Diameter Of Clear Zone Research Articles

Green Synthesis of Zinc Oxide Nanocrystals Utilizing Origanum majorana Leaf Extract and Their Synergistic Patterns with Colistin against Multidrug-Resistant Bacterial Strains

There is a crucial necessity for the formulation of efficient antimicrobial agents owing to the increasing prevalence of hospital-acquired bacterial infections triggered by multidrug-resistant microbes that result in significant deaths and illnesses around the world. Hence, the current investigation examined the antibacterial proficiency of zinc oxide nanoparticles formulated utilizing the green route against bacterial strains that were resistant to multiple drugs. In addition, the synergistic antibacterial action of ZnO nanoparticles (ZnO NPs) combined with colistin was investigated against the tested microbial strains to determine the efficiency of the bioinspired ZnO nanoparticles in boosting the antibacterial proficiency of colistin antibiotic. Incidentally, the bioinspired ZnO nanoparticles were synthesized using water extract of Origanum majorana leaves and these nanomaterials were physicochemically characterized using different analytical techniques. The bioactivity of the synthesized nanomaterials against multidrug-resistant bacterial strains was appraised using the agar diffusion method. The biogenic ZnO NPs at a concentration of 100 μg/disk revealed a compelling antimicrobial efficacy against the tested strains, expressing the maximum antimicrobial action against Escherichia coli strain with clear zone diameter of 38.16 ± 0.18 mm. The remarkable antibacterial proficiency might be accredited to the tiny particle size of the bioformulated ZnO NPs of 12.467 ± 1.36 nm. The net charge of ZnO nanomaterials was −14.8 mV while XRD analysis confirmed their hexagonal wurtzite structure. Furthermore, the bioformulated ZnO NPs showed a promising synergistic potency with colistin demonstrating respective synergism proportions of 91.05, 79.07, 75.04, 75.25, 56.28 and 10.60% against E. coli, Klebsiella pneumoniae, Acinetobacter baumannii, Salmonella typhimurium, Enterobacter cloacae, and Pseudomonas aeruginosa, respectively. In conclusion, the water extract of O. majorana leaves mediated green formulation of zinc oxide nanoparticles with unique physicochemical characteristics and effective antibacterial proficiency against the examined drug-resistant bacterial strains. These nanomaterials could be used in the synthesis of effective antibacterial coatings to control hospital acquired infections caused by multidrug-resistant bacterial pathogens.

Short-term Evaluation of Efficacy and Biocompatibility of Artificial Corneal Transplantation in Rabbit Model

Purpose: To examine the efficacy and biocompatibility of a new artificial cornea using a rabbit model.Methods: Artificial cornea were transplanted into 20 New Zealand white rabbits. The disc-shaped artificial cornea is of diameter 8.0 mm (the core, clear optical zone diameter is 5.0 mm and that of the peripheral skirt 1.5 mm); of thickness 0.5 mm; and is fabricated from PHEMA, PMMA, and PETTA. Transplantation proceeded in two stages; all rabbits were then observed weekly to 12 weeks. Anterior segment photographs were taken, and anterior segment optical coherence tomography and histological analysis performed, to confirm the biocompatibility of the skirt and the extents of cell proliferation in surrounding tissues.Results: Two rabbits were sacrificed for histological examination in weeks 4 and 8 (one each). Four eyes failed because of surgical errors (artificial corneal decentration or excessively thin flaps). Of the 12 eyes for which surgery was technically successful, six (50.0%) maintained the optical zone structure and transparency to 12 weeks. Histology revealed that cells proliferated in the skirt and bound to surrounding tissues. Six eyes (50.0%) evidenced protrusions of the artificial cornea.Conclusions: Transplantation of a new artificial cornea into rabbits met with some success (as confirmed anatomically and optically). However, corneal improvement and new surgical techniques are required to increase the success rate. Also, long-term follow-up is needed.

