Medium In Petri Dishes Research Articles

Técnica simples, rápida e barata de isolamento e multiplicação de Phytophthora infestans

ABSTRACT: In this study, we present a method for isolation and propagation of Phytophthora infestans, a challenging-to-isolate phytopathogenic oomycete. The procedure initiated with naturally infected potato leaves, which underwent a 30-minute sanitization under running water. Subsequently, healthy potato tubers were meticulously washed with a neutral detergent, sterilized using alcohol, and then flamed. Slices 4 mm thick were carefully cut out of the potato tubers. Slices were used to cover 2 x 4 mm sterilized leaf pieces cut from the border of two-day old young P. infestans lesions, within sterilized empty Petri dishes. The sealed plates were then transferred to BOD growth chambers set at 18 ºC in complete darkness for 5 days. At the end of this incubation period, the development of a sparse, white mycelium was observed on top of the potato slices. Using a Drigalski loop, the visible mycelium was carefully transferred to rye agar medium in Petri dishes. To avoid contamination, care was taken not no touch potato slices. After mycelium reaching the Petri dish border, and with aid of a Neubauer chamber, the inoculum density per plate was of 1.79 x 104 sporangia mL-1. Sporangia germination rate ranged from 69 to 78%. This isolation technique simplify in vitro production of P. infestans, enhancing the possibility for research with this important pathogen.

Antibacterial Potential of Chitosan Scaffolds Incorporated with Oregano and Thyme Essential Oils against Escherichia coli

The aim of this study was to evaluate the antibacterial potential of chitosan-based scaffolds associated with the essential oils of Origanum vulgare L. and Thymus vulgaris L. against a strain of Escherichia coli. The antibacterial potential was assessed by reading the inhibition halos formed around the chitosan-based scaffolds incorporated with thyme EO, oregano EO and thyme and oregano EO against the Escherichia coli strain, using the Mueller Hinton agar diffusion methodology per well. To do this, Mueller Hinton Agar was used as the culture medium in Petri dishes, and holes 6 mm in diameter were formed using a mold to create the wells. The plates were inoculated with the microorganism using a swab, then incubated in a bacteriological oven at 37 °C for 24 hours. Scaffolds, in the form of disks, were aseptically deposited in the wells of the inoculated media, which were incubated at 37 °C for 24 hours. After incubation, the plates were observed for homogeneity of bacterial growth and the diameter of the inhibitory halo was measured using a millimeter ruler in cases where inhibition of bacterial growth was verified. The tests were carried out in duplicate and the results correspond to the average values. The association of chitosan with Origanum vulgare L. and Thymus vulgaris L. EOs was found to have antibacterial activity against the Escherichia coli strain. For the scaffolds incorporated with Origanum vulgare L. EO, Thymus vulgaris L. EO and associated Origanum vulgare L. and Thymus vulgaris L. EOs, 16 mm inhibition halos were formed against the Escherichia coli strain. The association of chitosan with the EOs of Origanum vulgare L. and Thymus vulgaris L. has antibacterial activity, acting as a bactericide against the Escherichia coli strain tested.

THE ANTIBACTERIAL EFFECT OF ROSEMARY (ROSMARINUS OFFICINALIS L.) ON ENTEROCOCCUS FAECALIS BACTERIA AS AN ALTERNATIVE FOR ROOT CANAL IRRIGATION

Background: Root canal treatment is one of the endodontic treatments to preserve teeth with bacterially infected pulp tissue. Root canal irrigation is one of the most important processes to eliminate bacteria in root canals. In the root canals of teeth with failed endodontic treatment, Enterococcus Faecalis bacteria were found, so that alternative irrigation materials were needed that were more effective.Purpose: The aim of this study was to explain the effect of the antibacterial power of rosemary (Rosmarinus officinalis L.) on Enterococcus faecalis bacteria.Methods: The samples tested were 24 in the form of Enterococcus faecalis bacteria culture in BHI agar media in petri dishes. This research uses the well method. Each 1 petri dish was divided into 4 wells and each was given rosemary extract (Rosmarinus officinalis L.) at 5% and 10% concentrations, as well as a positive control (NaOCl 2.5%). Bacteria were grown and incubated, then diluted with 0.5 McFarland standard. (1.5X108 bacteria permilliliter).Results: The average inhibitory power of Enterococcus faecalis in rosemary (Rosmarinus officinalis L.) extract at 5% concentration was 16.7 mm and at 10% concentration was 18.8 mm, while in 2.5% NaOCl solution it was 8 mm. The hypothesis test has a value of p = 0.000 (p < 0.05).Conclusion: Rosemary extract (Rosmarinus officinalis L.) has a more effective inhibition of Enterococcus faecalis bacteria.

