Paper Disc Diffusion Assay Research Articles

Essential oil of Lippia alba impedes the growth of Propionibacterium acnes by modulating membrane potential and ROS level

IntroductionPropionibacterium acnes (P. acnes) is a rod-shaped, anaerobic, Gram-positive, opportunistic bacterium, that causes infectious and inflammatory diseases, such as acne vulgaris synovitis-acnes-pustulosis-hyperostosis-osteitis syndrome, sarcoidosis, and prostate cancer. Earlier evidence suggests that essential oils have been used to treat skin diseases and disorders since ancient times. Thus, the present study investigated the anti-microbial activity of 28 essential oils from nine families, including Lamiaceae, Poaceae, Geraniaceae, Myrtaceae, Zingiberaceae, Verbenaceae, Cupressaceae, Asteraceae, and Cyperaceae against P. acnes. MethodsThe anti-bacterial susceptibility and efficacy of the essential oils were examined using paper disc diffusion, broth micro-dilution, time-kill kinetics and ROS assays. P. acnes was cultured under anaerobic conditions. The kinetic process evaluated the time and dose-dependent effects of essential oils. The alteration in membrane potential and ROS production were measured in terms of mean fluorescence intensity. Consequently, the chemical composition of essential oil was analyzed by GC and GC/MS analysis. ResultsEighteen essential oils inhibited the growth of P. acnes with a clear zone of 5 – 20.33 mm. Eucalyptus, Mentha, Palmarosa, Lemongrass, Citronella, Geranium, Patchouli, Ocimum, and Clarysage possess better antibacterial activity (ZGI: 10.33 ± 2.31 mm - 20.33 ± 4.72 mm). Lippia alba oil showed the minimum inhibitory concentration (MIC) of 0.125% v/v, and the MIC of Mentha, Ocimum, and Patchouli oils ranged from 0.25% to 0.50% v/v. Further, the concentration and time-kill kinetic study indicated that L. alba and O. sanctum oils suppress the growth at MIC till 12 h and at 2 × MIC until 72 h. Moreover, the oils induced ROS production with one fold change at 2 × MIC. In addition, O. sanctum oil altered the membrane integrity with a fold change of 1.0 and 2.0 at MIC and 2 × MIC, respectively, while L. alba oil modified a fold change of 1.0. Discussion/conclusionThe essential oils suppressed bacterial growth by inducing ROS and modulating membrane integrity. Therefore, L. alba and O. sanctum essential oils could be used as an alternative to chemicals/drugs for treating microbe-associated acne problems.

Antimicrobial Activity of Bacterial Strains Isolated from Macrotermes belli-cosus Termite Mound

Natural environments like termite mounds can be a reservoir for novel microbial strains and antimicrobial metabolite producers. Hence, this study aimed to investigate the antimicrobial activities of bacterial strains isolated from Macrotermes bellicosus (M. bellicosus) termite mound materials. These materials were sampled from active termite mounds in the Somgandé botanic reserve in Ouagadougou, Burkina Faso. The study collected sixty-three bacterial isolates and assessed their antimicrobial activity against several pathogenic bacteria (Bacillus subtilis, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa and Staphylococcus aureus) and two pathogenic fungi (Aspergillus niger and Candida albicans). The dual culture and paper disc diffusion assays revealed that 10 isolates (5 bacteria and 5 actinobacteria) inhibited the growth of at least one pathogenic microorganism. In comparison, four isolates inhibited both Gram-positive and Gram-negative bacteria. Overall, isolates MBm2, MBm8 (bacteria), and MBm26 (actinobacterium) displayed better antibacterial- and antifungal activity against all tested pathogenic microorganisms. It is germane to indicate here that several typical bacteria and actinobacteria isolated from the M. bellicosus termite mound materials were good producers of antibacterial and antifungal agents. Thus, future studies could further characterize these isolates and optimize their growth for producing antimicrobial compounds. The bioactive compounds should also be identified for further biotechnological applications.

