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In recent years, bio-healing based on microbial induced carbonate precipitation in cracks has been widely exploited to improve concrete properties and thus increase its durability. In this context, the present study aims to explore the possibility of using nine bacterial isolates as biohealing agent of cementitious materials; these bacteria (coded B1 to B8) were obtained from the three different rocky sites, i.e., 795 L1 (limestone rock site), 795 L2 (ordinary soil site), and 812 (clayey site); situated in Oulad Rahmoun (Constantine-Algeria). The primary identification showed that eight isolates belonged to a Bacillus genus, and one isolate B8 developed particularly morphological characterized by branched and septate hyphae. The isolates B4 and B8 were selected for their ability to produce calcium carbonate in precipitate calcium (PC) liquid and solid media after five days of incubation. The addition of urea in PC liquid media accelerated the formation of calcite which appeared after 3 days of incubation. The growth curve of both selected isolates on LB liquid medium showed that B8 was characterized by a long exponential growth phase (up to 72 hours) compared to B4 which had an exponential phase up to 48 hours, which could explain the largest amount of calcite precipitate observed in the case of B8 cultivated in PC liquid medium. Results of the bio-healing experiment carried on cementitious batches showed that a beginning of a slight repair of the cracks from the 11th day was only observed in the case of the bacterium B8 but the bio-healing capacity was absent in the control. This bio-healing agent was identified as Micromonospora echinospora (NCBI-NO139612), according to N-Blast of 16S-DNA sequence. In conclusion, the present study is the first to isolate M. echinospora species from rocky sites; and to describe it as an efficient bacterial agent in concrete bio-healing applications.

Laccase production by fungal growth on agrifood waste is still poorly studied. Trametes versicolor K1 isolated from palm bark produced a yellow non glycosylated laccase from tomato waste based medium (TMT) and a blue glycosylated laccase on glucose medium (GLU). Lignocellulosic biomass, such as pinecones (PIN), palm leaves (PLM), olive pomace (OLV), and alfa stems (ALF) have also been used as growth medium for T. versicolor K1. In these conditions, very low or no laccase production was observed. When peptone was supplied in TMT medium, the laccase activity increased from 4170 U/L to 8618 U/L. By increasing the culture volume up to 1 L, laccase production on TMT was 9929 U/L. The yellow laccase (TmtLac) was purified from the supernatant TMT medium and has shown similar characteristics with the blue laccase (GluLac) purified from the GLU medium. Their apparent protein size was 63 kDa. Catalytic activities of the yellow form were not very different from those of the blue form, but specific activity of the purified yellow laccase produced on tomato waste was much higher. The K

Facing the critical issue of high production costs for cellulase, numerous studies have focused on improving the efficiency of cellulase production by potential cellulolytic microorganisms using agricultural wastes as substrates, extremophilic cellulases, in particular, are crucial in the biorefinery process because they can maintain activity under harsh environmental conditions. This study aims to investigate the ability of a potential carboxymethylcellulose-hydrolyzing bacterial strain H1, isolated from an Algerian saline soil and identified as Bacillus velezensis, to use untreated olive mill wastes as a substrate for the production of an endo-1,4-β-glucanase. The enzyme was purified 44.9 fold using only two steps: ultrafiltration concentration and ion exchange chromatography, with final recovery of 80%. Its molecular mass was estimated to be 26 kDa by SDS-PAGE. Enzyme identification by LC-MS analysis showed 40% identity with an endo-1,3-1,4-β-glucanase of GH-16 family. The highest enzymatic activity was significantly measured on barley β-glucan (604.5 U/mL) followed by lichenan and carboxymethylcellulose as substrates, confirming that the studied enzyme is an endo-1,4-β-glucanase. Optimal enzymatic activity was at pH 6.0-6.5 and at 60-65 °C. It was fairly thermotolerant, retaining 76.9% of the activity at 70 °C, and halotolerant, retaining 70% of its activity in the presence of 4 M NaCl. The enzyme had a V

Fungal metabolites production at an industrial scale requires a sufficient yield at relatively low cost. Indeed, the scaling-up process is one of the main bottlenecks in the fermentation procedure; the reproduction of the best conditions achieved in small bio-reactors when transferring them to a much larger fermentation scale is near impossible.The present study seeks to study the fermentation profile of Aspergillus fumigatus fungi, in order to spot it logarithmic phase using xylose as substrate in different volumes; 250 mL flasks, 2 L and 20 L bioreactors, before conducting further experiments for an efficient secondary metabolite production (xylanase). The agitation speed impact on the morphological changing of this fungi was also studied.