Diterpenes and triterpenes show potential as biocides against pathogenic fungi and oomycetes: a screening study

ObjectivesThe aim was to screen di- and triterpenes as potential biocides against fungal pathogens (Alternaria sp., Fusarium avenaceum, F. sambucinum, Botrytis cinerea, Botryotina fuckeliana, Mycocentrospora acerina, Cylindrocarpon sp.) and oomycetes (Phytophthora cactorum, P. fragariae). Results We measured the antifungal activity of terpenes by estimating the growth area, ergosterol content and level of lipid peroxidation. Fungi and oomycetes were grown on solid media in Petri dishes. As a positive control, we used a common synthetic fungicide, fosetyl-Al. Di- and triterpenes showed promising potential as biocides against most of the studied species. The responses of fungi and oomycetes were dependent on the specific type of terpenes and identity of the fungi. Compared to synthetic fungicide, terpenes were equally effective as antifungal agents and even more effective for some species, especially for oomycetes. The terpene mode of action includes inhibition of ergosterol synthesis and increased lipid peroxidation. Conclusions Di- and triterpenes, natural compounds that are very abundant in northern countries, are excellent candidates for biocides.

Formulation and Antibacterial Activity Test of Salmonella thypimurium and Lactobacillus acidophilus in Microencapsulation of Mangosteen Peel Extract

Xanthone compounds in the ethanol extract of mangosteen peel have antibacterial activity against both pathogenic and beneficial bacteria. The purpose of this study was to examine the effect of various formulations of ethanol extract of mangosteen peel and maltodextrin from palm starch on Salmonella thypimurium and Lactobacillus acidophilus. This research was conducted by culturing the bacterial cultures of S. thypimurium and L. acidophilus on nutrient agar (NA) media in petri dishes according to the Kirby-Bauer method. The NA media that had been made in the petri dish was then made wells to test each treatment as much as 10 µL/disk at various concentrations (100, 75 and 50%). The formulations tested in this study consisted of: T1 (30% ethanol extract of mangosteen peel + 70% maltodextrin), T2 (40% ethanol extract of mangosteen peel + 60% maltodextrin), T3 (50% ethanol extract of mangosteen peel + 50% % maltodextrin), T4 (60% ethanol extract of mangosteen peel + 40% maltodextrin), T5 (70% ethanol extract of mangosteen peel + 30% maltodextrin), T6 (ethanol extract of mangosteen peel only), T7 (maltodextrin only), T8 (positive control containing 100 ppm bacitracin) and T9 (negative control/no treatment). The results of each sample were observed by measuring the sample inhibition zone on the growth medium that had been prepared. Data from the antibacterial activity test results were then analyzed using one-way ANOVA followed by Duncan's test. The results showed that the ethanol extract of mangosteen peel and maltodextrin had a significant effect (P<0.05) on the antibacterial activity of Salmonella thypimurium and Lactobacillus acidophilus. The results of this study indicated that the formulation of ethanol extract of mangosteen peel and maltodextrin had the ability as an antibacterial against Salmonella thypimurium and Lactobacillus acidophilus at a medium level.