Isolation, Molecular Identification and Antibacterial Activity of Endophytic Bacteria from Bark of the Plumeria acuminata

Endophytic bacteria are able to produce bioactive compounds that are important for applications in the medical field. This study aims to isolate, identify and test the antibacterial activity of endophytic bacteria from the bark of Plumeria acuminata growing in the Mataram area. Isolation was carried out using four types of media, namely NA, TSA, MAC, and BHI. The well diffusion technique was used to test the inhibitory ability of the endophytic bacterial extract against the test pathogenic bacteria. The four test bacteria used were S. aureus, B. cereus, P. aeruginosa, K. pneumoniae. Isolates that showed inhibitory activity were then identified morphologically, biochemically and molecularly based on the 16S rRNA gene. The results of the isolation process obtained 35 colonies. where 9 of them inhibit the growth of test bacteria. There were 2 isolates that able to inhibit the growth of 4 types of test bacteria with an average clear zone diameter of very strong category (21–30 mm), namely isolates T1 and T2. The N2 isolate had the highest average inhibition zone compared to all isolates of endophytic bacteria, which was 32 mm, but was specific for P. aeruginosa. Two isolates, namely B1 and M3 gave various growth inhibitory effects with strong to very strong categories. Other isolates showed various antibacterial effects against at least 2 types of test bacteria. S. aureus was the most resistant pathogenic bacteria to the treatment of endophytic bacterial isolate extract. The cell shape of all endophytic isolates was streptobacillus with or without spores, and 50% of them were Gram-positive. Molecular identification based on the 16S rDNA gene grouped the 9 isolates into 2 main clusters, namely the genus Bacillus and the genus Pseudomonas. Isolates that were closely related to the genus Bacillus showed higher inhibitory activity than those of Pseudomonas. The results showed that isolates of endophytic bacteria from the bark of P acuminata have the potential as an important source of antibacterial substances.

FORMULASI GEL EKSTRAK ETANOL DAUN SIRIH CINA SERTA AKTIVITASNYA TERHADAP PERTUMBUHAN BAKTERI PENYEBAB JERAWAT Propionibacterium acne DAN Staphylococcus aureus

Pepper elder is a weed plant whose leaves contain anti-bacterial compounds such as flavonoids, tannins, triterpenoids, and saponins that can be used as acne treatment therapy. Pepper elder leaves can be made into anti-acne gel preparations by formulating the right gelling agent. This study aims to obtain a gel with good physical stability from variations in the gelling agent base and its activity against acne-causing bacteria. Formulation of Pepper elder leaf extract gel is made with variations in the base of Na.CMC, Carbopol, and HPMC, further stability evaluation includes organoleptic, homogentias, pH, viscosity, scattering power, and testing of antibacterial activity against the growth of Propionibacterium acne and Staphylococcus aureus . The results obtained from the stability test obtained by the Carbopol base and HPMC have good standards for organoleptics, homogenity, pH, viscosity, and scattering power. Antibacterial testing showed clear zone diameters formed against Propionibaceterium acne in naCMC, Carbopol, and HPMC variations of 17.7 mm, 16.3 mm, and 21.3 mm and staphylococcus aureus of 13.3 mm, 15.3 mm, and 14.3 mm, respectively. Based on the results obtained, HPMC gel has the best gel stability and can all formulas inhibit the growth of acne-causing bacteria Propionibacterium acne and Staphylococcus aureus evidenced by the diameter of the bland zone formed into the strong category.

