Publications Scientifiques
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Item Commercial thyme essential oil as natural beverage preservative and molecular docking study on its mode of action against Saccharomyces cerevisiae(Czech Academy of Agricultural Sciences, 2024) Lotmani, Zineb; Boukhatem, Mohamed Nadjib; Boudjema, Khaled; Rezzoug, Hamida; Benelmouffok, Amina Bouchra; Tomi, PierreThe present investigation explored the possible use of Thymus vulgaris essential oil (TVEO) as a beverage antifungal preservative instead of chemical ones. The chemical profile of TVEO exposed carvacrol (60.47%) as the predominant compound. The antifungal properties of TVEO were assessed on various food spoilage yeast and mould species using two tests. TVEO showed a powerful antimicrobial effect against all the fungal strains at the three volumes of essential oil (EO) used (i.e. 10, 20, and 30 µL). The minimum inhibition concentration (MIC) of TVEO was also evaluated and ranged from 0.0625% to 0.015% (v/v). Furthermore, the potency of TVEO as a beverage antimicrobial preservative was tested at four distinct concentrations (0.6, 1.25, 4, and 6 μL·mL–1) against Saccharomyces cerevisiae alone and combined with medium heating (70 °C for 2 min) in a real food matrix (Orangina® drink) for eight storage days. TVEO exhibited a significantly higher preservative effect than chemical preservatives (sodium benzoate and potassium sorbate). Lastly, a molecular docking examined the mechanism of action of carvacrol against two crucial enzymes in S. cerevisiae viability [ERG2 (sterol C8-isomerase) and ERG3 (sterol C5-desaturase)] compared to a chemical preservative (potassium sorbate). The two ligands highly interacted with the two target enzymes. However, carvacrol achieved a better score than potassium sorbate against ERG2 and ERG3, with binding energy of –10.19 kcal·mol–1 and –11.73 kcal·mol–1, respectively. Our results open up the perspective of using TVEO as a natural food preservative.Item Isolation and identifcation of thermotolerant yeast strains producing bioethanol from agro‐food wastes(Springer, 2023) Gherbi, Younes; Boudjema, Khaled; Djeziri, Mourad; Fazouane–Naimi, FethiaBioethanol production from agro-food industry waste is one of the suitable alternatives to fossil fuels. In this study, six agro-food wastes were evaluated to select those with a high concentration of starch or fermentable sugars for bioethanol processing. Yeast’s ability to produce biofuels by fermentation is afected by temperature. In this study, thermotolerant yeasts, obtained from natural sources in Algeria (soil and agro-food waste), were selected for their capacity to produce and tolerate bioethanol. Three wastes were selected, two of which had signifcant starch content. In order to get fermentable sugars, these wastes underwent chemical and enzymatic hydrolysis. The selected yeasts were identifed by morphological, physiological, biochemical, and molecular characterization. Enzymatic and acid hydrolysis of whole potato and durum wheat bran released (190 g/L and 130 g/L) and (138.40 g/L and 90.03 g/L) reducing sugars, respectively. Among the isolated strains, three were found to be able to produce bioethanol, namely Candida tropicalis, Candida glabrata, and Saccharomyces cerevisiae. These strains were identical to those stored in the data bank with 99%, 100%, and 100%, respectively. In addition, C. glabrata and C. tropicalis exhibited an ethanol tolerance of up to 14%, while S. cerevisiae tolerates up to 15%. Interestingly, enzymatic hydrolysis–treated potatoes produced a considerable amount of bioethanol after 48 h of fermentation by S. cerevisiae (7.525% (v/v)), C. glabrata (6.80% (v/v)), and C. tropicalis (4.50% (v/v)). Taken together, our fndings suggest that S. cerevisiae and whole potato waste could be considered good candidates for industrial bioethanol production at high temperatures.Item Factors affecting acid protease production by Mucor circinelloides MG603064.1 through SmF process: characterization and fromage frais making(BioTechnologia, 2023) Bensmail, Souhila; Boudjema, Khaled; Naimi-Fazouane, Fethia; Bensmail, Samira; Djouahra-Fahem, Djamila; Ferhoum, Fatiha; Bourfis, NassimaThe exploitation of food industry wastes and their conversion into value-added products present a promising and continuously growing field, given the diversity of elaborated wastes. The current work aimed to utilize sweet cheese whey as a