Hydrolytic and Antimicrobial Activities of Bacteria Isolated from Fermented Peppers Sold in Markets at Brazzaville, Republic of the Congo

Microorganisms are omnipresent in all environments and play mainly the role of transformers, thanks to the multiple enzymes they are able to produce. In order to valorize fermented foods in the Republic of the Congo, this work aimed to characterize and study some properties of microorganisms isolated from samples of peppers sold in three markets of Brazzaville. A numeration of the total aerobic mesophilic flora (TAMF) was made in a solid medium, allowing the evaluation of each sample’s microbial concentration. The microbial mass varied from 2.8 × 105 CFU/g for the Ouénzé sample to 1.8 × 104 CFU/g for the Total sample and 2 × 104 CFU/g for the Moungali market sample. The evaluation of the enzymatic properties of the Bacillus isolates showed that 68.42% were capable of producing cellulases and 78.94% were capable of producing amylases and proteases. Antimicrobial activities revealed that 63.15% of the isolates were able to secrete inhibitory substances against E. coli and Staphylococcus aureus. Molecular analysis by PCR amplification, sequencing of the 16S rRNA gene and BLAST bioinformatics analysis provides newly identified bacteria strains with new accession numbers in GenBank: Bacillus thuringiensis MBCBR322 (OP474008), Bacillus megaterium MBCBJ1822 (OP476493), Bacillus thuringiensis MBCBR222 (OP476494), Priestia megaterium MBCBJ2022 (OP476495) and Lactobacillus paraplantarum MBCBR1522 (OP476496). Multiple sequences alignment of identified sequences with their homologs of GenBank has shown high similarities. The phylogenetic inference assay has provided the two groups of strains observed in this study, and the two groups are very coherent with the phylogeny of the reference.

Antimicrobial activities and analysis of the crude extract,fractions and compounds from the Lomatogonium rotatum

This study was evaluated the antimicrobial activities of the crude extract,different fractions,and compounds from the plant of Lomatogonium carinthiacum.The fractions of chloroform and compounds 5,2 and 6 exhibited stronger antimicrobial activities.Compound 5 was the most active while Staphylococcus aureus and Candida albicans were sensitive to all the tested compounds.The existence of a relationship between the xanthone structures and inhibition of microorganism activity.The antimicrobial activity of this plant was reported here firstly.The results provided evidence that the studied plant extract,fractions as well as some of the isolated compounds might be potential sources of new antimicrobial drug.

New Hemisynthetic Oleanane Saponin with Antimicrobial Activities

A new hemisynthetic oleanane saponin: 4',2",3",4",6"-penta-O-acetyl-6'-O- methyl-3-O-β-D-glucopyranosyl-(1→2)-β-D-glucuronopyranosyl oleanolic acid (2) was obtained after acetylation and methylation reaction on 3-O-β-D- glucopyranosyl-(1→2)-β-D-glucuronopyranosyl oleanolic acid (1). Its structure was established by extensive analysis of 1D-(1H, 13C), 2D-(COSY, HSQC and HMBC) NMR data in conjunction with mass spectrometry (HR- TOFESIMS). The evaluation of antimicrobial activities using microdilution method showed that, reaction product (2) presented the lowest values of MIC against E. coli (MIC = 16 μg/mL), S. aureus (MIC = 8 μg/mL), C. tropicalis (MIC = 16 μg/mL) C. albicans (MIC = 8 μg/mL) compare to the substrate (1) against the same microbial strains: E. coli (MIC = 32 μg/mL), S. aureus (MIC = 16 μg/mL), C. tropicalis (MIC = 32 μg/mL), C. albicans (MIC = 16 μg/mL). These results indicate that, acetylation and methylation reactions of compound 1 increase its antimicrobial activities against the tested microorganisms.