BAKTERI PENGHASIL AMILASE YANG DIISOLASI DARI EKOENZIM LIMBAH BUAH-BUAHAN

Many of potential enzymes can be found in the ecoenzyme, one of them is amylase. Amylase is an enzyme that is able to hydrolize the glycoside bonds of starch or starch into dextrin, glucose and maltose which is widely used in various industries such as beverages. This study aims to isolate the ecoenzyme bacteria and test their ability to produce amylase. Isolation of ecoenzyme bacteria was carried out using serial dilution methods 10-1, 10-3, 10-5. A total of 0.1 ml of each dilution series was pipetted and spread on the Nutrient agar (NA) medium. The bacterial isolates that grew were then purified and identified by morphological observation, Gram staining and their enzymatic activity was tested using Starch Agar (SA) media qualitatively. The results of this study showed there were 39 bacterial isolates from ecoenzyme with different morphological characteristics. The amylase activity test were found that 34 isolates had a positive activity to hydrolize the starch in the SA media which was indicated by the formation of a clear zone around the bacterial colonies. Each bacterial isolate had a different hydrolysis index value, which ranged from 9.45 to 23.65. The highest clear zone diameter index value from starch hydrolysis was EJM 15 isolate.

Protease-producing lactic acid bacteria with antibacterial properties and their potential use in soybean meal fermentation

BackgroundAs an adequate plant protein raw material, soybean meal has attracted extensive attention because of its high protein content, abundant amino acids essential for animals, and many functional nutrients. Feed fermentation is a new way to improve nutrient absorption of animals by inoculating microorganisms, which can also play a probiotic role. In order to screen the lactic acid bacteria with remarkable protease-producing performance and excellent growth and fermentation characteristics, 1000 strains isolated from different materials were evaluated in this study. After primary and re-screening, 22 strains both with protein clear zone diameters larger than 15.00 mm (including the diameter of a hole puncher 10.00 mm) and protease activities greater than 20.00 U/mL were screened out for physiological and biochemical tests, as well as antimicrobial performance tests.ResultsStrains P (Pig) 15 and ZZUPF (Zhengzhou University Pig Fecal) 95, which have excellent physiological and biochemical characteristics, as well as good inhibition abilities for Staphylococcus aureus, Bacillus subtilis, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, and Micrococcus luteus, were selected and used as fermenting agents for 3- and 30-day (d) fermentation of soybean meal. The analysis of microorganisms, fermentation quality, and chemical composition during fermentation revealed that all lactic acid bacteria addition groups had lower harmful bacteria and pH value, as well as higher lactic acid bacteria content and lactic acid level compared with CK and protease-treated groups. These effects were even better especially after 30 days of fermentation.ConclusionsThis study indicated that the selected strains Lactiplantibacillus plantarum subsp. plantarum P15 and Enterococcus faecalis ZZUPF95 could be considered as potential probiotics for fermenting soybean meal for further research.Graphical abstract

Biological control of citrus canker pathogen Xanthomonas citri subsp. citri using Rangpur lime endophytic bacteria

BackgroundRangpur lime (RL) is a common rootstock cultivar used worldwide. However, it is known to have a high susceptibility to citrus canker (CC). To meet the increasing demand for healthy citrus seedlings, this research aimed to study the potency of RL endophytic bacteria as a biocontrol agent of the CC pathogen Xanthomonas citri subsp. citri. The isolates were collected from healthy RL leaves and subjected to in vitro and in planta antagonistic tests against XCC, alongside its cell-free supernatant (CFS). Potential isolates were identified according to their 16S rDNA sequence similarities.ResultsAs many as 21 isolates were obtained from the leaves of healthy RL trees. Two (B1 and C8) isolates demonstrated promising inhibitory activity against XCC. Based on the in vitro assays, the cell suspensions (CS) of these isolates could effectively inhibit the growth of XCC, with an optimum clear zone diameter of 8.41 and 7.51 mm, respectively. Consistent with CS, their CFSs also displayed similar antagonistic potencies against XCC with the highest clear zone recorded being 7.23 mm and 6.22 mm, respectively. Further investigations revealed that the minimum inhibitory concentration of B1 and C8 CFSs was 25 µg/ml. It was also found that both CFSs were sensitive to high heat and very low pH, but stable in the presence of proteinase-K. In the in vivo assay, both CS and CFS treatments of B1 and C8 could effectively protect the Rangpur lime from CC. Treated plants had significantly lower disease incidences and developed less severe symptoms than the control plants. Based on their 16S rDNA sequence, B1 and C8 were identified as Staphylococcus pasteuri and Staphylococcus warneri, respectively.ConclusionIt was concluded that Staphylococcus pasteuri and Staphylococcus warneri could be promising biocontrol agents of XCC. These bacterial isolates can be used as an alternative prevention measure to CC as opposed to commonly used chemicals.

