Agar-solidified Medium Research Articles

In vitro viability and germination of Carya illinoinensis pollen under different storage conditions

Pecan (Carya illinoinensis) is a crossing-pollinated nut tree with male and female flowering separated and matured at different time. This dichogamy pattern requires appropriate pollen storage strategy making hybridization successful in the pecan breeding program. In this study, we used pecan cultivar ‘Pawnee’ pollen to optimize germination medium composition on basis of four published formulas. Consequently, an agar-solidified medium containing 15 g sucrose, 0.005 g boric acid, and 0.075 g calcium nitrate per 100 mL at pH 7 was optimal to the pecan pollen germination. Pollens of 14 pecan cultivars and 1 breeding line (7 protandrous and 8 protogynous genotypes) were collected and examined for germination rates on the optimized medium in order to determine germination variation among genotypes. ‘Pawnee’ pollen was investigated for germination pattern at four storage temperatures with different time intervals. As results, pollen germination rates varied among cultivars, possibly due to the difference in flowering pattern and catkin maturity level at the time of harvest. ‘Pawnee’ pollen remained viable after storage at -20 °C for six weeks (58.5 % germination rate) or 4 °C for four weeks (57.5 %), and still maintained 51.8 % viability when stored at −80 °C for one year. Pollen remains viable when removed from ultralow temperature and acclimated at 4 °C for 8−10 h and at RT for additional hour without typical rehydration before pollination to female flowers. These results provide useful information for short-term storage of pollen source in the pecan crossbreeding program.

Bio-interaction of Agrobacterium rhizogenes with Capsicum annuum L. (sweet variety) and Establishment Hairy Roots Cultures

Genetic transformation using Agrobacterium is one of the techniques used to transfer desired genes to plants. This protocol is considered a short – cut to get transformed plants which could be an alternative method and suitable system compared with the classical methods. This study aimed to investigate the response of C. annuum seedlings (sweet variety) to the formation transformed hairy roots induced by A. rhizogenes strain R1601. Sterilized seeds of Capsicum annuum were inoculated with the Agrobacterium rhizogenes inoculum. The samples were then transferred to the surface of solidified MS medium. Hairy roots were developed at the inoculation sites and were enucleated 1.0-1.5 cm length and placed in 9.0 cm Petri-dishes containing 15 ml of agar solidified MS medium. Agropine test was performed according to the standard method. The inoculated seedlings showed a good response 90%. Transformed hairy roots were established at the injection sites within 10 days and these roots were easily grown on agar-solidified MS medium. The results are confirmed that these roots were transformed roots it in terms of positive agropine detection. The current study concluded that the biological interaction between Agrobacterium rhizogenes strain R1601 and Capsicum anuum L. seedlings, was successful. This study encourages future research to improve this plant by continuing and applying modern technologies to obtain genetically modified plants.

Optimisation of growth conditions for maximum degradation of poly βhydroxyl butrate by two soil fungi

Poly β- hydroxyl butrate (PHB) is a polymer produced by bacteria and can be used safely in different modern application to replace biobased plastic which has adverse effects on the environments. This study is aimed to isolate some fungi for PHB degradation and optimise the growth conditions for maximum degradation. Contaminated soil samples were collected from the industrial area of Jeddah and used for fungal isolations. All fungal isolates were screened for PHB biodegradation on solid agar medium. Out of 20 isolates, 2 isolates were the most active in PHB degradation. They were identified as Trichoderma asperellum NM 6, and Aspergillus fumigates NM10 using morphological and molecular methods. The effects of some growth factors on growth and PHB degradation by the two isolated fungi were determined. Growth was measured by either CPV (ml) or dry weight (g/l) while PHB degradation was detected by depolymerase assay (U/ml). Presence of yeast extract (2.5 g/l) and glucose (1 g/l) enhanced both growth and PHB degradation by the two isolates. Similarly, adjusting medium pH at 7-7.5 and incubation at 25°C after for five days led to maximum growth and PHB degradation. The presence of PHB in growth medium enhanced both growth and PHB degradation and the maximum growth (CPV ml or dry weight (g/l) were in medium containing 0.5 g/l of PHB for both tested fungi. The maximum growth, measured by either CPV (ml) or dry weight (g/l), was in the medium that was inoculated with 10x106 spore/ml for the two tested fungi. In conclusion, PHB degradation by the two tested fungi was similar. It was affected by the same physical and biochemical factors and optimisation of these conditions enhanced both growth and degradation process by the two tested fungi.