Among the postharvest pathogens of apple fruit, Penicillium expansum (P.expansum) is considered to be one of the most common fungal pathogens worldwide. It is the causal agent of blue mold decay; the main serious economically disease of apple fruits, and the main producer of patulin (PAT). The principal objective of this work was to evaluate the aggressiveness and the PAT production of three isolated strains from apples produced in the East of Algeria. These strains were isolated then screened for their inhibitory activity against Escherichia coli and Bacillus subtilis (18 mm and 18 mm for S7; 10 mm and 11mm for S3), as well as their ability to cause blue rot (S4). The three strains S7, S3, and S4 (MN904448, MT023795 and MN904449, respectively) were identified as P. expansum by ITS1, ITS4, and β-tubulin gene sequences analysis. The in vitro ability to produce PAT was confirmed by Gas chromatography-mass spectrometry of strains’ crude extracts cul-tured on YES (Yeast-Extract-Sucrose) medium. Indeed, these strains exhibited a great capacity to cause blue mold decay for all tested apples (26 to 52 mm lesion diameter), after nine days of incubation at 25°C. Apples rotten area analysis that was performed by UPLC analysis revealed that these three strains were able to produce PAT at different concentrations ranging from 0.57 to 469 μg/mL. Thus, these strains constitute a risk to consumer health because these amounts exceed the permissive level of PAT.

Among the species belonging to the Aspergillus section Versicolores, Aspergillus creber has been poorly studied and still unexplored for its biological activities. The present study was undertaken to analyze A. creber extract and to evaluate its in vitro antimicrobial and anti-oxidant activities. UHPLC-MS/MS analysis of A. creber extract allowed the characterization of five known fungal metabolites including: asperlactone, emodin, sterigmatocystin, deoxybrevianamide E, and norsolorinic acid. The highest antimicrobial activity was displayed against Candida albicans, with a mean strongest inhibition zone of 20.6 ± 0.8 mm, followed by Gram-positive drug-resistant bacteria. The MIC values of A. creber extract varied from 0.325 mg/ml to 5 mg/ml. A. creber extract was shown a potent antioxidant activity and a high level of phenolic compounds by recording 89.28% scavenging effect for DPPH free radical, 92.93% in ABTS assay, and 85.76 mg gallic acid equivalents/g extract in Folin-Ciocalteu assay. To our knowledge, this is the first study concerning biological and chemical activities of A. creber species. Based on the obtained results, A. creber could be a promising source of natural antimicrobial and antioxidant compounds. Among the species belonging to the Aspergillus section Versicolores, Aspergillus creber has been poorly studied and still unexplored for its biological activities. The present study was undertaken to analyze A. creber extract and to evaluate its in vitro antimicrobial and anti-oxidant activities. UHPLC-MS/MS analysis of A. creber extract allowed the characterization of five known fungal metabolites including: asperlactone, emodin, sterigmatocystin, deoxybrevianamide E, and norsolorinic acid. The highest antimicrobial activity was displayed against Candida albicans, with a mean strongest inhibition zone of 20.6 ± 0.8 mm, followed by Gram-positive drug-resistant bacteria. The MIC values of A. creber extract varied from 0.325 mg/ml to 5 mg/ml. A. creber extract was shown a potent antioxidant activity and a high level of phenolic compounds by recording 89.28% scavenging effect for DPPH free radical, 92.93% in ABTS assay, and 85.76 mg gallic acid equivalents/g extract in Folin-Ciocalteu assay. To our knowledge, this is the first study concerning biological and chemical activities of A. creber species. Based on the obtained results, A. creber could be a promising source of natural antimicrobial and antioxidant compounds.

In the interest of discovering new antibiotic molecules, the antibacterial activity of three fungal strains namely: Aspergillus quadrilineatus, Aspergillus niveus, and Aspergillus wentii isolated from particular ecosystems was sought against six bacterial strains including three with Gram-positive staining (Staphylococcus aureus, Bacillus subtilis, Enterococcus faecalis) and three with Gram-negative staining (Escherichia coli, Pseudomonas aeruginosa, Klebsiella pneumoniae). The results of the agar cylinder technique highlighted that the three fungal strains showed a considerable antibacterial activity. In order to optimize the extraction conditions of the bioactive molecules, five solvents in different polarities were tested, of which chloroform turned out to be the best one. After the selection of this solvent, four culture media of different compositions were used in order to determine the most adequate medium for the production of antibacterial substances. The results revealed that Czapek-dox medium supplemented with yeast extract turned out to be the most favorable one for the production of bioactive molecules from both strains: A. quadrilineatus and A. niveus, while the most suitable medium for the A. wentii strain was Sabouraud. In addition, a study of the antibacterial effect of organic extracts by the Biolog micro-culture system was performed using a range of concentrations. The obtained results revealed that the extracts of the three fungal strains presented a remarkable activity with different concentrations and this, against all the tested bacterial strains. It was recorded only for the three used fungal species, the antibacterial activity was studied for the first time by the Biolog system.