Study on Antimicrobial Activities of Ethanol Extracts from Different Capsicum Cultivars

[Objective] This study aimed to provide basis for exploring the antimicrobial activity of capsaicin from different Capsicum cultivars and different locations in the same Capsicum fruit. [Method] Capsaicin was extracted from pericarp and seeds of three Capsicum cultivars using the alkaline ethanol extraction method. The antimicro- bial activities of capsaicin against Staphylococcus aureus, Saccharomyces cerevisiae and Asergillus niger were also studied. [Result] Capsaicin content in the ethanol ex- tracts of three Capsicum fruit followed： C. annuum L. var. conoides〉C, annuum L.〉C. annuum L. var. Iongum, and the capsaicin content in pericarp was 1.5-3.9 times that in seeds. Within the concentration range designed in this experiment （0.5-1.5 mg/ ml）, antimicrobial activities of the ethanol extracts from fruits of three Capsicum culfi- vars against the three experimental strains were obvious, with the highest antimicro- bial activity in C. annuum L., and similar antimicrobial activity in C. annuum L var. Iongum and C. annuum L, var. conoides. [Conclution] Both pericarp and seeds of three Capsicum cultivars contained capsaicinoids with high broad-spectrum antimicrobial activity.

Antimicrobial activities of essential oil from Artemisiae argyi leaves

A study was conducted to determine the antimicrobial activities of essential oil from Artemisiae argyi leaves. The sample of the essential oil was analyzed by GC-MS. From 18 compounds representing the oils, Eucalyptole （18.42%）, Spathulenol （14.32）, 4-Methyl-1-（1-methylethyl）-3-cyclohexen-1-ol （3.10%）, 3-Carene （2.64%） appeared as the main components. The screening of antimicrobial activity of the essential oil was evaluated using agar diffusion and broth microdilution methods. Gram-positive bacterial were more sensitive than gram-negative bacterial of the 8 microorganisms, and Staphylococcus aureus ATCC 6538 showed the lowest MIC （0.3125%） and MBC （0.625%）. In the disc diffusion assay, Staphylococcus epidermidis ATCC 49134 and Bacillus subtilis ATCC 6633 showed obvious inhibitory activity. Survival curve showed that, 2MIC ofArtemisiae argyi essential oil had a lethal effect on Candida albicans within the first 1 h. Results presented here suggest that the essential oil of Artemisiae argyi leaves possesses antimicrobial properties, and provides scientific foundations for exploition ofArtemisiae argyi.

Antioxidant and Antimicrobial Activities of Echinacea (Echinacea purpurea L.) Extracts Obtained by Classical and Ultrasound Extraction

Antioxidant and antimicrobial activities of Echinacea purpurea L. (Asteraceae) extracts obtained by classical and ultrasound solvent extraction were compared. The dry aerial part of plant was extracted by 70% etha-nol at a solid-to-liquid ratio of 1︰10 (m/v) and 25°C. The extract obtained by classical solvent extraction contained 29% larger amounts of phenolic compounds and 20% higher content of flavonoids. 2,2-diphenyl-1-picril hydrazyl radical (DPPH) scavenging reached 93.6% and the values of EC50 were (34.16±0.65) μg·ml-1 and (65.48±1.12) μg·ml-1 for the extracts obtained by the classical and ultrasound extractions, respectively. The extracts, independent of the extraction technique applied, showed a considerable growth inhibition on Candida albicans and Saccharo-myces cerevisiae, while no growth inhibition zones were observed for Aspergillus niger. The diameters of inhibition zone observed for all the microorganisms were larger for extracts obtained by classical extraction than those by ul-trasound extraction.

Comparison of Antioxidant and Antimicrobial Activities of Methanolic Extracts of the Artemisia sp.Recovered by Different Extraction Techniques

The polyphenol content,antioxidant and antimicrobial activities of the extracts obtained by classical, ultrasonic and Soxhlet extractions from dry aerial parts of two Artemisia species(Artemisia vulgaris and Artemisia campestris)were compared.Ultrasound positively affected the yield of extractive substance and the kinetics of extraction,but the extract obtained by the classical extraction showed the highest antioxidant activities and contained higher total contents of phenolic compounds and flavonoids than the extracts obtained by two other extraction techniques.Both flavonoid aglycones(apigenin,quercetin,quercetin 3,3′-dimethyl ether)and flavonoid glycosides(rutin,hyperoside and kaempferol 3-rhamnoside)were identified by thin layer chromatograph(TLC)analysis in the extracts from both species.A.campestris extracts were richer in quercetin than A.vulgaris and its antimicrobial activity was also better than A.vulgaris.Extracts obtained from both species were found to be more effective on the tested yeasts than bacteria.The kinetics of the total extractive substances,such as phenolic,flavonoids and quercetin extraction,was successfully described by the model of unsteady-state diffusion.

