Browsing by Author "Sahir-Halouane, Fatma"

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Effect of exhaustion of olive pomace on cellulases production from Trichoderma reesei RUT C30 and identification of the enzyme complexes
(Springer, 2024) Boutiche, Malika; Bennacer, Amel; Aissaoui, Mohammed; Meziant, Leila; Saci, Fairouz; Siar, El-Hocine; Boulaouad, Ilyes; Bekrar, Amel; Fiala, Samah; Hemoui, Hadjer; Sahir-Halouane, Fatma
Olive industry generates large quantities of solid by-products such as olive pomace. The objective of present work is to study the effect of exhaustion (residual oil extraction) by acetone solvent on the improvement of cellulase production using olive pomace as substrate, and to identify the crude enzymatic extract by electrophoretic analysis. The production of cellulases was done by the solid fermentation process using Trichoderma reesei RUT C30 as cellulolytic fungus grown on olive pomace. Cellulolytic activity was assessed by the filter paper method (FPase). Electrophoretic analysis by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) was performed for the identification of enzymatic extract of T. reesei RUT C30. Chemical composition (lipids, proteins, sugars and ash) was significantly (P < 0.05) affected after olive pomace exhaustion. In general, exhaustion by acetone solvent increased the fiber fraction. Exhaustion improved the results of FPase activity compared to those obtained on untreated substrate, giving values of 2.63 IU/gds and 1.1 IU/gds, respectively. The results of SDS-PAGE analysis revealed that the crude enzymatic extract contains two different enzyme complexes including cellulases and xylanases.
Effect of pretreatments on physicochemical Characteristics of Olive Pomace and on Production of cellulases from trichoderma reesei RUT C30 under solid-state fermentation
(2023) Boutiche, Malika; Sahir-Halouane, Fatma; Meziant, Leila; Saci, Fairouz; Oudjedi, Kahina; Derdour, Mouna; Ouffroukh, Karima; Maghboune, Ibtissem; Fiala, Samah; Bekrar, Amel
Olive pomace (OP) is a cheap and abundant agricultural by-product that could be valorized by different biotechnological processes. The present study was conducted to better understand the effects of alkaline, milling and thermal pretreatments on OP for obtaining high value-added products (cellulases). Trichoderma reesei RUT C-30 fungus was used for cellulases production on OP substrate under Solid-State Fermentation (SSF) process and cellulases activity was assessed by the filter paper method (FPase). The effect of the three pretreatments and their combinations on physico-chemical composition and cellulases production was investigated. Results showed that untreated OP was a favorable environment for the growth of T. reesei and a good fermentation substrate that gave FPase activity of 0.83 IU/g DS. The chemical composition (lipids, proteins, carbohydrates and ash) was significantly (P < 0.05) affected by the different pretreatments as well as their combinations. Regarding the fiber fraction, alkaline and thermal pretreatments did not affect the NDF content, while a remarkable decrease (29.88%) was recorded after milling pretreatment. Alkaline pretreatment decreased significantly the cellulose contents whereas milling increased it of 35%. ADL fraction was only decreased by the milling treatment of 42%. No significant effect of thermal pretreatment was noticed on ADL and cellulose. The alkaline pretreatment with 1% NaOH improved the cellulase activity to a value of 1.28 IU/g DS, while lower yields were obtained after milling (0.2 IU/g DS) and thermal (0.15 IU/g DS) pretreatments. This study showed that only alkaline treatment improved the production of cellulase from OP without being combined with milling and thermal treatment
Effective biofertilizer trichoderma spp. isolates with enzymatic activity and metabolites enhancing plant growth
(Research square, 2022) Reghmit, Abdenacer; Benzina-tihar, Farida; Djeziri, Mourad; Hadjouti, Rima; Oukali, Zahia; Sahir-Halouane, Fatma
Trichoderma species have been widely recognized as biofertilizer fungi for their ability to produce phytohormones and enhancing plant growth. In our current study, fifteen strains of Trichoderma spp (T1- T15) were screened for their capacity to produce phytohormones and metabolites eliciting plant growth. The stains were previously isolated from olive rhizosphere soil in northern Algeria. Plant growth promoting (PGP) potential of Trichoderma spp. was evaluated in-vitro through the production of phosphatases, iron chelators (siderophores), cyanhydric acid (HCN) and ammonia (NH3). Besides, Plant growth phytohormones such as gibberellic acid and indole-3-acetic acid (IAA) were assessed quantitatively by a colorimetric assay. Results showed an effective potential of Trichoderma isolates in PGP biomolecules production. Importantly, qualitative estimation of phosphate solubilization indicates that T10 gave the highest P-solubilization on medium Pikovskaya’s with a solubilization index (SI) of 3, whereas, the high capacity nitrogen-fixing was related to T8. In other hand, quantitative analysis of IAA and gibberellic acid revealed a production varying between (1.30 µg mL − 1 − 21.15 µg mL − 1 ) and (0.53µg/ml − 7.87µg/ml), respectively, the highest amount of both phytohormones was obtained by T11 isolate. Indeed, analysis of ethyl acetate extracts of T11 isolate by high-performance liquid chromatography (HPLC) revealed a high amount (71.19 mgL − 1 ) of IAA. Overall, Results showed clearly that isolate T11 has promising plant growth promoting properties. Hence, this native Trichoderma isolate (T11) identified as Trichoderma harzianum strain (OL587563) could be used later as biofertilizer for sustainable olive crop agriculture