The phytotoxicity activity of EtOAc extract obtained from Agaricus litoralis showed high phytotoxicity on tomato (Lycopersicon esculentum L.) leaves. A well-known phytotoxic metabolite: tyrosol [2-(4-hydroxyphenyl)-ethanol], was isolated and identified from A. litoralis by spectroscopic methods. Phytotoxic activity of tyrosol was tested on seven agrarian plants: eggplant (Solanum melongena L.), fig (Ficus carica L.), apricot (Prunus armeniaca L.), peach (Prunus persica (L.) Batsch), lemon (Citrus limon (L.) Osbeck), Cucurbita (Cucurbita L.), grapevine (Vitis vinifera L.) and two wild plants: willow oak (Quercus phellos L.), blackberry (Rubus fruticosus L.) using the leaf puncture assay, it showed weak phytotoxicity. The highest effect was observed on grapevine, apricot, peach, cucurbita and blackberry at 1 mg/ml; moderately phytotoxicity on eggplant, less phytotoxicity on fig, lemon and no necrosis on willow oak leaves. Tyrosol has been previously isolated from microorganisms, fungi, and plants, this being the first record from Agaricus litoralis as a phytotoxic metabolite

Algeria is facing two serious constraints, energy shortage and environment pollution. To overcome these two problems, renewable energies are the best sustainable alternatives. In this context, Algeria Government has established in 2011 a program for the development of renewable energies. The prospective results show a substantial contribution to supplying national energy demand as well as some significant environmental benefits, namely through major greenhouse gas savings. In fact, lignocellulosic sources as Algerian Alfa, olive pomace and cereal straw could provide up to 0.67 Mtoe which represents 4.37% of the energy consumption of transport sector in Algeria. In the same vein, introducing energy crops and dedicated cereal crop technologies allows Algeria to progressively increase its renewable energy supply. Up to 73.5 Mtoe and 57.9 Mtoe can be produced from the two cited resources respectively. That is more than the national energy consumption which reached 60.96 MToe in 2018.

The present work investigates for the first time the presence and isolation of the thermophilic fungi from hydrothermal spring situated at the locality of Guelma, in the Northeast of Algeria. The production of the thermostable proteases and the optimization of culture conditions under agro-wastes solid-state fermentation to achieve optimal production capacity were explored. A statistical experimental approach consisting of two designs was used to determine the optimum culture conditions and to attain the greatest enzyme production. Besides, different agricultural wastes were initially evaluated as a substrate, whereby wheat bran was selected for enzyme production by the isolate under solid-state conditions. The isolate thermophilic fungi were identified as Mycothermus thermophilus by sequencing the ITS region of the rDNA (NCBI Accession No: MK770356.1). Among the various screened variables: the temperature, the inoculum size, and the moisture were proved to have the most significant effects on protease activity. Employing two-level fractional Plackett–Burman and a Box–Behnken designs statistical approach helped in identifying optimum values of screened factors and their interactions. The analysis showed up 6.17-fold improvement in the production of proteases (~1187.03 U/mL) was achieved under the optimal conditions of moisture content 47%, inoculum 5 × 105 spores/g, and temperature at 42 °C. These significant findings highlight the importance of the statistical design in isolation of Mycothermus thermophilus species from a specific location as well as identifying the optimal culture conditions for maximum yield.