Inhibitory potential of some selected essential oils and their main components on the growth and quorum-sensing based pigment production of Serratia marcescens

"In this study the antibacterial potential of ten essential oils (EOs) and their main compounds against the development and quorum sensing (QS) mechanisms of the opportunistic bacterium Serratia marcescens was determined. The growth and QS inhibitory effect was evaluated by paper disc diffusion assay. The effect of EOs and components on QS-regulated prodigiosin biosynthesis was also studied. The results of our study indicated that some of the investigated EOs influenced the development and the QS-based activity of S. marcescens. Oregano and thyme oils showed the most pronounced antibacterial effect and had the strongest anti-QS potential. From the main oil compounds the phenolics, eugenol, carvacrol and thymol, proved to be efficient growth inhibitors. While eugenol and carvacrol had also a strong negative influence on AHL-mediated QS-systems in low concentrations, thymol was not effective in QS inhibition. Keywords: essential oils, quorum-sensing, prodigiosin."

Antibacterial activity of <i>Leptogium cochleatum</i> and <i>Leptogium moluccanum</i>

There is an increase in the emergence and re-emergence of bacterial infections nowadays, and lichens are potential sources of pharmaceutically important secondary metabolites to halt this problem. Lichens are unique plant-like organisms which are relatively less explored in the Philippines. Here, lichen extracts of<italic> Leptogium cochleatum</italic> and <italic>Leptogium moluccanum</italic> were tested against <italic>Escherichia coli</italic>, <italic>Enterobacter agglomerans</italic>,<italic> Klebsiella pneumoniae,</italic> <italic>Pseudomonas aeruginosa</italic>, and <italic>Staphylococcus aureus</italic> using paper disk diffusion assay. Hexane extract of <italic>L. moluccanum</italic> led to a 17.14 mm zone of inhibition (ZOI) against <italic>K. pneumoniae,</italic> while hexane extract of <italic>L. cochleatum</italic> led to a 15.28 mm ZOI against <italic>E. agglomerans</italic>. Dichloromethane extracts of <italic>L. cochleatum</italic> exhibited a ZOI of 15.86 mm against <italic>E. agglomerans</italic> and 14.84 mm ZOI against <italic>E. coli</italic>. The bioactivities exhibited by the lichen extracts may be due to the secondary metabolites detected using thin layer chromatography. Indeed, lichen-derived bioactive compounds hold great promise for pharmaceutical applications for the benefit of human life.

Green and cost-effective synthesis of zinc oxide thin films by L-ascorbic acid (AA) and their potential for electronics and antibacterial applications

The evolution of eco-friendly, green route and cheap technology for synthesizing nanostructured zinc oxide (ZnO) thin films using plant extracts is a promising choice because such materials present a widespread potential for numerous technological applications. This study proposes the green and cost-effective technique to synthesize stable ZnO thin films using a good reducing agent and facilitating many natural L-ascorbic acids (AA) metabolic reactions capacity. The influence of AA concentrations in the starting bath solution on ZnO samples' structural, morphological, electrical and antibacterial performances has been reported in detail. The main physical characteristics of the ZnO materials were improved by supplementing of reducing and capping agents AA. Average particle size varies with the adding AA from 58.29 to 48.68 nm and also thickness of these films was decreased from 0.82 to 0.44 μm. Also, it was seen that, the presence of AA in the bath solution significantly affected the absorption process and causes a morphological alteration due to the reaction between Zn2+ and AA during the deposition process. FTIR transmittance spectra of bare ZnO presented that a transmittance peak about 886 cm−1 and 748 cm−1 was created by the characteristic stretching vibration mode of the Zn–O. The resistivity of the produced films significantly changed with AA concentration in the bath solution. Antibacterial potentials of bare ZnO and ascorbic acid added ZnO films were examined against economically important Staphylococcus aureus (ATCC 25923) gram-positive bacteria and Escherichia coli (ATCC 35218) gram-negative bacterial disease agents via handling paper disc diffusion assay. The obtained diameter of the zones of inhibition was 20.1 mm for E. coli and 28.1 mm for S. aureus at the dose of ZnO+AA 8.0%. These inhibition diameters were larger than the diameter of ampicillin as our positive control alone. This proves that the newly synthesized compound is a powerful antibacterial agent.