Antimicrobial Activity of Bee Queen Larvae and Royal Jelly

Royal jelly has unique healing properties due to the presence of a number of biologically active compounds and yet unidentified components that are used for the prevention and treatment of many diseases. Purpose. To investigate the antimicrobial activity of homogenate of bee queen larvae and royal jelly against four phytopathogenic bacteria. Methods. Method of diffusion of biologically active compounds into agar medium sown with test cultures of phytopathogenic bacteria. Homogenates of bee queen larvae and royal jelly were diluted with sterile distilled water 1:5, centrifuged at 10,000 rpm to precipitate insoluble components, and 100 μL were added to the holes of the medium in Petri dishes seeded with phytopathogenic bacteria. After incubation of the dishes at 28ºC, the bactericidal effect of royal jelly was detected in the form of non-growth zones of phytobathogenic bacteria. Results. Royal jelly inhibited the growth of Clavibacter michiganensis subsp. michiganensis 102, Pectobacterium carotovorum 8982, Xanthomonas campestris pv. campestris 8003b, and Pseudomonas syringae pv. syringae 8511 around the holes in the medium. The largest zone of no bacterial growth (45.0 mm) was observed around the wells with royal jelly on the lawn of P. carotovorum 8982, which indicates the high sensitivity of these bacteria to an unidentified compound in royal jelly. Homogenate of bee queen larvae delayed the growth of only X. campestris pv. campestris 8003b. Thin layer chromatography revealed one similar and three different compounds in bee queen larvae and royal jelly. Conclusions. For the first time, the antibacterial activity of royal jelly against four phytopathogenic bacteria С. michiganensis subsp. michiganensis 102, P. carotovorum 8982, X. campestris pv. campestris 8003b, and P. syringae pv. syringae 8511 was established, which expands the spectrum of its antagonistic activity and can be used in the future for practical purposes.

Effectiveness of disinfecting substances of gutta-percha cones

Aim: To demonstrate the effectiveness of disinfecting substances with 2% and 5% Sodium Hypochlorite and 2% Chlorhexidine Gluconate at each of the pre-established times of 0:15 and 0:30 seconds, and 1, 2, 5, and 10 minutes. Methods: This study selected 96 gutta-percha cones that were contaminated with Enterococcus Faecalis, dried and treated with the aforementioned substances and applied at pre-established times. Subsequently, these were transferred to sterile Brain Heart Infusion broth and placed in a bacteriological incubator at 37°C for 24 hours to evaluate microbial growth, as well as in a nutrient agar medium in Petri dishes. Half of the cone was transferred to individual filter paper packages and exposed to the environment in a dental clinic at Universidade José do Rosário Velano, for 7 days, with subsequent evaluation for microbial growth. The bacterial phenotype test was performed using Gram stain and growth in 6.5% saline solution. The results were submitted to statistical analysis using the Kruskal Wallis H test, with a significance level of 5%. Results: The substances were effective at all times tested and individual storage supported disinfection. In the statistics test, the p-value was greater than 0.05, as there was no variability in the data configurations. Conclusion: The disinfection of gutta-percha cones and individual storage was an effective protocol to be adopted with 2% and 5% Sodium Hypochlorite and 2% Chlorhexidine.

ISOLATION OF METHANOTROPHIC BACTERIA FROM NATURAL BIOCENOSES AND SELECTION OF NUTRIENT MEDIA OPTIMAL FOR CULTIVATION IN LABORATORY CONDITIONS