Calycotome spinosa (L.) Link is one of the important plants in traditional medicine especially in Algeria. The present work deals with the phytochemical screening, the flavonoids extraction from leaves and flowers of this plant, the quantification of total polyphenols and flavonoids, as well as the evaluation of antioxidant and antimicrobial properties of ethyl acetate and n-butanol fractions. While, the rest, interacted with its phenolics identification. The results of preliminary phytochemical screening showed that C. spinosa contained various metabolites: Polyphenols, flavonoids, alkaloids, saponins etc. In addition, the findings of polyphenols determination using Folin Ciocalteu was high in all the fractions: 107.75±0.41 and 64.24±1.81 mg gallic acid equivalents/g extract for leaves ethyl acetate and n-butanol respectively and 81.45±0.6 and 96.06±2.72 mg gallic acid equivalents/g extract for flowers ethyl acetate and n-butanol successively. Conversely, the flavonoids content in the four fractions by AlCl3 was less important than polyphenols. Moreover, the obtained fractions were evaluated for their antioxidant capacity using DPPH assay. Besides, the obtained result revealed that Ethyl acetate and n-butanol fractions of leaves exerted very high antioxidant activities with IC50 equal to 45.25±1.8 and 52.80±2.05 µg/mL, respectively compared with flowers. Furthermore, the antimicrobial activity of those fractions against many microbial strains have also been investigated using the disc diffusion method; the leaves ethyl acetate fraction showed the highest activity against Acinetobacter baumannii with a zone inhibition diameter equal to 22±0.06 mm. Additionally, high-performance liquid chromatography/diode-array detector (HPLC/DAD) analysis performed with C. spinosa fractions revealed the richness of plant in many phenolic compounds. Key words: Calycotome spinosa (L.) Link, medicinal plant, phenolics and flavonoids content, antioxidant activity, antimicrobial potential, high-performance liquid chromatography/diode-array detector (HPLC/DAD).

Several Bacillus strains were isolated from “Ouled Yelass” hot spring soil, located in Setif city (Eastern Algeria). Three isolates of them coded (4RH), (14 RH), and (Set-oxy), were screened for their ability to inhibit the growth of some phytopathogenic fungi, such as Fusarium oxysporium, Botrytis cinerea, Aspergillus niger, Cladosporium cucumerinium and Alternaria alternata. The molecular identification of the strain (4RH) based on the 16S-DNA and gyrase-A genes sequences analysis, showed that it is closely related (99.9%) to the Bacillus amyloliquefaciens species. This bacterium was characterized by a high sporulation yield reaching 22±0.86 × 108 spores/ml and had important inhibition rates up to 80 and 70%, against F. oxysporium and B. cinerea, respectively. The bacterium (4RH) was able to produce cell wall degrading enzymes of cellulase and protease, in contrast to chitinase activity which was negative. Furthermore, it produced the three lipopeptides families, which are, iturins A (C14; C15), fengycin A (C14, C15, C16, C17, and C18), and surfactin (C12, C13, C14, C15, C16). Interestingly, LC-MS profiles of 80% acetonitrile fengycin extract of the (4RH) strain, showed the presence of some new molecular ions (MH+) with masses different, but near to conventional fengycin variants, which correspond to new variants described for the first time in this work. The isolate (4RH) produced 5 µg/ml of the phytohormone (IAA), on TGE medium and siderophores with more than 10 mm of yellow-orange zones, on CAS medium. To conclude, B. amyloliquefaciens (4RH) strain possessed interesting biocontrol and biofertilization characteristics, in vitro, in addition to its high sporulation yield, which make it a potential agent for future biopesticide that could be efficient in the integrate pest management and organic agricultural production systems. Key words: Bacillus, biocontrol, biofertilization, plant protection, hot spring, lipopeptides.

Two novel compounds were isolated for the first time from Calycotome spinosa (L.) Link, an alkaloid 5-Hydroxy-1H-indole (4) and a cyclitol D-pinitol (5), together with the three well-known flavonoids; Chrysin-7-O-(β-D-glucopyranoside) (1), Chrysin-7-O-β-D-(6″-acetyl)glycopyranoside (2) and Apigenin-7-O-β-D-glycopyranoside (3). The chemical structures of the isolated compounds were elucidated by spectroscopic data and mass spectrometric analyses; including a fresh approach 1D-NMR, 2D-NMR with LC-ESI-MS/MS. In this study, the new compound (4) that has been obtained from the leaves MeOH extract presented the best radical scavenging activity (DPPH) (IC

Among the species belonging to the Aspergillus section Versicolores, Aspergillus creber has been poorly studied and still unexplored for its biological activities. The present study was undertaken to analyze A. creber extract and to evaluate its in vitro antimicrobial and anti-oxidant activities. UHPLC-MS/MS analysis of A. creber extract allowed the characterization of five known fungal metabolites including: asperlactone, emodin, sterigmatocystin, deoxybrevianamide E, and norsolorinic acid. The highest antimicrobial activity was displayed against Candida albicans, with a mean strongest inhibition zone of 20.6 ± 0.8 mm, followed by Gram-positive drug-resistant bacteria. The MIC values of A. creber extract varied from 0.325 mg/ml to 5 mg/ml. A. creber extract was shown a potent antioxidant activity and a high level of phenolic compounds by recording 89.28% scavenging effect for DPPH free radical, 92.93% in ABTS assay, and 85.76 mg gallic acid equivalents/g extract in Folin-Ciocalteu assay. To our knowledge, this is the first study concerning biological and chemical activities of A. creber species. Based on the obtained results, A. creber could be a promising source of natural antimicrobial and antioxidant compounds.

