Publications Scientifiques

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Author: search.filters.author.Nouani, A.

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    Valorization Of Brown Algae (cystoseira Caespitosa) From Local Region In Algeria For Sodium Alginate Extraction And Their Application In The Immobilization Of Microbial Pectinases
    (Université M'Hamed Bougara Boumerdes, 2019) Benmalek, N.; Nouani, A.; Benchabane, A.
    Sodium alginate were extracted from brown algae (Cystoseira Caespitosa) collected from Algerian Mediterranean coast. the physicochemical characteristic of sodium alginate showed that the average yield was 12% and the average molecular masse was 9000Da calculated using intrinsic viscosity data. Fourier transform infrared spectroscopy was used to characterize the extracted powder of sodium alginate, COO- and C-O-C were evident in the finger print region, the ratio of guluronic acid (G) / mannuronic acid (M) was recorded to be 0.91. This polysaccharide were used to immobilize crude pectinolytic enzymes synthesized by a strain of Aspergillus niger sp. The immobilization was carried out by dropwise introduction of alginate-enzyme mixture into a 0.2M CaCl 2 solution, by this technique, alginates shrinking in the form of spherical beads. The calcium alginate beads have been analyzed using scanning electron microscopy (SEM), observation under SEM showed that the beads have a rough surface and the enzymes were successfully included in the beads. The immobilization efficiency was about 83.9% and the immobilized enzyme could be reused in 4 cycles keeping 42,14% of its initial activity. The beads were successfully used for apple juice clarification.
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    Valorization of algerian leguminous: extraction and characterization of galactomannans
    (Aljest, 2018) Bouhadi, N.; Hachemi, N.; Kahlouche, A.; Djeziri, M.; Touabia, M.; Nouani, A.
    This study has an environmental objective based on the valorization of the seeds of legumes in order to obtain a clean nature, its seeds are considered as a good source of galactomannans which can replace other synthetic polysaccharides.They consists on the evaluation of physicochemical properties of galactomanans isolated from different seeds parts of two leguminous species widely known in Algeria: Gleditsia triacanthos and Ceratonia siliqua (carob), which represent an important source of polyscharids. The extraction gave an appreciable yield assessed at 12.97% of Gleditsia triacanthos and 11.45% of Ceratonia siliqua; values witch encourage their valorization. The physicochemical composition of the extracted galactomanans showed comparable characteristics in term of humidity; pH; °Brix and ashes. While; rheologic properties revealed that galactomanans solutions have a pseudo plastic nature. In the other hand; the functional properties analysis showed that the galactomanans obtained are soluble in water; the water absorption capacity was higher for Gleditsia triacanthos than Ceratonia siliqua with 20.62 and 5.98 respectively. Infrared analysis demonstrate that the same chemical structures of galactomanans were extracted from the two spices. NMR analysis allowed us to estimate the galactose / mannose ratio of the two extracts. This ratiois 1.25/1 and 3.63/1 of Gleditsia triacanthos and Ceratonia siliqua respectively
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    Valorisationof microbial biodiversity : Characterization of a milk-clotting enzyme produced byBacillus velezensis FK6Astrain isolated from Algerian dairy farm soil in light of its usein the manufacture of hard cooked cheeses
    (2021) Boumediene, F.; Talantikite, S.; Haddad, S.; Nouani, A.; Triki, S.; Belbraouet, S.
    A strain known as FK6A, which produces a milk-clotting enzyme isolated from the soil of an Algerian dairy factory, was identified as Bacillus velezensis based on morphology and internal transcription spacer sequence. Phylogenetic and sequencing analysis of 16S rDNA gene showed a 100% identity match between the tested strainand the Bacillusvelezensis in the database (Code MH368142). This strain produced an active extracellular protease purified by partial purification using ammonium sulfate fractionation(40–80% saturation) followed by chromatography of molecular exclusion, which revealed the existence of tow active peaks. The optimal activity was observed at pH 5.7; 75°C and 40 mM of CaCl2. The clotting enzyme has been shown to be a metalloprotease inhibited by EDTA. The highly proteolytic activity of the Bacillus velezensis extracts observed on the curds appears a few minutes after the appearance of a firm coagulum reflected by the appearance of an abundant serum.Thus, to solve this problem and to inhibit proteolytic activity, the curds were cooked after brewing during the manufacturing process
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    Characterization and assessment of the antimicrobial function of total polyphenol extracts from pulps, leaves and seeds of two ceratonia siliqua L. varieties
    (2021) Yahiaoui, K.; Bouchenak, O.; Boumaza, S.; Toubal, S.; Blizak, Meriem Djanette; Nouani, A.; Arab, K.