Background. One of the most pressing problems in the world is the production of food protein. The global protein deficit is estimated at 30 million tons per year, for the Russian Federation it is estimated at 2-2.5 million tons of protein per year.
 The problem of protein deficit can be partially solved with the help of methanotrophic bacteria. Under optimal conditions, methanotrophic bacteria are able to oxidise actively natural gas – methane and increase their biomass, rich in valuable protein, vitamins and other biologically active substances. The feed product from methanotrophic bacteria is comparable to fish meal and soybean meal, the concentration of pure protein in it is more than 80%.
 Purpose. Isolation of methanotrophic bacteria from natural biocenoses and their cultivation on various nutrient media in laboratory conditions.
 Materials and Methods. The study was conducted from 2019 to 2022 in the microbiological laboratory of the Center for Technological Excellence “Advanced Chemical and Biotechnology” of the Tolstoy Tula State Pedagogical University. The object of the study was methanotrophic bacteria isolated from various natural and artificial ecosystems, collection strains of Methylococcus capsulatus B-2990 and Methylomonas methanica B-2110. To isolate methanotrophic bacteria, the method of seeding a accumulative culture on a solid agiarized sterile nutrient medium in Petri dishes was used. For the cultivation of methanotrophs, nutrient media of various compositions containing all the necessary macro- and microelements for the normal growth of bacterial colonies were used.
 Results. Colonies of methanotrophic bacteria were found in one sample of bottom sediments taken from the sphagnum swamp of the village of Kochaki in the Tula region and in samples from a methane reactor. As a result of comparison of nutrient media for isolation and cultivation of methanotrophs, it was found that the most suitable medium for isolation of methanotrophic bacteria is the standard nitrate mineral medium NMS. For the cultivation of methanotrophic bacteria, the best media were: the nutrient medium with the addition of anaerobic sludge, the ammonium mineral nutrient medium (AMS), and AMS with addition of methanol, the nutrient medium No.221 with addition of methanol.
 Conclusions. The use of various nutrient media for the cultivation of methanotrophic bacteria makes it possible to assess the effect of various organic substances on the growth and development of bacterial colonies. The study of various natural and artificial ecosystems makes it possible to expand taxonomic knowledge about this group of microorganisms, as well as to increase the potential of using methanotrophs in solving various problems of ecology and biotechnology.

Analisis Kualitas Udara Pada Rumah Warga Terhadap Parameter Bakteri dan Jamur

The final processing and disposal the waste occurs at the Final Disposal Facility (TPA). Because the rubbish heaps include a variety of contaminants and produce air pollution, landfills can have an impact on the environment's quality. This study intends to identify and contrast the outcomes of the analysis of the air quality in residents' homes near the Piyungan TPA location, which is 50 m, 350 m, 650 m, and 1000 m from the TPA, with quality standards according to the Decision of the Minister of Health No. 1077 of 2011 based on bacterial and fungal parameters. The ideal distance between residential areas and the TPA location is another goal of this study. Air sampling at each location used the air sampling method directly with NA media and PDA media in petri dishes. The results showed that the number of bacterial colonies at a distance of 50 m was 4,485.6 CFU m-3 and the fungal colonies were 2,306.4 CFU m-3. At a distance of 350 m, the number of bacterial colonies was 3,355.4 CFU m-3 and fungal colonies were 2,130.9 CFU m-3. The number of bacterial colonies at a distance of 650 m was 2,919.7 CFU m-3 and the number of fungal colonies was 2,001.3 CFU m-3. The number of bacterial colonies at a distance of 1000 m was 1,353.2 CFU m-3 and the number of fungal colonies was 765.2 CFU m-3. Air quality in residents' homes with a distance of 50 m to 1000 m does not meet the healthy air quality requirements based on Minister of Health Regulation No. 1077 of 2011 concerning Indoor Air Conditioning at Home with maximum levels of airborne microbes <700 CFU m-3.

Bacterial filtration efficiency of medical face masks – Evaluation of the use of disposable plastic petri dishes in Andersen impactor

Bacterial filtration efficiency is the main characteristic of medical face masks effectivity and quality. The testing method is given by European and US, respectively, standard. The method is based on the analysis of biological aerosol with the bacterium Staphylococcus aureus in Andersen cascade impactor. The Andersen impactor contains six stages simulating the different parts of the respiratory tract, from the upper part with the larger droplets to the lungs with the small aerosol particles of the submicron size. The particles are separated depending on the size and sediment on agar medium in Petri dishes filled in the impactor. The use of the glass Petri dishes is recommended for the Andersen impactor, but the most of laboratories prefer the disposable plastic dishes, actually. The evaluation of the use of plastic dishes in Andersen impactor for the determination of the bacterial filtration efficiency of the medical face masks is the aim of this study.

Practical Aspects of Processing and Interpretation of the Results of Microbiological Analysis of the Quality of Non-Sterile Medicines

The article presents materials on processing and interpretation of the results of microbiological analysis of the quality of medicines in accordance with the State Pharmacopoeia of the Russian Federation and the Pharmacopoeia of the Eurasian Economic Union. It exemplifies the use of the rules for processing test results and counting aerobic microorganisms and microscopic fungi on agar culture media in Petri dishes and on membrane filters. The author discusses the possibility of and prospects for applying various sample inoculation methods, as well as using calculation factors when interpreting their results. The text covers approaches to repeating microbiological testing of medicines to verify the reliability of a non-compliant first result.