Selected Thai traditional polyherbal medicines suppress the cariogenic properties of Streptococcus mutans by disrupting its acid formation and quorum sensing abilities

Ethnopharmacological relevanceThirty-five herbal formulations used in this current work are utilized as anti-cariogenic agents in Thai traditional medicine. Acidogenic properties play a crucial role in the initiation of dental caries caused by Streptococcus mutans, and a quorum sensing (QS) system is an associated virulence factor in dental caries. Aim of the studyThe current work aimed to determine the anti-acidogenic effect of these polyherbal formulas against S. mutans and explore their anti-QS activity using Chromobacterium violaceum as a biosensor. Materials and methodsEthanol and water extracts from the formulas were evaluated for their anti-acidogenic effects using glycolytic pH drop assays. Qualification and quantification of anti-QS activity indicated by the level of violacein production in C. violaceum were performed using paper disc-diffusion and flask incubation assays, respectively. ResultsAmong the extracts tested, THF-DC 02 and THF-DC 04 significantly inhibited the acidogenesis of S. mutans in a dose-dependent manner without affecting the cell viability. THF-DC 20 and THF-DC 29 sharply reduced the violacein production of C. violaceum, indicating the promising anti-QS activity of these extracts. ConclusionThe findings of the present study, preliminarily propose that the polyherbal formulas THF-DC 02, THF-DC 04, THF-DC 20, and THF-DC 29 produce promising anti-acidogenic or anti-QS activities. The anti-acidogenic effect of THF-DC 04 may possibly act by interrupting streptococcal membrane enzymes via its herbal components: Alpinia galanga (L.) Willd., Albizia myriophylla Benth., Avicennia marina subsp. eucalyptifolia (Valeton) J.Everett and Ocimum tenuiflorum L. The anti-QS activity of THF-DC 20 and THF-DC 29 could be due to their herbal ingredients, including Piper betle L., Terminalia bellirica (Gaertn.) Roxb., Terminalia chebula Retz., and Syzygium aromaticum (L.) Merr. & L.M.Perry.

Citrus scented natural essential oils for crystal salt deodorant

Alum natural mineral salt is the world's leading crystal deodorant which works in removing unpleasant body smell. Some other products attempt to block the sweat pores with harmful chemicals such as aluminum chlorohydrates or aluminum zirconium. However, crystal is hypoallergenic deodorant that is healthy, safe, and effective in inhibiting odor formation on the axillary. The light scent infused with natural essential oils might enhance the properties of the crystal deodorant and its antimicrobial activity in fighting against body odor bacteria. This study was conducted to evaluate the potential antimicrobial activity of both citrus essential oils and alum salt. The essential oils were extracted from Citrus aurantifolia, and Citrus sinensis peels by water-steam distillation and analysed using gas chromatography-mass spectrometry (GC-MS). Antibacterial assay against Escherichia coli was carried out on the extracted essential oils using paper disc diffusion assay. Results showed that no lead and cadmium constituents were detected, while low concentration of iron (0.993 ± 0.0059 ppm) and copper (0.134 ± 0.0078 ppm) were detected in the crystal salt (15% w/v). D-limonene, decanal and citral were major components responsible for the citrus scents aroma. The C. aurantifolia essential oil and 15% w/v alum salt were active against E. coli with inhibitory zones at 7.23 ± 0.15 mm and 11.13 ± 0.51 mm respectively. The citrus scented crystal deodorant was successfully developed and tested.

Greenhouse and field experiments revealed that clove oil can effectively reduce bacterial blight and increase yield in pomegranate