    The overall phytochemical test results suggested that pulp, seeds, and leaves of both grafted and spontaneous varieties are especially rich in tannins , saponins, and leuco-anthocyanins. The result of the determination of total polyphenols Ceratonia siliqua L. showed that spontaneous leaves showed that the highest value of spontaneous leaves was 14 EAGmg / g, followed by grafted seeds (11.5 EAGmg / g), and spontaneous pulps (10.2 EAGmg / g). Infra -red spectroscopy revealed the presence of many functional groups in both varieties. The antimicrobial activity is particularly found with the spantaneous leaves against Escherichia coli (21.83 ± 0.93 mm) and Staphylococcus aureus (16.36 ± 0.63 mm) Microccus sp (15.83 ± 0.73 mm) and leaves grafted against Pseudomonas aeruginosa (14.30 ± 0.35 mm)
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    Valorization of brown algae (Cystoseira caespitosa) from local region in Algeria for sodium alginate extraction and their application in the immobilization of microbial pectinases
    (Aljest, 2019) Hachemi-Benmalek, N.; Nouani, A.; Benchabane, A.
    Sodium alginate were extracted from brown algae (Cystoseira Caespitosa) collected from Algerian Mediterranean coast. the physicochemical characteristic of sodium alginate showed that the average yield was 12% and the average molecular masse was 9000Da calculated using intrinsic viscosity data. Fourier transform infrared spectroscopy was used to characterize the extracted powder of sodium alginate, COO- and C-O-C were evident in the finger print region, the ratio of guluronic acid (G) / mannuronic acid (M) was recorded to be 0.91. This polysaccharide were used to immobilize crude pectinolytic enzymes synthesized by a strain of Aspergillus niger sp. The immobilization was carried out by dropwise introduction of alginate-enzyme mixture into a 0.2M CaCl 2 solution, by this technique, alginates shrinking in the form of spherical beads. The calcium alginate beads have been analyzed using scanning electron microscopy (SEM), observation under SEM showed that the beads have a rough surface and the enzymes were successfully included in the beads. The immobilization efficiency was about 83.9% and the immobilized enzyme could be reused in 4 cycles keeping 42,14% of its initial activity. The beads were successfully used for apple juice clarification.
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    Influence of dairy cows race and diet on milk composition in Algeria
    (2013) Larbaoui, D.; Meribai, A.; Kouidri, A.; Amar Khodja, Mohamed Nadjib; Nouani, A.; Mouloud Bellal, Mohand
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    Purification and characterization of a milk-clotting protease from Mucor pusillus : method comparison
    (Academic Journals, 2011) Nouani, A.; Moulti-Mati, F.; Belbraouet, S.; Bellal, M.M.
    Crude enzymatic extract obtained from five fermentations (300 g of wheat bran) was characterized by a clotting activity of 0.34 ± 0.08 UP/ml with a strength ratio of 1/1: 200. The comparative study of the summaries from 2 purification protocols showed that it is possible to recover 6% of the initial proteins with a 44.54% activity after gel filtration (protocol I), which appeared more technically sound when compared to ion-exchange (1.80% of total proteins with a 23% performance) (protocol II). The protein homogeneity (a single electrophoretic band) of the monomeric protease was confirmed by both methods after precipitation with 80% saturated ammonium sulphate. Moreover, the fractional precipitation technique with this salt (40 and 80%) was useless in the experimental conditions employed and an important loss of activity was observed (28.53%) with a 3-fold purification. In another part of the study, without ammonium sulphate precipitation, the gel filtration enabled the elimination of almost 97% of the inactive proteins and improved the activity performance by 55.13%, while multiplying the specific activity of the coagulant by a factor of 20.88 against a 6.75-fold purification with ionexchange and the appearance of a more or less 20 kDa peptide after electrophoresis. The proteolytic activity of the purified extracts had a similar appearance to a more pronounced kinetic when compared with the reference rennet. The purification protocols did not seem to have an impact on the isolated protease activity
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    Extracellular protease from mucor pusillus : purfication and characterization
    (2009) Nouani, A.; Belhamiche, N.; Slimani, R.; Fazouane, F.; Belbraouet, S.; Bellal, M.
    Extracellular protease from Mucor pusillus was purified 18-fold with 7.56% recovery by ion-exchange chromatography and gel filtration. The enzyme was found to be monomeric in nature, having a molecular mass of 49 kDa. The enzyme acted optimally at 50°C and was stable in the temperature range 30–50°C. It was completely inactivated by heating for 30 min at 65°C. The optimum of activity for the purified extract was observed at milk CaCl2 concentration of 0.02 m and at milk pH of 5. These properties, except for temperature, were similar to those of rennet