Efficient and cost-effective production of Bacillus thuringiensis subsp. aizawai spores and delta-endotoxins using agricultural raw materials and agro-industrial wastes under submerged fermentation
(Elsevier, 2022) Gounina-Allouane, Rabia; Acheuk, Fatma; Sahir-Halouane, Fatma
In this study, cost-effective liquid culture media based on agricultural raw materials and agro-industrial wastes were developed for spores and delta-endotoxins production by a strain of B. thuringiensis subsp. aizawai used as a larvicide in wax moths control. The raw materials used include edible leguminous seeds, corn, wheat bran, dry palm date pulps, and corn forages. The agro-industrial wastes were dry palm dates pits and olive mill solid wastes. The protein and carbohydrate contents of the developed media were measured. Sporulation on the different developed media was monitored and delta-endotoxins produced were quantified. Mono-component media containing chickpea, red lentils, and wheat bran produced a spore count compared to the reference medium NYSM. The results showed that the dry palm date's pulp extract was the most efficient medium for spore production (1.43 × 1010 spores ml−1), and the chickpea medium was the most efficient for delta-endotoxins production
Exploring the antifungal properties of tannin extracts from Olea europaea var. rougette leaves against Aspergillus spp.
(Springer, 2024) Bennacer, Amel; Sahir-Halouane, Fatma; Aitslimane-Aitkaki, Sabrina; Tihar-Benzina, Farida; Oukali, Zahia; Oliveira, Ivo Vaz; Rahmouni, Naima; Aissaoui, Mohammed; Mohankumar, Ramar
Due to significant health risks associated with chemical antifungal agents in food storage, safe and natural sources are now one of the most frequently demanded ingredient for food preservation. Byproducts from olive trees provide an affordable and sustainable source of bioactive chemicals. This study will examine the mycelial growth and germination-inhibitory properties of Olea europaea var. rougette leaves and characterize their phytochemical makeup.The phytochemical screening revealed the presence of polyphenolics compounds mainly tanins.The chemical composition was analyzed by gas chromatography mass spectrometry (GCMS). Total polyphenolic content (TPC), hydrolysable tannins content (HTC) and condensed tannin content (CTC) were assessed using Foilin ciocalteu, potassium iodide and vanilline methods, respectively. The mycelial growth and germination inhibition properties were examined on soft wheat based solid and liquid media. Tannic extract (ethyl acetate extract) revealed highest amounts in polyphenols, hydrolysable tanins and condensed. GC–MS profile of tannic extract showed the presence of 26 bioactive molecules known for their antifungal potential, mainly: Guaiacol (0.12%), 2-methoxy-4-vinylphenol (1.52%), Syringol (0.18%), p-tyrosol (4.70%), homovanillyl alcohol (1.32%), 4-propylresorcinol (1.07%), β-camphor (0.17%), β-turmerone (1.57%) and 4-phenyl-quinolin-2-ol (6.58%). The tannic extract (ethyl acetate fraction) showed significant mycelial growth and germination inhibition activities in contrast to hydro-acetonic and dichloromethanic extracts. Furthermore, myelial growth inhibition showed more effectiveness in comparison to germination inhibition technique.The results suggested that byproducts of Olea europaea var. rougette leaves are a substantial natural source of bioactive compounds, especially tannins with potent antifungal characteristics in vitro which make it interesting to investigate its effectiveness in vivo.
Insecticidal and Histological Effects of Extracts from Leaves of Juglans regia L. Against Sitophilus oryzae (Coleoptera: Curculionidae) Isolated from Soft Wheat in Post-harvest
(Springer Science and Business Media Deutschland GmbH, 2025) Bennacer, Amel; Sahir-Halouane, Fatma; Smaili, Oussama; Oukali, Zahia; Mouhouche, Faiza; Bennacer, Nour El Houda; Chaib, Ratiba; Kumar, Ramar Muhan
In Algeria, the cultivation of soft wheat (Triticum aestivum Linn.) plays a crucial role in the food chain. However, the crop faces a threat from Sitophilus oryzae (Coleoptera: Curculionidae), which causes substantial economic losses. This study aims to discover novel bioactive compounds derived from Juglans regia Linn., a walnut tree grown in Algeria, to combat S. oryzae. This study focuses on extraction, phytochemical characterization, insecticidal effect against S. oryzae adults, and histological impact. GCMS analysis of the petroleum ether (EPJ) and chloroform (CHJ) fractions indicated the presence of a diverse range of bioactive molecules, including myrtenal (1.17%), eugenol (46.17%), methyl ester (25.84%), lycophyll (5.16%), and hexadecane (1.22%), which are derived from terpenoids, phenols, and fatty acids. LCMS/MS analysis of the ethyl acetate (AEJ) and butanolic (BTJ) fractions identified compounds mainly associated with hydrocinnamic acids, flavonols, flavones, and naphtoquinones, such as 3-caffeoylquinic acid, epi-catechin isomer, kaempferol-3-glucoside, and hydro-juglone derivative. Furthermore, the efficacy of the five extracts (hydromethanolic extract and the four fractions) against S. oryzae adults was evaluated at 625, 315, and 75 µg/mL concentrations over 7 days. EPJ and BTJ demonstrated the highest effectiveness among these extracts, as indicated by their relatively low LC50, LC90, LT50, and LT90 values. These results highlight the potential of EPJ and BTJ, derived from walnut leaves, as biocontrol agents against S. oryzae. Histological analysis of the treated insects revealed significant alterations in various tissues compared to untreated adults. This research gives the first evidence that J. regia grown in Algeria is a promising biocontrol agent against pest beetles in stored soft wheat.