Diversity and distribution of marine heterotrophic bacteria from a large culture collection

BackgroundIsolation of marine microorganisms is fundamental to gather information about their physiology, ecology and genomic content. To date, most of the bacterial isolation efforts have focused on the photic ocean leaving the deep ocean less explored. We have created a marine culture collection of heterotrophic bacteria (MARINHET) using a standard marine medium comprising a total of 1561 bacterial strains, and covering a variety of oceanographic regions from different seasons and years, from 2009 to 2015. Specifically, our marine collection contains isolates from both photic (817) and aphotic layers (744), including the mesopelagic (362) and the bathypelagic (382), from the North Western Mediterranean Sea, the North and South Atlantic Ocean, the Indian, the Pacific, and the Arctic Oceans. We described the taxonomy, the phylogenetic diversity and the biogeography of a fraction of the marine culturable microorganisms to enhance our knowledge about which heterotrophic marine isolates are recurrently retrieved across oceans and along different depths.ResultsThe partial sequencing of the 16S rRNA gene of all isolates revealed that they mainly affiliate with the classes Alphaproteobacteria (35.9%), Gammaproteobacteria (38.6%), and phylum Bacteroidetes (16.5%). In addition, Alteromonas and Erythrobacter genera were found the most common heterotrophic bacteria in the ocean growing in solid agar medium. When comparing all photic, mesopelagic, and bathypelagic isolates sequences retrieved from different stations, 37% of them were 100% identical. This percentage increased up to 59% when mesopelagic and bathypelagic strains were grouped as the aphotic dataset and compared to the photic dataset of isolates, indicating the ubiquity of some bacterial isolates along different ocean depths. Finally, we isolated three strains that represent a new species, and the genome comparison and phenotypic characterization of two of these strains (ISS653 and ISS1889) concluded that they belong to a new species within the genus Mesonia.ConclusionsOverall, this study highlights the relevance of culture-dependent studies, with focus on marine isolated bacteria from different oceanographic regions and depths, to provide a more comprehensive view of the culturable marine bacteria as part of the total marine microbial diversity.

Response of seed germination and seedling growth of Physalis accession from East Java

Environmental conditions significantly affects response of seed germination. This study aims to determine ex vitro and in vitro seed germination capacity and seedling growth of accession of Physalis sp derived from East Java including Madura Island. Ex vitro germination was carried out in mixed soil media: compost: husk charcoal while in vitro germination was carried out in agar-solidified medium. Ex vitro germinated seeds are generally able to produce 80-100% seedling in all accessions. Accessions from Madura Island have a better growth response compared to accessions from East part of Java Island. Although in vitro germination response was lower, the four accessions from the island of Madura namely A1 (Sumenep), A2 (Sampang), A4 (Sampang) and A5 (Pamekasan) have been able to produce regeneration and multiplication of shoots in vitro. The potential for in vitro growth in Physalis accessions needs to be developed to supply germplasm as a source of natural products in a controlled environment.

In vitro biological control of Ceratobasidium ramicola by using tannin extracts from Acacia villosa, Myristica fragrans, Acacia mangium, and Calliandra calothyrsus leaves.

Ceratobasidium ramicola is a fitopathogenic fungus that harmful and causes various levels of damage on several types of forestry and horticultural crops. The purpose of this study was to examine the effect of Acacia villosa, Myristica fragrans, Acacia mangium and Calliandra calothyrsus leaf extracts as tannin sources related to the in vitro inhibition of Ceratobasidium ramicola growth. The in vitro inhibition was performed by employing solid potato dextrose agar (PDA) medium to obtain the radial inhibition, while liquid potato dextrose broth (PDB) medium was used to obtain the biomass inhibition. Experimental design was based on in time nested-completely randomized design and statistical analysis was carried out with SAS software version 9.1. The result of radial growth inhibition of Ceratobasidium ramicola showed that tannin extracts of A. mangium and M. Fragrans were not significantly different to each other. Treatment of tannin extracts from A. villosa, M. fragrans, A. mangium and C. Calothyrsus with a concentration of 1% were significantly different with other concentrations and resulted the greatest inhibition values. Tannin extract of A. Mangium at 1% concentration produced the greatest radial inhibition by 33.2%. In most cases, the effective inhibition from tannin extract occurred at the 24h of incubation. The greatest biomass inhibition was produced on 1% tannin extract of A. mangium by 64.3%, while the lowest was produced from 1% tannin extract of M. fragrans by 27.0%.