A comparative study of Kigelia pinnata fruit extracts in terms of antimutagenic potential and antimicrobial efficacy against antibiotic-resistant microbial strains

In recent years, antibiotic-resistant microbes have become a serious concern which needs proper attention either to solve the problem or to find out the solution to treat it. In this study, antibiotic resistant strains of Pseudomonas, Enterococcus, and Escherichia coli (E. coli) were used to assess the antimicrobial potential of Kigelia pinnata fruit extract. Further, antimutagenic potential of Kigelia pinnata fruit extract was also assessed by Ames assay using Salmonella typhimurium strain TA 98 and TA 100. In antimicrobial assay, only chloroform, ethanol and hexane extract was found to produce clear zone diameter between 1.08±0.1 to 2.1±0.2 mm. Results of minimum inhibitory concentration revealed the effectiveness of chloroform extract on Pseudomonas, Enterococcus and E.coli at 1.8 mg/mL concentration. However, better antimicrobial activity was found with ethanol extracts at 2.1x10-2 mg/mL concentration revealing the effectiveness of the low dose of ethanol in killing the antimicrobial resistant strains. In the time-kill test method, chloroform extract of K. pinnata was found to be most effective in reducing 98-99% test microbial population at both dilutions in 30 min. Antimutagenicity test showed the equal potential of chloroform and ethanol extracted Kigelia fruit sample in reducing the number of revertants. Kigelia fruit extract (1000 μL) dose can reduce the mutagens at 5 μg/plate level but not at 10 μg/plate dose level. Further research will open the new scope in the field of development of herbal antimicrobials and antimutagenic compound for treating antibiotic-resistant microbes and cancer.

UJI AKTIVITAS ANTIBAKTERI EKSTRAK DAUN TABAT BARITO (Ficus deltoidea) TERHADAP BAKTERI Bacillus substillis DENGAN TINGKATAN POLARITAS PELARUT

Tabat barito leaf (Ficus deltoidea) is a single leaf of a sole form, the leaf has round tip with a flat edge and a pointed base. These leaves have a smooth surface, coloured green above and brownish yellow beneath. This study aims to determine the antibacterial activity of polar, semi-polar and non-polar compounds contained in Tabat barito leaf extract extracted with solvents of different polarity. The highest bacterial inhibition was also measured against Bacillus substillis which is a gram-positive bacterial. The maceration method uses 3 levels of solvents with different polarities, started with a non-polar solvent (n-hexan), a semi-polar solvent (ethyl acetate) and finally macerated with a polar solvent (methanol). The bacterial activity test was done with diffusion method. The results showed that the Tabat Barito leaf extract contained antibacterial compounds that were non-polar, semi-polar and polar. The highest inhibition of the hexane extract at concentration 15% with a clear zone diameter of 22.33 mm in very strong inhibition category against Bacillus substilis bacteria

AKTIVITAS ANTIOKSIDAN DARI TUMBUHAN PEPAYA (Carica papaya L.)