The strain, Lactobacillus plantarum F12 with probiotic traits was isolated from Algerian healthy children faeces and identified by 16S rDNA sequencing. In this study, the antimicrobial activity and physicochemical properties of bacteriocin-like substance (BLS) produced by this strain were determined. Also, the bacteriocinogenic genes of plantaricin A, plantaricin J and plantaricin K were screened in this strain. The BLS inhibited a range of pathogenic and spoilage bacteria including Escherichia coli, Salmonella infantis, Salmonella typhimurium, Shigella sonnei, Staphylococcus aureus, Listeria monocytogenes, Listeria innocua, Bacillus subtilis and some lactobacilli sp. The BLS was proteinaceous since it was inactivated by the proteolytic enzymes (trypsin, proteinase K and pronase) but not by α-amylase and lipase. It was heat stable at different temperatures (40 - 121°C) for 30 min and retained its activity at a wide range of pH values (2 to 10). Its activity was totally preserved at -80°C for 120 days and at -20°C for 60 days. The amplification of genetic determinants of plnA, plnJ and plnK has shown the presence of these genes in L. plantarum F12. The ability of the BLS from L. plantarum F12 to inhibit several pathogenic/spoilage bacteria and its characterization demonstrated its interest as a natural food preservative, in addition to its probiotic potential in prevention and treatment of infectious diseases. Key words: Lactobacillus plantarum, plantaricin J/K, plantaricin A, bacteriocin-like substance, characterization.

Synthesis, characterization, corrosion inhibition as well as antimicrobial activity of the coordination compounds {Co(bbms)Cl2}, {Zn(bbms)Cl2}, {Co(btmb)Cl2} and {Zn(btmb)Cl2} containing benzimidazole thioether have been described. Co(bbms) and Zn(bbms) as well as Co(btmb) and Zn(btmb) are isostructural with space group Pbca and P21 respectively. The coordination polyhedron around the metal center for all complexes may be described as a quasi-regular tetragonal geometry. The corrosion inhibition study of these complexes for steel in 0.5 M H2SO4 medium has been investigated using potentiodynamic polarization and EIS techniques. These later show the corrosion inhibition ability of the prepared complexes for steel in acid medium. A new procedure has been developed for antimicrobial assay using a solid tablet of the corresponding complexes. These later show moderate to significant antimicrobial activities against: Pseudomonas syringae, Staphylococcus aureus and Pichia caribbica. DFT/BP86 calculations have been carried out on the neutral complexes and on the monoanionic of (1) and (3) forms of singlet and triplet species. The optimized structures reproduce those observed experimentally, while the reduced ones undergo remarkable geometrical parameters variations.

International audience; Two novel compounds were isolated for the first time from Calycotome spinosa (L.) Link, an alkaloid 5-Hydroxy-1H-indole (4) and a cyclitol D-pinitol (5), together with the three well-known flavonoids; Chrysin-7-O-(β-D-glucopyranoside) (1), Chrysin-7-O-β-D-(6″-acetyl)glycopyranoside (2) and Apigenin-7-O-β-D-glycopyranoside (3). The chemical structures of the isolated compounds were elucidated by spectroscopic data and mass spectrometric analyses; including a fresh approach 1D-NMR, 2D-NMR with LC-ESI-MS/MS. In this study, the new compound (4) that has been obtained from the leaves MeOH extract presented the best radical scavenging activity (DPPH) (IC50 < 10 µg/mL) compared to the standard butylated hydroxytoluene (BHT, IC50 = 34.73 ± 0.23 μg/mL) and showed the highest total antioxidant capacity (TAC = 985.54 ± 0.13 mg AAE/g extract) in contrast to ascorbic acid (TAC = 905.95 ± 0.07 mg AAE/g extract). Furthermore, the strongest reducing power (EC50 = 344.82 ± 0.02 µg/mL), as well as the remarkable scavenging potential by ABTS assay (IC50 = 7.8 ± 0.43 µg/mL), were exhibited by the same composite (4). Followed by the methanol crude extract and the compound (3) that also showed a potent antioxidant (DPPH; IC50 = 41.04 ± 0.15 and 47.36 ± 0.21 µg/mL, TAC; 671.02 ± 0.21 and 608.67 ± 0.34 mg AAE/g extract, FRAP; EC50 = 763.73 ± 0.32 and 814.61 ± 0.31 µg/mL, ABTS; IC50 = 19.18 ± 0.06 and 63.72 ± 0.64 µg/mL, respectively), but less than the previous samples. On the opposite side, compound (5) had the lowest activity, in which its values were less interesting to determine. Moreover, compound (4) has equally exerted an attractive antibacterial activity against Staphylococcus aureus (ATTC-25923), Pseudomonas aeruginosa (ATTC- 27853) and Salmonella abony (NCTC 6017), as measured by the disc diffusion assay, with inhibition zones of 16 ± 0.5, 9.83 ± 0.29 and 8 ± 0.28 mm, in that order. To the best of our knowledge, 5-Hydroxy-1H-indole was isolated from plants for the second time in our current work. Thus, the obtained results from this investigation propose that the leaves of C. spinosa are a rich natural source for value molecules as potential antioxidants and antimicrobial agents for best human health.

