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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.

Tetraclinis articulata is a forest plant species that is widely used in North African folk medicine due to its immense bioactive potential. The objective of the present study was to characterize flavonoids present in butanolic extract of aerial part of T. articulata (TABE) and to test its antibacterial synergistic effect, anticoagulant and antioxidant properties. The analysis of the TABE by colorimetric tests and TLC revealed the presence of flavonoids. The dosage showed that the proportions of total flavonoids and flavonols were 19.25 ± 0.07 and 13.6 ± 1.6 mg QE/g DW, respectively. Besides, the greatest antibacterial activity of the extract was shown against S. aureus. In contrast no effect was observed against E. coli. Furthermore, the most synergistic potential inhibitory effect was noted in the case of E. coli, when the extract was combined with penicillin. In addition, the MICs was determined used microdilution method, the values obtained were ranged from 2.5 to 20 mg/ml. Moreover, the in vitro anticoagulant activity was assessed by PT and KCT tests. The results showed interesting anticoagulant activity, with KCT value of 55.4 s which is superior to that obtained by the anticoagulant drug –Lovenox- (39.37s). The antioxidant activity was evaluated in vitro using DPPH• method. The result expressed in terms of IC50 was found to be 0.04 mg/ml. To conclude, the TABE constitutes a valuable source of anticoagulant, antioxidant and antibacterial synergism metabolites, which makes it a potential candidate to isolate responsible flavonoids and to develop novel pharmaceutical formulations.

In order to valorize Algerian medicinal plants, this work aims to characterize quantitatively and qualitatively Artemisia campestris L. fractions, a medicinal plant from the Aures-Algeria area, and investigate its biological activities in vitro. During preliminary phytochemical screening, flavonoids, saponins, tannins, alkaloids, reducing compounds, and coumarins were discovered. Total polyphenols and flavonoids are greater in the n-butanolic fraction than in ethyl acetate and petroleum ether. The resulting antioxidant capability was assessed in vitro using three methods: DPPH free radical scavenging, hydrogen peroxide trapping, and iron reduction. The n-butanolic extract suppresses DPPH oxidation with an IC50 of 2.239±0.32mg/ml, which is comparable to that of standard (1.824±0.97mg/ml). Despite the fact that similar findings were seen in the neutralization of hydrogen peroxide and the iron chelating activity, The anti-inflammatory action was proven in vitro by inhibiting protein denaturation and increasing HRBC membrane stability (Human Red Blood Cells). The n-butanolic fraction was more effective than diclofenac in preventing BSA degradation. It also inhibited membrane hemolysis in human erythrocytes by up to 83%. Activated partial thromboplastin and prothrombin times were used to analyze extrinsic and intrinsic coagulation pathways in A. campestris in order to determine its anticoagulant activity. The n-butanol fraction had the greatest impact on PT and aPTT lengthening, with 75.2s and 351s at 3 mg/ml concentration, respectively. The n-butanolic fraction of the A. campestris aerial part exhibited antioxidant, anti-inflammatory, and anticoagulant activities. As a result, it may be a viable natural resource for mitigating the impact of stress, which causes inflammatory and cardiovascular disorders.

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.