Pepper elder is a weed plant whose leaves contain anti-bacterial compounds such as flavonoids, tannins, triterpenoids, and saponins that can be used as acne treatment therapy. Pepper elder leaves can be made into anti-acne gel preparations by formulating the right gelling agent. This study aims to obtain a gel with good physical stability from variations in the gelling agent base and its activity against acne-causing bacteria. Formulation of Pepper elder leaf extract gel is made with variations in the base of Na.CMC, Carbopol, and HPMC, further stability evaluation includes organoleptic, homogentias, pH, viscosity, scattering power, and testing of antibacterial activity against the growth of Propionibacterium acne and Staphylococcus aureus . The results obtained from the stability test obtained by the Carbopol base and HPMC have good standards for organoleptics, homogenity, pH, viscosity, and scattering power. Antibacterial testing showed clear zone diameters formed against Propionibaceterium acne in naCMC, Carbopol, and HPMC variations of 17.7 mm, 16.3 mm, and 21.3 mm and staphylococcus aureus of 13.3 mm, 15.3 mm, and 14.3 mm, respectively. Based on the results obtained, HPMC gel has the best gel stability and can all formulas inhibit the growth of acne-causing bacteria Propionibacterium acne and Staphylococcus aureus evidenced by the diameter of the bland zone formed into the strong category.

Screening of antimicrobial, anti-quorum sensing activity and cytotoxicity of origanumoil against Gram-positive and Gram-negative bacteria

Introduction and Aim: Essential oils have been used from ancient times to treat different gram-positive and gram-negative bacterial-related infections. The study aims to screen the antibacterial, anti-quorum sensing activity of origanum oil against the common infection causing gram-negative and gram-positive bacteria.
 
 Material andMethods: The MIC (minimum inhibitory concentration) and antibacterial activity of origanum oil against the eight bacterial species, namely, Pseudomonas aeruginosa, Shigella flexneri, Salmonella enterica, Klebsiella pneumoniae, Streptococcus pneumonia, Streptococcus pyogenes, Staphylococcus aureus, and Enterococcus faecalis, was assessed by broth-dilution method and well diffusion method. The anti-quorum sensing activity was analyzed using bioreporter strain CV026 at sub-MIC concentrations, while the cytotoxicity of the origanum oil was analyzed using the SW480 cell line.
 
 Results: The oil's antibacterial activity was analyzed by measuring the clear inhibitory zone diameter, and maximum inhibitory zone of 36.66 mm zone against Staphylococcus aureus (Gram-positive) and 33.33 mm against Salmonella enterica (Gram-negative) of origanum oil was measured. And the minimum inhibitory zone of 16.66 mm zone of Enterococcus faecalis (Gram-positive) and 19.66 mm against Klebsiella pneumoniae (Gram-negative) of oil was noted. And the lowest MIC (0.1 mg/ml) of oilwas found against Streptococcus pneumonia. The oil significantly inhibited the violacein pigment production (30.29 %) at 0.02 mg/ml concentration (this oil concentration did not significantly affect the growth curve). The in vitro cytotoxicity assay shows that the oil inhibited the SW480 cells growth with increasing concentration.
 
 Conclusion: The origanum oil possesses antibacterial and anti-quorum sensing activity and can be used as an alternative for treating tested bacterial infection.

Isolation and selection of bacteria inhibiting Streptococcus agalactiae causing dark-body disease on snakeskin gourami fish (Trichogaster pectoralis)

Streptococcus agalactiae is one of the microbial pathogens causing the dark-body disease on snakeskin gourami fish (Trichogaster pectoralis) that affects the growth and quality of fish. This research aimed to isolate and select bacteria inhibiting S. agalactiae which are able to use for controling pathogenic bacteria instead of antibiotics. Fourteen bacteria strains were isolated and screened from healthy fishes, sediment and water samples at fish ponds in Dong Thap province. Among these strains, L7 strain showed the highest inhibition ability with the clear zone diameter was 9,3 mm. The results of the 16S rRNA sequence analysis indicated that the L7 strain belonged to Bacillus subtilis. The experiment to evaluate the inhibition capacity and fish disease control of selected B. subtilis in experimental conditions was conducted by challenging fish with S. agalactiae. Fishes in the control treatment was infected with S. agalactiae at 106 CFU/mL had survival rate 41,7%. The experimental treatments NT1, NT2, NT3 which were treated with B. subtilis at concentrations of 105 CFU/mL, 106 CFU/mL, and 107 CFU/mL gave higher survival rates compared with the non-treated control, with the rates of 60%, 76,7%, and 81,7%, respectively. These results revealed that the isolated B. subtilis is potential used in control dark-body disease on snakeskin gourami fish.