AbstractBacterial blight in pomegranate is a devastating disease caused by bacterial pathogen Xanthomonas axonopodis pv. punicae (XAP), recording huge damage to pomegranate crop worldwide. Antibiotics and copper‐based chemicals are being used for the management of this blight, while in this present work, we investigated the effect of eugenol and clove oil either singly or in combination with copper oxychloride (COC) on the induction of plant defense responses and concomitant prevention of bacterial blight. Our results provided evidence that clove oil (0.2%–1%) and eugenol (0.1% and 0.2%) successfully inhibit the growth of XAP in paper disk diffusion assay. Strikingly under the greenhouse condition, clove oil (0.2%) as foliar application 24 h before XAP inoculation recorded the lowest disease severity of 7.34%, whereas eugenol (0.2%) recorded maximum disease severity of 14.56%. However, the combination of clove oil (0.2%) and copper oxychloride (0.3%) recorded the least disease severity of 2.38%. A similar trend was observed in field conditions. Prophylactic application of clove oil leads to enhanced nitrate reductase activity and nitric oxide production which was further enhanced in clove oil pre‐treated plants challenged with XAP. Strikingly, the total ROS and H2O2 levels were reduced in response to clove oil application. Clove oil also induced the systemic response by inducing expression levels of defense genes. The reduction of disease severity by clove oil and COC combination also reflected on total yield recording via large‐scale field experiments where maximum yield of 14.04 tonnes/acre was observed, whereas streptocycline application recorded 11.12 tonnes/acre. Application of COC and clove oil resulted in a high remunerative value of ₹ 1:5.6, compared to streptocycline (1:4.85) and control (1:1.85). The present study revealed that clove oil as a plant derivative and eugenol as a synthetic option can be effectively used for the successful management of bacterial blight in pomegranate.

Chemical and Antibacterial Activity Evaluation of Alpinia calcarata and Alpinia zerumbet Grown in Foothills Agroclimatic Conditions of Northern India

Background: The member of the genus Alpinia (family: Zingiberaceae) is used in traditional medicine for various formulations for the food, spices, medicines, and perfume. Objective: The present study was carried out to analyse the compositional variability in leaf and rhizome essential oils of Alpinia calcarata Roscoe and Alpinia zerumbet (Pers.) B.L. Burtt &amp; R.M. Sm. and to evaluate their antimicrobial activity against eight pathogenic bacteria strains. Methods: The essential oils were extracted by hydrodistillation and analysed by GC and GC-MS and the antibacterial activity was evaluated by filter paper disc diffusion and micro dilution broth assay. Results: A total of 31 compounds identified, forming 89.26-94.32% composition of A. calcarata and A. zerumbet. The leaf and rhizome oil of A. calcarata and A. zerumbet were mainly characterized by 1,8-cineole (15.61-43.63%), β-pinene (5.02-23.52%), terpinen-4-ol (1.00-20.87%), camphor (1.94-11.60%), and (Z)-β-ocimene (0.16-11.86%). endo-Fenchyl acetate (13.12-24.39%) was identified as marker constituents of rhizome essential oil of both A. calcarata and A. zerumbet. The antibacterial assay showed that leaf oil of A. calcarata has good activity against S. mutans, whereas its rhizome oil possess good activity against K. pneumoniae, E. coli, S. aureus, and S. epidermidis. However, the rhizome oil of A. zerumbet showed activity against S. mutans, B. subtilisS. aureus-2940 and S. epidermidis. Conclusion: The essential oils of A. calcarata and A. zerumbet with aroma chemicals viz. 1,8-cineole, ocimenes, terpinen-4-ol, α-pinene, β-pinenes and fenchyl acetate and significant antibacterial activities could be used for perfumery and fragrance related formulation.

Barnyard grass [Echinochloa crus-galli (L.) Beauv] leaves extract against tomato pests.

Tomato is one of the widely cultivated crops worldwide that is affected by several pests, such as fungi (Fusarium oxysoporum, Alternaria solani), bacteria (Pectobacterium carotovorum) and weeds (Cyperus iria L., Amaranthus spinosus). A growing interest has emerged for developing plant-derived pesticidal compounds to counteract these pests. One attractive alternative is to use barnyard grass (Echinochloa crus-galli), known to be widely resistant to synthetic herbicides, as a potential biopesticide compound source. Phytochemical screening of the crude extract showed that phenolic compounds were the most abundant component present in barnyard grass. The crude extract was evaluated for antifungal, antibacterial and herbicidal activities. Bioassays showed inhibition against F. oxysporum (10.73 ± 1.30%) and A. solani (20.47 ± 3.51%), the causative agent of Fusarium rot and early blight disease in tomato, respectively. Antibacterial activity against P. carotovorum gave a mean zone of inhibition (paper disc diffusion assay) of 17.00 ± 1.00 mm and an IC50 (dose-response assay) of 2.26 mg mL-1 was observed. Dose-responsive herbicidal activity on the lettuce seed germination bioassay produced an IC50 of 459.30 ppm. Selectivity studies showed inhibition towards C. iria and A. spinosus with no effect on tomato. Lastly, bioassay-guided fractionation coupled with untargeted metabolomics studies using ultra-performance liquid chromatography with diode array detection-tandem mass spectrometry mass analyses revealed loliolide and tricin as the putative metabolites present in barnyard grass. To date, this is the first reported study on using barnyard grass as a potential alternative biopesticide against tomato pests such as fungi, bacteria and weeds. © 2021 Society of Chemical Industry.