One-pot Synthesis,Crystal Structures and Antimicrobial Activities of Two New 1,4-Disubstituted 1,2,3-Triazole-4-Carboxylates

Two new 1,4-disubstituted 1,2,3-triazoles-4-carboxylates were synthesized via click reaction. Compound 1a was synthesized by the interaction of 6-nitro-tetrazolo[1.5-a]-pyridine with ethyl propynoate at room temperature in the presence of Cu（OAc）2 as a catalyst and THF as solvent. Compound 1b was also synthesized by the same manner except that tert-butyl propionate, instead of ethyl propynoate, was used. The compounds were characterized by IR, 1H-NMR, 13C-NMR and single-crystal X-ray diffraction analysis. Compound 1a（C10H9N5O4） crystallizes in the triclinic system, space group P1 with a = 5.0894（9）, b = 8.9834（13）, c = 13.089（2） ？, α= 83.041（7）, β= 80.256（7）, γ=87.296（8）°, V = 585.24（16）？3, Z = 2, Mr = 263.22, crystal size（mm） = 0.37 × 0.20 ×0.18,（I 〉 2σ（I）） = 8557, 2493, 1229, Rint = 0.057. Compound 1b（C12H13N5O4） crystallizes in the monoclinic system, space group P21/c with a = 6.8854（5）, b = 21.783（2）, c = 9.3986（8） ？,β = 93.239（4）°, V = 1407.4（2）？3, Z = 4, Mr = 291.27, crystal size（mm） = 0.38 × 0.22 × 0.20,（I 〉 2σ（I）） = 11842, 3172, 1866, Rint = 0.047. Antimicrobial assay results showed that the title compounds display excellent activities to different bacterial and fungal strains.

Antioxidant antileishmanial cytotoxic and antimicrobial activities of a local plant Myrtus nivellei from Algeria Sahara

To study the phytochemical constituents and in vitro biological activities of hydromethanolic extract and fractions from Algerian Sahara Myrtus nivellei (M. nivellei) collected in Hoggar region and to identify the active fraction that can act as an alternative of commonly used antibiotics and as antileishmanial or antioxidant agents.MethodsPhytochemical screening of M. nivellei aerial parts was realised according to the literature. Extract was firstly prepared by using aqueous methanol then fractionated with ethyl acetate and butanol solvents. Total phenolics, tannis and flavonoids, of the hydromethanolic extract and their fractions were determined by Folin-Ciocalteu method as gallic acid equivalents and by aluminium chloride as rutin equivalent respectively. Extract and fractions were tested for their antimicrobial and antiparasital activities against standard bacteria using agar diffusion method and two kinds of leishmania visceral and cutaneous. The antioxidant activities were realized using phosphomolybdenum, FRAP and DPPH tests.ResultsPreliminary phytochemical screening exhibited the presence of flavonoids, tannins, saponins, and alkaloids. The experimental results showed that plant extract and fractions were high in phenolic compounds and exhibited an important role as antioxidant, antimicrobial and had a moderate antileishmanial activity.ConclusionsThese observations lead us toward more studies in this field, so that we can get more benefits from our local Algerian medicinal plants.

Syntheses,Crystal Structures,and Antimicrobial Activities of 3-Bromo-N'-(2- chloro-5-nitrobenzylidene)benzohydrazide and 3-Bromo-N'-(4-nitrobenzylidene)benzohydrazide

Two new hydrazone compounds, 3-bromo-N＇-（2-chloro-5-nitrobenzylidene）-ben- zohydrazide 1 and 3-bromo-N＇-（4-nitrobenzylidene）benzohydrazide 2, have been synthesized and characterized by elemental analysis, IR spectra, 1H NMR, and single-crystal X-ray diffraction. Compound 1 crystallizes in monoclinic, space group P21/c with a=7.7924（10）, b=24.490（3）, c=7.8989（9） , β=94.987（6）°, V=1501.7（3） 3, Z=4, R=0.0345 and wR=0.0739. Compound 2 crystallizes in monoclinic, space group P21/c with a=7.4099（11）, b=24.868（4）, c=8.3255（12） , β=112.796（8）°, V=1414.3（4） 3, Z=4, R=0.0744 and wR=0.1912. Both compounds display E configurations with respect to the C=N double bonds. In the crystal structure of 1, molecules are linked through N-H…N and N-H…O hydrogen bonds, forming chains running along the c axis. In the crystal structure of 2, molecules are linked through N-H…O hydrogen bonds, forming chains running along the c axis. The preliminary antimicrobial activities were studied.