Structural characterization of phytochemical content, antibacterial, and antifungal activities of Juglans regia L. leaves cultivated in Algeria
(Elsevier, 2022) Bennacer, Amel; Sahir-Halouane, Fatma; Aitslimane-Aitkaki, Sabrina; Oukali, Zahia; Oliveira, Ivo Vaz; Rahmouni, Naima; Aissaoui, Mohammed
Many microorganisms cause diseases to plants, animals and humans. Recently, natural compounds extracted from different medicinal and officinal plants have had a promising antimicrobial potential. In this present study, the antifungal and antibacterial activities of Juglans regia leaves cultivated in Algeria have been evaluated. The chemical composition was analyzed by GCMS spectroscopy. Total polyphenolic content (TPC), hydrolysable tannins content (HTC) and condensed tannin content (CTC) were assessed using Foilin ciocalteu, Potassium iodide and vanilline methods respectively. The antibacterial activity was tested against five bacterial strains and the antifungal activity was tested against seven fungal strains. The GC-MS profile of ethyl acetate fraction (tannic extract) revealed the presence of many interesting biomolecules we note: Phenol (0.19%), gaiucol (0.16%), catechol (0.65%), 2-Methoxy-4-vinylphenol (1.77%), eugenol (0.78%), (E)-coniferol (0.66%), 1, 5-naphthalenediol (2.01%) and 5-hydroxy-1, 4-naphthalenedione or juglone (0.18%). The tannic extract (ethyl acetate fraction) presented a high antifungal activity on Aspergillus terreus, Aspergillus ochraceus and Aspergillus Brasilliensis ATCC 16404 with percentage of growth inhibition of 77,033 ± 3,395, 73,327 ± 3,851 and 71,850 ± 0,641 respectively for the highest concentration. It also showed an interesting antibacterial activity against Klebseilla pneumoniae ATCC 70063 with minimal inhibitory concentration of 3.125 μg/ml comparing to the hydro-acetonic extract(MIC value). Our finding provides for the first time the chemical profiling of this species grown in Algeria and also an efficient and targeted natural approach to the discovery of classes of antibacterial and antifungal compounds for various applications
Volatile organic compounds activities of Trichoderma species isolated from olive grove soil against the wilt pathogen, Verticillium dahliae
(Springer Nature, 2024) Reghmit, Abdenaceur; Benzina-Tihar, Farida; Sahir-Halouane, Fatma
Production of volatile organic compounds (VOCs) is one of the modes of actions of Trichoderma spp. They inhibit pathogenic fungi/bacteria, promote plant growth, and also affect interactions of plants with pathogens. However, the study of VOCs emitted by Trichoderma species associated with olive roots and its benefits are still limited. In the present study, two strains of Trichoderma collected from olive grove soil were evaluated for their antagonistic activity against five strains of Verticillium dahliae named (Vd1 to Vd5) by indirect confrontation assay. In addition, identification and quantification of volatile compounds produced by each strain were assessed through gas chromatography-mass spectrometry (GC–MS). The extraction of metabolites was performed from filtrates using liquid–liquid extraction. Extracts obtained were taken for analysis through GC–MS. Results of indirect confrontation assay showed a high inhibitory activity against V.dahliae. Trichoderma asperellum (T4) and Trichoderma harzianum (T12) exhibited an average inhibition rate of 64.49% and 61.59% respectively. Besides, 98 volatile compounds were detected through GC–MS analysis, including important volatile compounds with antifungal activities, such as D-limonene, octadecanoic acid methyl ester, hexadecanoic acid, toluene, phenylethyl alcohol, benzene derivatives, several phenolic isomers, citral, eicosane and 13-docosenamide. Other volatile compounds revealed antibacterial activity, providing growth promotion, or antioxidant activity, such as oleic acid. Importantly, 7-epi-nemorosone was detected for the first time as new molecule produced by Trichoderma harzianum (T12). This molecule provides anticancer and antioxidant activity. Overall, these strains with various activities are considered as excellent source for discovery of bioactive molecules with eventual application in different biological fields. However, they could be beneficial mainly for suppressing plant pathogens and stimulation of plant growth.