Purification Process of Mangiferin from Mangifera indica L. Leaves and Evaluation of Its Bioactivities

Mangiferin (C19H18O11) is a C-glucoside xanthone that is mainly found in the leaves of mango (Mangifera indica L). The compound has been recognized for several pharmacological values, including antioxidant and antibacterial activities. Therefore, the present study aims to utilize the old leaves of mango as a potential source for mangiferin extraction and purification, and evaluate its antimicrobial and antioxidant properties. In the present study, mangiferin was extracted from a local variety of mango leaves using ultrasonic-assisted extraction methods and ethanol as the extraction solvent. The crude ethanolic extract of mangiferin was then purified by the liquid–liquid fractionation method with dichloromethane and ethyl acetate, then further separated by HPLC. The crude extract, ethyl acetate fractions and purified mangiferin were investigated for anti-microorganism activity against Escherichia coli, Salmonella spp. and Aspergillus flavus by using the paper disc diffusion assay. The results have shown that the extraction efficiency was 14.17%. The obtained mangiferin was 1.97 g of content and 94.2% of purity. The oxidation resistance of purified mangiferin was 1.77 times higher than the crude extract and 1.05 times higher than the standard mangiferin (IC50 = 13.841 μg/mL). However, the purified mangiferin has shown no inhibitory action against the experimental strains of microorganisms. The findings from the present study suggest an effective scheme of extraction and purification to obtain mangiferin from the local variety of mango with high purity and antioxidant potential.

Antioxidant and anti-Helicobacter pylori activities of Hericium erinaceus mycelium and culture filtrate

Introduction: Hericium erinaceus is known as a medicinal edible mushroom owing to its antimicrobial, antioxidant, anti-tumor and immunomodulatory effects. Helicobacter pylori infection is one of the major health concerns worldwide due to its high rate in global populations, frequent recurrence, and rapid emergence of drug-resistant strains. The present study aims to investigate antioxidant anti-H. pylori and urease inhibitory activities of solvent fractions from H. erinaceus mycelium and culture filtrate.&#x0D; Methods: H. erinaceus mycelium was purely cultured in a liquid medium. A polysaccharide fraction was obtained from the culture filtrate by precipitation with ethanol. The mycelium and culture filtrate were extracted by liquid extraction to obtain solvent-soluble fractions. The antibacterial effects of these fractions were determined using paper disc diffusion and broth microdilution assays. Urease inhibition was determined using the salicylate-hypochlorite method. The antioxidant activity of H. erinaceus was evaluated via 2,2,1-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activity.&#x0D; Results: The ethyl-acetate (EtOAc) fractions derived from H. erinaceus culture filtrate (fEtOAc Fr.) and mycelium (mEtOAc Fr.) showed the strongest anti-H. pylori activity with MIC (MBC) of 1.25 – 1.5 (5.0 – 7.5) mg/mL and potential urease inhibitory activity with IC50 of 0.34 – 0.35 mg/mL. In addition, fEtOAc Fr. exhibited the greatest antioxidant activity (IC50, 11.83 mg/mL), which was slightly stronger than that of mEtOAc Fr. (IC50, 14.75 mg/mL). Moreover, our study also found that the water fractions from the culture filtrate (fWater Fr.) and the mycelium (mWater Fr.) displayed considerable inhibitory activities against bacterial urease (IC50, 1.26 – 1.40 mg/mL), although they had low or no anti-H. pylori activities and low antioxidant properties.&#x0D; Conclusion: The present study revealed that the EtOAC fractions derived from the H. erinaceus mycelium and culture filtrate potentially have anti-H. pylori, anti-urease and antioxidant activities. These results suggest that H. erinaceus mycelium and culture filtrate could be utilized to develop functional foods and nutraceuticals to prevent H. pylori infection. More research is needed to prove the safety of the H. erinaceus mycelium and culture filtrate fractions and their in vivo efficacy in the treatment of H. pylori infection.