Syntheses, Crystal Structures and Antimicrobial Activities of Vanadium(V) Complexes with Similar Tridentate Hydrazone Ligands

Two hydrazone ligands （E）-N＇-（2-hydroxy-5-methoxybenzylidene）-2-hydroxybenzo- hydrazide （HLa） and （E）-N＇-（3,5-dichloro-2- hydroxybenzylidene）-4-methoxybenzohydrazide （HLb） were prepared and characterized by IR, UV-Vis and 1H NMR spectra. Based on the hydrazone ligands, two new structurally similar vanadium（V） complexes, [VOLaL].CH3OH （1） and [vOLbL] （2）, where L is the monoanionic form of benzohydroxamic acid （HL）, were prepared and characterized by IR and UV-Vis spectra, and single-crystal X-ray diffraction. Complex 1 crystallizes as the monoclinic space group P21/n, with a = 7.5208（10）, b = 15.490（2）, c = 20.8929（18） A, β = 96.373（2）°, V = 2418.9（5） A3, Z = 4, R = 0.0831, wR = 0.2607 and GOOF = 1.061. Complex 2 crystallizes as the monoclinic space group P21/c, with a = 11.8577（18）, b = 16.468（2）, c = 12.2288（18） A, β = 106.064（2）°, V= 2294.7（6） A3, Z = 4, R= 0.0741, wR= 0.1745 and GOOF= 1.014. X-ray analysis indicates that the complexes are mononuclear vanadium （V） species, with the V atoms located in the octahedral coordination. The hydrazone ligands and the complexes were evaluated for their antibacterial （Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Pseudomonas fluorescence） and antifungal （Candida albicans and Aspergillus niger） activities by MTT （3-（4,5-dimethylthiazol-2-yl）-2,5-diphenyl tetrazolium bromide） method.

Synthesis of Stable Silver Nanoparticles with Antimicrobial Activities in Room-temperature Ionic Liquids

Stable silver nanoparticles was successfully synthesized by chemical reduction of silver nitrate in an ionic liquid,1-n-butyl-3-methylimidazolium tetrafluoroborate（[BMIM]·BF4） at room temperature.Results of UV-Vis diffuse reflectance spectroscopy show as-prepared Ag nanoparticles exhibit a typical emission peak at 400―430 nm.By varying the reaction temperature and the precursor concentration,the size and the shape of the silver nanoparticles could be easily controlled under mild conditions.Analyses of transmission electron micrographs,X-ray diffraction pattern and X-ray photoelectron spectrum further reveal that the silver nanoparticles were coated incompletely by [BMIM]·BF4.Microbial experiments indicate that as-prepared silver nanoparticles show a wide spectrum of antimicrobial activities and have better antimicrobial activities to Pseudomonas aeruginosa than silver nitrate with the same concentration of silver.

Antioxidant and Antimicrobial Activities of Essential Oils Extracted from Laurus nobilis L.Leaves by Using Solvent-Free Microwave and Hydrodistillation

In this study, laurel essential oils were obtained by using solvent-free microwave extraction (SFME) and hydrodistillation (HD) methods from Laurus nobilis leaves and determined their antioxidant and antimicrobial activity. Extraction time was reduced by about 43% in SFME at 622 W and 67% in SFME at 249 W compared to hydrodistillation. Essential oil of laurel was extracted by SFME at 622 W (100%) and 249 W (40%) power levels and HD inhibited oxidation generated by ABTS radical by 93.88%, 94.13% and 92.06%, respectively. Trolox equivalent antioxidant capacities (TEAC) of essential oils were 0.18 mM/mL oil for SFME at 622 W, 1.36 mM/mL oil for SFME at 249 W and 2.40 mM/mL oil for HD (p < 0.05). Essential oils of L. nobilis were extracted by SFME at 100% and 40% power levels and HD inhibited linoleic acid peroxidation by 70.57%, 63.53% and 89.18% respectively. Inhibition effects of laurel essential oils obtained by SFME at different power levels and HD on DPPH radical cation oxidation were not significantly different. The strongest antioxidant activity against DPPH radical was found in the essential oil obtained by SFME at 100% power level. Essential oils displayed antimicrobial activity against Staphylococcus aureus 6538P, Escherichia coli O157:H7 and Salmonella typhimurium NRRL E 4463 except for Listeria monocytogenes. The inhibitory effect on Staphylococcus aureus 6538P survival of laurel oil obtained from SFME by using lower power level was found to be lower than that obtained from SFME at 100% power level and HD