Isolasi dan Karakterisasi Bakteri Pemacu Pertumbuhan Tanaman (Plant Growth Promoting Rhizobacteria) Asal Tanah Desa Akar-Akar, Lombok Utara

<p><strong>Plant Root Growth Promoting Bacteria or PGPR are bacteria that colonize plant rooting areas or the rhizosphere to increase the quality or quantity of plant growth. PGPR can provide dissolved phosphate for plants to be absorbed by the plant root system since 95-99% of phosphate in nature is present in insoluble form. Soil samples from different irrigation systems from Akar-akar village were isolated through serial dilution techniques and grown on NA media shown that the higher the dilution, the fewer colonies that grew on the media. Macroscopic and microscopic observations were made to see the criteria for bacteria, shown that the bacteria in the three soil samples were gram negative and was known that bacillus and cocobacillus bacteria present in the three soil samples. Coccus bacteria was found in soil without irrigation and drip-surface irrigated soil, while streptococcus bacteria was found in drip-surface and drip-subsurface irrigated soil. As many as 22 bacterial isolates were isolated and grown on Pikovskaya media, only one bacterial colony was phosphate solvent through a clear zone that grew around the bacterial colony. The bacterial colony has a phosphate dissolving index (IPF) of 250, the ratio between colony diameter and clear zone diameter was 1: 1.5.</strong></p><p><strong>Keywords – </strong><em>PGPR, Drip-surface irrigated soil, Drip-subsurface irrigated soil</em></p>

ANTIMICROBIAL POTENTIAL OF GARLIC FRESH (Allium sativum L.) AND LAKOR ONION (Allium ascalonicum L.) ON THE GROWTH OF Staphylococcus aureus

Garlic (Allium sativum L.) and shallot Lakor (Allium ascalonicum L.) local products are plants that are used as spices for various dishes and can be used as herbal medicine. For natural use, safe and easy to consume which can be seen through its potential as herbal medicine, a study was carried out to test the antimicrobial potential of garlic (Allium sativum L.) and Lakor shallot (Allium ascalonicum L.) juice on the growth of bacteria (Staphylococcus aureus). Lakor garlic and shallots are grated, the results of grated Lakor garlic and shallots are squeezed to produce 100% pure onion bulb juice. Lakor garlic and shallot juice was diluted with concentrations of 25%, 35%, 45%, 55%, 65%, 75%, 85% and 95%, respectively. Antimicrobial activity was tested by the diffusion method using a disk to measure the diameter of the clear zone. The results showed that garlic (Allium sativum L.) was able to inhibit the growth of Staphylococcus aureus which could be demonstrated by the clear zone diameter of 16.3 mm at a concentration of 35% and at a concentration of 65% the diameter of the clear zone exceeded the clear zone of the amoxycillin antibiotic. Lakor red onion (Allium ascalonicum L.) showed antimicrobial potential but was unable to damage the bacterial cell wall as indicated by the diameter of the clear zone of 7.7 mm at a concentration of 95%. There is potential for both onion bulbs but have different antimicrobial properties against the growth of Staphylococcus aureus.

Analog Kalkon (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one: Sintesis dan Uji Aktivitas Antimicrobia terhadap Bakteri Kontaminan Produk Darah