Lenses are a group of pulses having a socio-economic and nutritional significance. The study was conducted on two fields of Lens culinaris in Constantine region contaminated with molds, had the objective to put a relationship between pathogenic molds associated with these plants and their environment. This study revealed the presence of 20 genera in soils (Absidia, Acremonium, Alternaria, Aspergillus, Bysochlamyces, Chaetomium, Cladosporium, Emericella, Eurotium, Fusarium, Mucor, Paecilomyces, Penicillium, Peronospora, Phytophotora, Pseudalesheria, Scopulariopsis, Scytaldium, Trichoderma and Ulocladium) and 20 genera also in plants (Absidia, Acremonium, Alternaria, Aspergillus, Botrytis, Chaetomium, Cladosporium, Cylindrosporium, Curvularia, Eurotium, Fusarium, Myrothecium, Onychocola, Phytophthora, Pseudalescheria, Penicillium, Peronospora, Rhizoctonia, Trichoderma and Ulocladium). They contribute approximately 54% of the total micropopulation enumerated in studied samples. The development of these pathogenic strains is governed by environmental conditions namely the chemical elements in soil, pH, electrical conductivity, Nitrogen, Carbon and saturation. The results we have obtained shows that the chemical variations ground contribute to the right development fungi and their transfer to plants Key words: Lens culinaris, soil, fungi.

The growth kinetics and modeling of ethanol production from inulin by Pichia caribbica (KC977491) were studied in a batch system. Unstructured models were proposed using the logistic equation for growth, the Luedeking-Piret equation for ethanol production and modified Leudeking-Piret model for substrate consumption. Kinetic parameters (X0, μm, m, n, p and q) were determined by nonlinear regression, using Levenberg-Marquart method implemented in a Mathcad program. Since the production of ethanol was associated with P. caribbica cell growth, a good agreement between model predictions and experimental data was obtained. Indeed, significant R2 values of 0.91, 0.96, and 0.95 were observed for biomass, ethanol production and substrate consumption, respectively. Furthermore, analysis of variance (ANOVA) was also used to validate the proposed models. According to the obtained results, the predicted kinetic values and experimental data agreed well . Finally, it is possible to predict the development of P. caribbica using these models. Key words : Pichia caribbica, inulin, bioethanol, numerical simulation.

A total of 24 lipolytic yeasts were isolated from the spent olive derived from olive fruits of the Algerian variety Chemlal. One strain, G5, had the highest lipolytic activity (20 mm) on the tributyrin agar plate. The morphological, biochemical characterization and 18S rDNA gene analysis of the selected strain, confirms that it is Candida boidinii KF156789. The production of lipase and biomass were carried out in liquid and solid (spent olive) media. In submerged fermentation, it seemed that the production of enzyme reached its maximum 7.3 U/ml, whereas; the growth cells reached its maximum at 1.9 × 108 cell/ml. That can be explained by the assimilation of free fatty acids by this strain after degradation of olive oil by the enzyme. The production of lipase and biomass, in solid state fermentation, gave the maximum yield for cell growth (1.3 × 109 cell/ml), while lipolytic activity reached 4.8 U/g. The highest activity of the studied enzyme was at pH 7.0 and 37°C. The enzyme maintained more than 90% of its activity at pH 8.0-9.0 and 70% at temperature range of 4-40°C; it was concluded that the lipase from C. boidinii KF156789 has the potential to be an alkaline cold-adapted enzyme.Keywords: Candida boidinii KF156789, higher lipase, alkaline cold-adapted lipase, chemlal spent olive, solid state fermentation.African Journal of Biotechnology, Vol 13(11), 1287-1294