Antimicrobial activities of novel cultivable bacteria isolated from marine sponge Tedania anhelans

Marine sponge Tedania anhelans distributes throughout the intertidal zone of Fujian, southeastern China, and is a potential source of natural bioactive products. The sponge harbors a large number of bacterial groups that have been identified using various techniques, including fluorescent in situ hybridization （FISH）. Fractionation of dissociated sponge allowed isolation of 25 bacterial species. Based on 16S rRNA gene sequencing, phylogenetic analysis attributed most of these eubacteria to cL-Proteobacteria, y-Proteobacteria, Cytophaga/Flavobacterium/Bacteroidetes （CFB group）, and the family Bacillaceae of Gram-positive bacteria. In sequence similarity, five putatively novel species were identified with less than 98% similarity to other strains in the NCBI database. Tests for antimicrobial activities were performed against Gram-positive bacteria, Gram-negative bacteria, fungi, antitumor indicators Escherichia coli 343/591 （with DNA repair deficiency）, regular E. coli 343/636 （with different DNA repair capacity）, and 10 bacterial isolates exhibited inhibitory bioactivities. Among these strains, three isolates were detected involving function gene NRPS-A domains, which were most closely related to the amino acid sequences of linear gramicidin synthetase and pyoverdine synthetase. These results contribute to our knowledge of the microbes associated with marine sponges and further reveal novel bacterial resources for the screening of bioactive marine natural products.

Phytochemical screening and in vitro evaluation of antioxidant and antimicrobial activities of Kedrostis africana(L.)Cogn

Objective: To investigate phytochemical, antioxidant and antimicrobial activities of Kedrostis africana(K. africana).Methods: Dried tubers of K. africana were extracted in acetone, water and ethanol. The total phenol, flavonoid, proanthocyanidin and tannin contents were determined spectrometrically. The antioxidant activity was examined using 2,2-diphenyl-1-picrylhydrazyl,2,2’-azino-bis-(3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt, nitric oxide and hydrogen peroxide assays. The antimicrobial activity was determined by agar dilution method using minimum inhibitory concentration against 3 g positive and three gram negative strains while four fungal strains were also investigated.Results: Total phenol, flavonoids, proanthocyanidin and tannin contents ranged from(5.32 ± 0.01) to(10.51 ± 0.01) mg GAE/g;(42.58 ± 0.02) to(529.23 ± 0.01) mg QE/g;(15.05 ± 0.00) to(585.64 ± 0.00) mg CE/g and(0.301 ± 0.010) to(0.937 ± 0.000) mg TAE/g, respectively. The IC_(50) values of the ethanol extract for 2,2’-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid) and hydrogen peroxide were 0.054 and 0.057 mg/mL,respectively, aqueous extract had an IC_(50) value of 0.135 7 mg/mL for nitric oxide while the acetone extract had an IC_(50) value of 0.300 mg/mL for 2,2-diphenyl-1-picrylhydrazyl.The ethanol extract demonstrated effective antimicrobial activity against the tested pathogenic species with minimum inhibitory concentrations values ranging from 2.5–5.0 mg/mL for bacteria and(0.312 5–5.000 0) mg/mL for fungi, respectively.Conclusions: The tuber of K. africana showed potent free radical scavenging property and antimicrobial activity.

