.05) lower fat content and acidity were observed in kiwifruit protease coagulated cheese. However, a non-significant (p>0.05) difference in protein content was obtained between both cheeses. This study highlighted that kiwifruit protease has the ability to be used as an efficient milk clotting enzyme in fresh cheesemaking.

PURIFICATION AND CHARACTERIZATION OF ANTI-BACTERIAL BACTERIOCIN ISOLATED FROM HOSPITAL ACQUIRED MULTI DRUG RESISTANT Staphylococcus aureus

Concerns for public health have been raised all over the world as a result of a significant increase in bacterial resistance to the antibiotics that are currently available. As a result, antimicrobial peptides (AMPs) have emerged as a promisingly novel class of infectious disease treatment options. The current study focuses on the isolation and purification of a bacteriocin from clinically Multi-Drug Resistant Staphylococcus aureus (HA MRSA_1) that was acquired in a hospital including characterization. The ribosomally synthesized peptides have significant potential as an anti-bacterial peptide, and it was demonstrated that the bacteriocin has strong antagonistic activity against many pathogenic organisms. Ammonium sulfate precipitation, dialysis, Gel filtration chromatography, RP-HPLC, and SDS-PAGE were the initial methods used to purify it. A combination of LCMS analysis and Mass matrix-assisted laser desorption/ionization-mass spectrometry (MALDI TOF/MS) was used. The physio-chemical characterization of purified bacteriocin was studied using FT-IR, and XRD. The LCMS analysis of the RP-HPLC-collected active component revealed the amino acid sequence of the purified peptide (bacteriocin). After being subjected to high-performance liquid chromatography, a peak was discovered with a retention time of 5.330 minutes. The amino acid of bacteriocin was identified by LCMS, and the query sequence shared a match with the Staphylococcus aureus protein. In-silico molecular docking study investigated the significant evidence for the role of bacteriocin identified from Multi-Drug Resistant Staphylococcus aureus as an anti-bacterial agent. In conclusion, the bacteriocin found in this study may be a promising agent that should be further investigated for it’s cytotoxicity and in-vivo anti-bacterial activity in the future.