THE EFFECT OF REINFORCED POLYETHYLENE FIBER ON FLOWABLE RESIN COMPOSITE AS SPLINTING MATERIAL ON ATTACHEMENT OF Streptoccocus mutans

Introduction : Tooth mobility is one of the symptoms of periodontal disease which is characterized by loss of attachment and vertical bone damage. One method to overcome this is by splinting. The development of dental materials science has resulted in an innovative splinting technique using a thin band of material, easily bonded, consisting of a series of criss-crossed strands of thin polyethylene fibers. Fiber in the oral cavity will interact with saliva and microorganisms, especially Streptococcus mutans. Objective: The purpose of this study was to determine the effect of adding polyethylene fiber to flowable composite resin as a splinting material on the attachment of Streptococcus mutans. Materials and Methods: This research method was an experimental laboratory using a post-test only control group design. Samples in the form of blocks with a size of 5x4x2 mm were immersed in artificial saliva for 1 hour then soaked in liquid medium containing Streptococcus mutans and incubated for 2x24 hours, diluted to 100 or dilution of 10-2 then 0.1 mL of liquid medium put into TYC agar media in petridishes and incubated at 37oC for 48 hours anaerobically. Results and Discussion: Statistical tests showed that the addition of polyethylene fiber to the flow composite resin splinting material increased the attachment of Streptococcus mutans bacteria . The results of the Saphiro-Wilk test showed that the growth of Streptococcus mutans bacteria in each group was normally distributed (p>0.05). Lavene's test results obtained a statistical levene value of 0.695 with a significance value of 0.410 > 0.05, this proves that the data used is homogeneous. In the One Way Anova test, it can be seen that the sig value is 0.000 (p<0.05). From the results of the analysis with LSD shows there is a significant difference in treatment between variables. Conclusion: From the results of the study, there is an influence of the addition of polyethylene fiber to flowable composite resins as a splinting material on increasing the attachment of Streptococcus mutans.

ЗНЕЗАРАЖЕННЯ ПИТНОЇ ВОДИ ЗА ДОПОМОГОЮ ПЛАЗМИ ЕЛЕКТРИЧНОГО РОЗРЯДУ

For today, taking into account the low efficiency of the disinfection technologies using chlorine-containing compounds and the growing number of chlorine-resistant microorganisms, the question of introducing alternative methods of disinfection in the field of water supply and drainage is relevant. One such alternative method is the treatment of liquids with plasma of electric discharge. This article describes our experiments on the treatment of different types of water from surface sources in Kyiv and water intentionally infected with Escherichia coli (E. coli). The experiments were performed on a laboratory installation with a circulating pump and an ejector-type reactor with integrated electrodes. In the reactor a water-air mixture is formed, in which an electric discharge takes place. The disinfection reactor and at the same time the device for the formation of a heterogeneous water-air environment is an ejector with electrodes inserted into it, which receive pulses of electric current. Discharges initiate a range of different physicochemical phenomena, such as a strong electric field, intense ultraviolet radiation, shock waves of excess pressure and, in particular, the formation of various highly active chemicals such as radicals (OH •, H •, O •) and molecules ( H2O2, H2, O2, O3). All these physicochemical processes occur during the discharge itself, for example, the formation and action of short-lived radicals, as well as the action of relatively long-lived oxidants. The effect of the concentration of microorganisms on the rate and completeness of water disinfection was studied in technical (tap) water with the introduction into the reaction tank of the washoff from two test tubes. This provided an initial concentration of E. coli of 3.4 ∙ 106 CFU / cm3. Water treatment for 30 seconds reduced the concentration of microorganisms by two orders of magnitude (up to 5.4 ∙ 104). After 1 minute of treatment, this figure decreased to 1.7 ∙ 102, and after 3 minutes to 5.2 CFU / cm3, i.e., the treated water corresponded to norms for almost pure water. Experiments have proven the effectiveness of plasma disinfection, even for liquids with a concentration of microorganisms significantly exceeding the maximum allowable concentrations. The content of microorganisms before and after treatment was determined by the method of limiting dilution of samples with subsequent sowing on a nutrient medium in Petri dishes