Gas Chromatography / Mass Spectroscopy Analysis, antibacterial Activity of Fixed Oil from Acacia polyacantha (Sudanese Kakamout) Seeds

The objective of this study was investigating the chemical constituents and to assess it is potential antibacterial of Fixed Oil from Acacia polyacantha (Sudanese Kakamout) Seeds. Using cold maceration method to extract the Fixed Oil from Acacia polyacantha (Sudanese Kakamout) Seeds. Where paper disc diffusion assay were employed to evaluate the antibacterial activities .GC-MS analysis were identified and quantified the constituents of Oil. Thirty seven components in the Fixed Oil from Acacia polyacantha (Sudanese Kakamout) Seeds. Five of them are major namely, the predominant compounds. were 9,12-Octadecadienoic acid (Z,Z),methyl ether(31.24%), 11-Octadecenoic acid, methyl ester(11.45%), Hexadecanoic acid, methyl ester(12.81%) , Methyl stearate(21.54%) and Eicosanoid acid, methyl ester (8.28%). The present work reveals that the extract confirm activity against Escherichia coli (18), Pseudomonas aureus (16), Staphylococcus (14) and Candida albicans (20) In conclusion, the results showed that the Oil of Acacia polyacantha is a potential source of natural antibacterial and justify its uses in folkloric medicines.

Catechin Contents, Antioxidant and Antibacterial Activities of Different Types of Indonesian Tea (Camellia sinensis)

Tea is one of the most popular beverages in the world. Produced from Camellia sinensis leaves, tea has been studied to provide health benefits due to the content of important metabolites. This study aimed to investigate the catechin contents, antioxidant, and antibacterial activities of Indonesian tea varieties, namely green tea, black tea, and white tea. Tea infusion was prepared by extracting 1 g of each sample into 10 mL of distilled water and incubated at 80 °C for 60 min. The catechin and epigallocatechin gallate (EGCG) contents of tea extracts were determined using high-performance liquid chromatography (HPLC). Antioxidant activity was measured using the free radical method with 2,2-diphenyl-1-pycrylhidrazyl (DPPH), while antimicrobial activity was assesed using paper disc diffusion assay. The results indicated that green tea had the highest contents of catechin (646 ± 17.14 mg/L) and EGCG (997.8 ± 36.72 mg/L), and antioxidant activity with IC50 of 5.65 µg/mL. Furthermore, green tea and white tea extracts showed inhibitory activity against Gram-positive bacteria such as Micrococcus luteus, Bacillus subtilis, and Staphylococcus aureus whereas black tea had no activity against all bacterial strains tested. Generally, we concluded that white tea and green tea contributed to the higher content of catechins and exhibited strong antioxidant and antibacterial properties.

Antioxidant and Antimicrobial Activity of Endophytyc Fungi Isolated from Syzygium aqueum Leaves

Syzygium aqueum is a widely used medicinal plant species with ethnomedicinal values. Despite the plant, the endophytes are recognized as a rich source of secondary metabolites with potentially useful pharmacological properties. This study was aimed to identify the endophytic fungi from S.aqueum leaves and discover their antioxidant and antimicrobial activity. The ethyl acetate extracts of the isolated endophytic fungi were investigated for their antioxidant and antimicrobial activity using 1,1diphenyl-2-picryl hydrazyl (DPPH) method and paper disc diffusion assay, respectively. The antimicrobial activity was evaluated against three pathogen bacteria : Staphylococcus aureus, Salmonella thypi, and Escherichia coli, and one yeast: Candida albicans. Three endophytic fungi were obtained from S. aqueum leaves. Based on morphological characteristics, those fungi identified as Cochliobolus sp (D22), Penicillium sp. (D32), and Fusarium sp. (D41). Penicillium sp. (code D32) showed significant antioxidant potential activity as an also significant antimicrobial activity with IC50 59,16% and highest zone inhibition against E. coli 13.38 ± 0.25 mm. It is worth considering a further investigation of their bioactive secondary metabolites and isolates the bioactive compound for the antioxidant and antimicrobial agents.