Bacterial infection remains a leading cause of death in the world. It caused by incorrect antimicrobial used in the hospital, bacterial resistance caused by prolonged use of antimicrobial, minimum controlling of antimicrobial utilization, and late development of new antimicrobial drugs. Chalcone compounds with particular structure are believed to have the capability as an antimicrobial agent. The objective of this study is to synthesize and examine the activity of chalcone analogue compound with two hydroxyl substituents groups in ring A and B as a characteristics. Chalcone analogue (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one was successfully synthesized by Claisen-Schmidt condensation method and produced a pale-yellow crystalline powder with 89.40% yield as reaction powder. The elucidation of reaction product structure using FTIR and GC-MS. Furthermore, the GC-MS test was obtained one-peak chromatogram with 100% of relative purity and m/z 240 as molecular ions detected according to the target compound of (E)-1,3-bis(4-hydroxyphenyl)-prop-2-en-1-one molecular weight. Antimicrobial activity examination was performed by paper disk diffusion method and the result showed that chalcone analog compound (E)-1,3-bis(4-hydroxyphenyl)prop-2-en-1-one has medium inhibition activity to Staphylococcus aureus as positive gram bacteria, with the clear zone diameter was 9,2 mm in the 25,00 ppm of concentration. This compound were indicated to work selectively into Staphylococcus aureus, because it was not actively inhibit the growth of another bacterial test such as Bacillus sp., Escherichia coli and Acinetobacter

ANTIBACTERIAL ACTIVITY Streptomyces spp. ENDHOPHYTIC TO Staphylococcus aureus AND Eschericia coli

The objective of this research was to known antibacterial activity of 4 endhophytic Streptomyces namely Streptomyces griseorubiginosus, Streptomyces vellosus, Streptomyces diastaticus and Streptomyces griseoruber against Staphylococcus aureus and Eschericia coli and measure the biggest antibacterial activity which is indicate by clear zone diameter. Antibacterial activity by using agar plug diffusion method showed that Streptomyces vellosus has capable to inhibits growth of Staphylococcus aureus but not with Eschericia coli and Streptomyces diastaticus has capable to inhibits growth of Eschericia coli but not with Staphylococcus aureus. The clear zone of Streptomyces vellosus and Streptomyces diastaticus are 5,18 mm and 7 mm respectively. Streptomyces griseoruber and Streptomyces griseorubiginosus can’t grow during isolation. Keyword: Streptomyces vellosus, Streptomyces diastaticus, agar plug diffusion method

ANTIBACTERIAL ACTIVITY Streptomyces spp. ENDHOPHYTIC TO Staphylococcus aureus AND Eschericia coli

The objective of this research was to known antibacterial activity of 4 endhophytic Streptomyces namely Streptomyces griseorubiginosus, Streptomyces vellosus, Streptomyces diastaticus and Streptomyces griseoruber against Staphylococcus aureus and Eschericia coli and measure the biggest antibacterial activity which is indicate by clear zone diameter. Antibacterial activity by using agar plug diffusion method showed that Streptomyces vellosus has capable to inhibits growth of Staphylococcus aureus but not with Eschericia coli and Streptomyces diastaticus has capable to inhibits growth of Eschericia coli but not with Staphylococcus aureus. The clear zone of Streptomyces vellosus and Streptomyces diastaticus are 5,18 mm and 7 mm respectively. Streptomyces griseoruber and Streptomyces griseorubiginosus can’t grow during isolation. Keyword: Streptomyces vellosus, Streptomyces diastaticus, agar plug diffusion method

Antibacterial activity of endosymbiotic bacterial compound from Pheretima sp. earthworms inhibit the growth of Salmonella Typhi and Staphylococcus aureus: in vitro and in silico approach.