Effectiveness of Using Gases for Water Purification with the Same Microbial Load

Purpose of the study is to іnvestigate the effect of gases on the process of water purification from aerobic microorganisms (MO) with the same initial content in the aquatic medium and to identify the nature of the gas in the atmosphere in which the highest degree of destroyed microbial cells per unit volume of water is achieved. Methods. Aerobic bacteria of the Bacillus cereus bacteria type with the initial content of 7 · 104 CFU/cm3 were used for research. The investigated water was model water created on the basis of distilled deaerated waterwith the introduction of bacteria of a specific species. Oxygen, carbon dioxide, as well as inert - argon and helium were used as a studied gases. Process conditions were: duration - 2 hours, gas bubbling rate - 0.2 cm3/c, T = 288 ± 1 K. Has been used a quantitative method of counting the initial and final number of microorganisms (NM) by sowing samples of test water on nutrient medium in Petri dishes before and after experiments. Results. The different efficiency for the water purification process depending on the gas nature is shown. The NM value change of the time of bubbling gases is presented. The degree of destruction of the studied microorganisms was calculated depending on the mode of water treatment and the process duration. The oxygen influence on the process of MO destruction consists of two stages - a slight accumulation of cells (I stage) and their subsequent destruction in the II stage. The percentage of cell accumulation during 3600s during oxygen bubbling into the aqueous medium was 9.43%, which is due to the consumption of bubbling oxygen by bacteria. This led to the lowest process efficiency for the oxygen action in the end of the result (Dd is 34.73% only). The greatest efficiency of MO destruction was found during carbon dioxide bubbling (Dd = 91.0%), which is obviously due to the increase in the acidity of the test medium (pHinitial = 6.1 and pHend = 4.3). The influence of helium on water purification at different microbial load has been studied. It has been shown that the efficiency of cell destruction increases with a decrease of its number per unit volume of water. Conclusions. The influence of the different gases nature on the destruction process of aerobic MO in water with the same and different microbial load is shown. It is established that the process of water purification from MO depends on the nature of the bubbled gas. The gas, the supply of which allowed to achieve the largest number of destroyed cells after 7200 s, was experimentally determined. The highest efficiency of water disinfection is achieved during the action of carbon dioxide. A relative series of effective action of the investigated gases on microbial water purification is established.

Effect of Seaweed Extract Applied to Growth Media on Mycelium Growth of Oyster Mushroom

This study was carried out to determine the effect of Ecklonia maxima type seaweed extract applied to growth media on mycelium growth of oyster mushroom (Pleurotus ostreatus). In the experiment, most common 2 growth media [Malt Extract Agar (MEA) and Potato Dextrose Agar (PDA)] were used. After the prepared MEA (48 g L 1) and PDA (39 g L 1) medium was autoclaved at 121 ° C for 20 minutes, half was separated and 2% E. maxima seaweed extract (DY) was added. The experiment consisted of 4 growth media: MEA, PDA, MEA + DY and PDA + DY. While the prepared environments were warm and fluidal, they were filled in petri dishes under UV light in a sterile cabinet and left to cool. After surface disinfection of oyster mushrooms, clones were taken and placed on the medium in petri dishes and petri dishes were closed with parafilm. The petri dishes (n=15) were placed in the incubator at 24 °C. Daily mycelia lengths and weight of petri dishes were measured and mycelia growrth pwriod (day) and rate (cm day 1) were calculated. Among the used growth media, PDA was given more and heavier mycelia growth in a shorter time than MEA. DY application was increased mycelia growth period and reduced growth rate. DY was showed better performance in PDA medium. As a result of the research, it has been determined that the addition of liquid seaweed extract preparation to PDA at a rate of 2% (PDA + DY) increased micelle growth and shortened micelle growth period. Keywords: PDA, MEA, Ecklonia maxima, Oyster mushroom DOI: 10.7176/JSTR/7-03-02