Phytochemical Screening, Antimicrobial and Antioxidant Activities of Sonchus Oleraceus l (Leaves) Extracts

The objective of this study to examine phytochemical analysis of sonchus oleraceus l, (asteraceae) (moliata) extracts which were extracted by four solvents, petroleum ether, chloroform, methanol and distill water and to assess their potential antibacterial against four standard bacteria gram-positive and gramnegative (bacillus subtilis staphylococcus aureu, salmonella typhi, and pscudomona aeruginosa) and antioxidant activities. (moliata) extracts using cold maceration method to extract sonchus oleraceus l, (asteraceae) locally known as (moliata) extracts, where dpph assay and paper disc diffusion assay were employed to evaluate the antioxidant and antibacterial activities respectively. The results showed that tannins, triterpenes, a sterols, flavonoids and cardiac glycosides compounds were present in the sonchus oleraceus l, (asteraceae) lives (moliata) extracts. The methanol extract of leaves showed high antioxidant potential (77± 0.03 % ) and chloroform showed low antioxidant potential activity (4±0.09) compare with propyl gallate as standard (93± 0.010 %) against dpph. Chloroform extract was effective and give moderate zone of inhibition against staphylococcus aureus. Methanol extract was effective and showed moderate zone of inhibition against staphylococcus aureus, bacillus subtilis, salmonella typhi and pseudomonas aeruginosa.

Antibacterial Activity of Common Spices Extracts on Bacterial Isolates found in Kachhila, a Newari Cuisine

Objectives: The objective of this study was to determine the antibacterial property of aqueous extracts of common spices used in the preparation of Kachhila such as garlic, ginger, and turmeric.&#x0D; Methods: After washing and cleaning separately, aqueous extracts were extracted from each spice by crushed with mortar and pestle. Antibacterial activity of aqueous extracts of each spice was evaluated by using agar well diffusion assay and paper disc diffusion assay against test bacteria isolated from buff meat used in Kachhila preparation. &#x0D; Results: Minimum inhibition concentration value of each spice was evaluated against all bacterial isolates. Total bacterial count (CFU/g) of prepared Kachhila was determined in each 30 mins interval up to 150 mins to reveal antibacterial activities of spices used in Kachhila. The antibacterial effect of aqueous extract of garlic extract was found to be the stronger in comparison, followed by turmeric and ginger against test bacterial isolates. The MIC of individual spice extract was found to be 125 to 4000 μl/ml against all the test bacteria. Spices used in Kachhila revealed that bacterial load decreased with time due to the antibacterial property of spices.&#x0D; Conclusion: This study concluded that the antibacterial effect of aqueous extract of Garlic extract was stronger in comparison, followed by Turmeric and Ginger against four test bacteria isolated from buff meat namely; E. coli, Salmonella spp., Pseudomonas spp., Staphylococcus aureus. Therefore this study revealed that spices used in Kachhila have an antibacterial property and enhance the shelf life of Kachhila.