The soil bacteria, CWBI-B1567 and CWBI-B1568, isolated from arid regions and identified as Bacillus subtilis (accession number KC341751) and Bacillus mojavensis (accession number KC341749) respectively, were screened and evaluated for their antifungal activity against Candida albicans, one of the most important human fungal pathogens. In vitro assay with the antagonists and their cell-free culture supernatants on agar plates showed that the two Bacillus strains effectively inhibited growth of the yeast. The capacity of these Bacillus strains to produce the cell-wall degrading enzymes was further studied. B. subtilis and B. mojavensis are able to produce cellulase and protease, but not chitinase. Bioactive molecules were produced by B. subtilis CWBI-B1567 and B. mojavensis CWBI-B1568 in a liquid culture medium optimised for lipopeptide production. The antifungal activity was equally demonstrated by testing the resulting supernatants and lipopeptide-enriched extracts. The electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC-MS) analysis showed that both the B. subtilis and the B. mojavensis produced surfactin and iturin. However the fengycin group was produced only by B. mojavensis. Through this study, we have demonstrated that B. subtilis and B. mojavensis have a strong antifungal activity especially against C. albicans. This growth inhibition is probably due to the production of cell-wall degrading enzymes and different families of lipopeptide including iturins, fengycins and surfactins. Key words: Bacillus subtilis CWBI-B1567, Bacillus mojavensis CWBI-B1568, antifungal activity, Candida albicans, lipopeptides, electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC-MS), arid regions.

This report is to our knowledge the first to study plant growth promotion and biocontrol characteristics of Bacillus isolates from extreme environments of Eastern Algeria. Seven isolates of 14 (50 %) were screened for their ability to inhibit growth of some phytopathogenic fungi on PDA and some roots exudates. The bacteria identification based on 16S r-RNA and gyrase-A gene sequence analysis showed that 71 % of the screened isolates belonged to Bacillus amyloliquefaciens and the rest were closely related to B. atrophaeus and B. mojavensis. Most of them had high spore yields (22 × 10(8)-27 × 10(8) spores/ml). They produced protease and cellulase cell wall-degrading enzymes while the chitinase activity was only observed in the B. atrophaeus (6SEL). A wide variety of lipopeptides homologous was detected by liquid chromatography-electrospray ionization-mass spectrometry analysis. Interestingly, some additional peaks with new masses were characterized, which may correspond to new fengycin classes. The isolates produced siderophores and indole-3- acetic acid phytohormone. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. atrophaeus (6SEL) significantly increased the size of the chickpea plants and reduced the stem rot disease (P < 0.05). These results suggest that these isolates may be used further as bio-inoculants to improve crop systems.

The recovery of dates downgraded as a fermentation medium for the production of extracellular catalase by Aspergillus phoenicis K30 was studied. Analysis of the chemical composition of pulp and kernel flour of dates showed that the pulp had a considerably greater carbohydrate content compared to the kernel (84 vs 2.93% respectively). However, the kernel flour was richer in nitrogen (0.68% vs 0.34), mineral elements (3.63 vs 1.28%) and in essential fatty acids C18: 2 vs C18: 3 than the pulp flour. The soluble extract of the date flour showed that sugars solubilised at 90% consisted of sucrose, fructose and glucose. Therefore, this extract, being an important source of carbon and energy, was used in the current study as a fermentation medium (after supplementation with 20% of corn steep) for the production of extracellular catalase by A. Phoenicis K30. During the course of this fermentation, the biomass was estimated at 18.6 g / L after 72 h of culture, while the maximum concentration of extracellular catalase (47.5 U / ml) was reached at 96 h of fermentation. The mycelium obtained in pellet form is suitable for industrial exploitation of this process.

Tomato, Solanum lycopersicum is one of the most important vegetable crops consumed in Algeria. Tomato crops are often infected by Alternaria alternata, which causes early blight disease. Chemical pesticides are intensively used to protect this plant, which lead to environmental pollution that might endanger animal and human health. The main objective of this study is to select potential biocontrol agents from arid soil as an alternative to chemical products. The phytopathogenic fungus which was isolated from infested tomato leaves, stems and fruits cultured in Constantine-Algeria, was identified as Alternaria cf. alternata. Thirty five bacteria isolates were obtained from arid soil in the south of Algeria. Three of the isolates inhibited the growth of A. alternata. However, the most potent isolate, E1B3 reached a 75% inhibition rate. The molecular identification of this isolate showed that it was closely related to Bacillus mojavensis (KC977492). This strain does not produce chitinase, but does produce lipase, protease and lipopeptides. The interaction between A. alternata and B. mojavensis was investigated for the first time in this work by flow cytometric analysis. In conclusion, B. mojavensis strain was antagonistic to A. alternata which could possibly be exploited as a biopesticide in tomato crops management. Key words: Tomato, Bacillus mojavensis, early blight, Alternaria alternata, flow cytometry.