growth medium for acid protease production by a local fungus strain. The biochemical and physicochemical properties of the cheese whey, such as pH, conductivity, chemical oxygen demand, biological oxygen demand (BOD5), total nitrogen and protein contents, and mineral salts, were assessed using various analytical methods. The effect of certain parameters on acid protease production by Mucor circinelloides MG603064.1 through the SmF process was investigated using the conventional design method "One factor at a time". Subsequent to characterization, the crude extract was used in a trial to create fromage frais, compared to the commercial rennin CHY-MAX® Powder Extra. Cheese whey characterization revealed its richness in total nitrogen (1.044 ± 0.044 g/l), protein content (6.52 ± 0.04 g/l), and principal mineral salts: calcium (1.637 ± 0.037 g/l), phosphorus (1.173 ± 0.023 g/l), and chloride (1.66 ± 0.09 g/l). The optimal values of the SmF process for acid protease production, such as the inoculum size, beef extract, and KH2PO4 supplements, the initial pH of cheese whey, and incubation temperature were, respectively, 11% (v/v), 0.4% (w/v), 0.5% (w/v), 5.5, and 30°C. Under these conditions, the lowest milk-clotting time of 290 s was achieved, representing an 18.41-fold increase compared to the initial step using the unoptimized medium. The enzyme showed maximum milk-clotting activity at pH 5, a temperature of 60°C, and in the presence of 0.025 M of CaCl2. The enzyme activity also significantly improved with sonication (35 kHz) for 10 min. The crude extract of M. circinelloides ensured the production of fresh cheese samples with characteristics roughly similar to those obtained by the control (CHY-MAX® rennin). The acid protease of M. circinelloides could successfully substitute the conventional rennin in the manufacture of fresh cheese.Item A novel anti-candidiasis cream formulation based on Melissa officinalis and Lavandula stoechas essential oils synergism(Taylor & Francis, 2024) Rezzoug, Hamida; Bouchenak, Ouahiba; Boudjema, Khaled; Benabdelkader, Tarek; Felix, Tomi; Pierre, Tomi; Djilani, SelmaCandida albicans is the yeast strain that causes candidiasis, which can vary from minor skin and soft tissue infections to potentially fatal infections like candidemia, which can get worse due to drug resistance. Natural substances could be used as antifungal agents’ alternatives, especially against C. albicans. Thereby, the main objective of this research was to define the chemical content and evaluate the bioactivity of Melissa officinalis and Lavandula stoechas essential oils (EOs). Additionally, the synergistic effect of both oils was carried out against C. albicans, in order to formulate EOs combination-based creams. Their chemical compositions were analyzed using the combination of gas chromatography-flame ionization detector (GC-FID) and GC-mass spectrometry (GC-MS). The interaction with both EOs was also evaluated and analyzed by GC-FID and GC-MS, and the development of anti-candidiasis formulations was tested in vitro. Our results showed that the main compounds of M. officinalis EO (MOEO) were geranial (35.7%) and neral (24.1%), whereas, 1.8-cineole (61.9%) was dominant in Lavandula stoechas essential oil (LSEO) and the main compounds of the combination between both EOs were 1,8-cineole and geranial. Moreover, the MOEO exhibited substantial antifungal action against all tested microorganisms with MIC values ranging from 0.125 to 0.0019. This EO also showed synergistic effect when combined with that of L. stoechas. These findings, suggest the good bioactive qualities of the topical creams developed against C. albicans, revealing their potential to be possibly applied as an antifungal agent in industrial pharmaceutics.Item Valorization of carob seeds as a functional food(2023) Lagha-Benamrouche, Samira; Boudjema, Khaled; Rezgui, Walid; Djeziri, Mourad; Hezil, DjamilaOur study aims to promote carob seeds as a functional food. For this; the nutritional value, the compounds with beneficial physiological effects and functional properties (fibers and gums), as well as the antioxidant potential were determined. Analysis of the chemical composition of carob seeds reveals their high protein, ash and fat content. However, the total sugars content was estimated to be moderate. The quantification of the compounds with a beneficial physiological effect shows that the seeds are rich in crude dietary