Antifungal effect of essential oil and different extracts obtained from Nepeta meyeri on Botrytis cinerea

The study concerns the antifungal effect of the aqueous and methanolic extracts, and the essential oil obtained from the aerial parts of Nepeta meyeri Benth. on Botrytis cinerea Pers. The fungus has been isolated from the infected plants of common grape Karaerik (Vitis vinifera L.) cultivating in vineyards in Üzümlü district, Erzincan (Turkey), and was cultured on potato dextrose agar medium in Petri dishes after the identification by 18S rRNA gene-based PCR assay. The concentrations of extracts from N. meyeri in Petri dishes were 2%, 5% and 10% (w/v) for aqueous extract (AE); 500, 1000 and 1500 ppm (v/v) for methanolic extract (ME), and 0.6, 0.8 and 1 µL for essential oil (EO). After the treatments, mycelial growth, spore germination, and germ tube elongation were determined. Sterile distilled water at the same ratios was used for the control treatment. Thirty-six different compounds were identified in the EO of N. meyeri by GC/MS. The highest antifungal activity has been registered for EO of N. meyeri. The inhibition rates in 1 µL/Petri of the EO were 80.72%, 18%, 38.15% on mycelial growth, spore germination and germ tube elongation, respectively. However, AE and ME of N. meyeri showed diverse effects on the studied parameters of B. cinerea. It is suggested that the favourable concentration of EO from N. meyeri can contribute to the prevention of B. cinerea infection (grey mould) which causes disease in vineyards.

Complex impact of polarized and non-polarized low intense light and methylene blue on growth rate of some opportunistic microorganisms

Resistance to antibiotics is considered as a global and unsolved problem in the branch of medicine. That is why the use of novel non-drug methods of treatment of bacterial and fungal infections is of great relevance. One of such methods is photodynamic treatment, which is a treatment procedure that uses light energy to activate a photosensitizing agent in the presence of oxygen. Due to the broad spectrum of action, the efficacy against antibiotic resistant cells and the lack of selection of photoresistant strains, antimicrobial photodynamic therapy compares favourably with traditional drug therapy, and has emerged in the clinical field as a potential alternative to antibiotics to treat microbial infections. In this article results of studies of the complex effect of methylene blue (0.1% aqueous solution) and LED radiation of the red-infrared spectrum as well as methylene blue and polarized incoherent low-energy radiation (PILER) with a red light filter on the growth rate of some opportunistic microorganisms on solid nutrient media are presented. Standardized suspensions of microorganisms were prepared for research with the subsequent determination of direct impact of polarized and non-polarized radiation (at duration of exposure of 5 min), photosensitizer, and also the set of these factors on growth of the studied microorganisms. The growth intensity of bacteria and yeast-like fungi was determined by the number of their colonies after reseeding on nutrient media in Petri dishes. The obtained data were compared with control groups, which were not influenced by any factors. The results indicate a significant antimicrobial effect of the combined action of different types of radiation and methylene blue on microorganisms, which was manifested in a reduction in the number of colonies by on average 35–45%, compared with the control groups. Comparing the effect of exposure when using LED and PILER light, we have noted its similarity. It is also worth noting a certain antimicrobial activity of 0.1% methylene blue solution on the studied strains, but this was much less pronounced than in the complex effect. The direct effect of both LED and PILER radiation with low duration of exposure caused the stimulation of the growth of the studied microorganisms with an increase in the number of their colonies on Petri dishes by 15–35%. Given the rapid growth of resistance to antimicrobial agents, the described technique can be used as an alternative to traditional antibiotic therapy for the treatment of purulent-inflammatory diseases of the skin and mucous membranes.