Morphophysiological responses of Aechmea blanchetiana (Bromeliaceae) to excess copper during in vitro culture

The use of plants as bioindicators can be effective for environmental monitoring, mainly related to heavy metals such as copper (Cu). In vitro conditions are more easily controlled, to enable isolating the stress factors that can interfere in plants’ responses. The aim was to investigate the morphophysiological responses of Aechmea blanchetiana submitted to excess Cu, and to verify the degree of tolerance and potential as a bioindicator of this species. Previously cultured shoots of A. blanchetiana were transferred to agar-solidified MS medium. After 60 days, the tank system was recreated, with the addition of stationary liquid MS medium with different concentrations of Cu (0, 25, 50 and 100 μM). After 90 days with excess Cu, anatomical analysis along with quantification of the contents of nutrients, photosynthetic pigments and chlorophyll a fluorescence were carried out. Alterations in the stomatal density and chlorenchyma thickness were observed in the plants grown with excess Cu. There was an increase in the Cu content in the plants in function of the Cu levels. However, the adjustments in the content of the other nutrients were essential for tolerance to excess Cu. Aechmea blanchetiana tolerates high Cu concentrations and has potential for use as a bioindicator.

Elicitation-Based Method for Increasing the Production of Antioxidant and Bactericidal Phenolic Compounds in Dionaea muscipula J. Ellis Tissue.

The carnivorous plant Dionaea muscipula J. Ellis (Venus flytrap) is a widely known medical herb, capable of producing various phenolic compounds known for their strong antioxidant and antibacterial properties. In the pharmaceutical industry, Venus flytrap is grown in tissue cultures, as the natural population of D. muscipula is very limited. Here, we describe an improved method to increase the quantity and quality of phenolic compounds produced in D. muscipula. This is achieved by combining biotic elicitation (using Cronobacter sakazakii bacteria lysate) of D. muscipula cultured with rotary shaking (hydromechanical stress), which we describe here for the first time. The antibacterial activity and the antioxidant properties of the obtained compounds were studied on two antibiotic-resistant human pathogenic bacteria. The proposed plant culture conditions resulted in an increase in fresh weight, as well as a higher total phenolic content, in comparison to traditional tissue cultures on agar-solidified medium. With the use of high-performance liquid chromatography, we demonstrated that the described elicitation strategy leads to an increased synthesis of myricetin, caffeic acid, ellagic acid and plumbagin in D. muscipula tissue. We also found that a higher level of antioxidant activity, exhibited by the plant extract, corresponded with its higher phenylpropanoid content. The bactericidal activity of the extract against Staphylococcus aureus was dependent on the duration of plant culture under described elicitation conditions, whereas neither elicitation condition (duration or elicitor concentration) seemed relevant for the bactericidal activity of the extract towards Escherichia coli. This suggest that Gram-negative bacteria are less sensitive to compounds derived from Venus flytrap tissue.

The influence of migratory Paraburkholderia on growth and competition of wood-decay fungi

Certain bacteria are capable of migrating along fungal hyphae, using them as a dispersal mechanism to cross otherwise-prohibitory distances. Three strains of fungal-migratory Paraburkholderia were isolated from the mycelium of wood-decay fungi, and inoculated onto ten strains of wood-decay fungi growing on solid agar medium. Two of the three bacteria were able to migrate along the hyphae of all fungi, although to differing extents. No bacteria-associated growth inhibition was observed with eight of the ten fungi, but mycelial extension rate of two strains of Phanerochaete was significantly reduced. Bacteria were also introduced into fungus-fungus competitive pairings, and significantly reduced the competitive performance of one of the Phanerochaete strains. Additionally, in several cases, introducing bacteria into competitive interactions made the outcome unpredictable, whereas in the absence of bacteria one fungus was consistently dominant. This is the first time that bacteria have been shown to influence fungal inter-specific competition.

Differential Microwave Resonator Sensor Reveals Glucose-Dependent Growth Profile of E. coli on Solid Agar

This letter presents a practical application of a differential microstrip microwave sensor for label-free and realtime monitoring of Escherichia coli (E. coli) growth under different nutritional conditions on solid agar media. Two planar microstrip ring resonators coupled with a one-port power divider form the core of the sensing system. The sensing resonator operates at 1.509 GHz with an amplitude of -10.21 dB and the reference resonator operates at 1.798 GHz with an amplitude of -11.75 dB. The growth profile of E. coli at each glucose concentration in Luria-Bertani (LB) agar was derived by measuring the resonant amplitude variations (AA) and is further supported by microscopic images. A complete inhibition of growth was observed at 10% glucose concentration. This research expands the application of microwave sensors to investigate the effect of nutritional parameters on bacterial growth.