Antimicrobial Activities of Solanum aculeastrum Fruit Extract against Escherichia coli, Staphylococcus aureus and Candida albicans: Significance of African Traditional Medicine in Combating Infections and Attaining Universal Health Coverage

Solanum aculeastrum, a member of the Solanum genus, has a rich history of traditional use in various populations throughout tropical and southern Africa for treating different ailments. This study investigated the antimicrobial activities of S. aculeastrum fruit extracts grown in Zambia against Escherichia coli (E. coli) (ATCC 25922), Staphylococcus aureus (S. aureus) (ATCC 25923), and Candida albicans (C. albicans). After being dried in an oven at 50°C for eight days, the fruits of S. aculeastrum were pulverised and subjected to extraction using methanol and distilled water as solvents. The resulting crude extract was then filtered, concentrated using a water bath, and packed into airtight containers separately. The disc diffusion method was employed to evaluate the antimicrobial activity of the extracts. The results showed that both the methanolic and aqueous extracts demonstrated antimicrobial activity against S. aureus and C. albicans, but not against E. coli. The zone of inhibition was greater in S. aureus than in C. albicans. This study highlights the importance of researching plants for their medicinal properties, which can pave the way for discovering natural product-based drugs with potential antimicrobial properties. These findings recommend further studies on plants used in African traditional medicine.

Triterpenoids and Semisynthetic Derivatives with Antimicrobial Activities from the Leaves of <i>Caloncoba glauca</i>(Flacourtiaceae)

Chemical investigation of the MeOH extract from the leaves of C. glauca yielded nine known triterpenoids (1-9) belonging to the cycloartane and friedelane series. Two of these compounds namely glaucartanoic acid A (1) and 3β,21β-dihydroxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic acid (5) were subjected to chemical derivatizations and afforded five new derivatives: diacetylglaucartanoic acid A (1a), 24-acetylglaucartanoic acid A (1b), glaucartanoic acid A methyl ester (1c), 24-methoxyglaucartanoic acid A methyl ester (1d), and 3β,21β-diacetoxy-30-nor-(D:A)-friedoolean-20(29)-en-27-oic acid (5a). Their structures were assigned based on their NMR and MS data and by comparison with literature values. The MeOH extract, isolated compounds and some new semi-synthetic derivatives were subjected to in vitro antimicrobial assays against a panel of pathogenic microorganisms, including Gram-positive and Gram-negative bacteria, and fungi using broth microdilution method. The MeOH extract displayed activity towards all the tested pathogenic bacterial and fungal strains with good activity (MIC < 100 μg/mL) against Staphylococcus aureus ATCC25923 and Shigella flexneri SDINT. Compounds 3 and 5 showed the most potent antimicrobial effect.

Antagonistic Effect of Bacteria Isolated from the Digestive Tract of Lutzomyia evansi against Promastigotes of Leishmania infantum, Antimicrobial Activities and Susceptibility to Antibiotics

Lutzomyia evansi is a phlebotomine insect endemic to Colombia’s Caribbean coast and is considered the main vector of visceral and cutaneous leishmaniasis in the region. Specific studies of the direct effects generated by bacteria in the digestive tract of the insect vectors, under Leishmania infantum using in vitro models, represent a novel alternative as a control strategy for the transmission of leishmaniasis and also provide the opportunity to detect natural products or antimicrobial peptides with different biological activities. In this study, we evaluate the leishmanicidal and antimicrobial activities of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae, isolated from the digestive tract of Lutzomyia evansi and the susceptibility of these bacteria to commonly used antibiotics. The antagonistic effect of Pantoea ananatis, Ochrobactrum anthropi and Enterobacter cloacae was evaluated against six species of human pathogenic bacteria and against stationary (Metacyclic-like) and exponential promastigotes (Procyclic-like) of Leishmania infantum (BCN-GFP strain) by co-culture assays for 24 hours. The activity of the bacterial isolates on Leishmania infantum promastigotes was quantified by flow cytometry. The susceptibility of the bacterial strains to clinically used antibiotics was analyzed by antibiogram. The highest percentage of inhibition was observed against exponential promastigotes with bacterial concentrations of 108 CFU/ml of Enterobacter cloacae (77.29% ± 0.6%) and Pantoea ananatis (70.17% ± 1.1%). The extracts produced by three bacterial isolates showed similar biological activity (13 mm - 22 mm inhibition halos) against all tested bacteria;however, significant differences were observed with respect to gram-positive bacteria (P < 0.003557). The most active antibacterial activity was displayed against the pathogenic bacteria Bacillus cereus. Ochrobactrum anthropi was the isolate with the highest number of antibiotic resistance patterns while Pantoea ananatis and Enterobacter cloacae showed greater susceptibility to the evaluated antibiotics. The growth inhibitory activity of exponential Leishmania infantum promastigotes shown by extracts of Enterobacter cloacae and Pantoea ananantis suggests that the presence of these bacteria in the vector intestine may affect the parasite development to metacyclic stages, infective to human hosts. This in turn confers said bacteria, a potential in controlling the transmission of Leishmania spp. that deserves to be studied in depth.