Screening of Soil Streptomycetes – Producers of Antibiotics against Phytopathogenic Bacteria

Soil is an inexhaustible source of bacteria of the genus Streptomyces – the producers of the vast majority of known antibiotics that are successfully used in medicine, veterinary and agriculture. The emergence and spread of pathogenic bacteria resistance to antibiotics requires the search for new antibiotic compounds capable of overcoming this problem. Aim. The purpose of this work was to isolate streptomycetes from soil samples of Kyiv and the Kyiv region and study their antibiotic activity against four strains of the different species of phytopathogenic bacteria. Methods. A suspension of soil in distilled water was sown on solid Chapek or corn-soybean medium in Petri dishes, in which trimethoprim and nystatin were introduced to inhibit bacterial and fungal growth. The antibiotic activity of the streptomycetes was tested by setting their agar discs on lawns of phytopathogenic bacteria in Petri dishes. Antibiotics were extracted from the streptomycetes agar cultures with a mixture of chloroform and acetone (2:1), dried in a rotary vacuum evaporator, dissolved in ethanol, separated and purified by thin layer chromatography on aluminum plates (Silica gel 60 F254 from Merck KGaA). The UV/Vis absorption spectra of the antibiotics were measured with a Beckman DU 8 spectrophotometer. Results. 10 strains of streptomycetes were isolated from the soil samples of Kyiv and the Kyiv region, whose antibiotic activity was tested against four phytopathogenic bacteria using the agar block method. Three of the streptomycetes – B8, SK and KZ, formed growth inhibition zones of different phytopathogens on complete medium in Petri dishes, among which the strain SK was the most active. This strain showed antibiotic activity against all four phytopathogenic bacteria – P. syringae 8511, P. carotovorum 8982, C. michiganensis 10 and X. campestris 8003. Conclusions. The results obtained are of interest for the protection of sensitive plants by isolated antibiotics against phytopathogenic bacteria in hothouse conditions.

Evaluation of the development of Mycosphaerella Fijiensis Morelet, collected in the centre and linder in planting of Musa sp. AAA

The study evaluated the disinfection medium to obtain in vitro mycelia of M. fijiensis, in samples of banana leaves (Musa sp. AAA) collected in the center (BI) and the border (AI) of the banana, of the Hacienda El Playón, Pasaje canton, El Oro province. In order to unload the ascospores in the laboratory, cuttings of 7 x 7 cm leaves with SN symptoms were made in plastic containers with a capacity of 500 mL and incubated for 72 hours. The samples of the fragments were placed in sterile distilled water on sterile filter paper to remove water residues and with the help of a scalpel, they were sown in potato-dextrose-agar (PDA) culture medium in Petri dishes, sealed with paper. parafilm, then they were placed to incubate for 7, 14 and 21 dds, at an average temperature of 27 ° C ± 2 ° C. The experimental design was completely randomized, with six treatments and three repetitions, each consisting of 30 Petri dishes. Statistical differences were presented due to the effect of the treatments (P <0.01) for the germination and growth of the mycelia. Treatments T5L and T6C (disinfection with sterile distilled water + 1 minute immersion) showed between 93 and 100% germination and mycelia growth at 21 dds between 23 and 24 mm to guarantee an axenic culture.

Non-Thermal Plasma Can Be Used in Disinfection of Scots Pine (Pinus sylvestris L.) Seeds Infected with Fusarium oxysporum

The aim of this study was to use diffuse coplanar surface barrier discharge (DCSBD) non-thermal plasma for the disinfection of pine seed surfaces infected with Fusarium oxysporum spores. Artificially infected seeds of Scots pine (Pinus sylvestris L.) were treated with plasma for the following exposure times: 1 s, 3 s, 5 s, 10 s, 15 s, 20 s, 30 s, and 60 s, and subsequently germinated on agar medium in Petri dishes at room temperature for the estimation of seed germination and disinfection effect of plasma treatment. Results of the treated samples were compared to the control samples, which were prepared as follows: seeds uninfected and non-treated with plasma (first control); seeds infected with F. oxysporum and non-treated with plasma (second control); and seeds infected with F. oxysporum, non-treated with plasma, but sterilized with 30% perhydrol (third control). Obtained results indicate that 3 s plasma treatment was an optimal time to inhibit F. oxysporum growth, and at the same time, increase the seed germination. In addition, our results are the first to show the practical application of non-thermal plasma in disinfecting infected Scots pine seeds and improving their germination. According to the results of this study, non-thermal plasma can serve as a seed surface disinfectant in the regeneration of different pine species.