The structural and bioactive behaviour of strontium-doped titanium dioxide nanorods

In the present work, various concentrations of strontium ions loaded titanium dioxide nanorods and common titanium dioxide nanorods (control) were synthesized by electrochemical anodization technique to get the implant with superior bioactivity. Cell viability and antibacterial efficacy studies were estimated using MTT assay and solid agar medium. The characterisation results confirmed that Sr2+ was successfully incorporated into TiO2 nanorods. Compared with common TiO2 nanorods (control), Sr2+ loaded TiO2 nanorods showed higher surface roughness, adhesion strength, and water wetting angle. MTT assay showed better cell response on Sr-TiO2 nanorod surface as compared to control and the antibacterial test showed that Sr2+ loaded TiO2 nanorods have superior antibacterial activity against pathogenic bacterial strain E. coli and S. aureus. Sr2+ incorporated TiO2 nanorod arrays can be used as a potential candidate for hard tissue implant applications.

Biochemical control of Alternaria tenuissima infecting post-harvest fig fruit by chickpea vicilin.

Alternaria tenuissima was isolated from infected fig fruit and molecularly identified by rRNA gene sequencing. The objective of the current work was to test the inhibitory effect of vicilin as a glycoprotein, isolated from chickpea, against the fungus A. tenuissima, isolated from fig fruit, in vitro and in situ, to estimate its potential action in controlling the growth of A. tenuissima in postharvest fig fruit. Chickpea vicilin is a glycoprotein composed of three subunits of 135, 210, and 230 kDa. The linear growth of A. tenuissima on the solid agar medium and in liquid media (at 25 °C) was markedly reduced by 44%, 66%, 77%, and 83% and 20%, 24%, 42%, and 62%, respectively in response to vicilin applications of 0.1, 0.2, 0.3, and 0.4 g L-1 . Chickpea vicilin (at 0.4 g L-1 ) totally prevented fungal conidia germination during 24 h of incubation at 25 °C. Electron microscope scanning of A. tenuissima subjected to chickpea vicilin showed hyphae swelling and conidia deformation. Treating post-harvest fig fruit, artificially infected with A. tenuissima, with chickpea vicilin (0.1-0.4 g L-1 ) restricted the disease severity to 15% against 55% in the positive control after 7 days storage. Vicilin can be considered a potent antifungal agent that can be used in preserving fig fruit for 7-14 days with minimum disease severity. © 2020 Society of Chemical Industry.

Synthesis of new magnesium peroxide (MgO2) nano-rods for pollutant dye removal and antibacterial applications

In this literature, magnesium peroxide (MgO2) nanorods with an average Ddiameter = 166 nm have been successfully synthesized via fast and simple microwave assisted hydrothermal reaction for photocatalysis and antibacterial applications, for the first time. The as synthesized MgO2 nanorods are characterized by various techniques like XRD, FTIR, TEM, FE-SEM and BET. The photocatalytic activity of MgO2 nanorods has been studied for methyl orange (MO) degradation, and it is found that MO dye has been degraded after 50 min of the UV illumination. The antibacterial activity of the MgO2 nano-rods in solid agar media has been studied against (G + ve) bacteria and (G -ve) bacteria. The results of antibacterial activity demonstrated that MgO2 nanorods have bacteriostatic efficacy against Bacillus sp and E. coli bacteria. The antibacterial activity of MgO2 nanorods increases with increasing their concentrations in the tested media. Finally, these MgO2 nanomaterials may be used for different electronic nano-devices, photocatalysis reactors and biological applications thanks to their cheap price and easy scaling up.

Candida albicans Agar Invasion Assays.

The ability of the human fungal pathogen Candida albicans to disseminate into tissues is promoted by a switch from budding to invasive hyphal growth. This morphological transition is stimulated by multiple environmental factors that can vary at different sites of infection. To identify genes that promote invasive growth, C. albicans mutants can be screened for defects in growing invasively into solid agar medium as a substitute for studying tissue invasion. This in vitro approach has advantages in that it permits the media conditions to be varied to mimic different host environments. In addition, the concentration of agar can be varied to determine the effects of altering the rigidity of the matrix into which the cells invade, as this provides a better indicator of invasive growth than the ability to form hyphae in a liquid culture. Testing under multiple conditions can be used to identify mutant cells with the strongest defects. Therefore, protocols and media for analyzing invasive growth of C. albicans under different conditions will be described that are appropriate for testing a single strain or high-throughput analysis of a collection of mutant C. albicans strains.