Antimicrobial and Antioxidant Activities of a Brown Wood Rotting Mushroom Piptoporellus baudonii from Benin (Tropical Africa)

Piptoporellus baudonii, previously known as Laetiporus baudonii, is an African species that was considered to be a sister species to Laetiporus sulphureus, another European species known for its medicinal value. While much is known about the edibility and antimicrobial properties of L. sulphureus, African species like P. baudonii remain understudied. This study investigated the antimicrobial and antioxidant properties of P. baudonii extracts (powder maceration) prepared using ethanol, methanol and water with fractions obtained via differential solubility in hexane, ethyl acetate and n-butanol. Before the antimicrobial analysis, the study material was accurately identified using both morphology and molecular techniques. Antimicrobial activity was tested against fungi, gram-positive, and gram-negative bacteria using a broth serial microdilution method, while antioxidant activity was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH) and Ferric Reducing Antioxidant Power FRAP methods. Phylogenetic analysis confirmed the specimen as P. baudonii, with genetic material from Benin grouping it with other P. baudonii from Tanzania and other unknown regions, forming a well-supported clade (100/100). The ethanol (1.71), methanol (2.41) extracts, along with ethyl acetate (1.36), n-butanol (1.18), and hexane (12.91) fractions showed significant antioxidant activity with EC50 values below 20 µg∙mL−1. The highest antimicrobial inhibition was seen in the n-butanol (58%) and ethyl acetate (54%) fractions, followed by ethanol (49%) and hexane (48%). Methanol exhibited the lowest inhibition (46.10%). These values were compared to the standard (Vitamin C). The examined extracts demonstrated high bactericidal properties, with an MBC/MIC ratio (R) of 1 to 4, particularly effective ethyl acetate against Escherichia coli (R = 2) and ethanol extract with strong activity against Enterococcus faecalis (R = 4). Further chemical and cytotoxicity studies are warranted to fully explore the pharmaceutical potential of P. baudonii.

Chemical composition,antioxidant and antimicrobial activities of the essential oil of Santolina chamaecyparissus L.of Algeria

Objective:To investigate the chemical composition,antioxidant and antimicrobial activities of essential oil of Santolina chamaecyparissus L.cultivated in Algeria.Methods:The chemical composition of hydrodistilled essential oil from flowering aerial parts has been analyzed by gas chromatograph and gas chromatograph-mass spectrometer techniques.The antioxidant activities conducted by 2,2-diphenyl-1-picrylhydrazyl scavenging test andβ-carotene bleaching test.The antimicrobial activity was realised by agar disc diffusion method and cornell medical index was determined by agar dilution method in solid medium.Results:About 36 components accounting more than 82%of the total oil were identified.Oxygenated monoterpenes was the main fraction(54.66%)and was represented by artemisia ketone(40.33%)as major component of this oil.The other major constituents were(Z)-thujone(9.82%),(2Z,6E)-farnesol(7.30%)and limonene(6.87%)and concerning antiradical scavenging test(2,2-diphenyl-1-picrylhydrazyl)had demonstrated a weak activity obtained with an EC_(50) of(43.01±8.04)and moderate activity for β-carotene bleaching test(47.00±3.13)at 120 min.In the other hand,this oil was found effective against all tested strains except Pseudomonas aeruginosa and Aspergillus species.This activity was ranging from 10 mm to 24 mm with the lowest minimum inhibitory concentration value between under 0.070μg/mL to upper 9μg/mL.Conclusions:The results provided evidence that the studied plant might indeed be potential sources of natural antioxidant and antimicrobial agents.