fibers (8.39%). Regarding the gums, the yields are evaluated at 39.44% for the crude gums and at 4.026% for the purified gums. The phytochemical assays reveal a richness of the seeds in total polyphenols, in total flavonoids with a moderate content of flavonols and hydrolyzable tannins. The antioxidant potential was studied using two methods: reduction of the free radical 1,1-diphenyl-2-picryl-hydrazyl (DPPH) and the iron reduction method. According to the results, the carob seeds have a discreet antioxidant potential compared to the standards tested (gallic acid and quercetin).Item Evaluation of some biological activities of phenolic compounds obtained from two Algerian medicinal plants : mentha rotundifolia and satureja calamintha(2020) Benfares, Redhouane; Boudjema, Khaled; Behlali, Hadjira; Imedjdouben, Imene; Kennas, Abderrezak; Fazouane, Fethia; Jaroslava, Švarc-GajićIn this work phytochemical characterization of two medicinal plants from Lamiaceae family, Mentha rotundifolia and Satureja calamintha, has been carried out. Extracts obtained with different solvents were screened for different plant secondary metabolites and were biologically characterized by defining their antiradical and antibacterial activi-ties. Phytochemical screening of M. rotundifolia and S. calamintha confirmed their rich-ness in different secondary metabolites. The determination of phenolic compounds revea-led high polyphenols contents in water: methanol (30:70) extracts with concentrations of 20.64±1.74 mg EAG/g DW and 13.45±0.91 mg EAG/g DW for M. rotundifolia and S. calamintha, respectively. These extracts were also characterized by high concentrations of flavonoids (Mentha rotundifolia 12.33±1.58 mg EQ/g DW, Satureja calamintha 7.11±0.02 mg EQ/g DW). Furthermore, the water:methanol (30:70) extract of M. rotun-difolia was the most effective in inhibiting free radicals. Recorded inhibition diameters for both plant samples and tested microbial strains ranged from 6.66 mm to 13.66 mm. Presented results confirmed that tested indigenous Algerian plants are favorable sources of polyphenols with antioxidant and antimicrobial propertiesItem Production of Extracellular Rennin-Like Enzyme by a Newly Isolate Mucor circinelloides (von Tieghem) and its Application in Camembert Cheese Making(Baqiyatallah University of Medical Sciences, 2020) Bensmail, Souhila; Boudjema, Khaled; Naimi-Fazouane, FethiaIntroduction: Aspartic proteases produced by different non-pathogenic fungi belonging to mucorales, are commonly used as milk-coagulants. The present study aims to optimize conditions for milk-clotting protease production by a new strain of Mucor genus and to assess its ability in soft cheese making. Materials and Methods: About 20 fungal strains isolated from soil were investigated for their potential to produce milk-clotting proteases for further applications in cheese making. The hyper producer strain Mucor circinelloides 2095-2047 was selected for optimization of rennin-like enzyme production under solid-state fermentation (SSF) using the stepwise modifications of the selected parameters. The enzyme produced under the optimal conditions was partially purified and then applied in Camembert cheese making trials compared to the crude extract and commercial rennet. Results: The maximum milk-curdling activity achieved after optimization (571.43 SU/mL) was obtained using wheat bran (10 g) as the mainly source of carbon containing 1% galactose; moistened with the M-9 solution (pH 6.0) and incubated at 30°C for 96 hours. The enzyme of M. circinelloides was partially purified with a high recovery of 105% and 6.23-fold purity after (NH4)2SO4 fractionation and dialysis. The physicochemical properties of the three produced cheeses were very close. A low sensory quality of cheese was obtained with the crude extract which was getting better using the pre-purified enzyme. This extract was able to develop a very close or even a similar sensory quality to that obtained by the commercial rennet. Conclusions: According to findings, it is possible to propose the purified enzyme of M. circinelloides as a new alternative for rennet, but further optimization, purification and cheese production tests are required. © 2020 The Author(s)Item Optimization of the bioethanol production on sweet cheese whey by saccharomyces cerevisiae DIV13-Z087C0VS using response surface methodology (RSM)(2015) Boudjema, Khaled; Fazouane-Naimi, Fethia; Hellal, Amina