ANALYSIS AND PREVENTION OF RISKS IN THE MANUFACTURE OF LABORATORY MICROBIOLOGICAL CULTURE MEDIA BY FMEA METHOD

At all stages of the production of microbiological nutrient media (MNM), the manufacturer, and in particular, the microbiological laboratories that manufacture the media on site, face many operational risks. The presence of such risks, in almost every critical point of production and further operation of the MNM, is due to the presence of common basic requirements for all MNM, which must be taken into account and respected during their development and preparation; as well as the complexity and laboriousness of the very process of manufacturing high-quality differential-diagnostic and other nutrient media, requiring the availability of all the components necessary for preparing these media, equipment, sterile conditions and qualified personnel. In this regard, there is a need to search for effective methods to identify and prevent undesirable situations associated with the production and use of MNM. The aim of this work was to adapt the risk assessment methodology based on the expert method for analyzing the types and consequences of FMEA failures (Failure Mode Effect Analysis) set out in GOST R ISO 31010-2011 for the needs of microbiological laboratories, including those for veterinary and sanitary expertise, producing microbiological nutrient environments and using them. As part of this work, a comparative analysis of risk assessment methods was carried out in order to select the optimal one; adaptation of the QMS principle - risk-oriented thinking and the FMEA method for risk assessment in the implementation of MNM manufacturing processes in a microbiological laboratory (for example, solid agar media); risk assessment protocol forms were developed; calculations of a quantitative assessment of risk levels were carried out in order to determine the need for preventive actions and their implementation in order to minimize the negative consequences of risk in case of its implementation using the developed protocols. The results showed that this technique can be successfully implemented and used in the claimed area.

Micropropagation of Rosaceous Species SAM Grown in Temperate Climate.

The benefits of in vitro plant cultivation are mainly due to very high multiplication rate. Cultivation of plant material in vitro can be carried out during the whole year regardless of the time of the year or weather conditions. We create artificial conditions in the lab (heat, light, humidity), and we can regulate these conditions at any time. For the preservation of cultivar identity, we recommend establishing in vitro cultures from shoot tips usually larger than 0.2mm. In practice, in vitro cultivation of plants uses these growth regulators to achieve organogenesis, for example, root formation, prolonged growth, or multiplication. During each subculture, these cultures are then transferred on a solid agar medium in the form of actively growing multiple shoots with a well-differentiated shoot tip containing meristematic area. Cytokinins are important for cell division and causes branching of plants. Auxins, both endogenous and exogenous, act at as a trigger for the differentiation and formation of root primordia. Morphological characteristics (formation of leaves or callus) and shoot development should be observed during in vitro multiplication and after transfer to ex vitro conditions.

Biogenic Gold Nanoparticles from Fusarium oxysporum: The Impact of Fungal Morphology and Localization Studies

The synthesis of nanoparticles from biological sources has gained significant attention recently, however, with much emphasis on the novelty of sources. This study aims to provide a comprehensive overview on the aspects of fungal age and type of cultivation on the properties of the nanoparticles. The effect of age of Fusarium oxysporum developed in submerged culture and on solid agar medium was evaluated. When the gold salt solution was added to the fungal colony on agar medium, a deep purple colored radial zone developed in the 3 days old mycelium. The nanoparticles in the radial purple zone had two distinct characteristics when the agar blocks were dried by either lyophilization or heating in a hot air oven. The lyophilized sample contained square bi-pyramidal particles (1 to 2 μm). The oven-dried sample contained abundant truncated triangular nanoplates (150 to 500 nm), decahedrons and icosahedrons (20 to 70 nm), and a few triangular and hexagonal nanoplates (50 nm). The mycelium when suspended in 1 mM HAuCl4·3H2O presented distinct geometries of the nanoparticles in the cytoplasm and periplasm. The formation of gold nanoparticles of different morphologies within the cytoplasm, and the periplasm has implications in Surface Enhanced Raman Spectroscopic (SERS) measurements. HRTEM images of hyphae of Fusarium oxysporum suspended in 1 mM HAuCl4·3H2O for 24 h. The nanoparticles present in the electron dense cytoplasm are markedly different from those in the periplasmic space.