QUORUM SENSING ANALYSIS AND EFFECT OF BACTERIOCIN IN CONTROLLING THE BIOFILM FORMATION OF PSEUDOMONAS AERUGINOSA

Objective: Pseudomonas aeruginosa is the commonest causative agent of Hospital Acquired Infection (HAI). Resistance of Pseudomonas aeruginosa towards disinfectants and antibiotics is high when compared to other organisms. There are various reviews on antibacterial effect of herbal extracts and nanoparticles against Pseudomonas aeruginosa. Thus, this study aims to prove the effectiveness of bacteriocin against Pseudomonas aeruginosa, which may help in benefiting the health care center by replacing normal disinfectants.&#x0D; Methods: 100 strains of Pseudomonas aeruginosa were collected from different patients, with a study period of 6 mo. Ammonium sulfate precipitation method was used to extract bacteriocin and its efficiency was checked by paper disc diffusion assay. Biofilm formation assay and quorum sensing analysis was performed by Microtitre plate methods and Thin Layer Chromatography (TLC), respectively.&#x0D; Results: In this study, 91%of P. aeruginosa strains were strong, 8% were intermediate, and 1% were weak biofilm producers. From TLC analysis, 67% of the strains produced Acyl Homoserine Lactone molecules. Out of which, 49% has shown unknown analytes of Retardation factor (Rf) value greater than 1. The Rf values identified were 3 unsubstitutedC4 (5%), 3 unsubstituted C6 (4%), 3 oxo C8 (3%), 3 oxo C4 (3%), 3 oxo C6 (2%), 3 oxo C1 (1%). Biofilm production, before and after bacteriocin exposure, was proved significant by paired t-test.&#x0D; Conclusion: Quorum sensing was confirmed to play a major role in biofilm formation. As bacteriocin was found to be effective in controlling the biofilm formation, it can be incorporated in any disinfectant, which helps in controlling the transmission of infection caused by Pseudomonas aeruginosa.

Superior antibacterial activity against seed-borne plant bacterial disease agents and enhanced physical properties of novel green synthesized nanostructured ZnO using Thymbra spicata plant extract

An easy and eco-friendly approach using Thymbra spicata var. spicata L. (TS) plant extract was developed for the formation of nanostructured ZnO. TS aqueous leaf extract was used for the green synthesis of nanostructured ZnO via the Successive ionic layer adsorption and reaction (SILAR) method. Electron microscope images exhibit the morphological adjustments of the samples with respect to change in TS concentration in the growth solution. The nanostructured ZnO grown by SILAR was observed to be polycrystalline with hexagonal crystal structure. The optical energy bandgap value of the samples varies from 3.21 to 3.09 eV as the content of TS increases from 2.5 to 5.0%. Also, the effect of TS additive to ZnO on electrical properties was investigated. It was determined by Van der Pauw measurements that TS contribution to ZnO significantly increased electrical resistance. In addition, impedance analyzes of the produced films were carried out in the frequency range of 20Hz −1 MHz. Nyquist plots showed the single semicircle for all samples, and the values of capacitance and resistance were calculated. Its antibacterial activities was investigated against economically important Gram-positive (Clavibacter michiganensis subsp. Michiganensis) and negative (Pseudomonas syringae pv. Phaseolicola, Pseudomonas cichorii and Pectobacterium carotovorum subsp. Carotovorum) seed-borne plant bacterial disease agents by using paper disc diffusion assay for the first time. In vitro laboratory screenings of green synthesized nanostructured ZnO have given encouraging results, indicating their potential use in the management of seed-borne bacterial diseases.

다양한 배양조건에 따른 Lactobacillus plantarum BG0001 배양액의 항균활성

Lactic acid bacteria (LAB) has been known to produce various antimicrobial agents such as bacteriocin which causes cell growth restriction or death. LAB having antimicrobial activity was isolated and identified as Lactobacillus plantarum BG0001. The culture broth of L. plantarum BG0001 exhibited antimicrobial activity against the both of gram positive (Bacillus cereus, Staphylococcus aureus) and negative (Escherichia coli, Vibrio parahaemolyticus, Salmonella typhimurium) strains by paper disc diffusion assay. Since the optimization of fermentation conditions could promote antimicrobial activity, we compared the antimicrobial activity of L. plantarum BG0001 culture broth depending on fermentation temperatures. When L. plantarum BG0001 was fermented at 30℃, the lowest minimum inhibited concentration (9.92 ㎎/mL) was shown as compared to those from 32, 35, 37℃. When 100 mL/L of molasses and 80 mL/L of corn steep liquor (CSL) were used instead of MRS medium, the minimum inhibited concentration (MIC) was 17.36 ㎎/L which suggesting molasses and CSL could be used for the fermentation of L. plantarum BG0001 as an alternative fermentation medium.