Background and Objectives:Earthworms coexist with various pathogenic microorganisms; thus, their immunity mechanisms have developed through a long process of adaptation, including through endogenous bacterial symbionts. This study aims to identify earthworm endosymbiont bacteria compounds and their antibacterial activity through an in vitro approach supported by an in silico approach.Materials and Methods:This research was conducted using the in vitro inhibition test through agar diffusion and the in silico test using molecular docking applications, namely, PyRx and Way2Drugs Prediction of Activity Spectra for Substances (PASS).Results:The in vitro results showed a potent inhibition activity with a clear zone diameter of 21.75 and 15.5 mm for Staphylococcus aureus and Salmonella Typhi, respectively. These results are supported by chromatography and in silico tests, which showed that several compounds in endosymbiotic bacteria, cyclo (phenylalanyl-prolyl) and sedanolide, have high binding affinity values with several antibiotic-related target proteins in both pathogenic bacteria. Cyclo (phenylalanyl-prolyl) has the highest binding affinity of −6.0 to dihydropteroate synthase, −8.2 to topoisomerase, and −8.2 to the outer membrane, whereas sedanolide has the highest binding affinity to DNA gyrase with approximately −7.3. This antibiotic activity was also clarified through the Way2Drugs PASS application.Conclusion:Ten active compounds of endosymbiont bacteria, Cyclo (phenylalanyl-prolyl) and sedanolide were potential candidates for antibacterial compounds based on the inhibition test of the agar diffusion method and the results of reverse docking and Way2Drugs PASS.

Intensification process in thyme essential oil nanoemulsion preparation based on subcritical water as green solvent and six different emulsifiers

Abstract In order to alter the solubility and bioavailability of various functional lipids and plant essential oils (EOs), it is possible to prepare their oil in water (O/W) nanoemulsions. Thyme O/W nanoemulsions were prepared under subcritical water conditions (at 120°C and pressure of 1.5 atm for 2 h), using Tween 20, Tween 80, saponin, Arabic gum, xanthan gum, and sodium caseinate as emulsifiers. Results indicated that nanoemulsions with minimum mean droplet size of 11.5 and 12.6 nm were produced using Tween 20 and 80, respectively. Moreover, nanoemulsions with minimum polydispersity index (0.139) and maximum mean value of zeta potential (−24.5 mV) were provided utilizing xanthan gum and saponin, respectively. Results also revealed that the prepared nanoemulsions using saponin had maximum antioxidant activity based on percentage of scavenging ability (40.6%) and bactericidal effects against Streptococcus mutans as manifested in the formed clear zone (diameter of 21 mm). Morphological assessment of all the prepared nanoemulsions demonstrated that spherical thyme nanodroplets were formed in the colloidal solutions which revealed that all the prepared nanoemulsions had high thermodynamic stability due to the minimum surface energy level of the formed nanodroplets. This can increase applications of the prepared thyme O/W nanoemulsions in the aqueous food and pharmaceutical formulations.

Antibacterial activity of lactic acid bacteria isolated from Dengke Naniura of Carp (Cyprinus carpio) against diarrhea-causing pathogenic bacteria

Abstract. Nasri, Harahap U, Silalahi J, Satria D. 2021. Antibacterial activity of lactic acid bacteria isolated from Dengke Naniura of Carp (Cyprinus carpio) against diarrhea-causing pathogenic bacteria. Biodiversitas 22: 3098-3104. Diarrhea is the discharge of liquid or watery stools 3 to 4 times a day caused by a bacterial infection. Treatments for diarrhea are probiotics, which have a beneficial effect on the health of the host such as antibacterial. Traditional Batak Toba fermented food, Dengke Naniura, is a source of probiotics. This study aimed to determine the minimum inhibitory concentration, minimum bactericidal concentration, and leakage of DNA and protein from lactic acid bacteria against pathogens. Isolation of LAB was obtained from Dengke Naniura by pour plate method on deMann Rogosa and Sharpe Agar + CaCO3 1%. In this study, Characterization and analysis of bacterial sequencing used Polymerase Chain Reaction. Determination of MIC used the agar diffusion method. The MBC test used the streaking method which was a stroke from the inhibition zone formed. DNA and protein leakage was measured using spectrophotometry UV-VIS (260nm and 280nm). The isolation results obtained were Lactobacillus fermentum, the characterization showed that the bacteria were Gram-positive, bacilli, non-sporing, catalase-negative, and able to ferment sugar. The MIC determination was obtained at a concentration of 10%v/v with a clear zone diameter. Determination of MBC against pathogens was obtained at different concentrations. The results of DNA and protein leakage showed an increased absorption (260nm and 280nm).