A Label-Free, Non-Intrusive, and Rapid Monitoring of Bacterial Growth on Solid Medium Using Microwave Biosensor.

Microwave resonator sensors are attractive for their contactless and label-free capability of monitoring bacterial growth in liquid media. This paper outlines a new label-free microwave biosensor based on a pair of planar split ring resonators for non-invasive monitoring of bacterial growth on a solid agar media. The sensor is comprised of two split ring resonators with slightly different resonant frequencies for differential operation. The transmission coefficient (S21) of the sensor is considered as the sensor's response with a designed and measured quality factor above 200 to ensure a high-resolution operation of the biosensor. Two resonant frequencies of 1.95 and 2.11 GHz represent the sensing signal and the reference signal, respectively. The developed sensor demonstrates high performance in monitoring the growth dynamics of Escherichia coli (E. coli) on Luria-Bertani (LB) agar with 4 mm thickness. The sensor's resonant amplitude response demonstrated 0.5 dB variation corresponding to the bacterial growth over 48 hours when bacteria were spread on LB agar starting with initial OD600 = 1.5. Moreover, 0.6 dB change in the sensor's response was observed over 96 hours of bacterial growth starting with an initial OD600 = 1.17 spotted on LB agar. The measured results fit well to the curves created using Richards' bacterial growth model, showing the strength of the sensor as a potential candidate for use in predictive food microbiology systems.

Generation of effective zinc-deficient agar-solidified media allows identification of root morphology changes in response to zinc limitation

ABSTRACTEarlier, we demonstrated that transcript levels of METAL TOLERANCE PROTEIN2 (MTP2) and of HEAVY METAL ATPase2 (HMA2) increase strongly in roots of Arabidopsis upon prolonged zinc (Zn) deficiency and respond to shoot physiological Zn status, and not to the local Zn status in roots. This provided evidence for shoot-to-root communication in the acclimation of plants to Zn deficiency. Zn-deficient soils limit both the yield and quality of agricultural crops and can result in clinically relevant nutritional Zn deficiency in human populations. Implementing Zn deficiency during cultivation of the model plant Arabidopsis thaliana on agar-solidified media is difficult because trace element contaminations are present in almost all commercially available agars. Here, we demonstrate root morphological acclimations to Zn deficiency on agar-solidified medium following the effective removal of contaminants. These advancements allow reproducible phenotyping toward understanding fundamental plant responses to deficiencies of Zn and other essential trace elements.

SURVIVAL OF BACTERIA IN A SIMULATION OF SURROUNDING SURFACES OF CONSTRUCTIONS FOR SALT THERAPY

Introduction. Ground constructions for salt therapy, which differ in the composition of minerals and in the modification of therapeutic surfaces, are actively used in Russia and abroad. The abiotic surfaces of these devices are susceptible to microbial contamination, the sources of which are the upper respiratory tract, the skin of patients and medical staff. The aim of the work is to assess the viability of microorganisms on abiotic surfaces identical to the material for the manufacture of salt physiotherapy constructions. Material and methods. 6 and 24 hours after application to abiotic surfaces with different relief there was evaluated the survival rate of reference gram-positive and gram-negative cultures of microorganisms and isolated ones from salt rooms. Viable cells were determined by the method of decimal dilutions in terms of the number of colonies-forming units (CFU). Results. It was found that bacterial cells can preserve at the halite and various surfaces of sylvinite for at least 24 hours. The viability of microorganisms was independent of the ratio of minerals (halite/sylvin) in the samples. The structure of the surface of sylvinite: the largest number of microorganisms was retained on crushed sylvinite (7.98E+02 ± 1.62E+03 CFU/ml was a significant factor for the survival of bacteria. Despite a great survival of staphylococci in comparison with gram-negative opportunistic pathogenic bacteria on all the surfaces studied, no significant differences between the groups were detected. In this case, bacteria isolated from salt structures were more resistant to salt load due to adaptive modification of microorganisms, including increasing the hydrophobicity of the cell wall, increasing their ability to survive. Bacteria grown on a solid agar medium proved to be more tolerant of the conditions of osmotic stress. Conclusion. The obtained data confirm the dependence of the adaptive mechanisms on the environmental conditions and the initial physiological state of cells. The results of studies on the survival of bacteria on salt surfaces of various types indicate their resistance to high concentrations of salts, which raises the question of special methods for treating fences of salt therapy structures.