Lactic bacteria are used in fermentation and food bio‐preservation through their production of organic acids and other antimicrobial substances like bacteriocins which restrain certain fungal strains. The main objective of this study is the isolation of Lactobacillus strains from curdled milk samples, in order, to inhibit, in vitro, mycotoxins production by Aspergilus flavus. Six bacterial isolates were obtained from curdled milk commercialized in the region of Constantine. Among them, one isolate coded (B6) had a significant inhibitory effect against A. flavus (the diameter of colony not exceeding 1.5 cm after 72 hr of incubation at 28°C). This isolate (B6), was identified morphologically and biochemically. The obtained results showed that this bacterial isolate belongs Lactobacillus genus. In addition, its antimycotoxinogen activity had been confirmed using some test bacteria, such as E. coli, Staphylococcus aureus, Klebsiella sp., and Pseudomenas syringae. PRACTICAL APPLICATIONS: This paper describes the isolation of lactic bacteria strains from Algerian curdled milk and the study of their antifungal and antimycotoxinogen activity. The method used to test the effect of lactic bacteria strains against toxigenic fungi was not previously exploited. The main objectives were to: (a) Isolate and select the lactic bacteria from curdled milk; (b) Isolate and identify the toxigenic fungi; (c) Select bacterial isolates for antifungal effect against toxigenic fungi; (d) Study of their antimycotoxinogen activity, in vitro.

This work aims to study the production of the biomass of S. cerevisiae on an optimized medium using date extract as the only carbon source in order to obtain a good yield of the biomass. The biomass production was carried out according to the central composite experimental design (CCD) as a response surface methodology using Minitab 16 software. Indeed, under optimal biomass production conditions, temperature (32.9 °C), pH (5.35) and the total reducing sugar extracted from dates (70.93 g/L), S. cerevisiae produced 40 g/L of their biomass in an Erlenmeyer after only 16 h of fermentation. The kinetic performance of the S. cerevisiae strain was investigated with three unstructured models i.e., Monod, Verhulst, and Tessier. The conformity of the experimental data fitted showed a good consistency with Monod and Tessier models with R2 = 0.945 and 0.979, respectively. An excellent adequacy was noted in the case of the Verhulst model (R2 = 0.981). The values of kinetic parameters (Ks, Xm, μm, p and q) calculated by the Excel software, confirmed that Monod and Verhulst were suitable models, in contrast, the Tessier model was inappropriately fitted with the experimental data due to the illogical value of Ks (−9.434). The profiles prediction of the biomass production with the Verhulst model, and that of the substrate consumption using Leudeking Piret model over time, demonstrated a good agreement between the simulation models and the experimental data.

The phenotypic and genotypic diversity of the plant growth promoting Bacillus genus have been widely investigated in the rhizosphere of various agricultural crops. However, to our knowledge this is the first report on the Bacillus species isolated from the rhizosphere of Calendula officinalis. 15 % of the isolated bacteria were screened for their important antifungal activity against Fusarium oxysporum, Botrytis cinerea, Aspergillus niger, Cladosporium cucumerinium and Alternaria alternata. The bacteria identification based on 16S r-RNA and gyrase-A genes analysis, revealed strains closely related to Bacillus amyloliquefaciens, B. velezensis, B. subtilis sub sp spizezenii and Paenibacillus polymyxa species. The electro-spray mass spectrometry coupled to liquid chromatography (ESI-LC MS) analysis showed that most of the Bacillus isolates produced the three lipopeptides families. However, the P. polymyxa (18SRTS) didn’t produce any type of lipopeptides. All the tested Bacillus isolates produced cellulase but the protease activity was observed only in the B. amyloliquefaciens species (9SRTS). The Salkowsky colorimetric test showed that the screened bacteria synthesized 6–52 μg/ml of indole 3 acetic acid. These bacteria produced siderophores with more than 10 mm wide orange zones on chromazurol S. The greenhouse experiment using a naturally infested soil with Sclerotonia sclerotiorum showed that the B. amyloliquefaciens (9SRTS) had no significant (P > 0.05) effect on the pre-germination of the chickpea seeds. However, it increased the size of the chickpea plants and reduced the stem rot disease (P