Measurement report: Ice nucleating particles active ≥ −15 °C in free tropospheric air over western Europe

Ice nucleating particles (INP) initiate ice formation in supercooled clouds, typically starting at a few km above ground. However, little is known about the concentration and composition of INP in the lower free troposphere (FT). Here, we analysed INP active at −10 °C (INP−10) and −15 °C (INP−15) collected during FT conditions at the high-altitude observatory Jungfraujoch. We relied on continuous radon measurements to distinguish FT conditions from those influenced by the planetary boundary layer. Median concentrations in the FT were 2.4 INP−10 m−3 and 9.8 INP−15 m−3, with a multiplicative standard deviation of 2.0 and 1.6, respectively. A majority of INP was deactivated after exposure to 60 °C, thus probably originated from certain epiphytic bacteria or fungi. Subsequent heating to 95 °C deactivated another 15 % to 20 % of the initial INP, likely other types of fungal INP that might be associated with soil organic matter or with decaying leaves. Very few INP−10 withstood heating to 95 °C, but on average 20 % of INP−15 in FT samples did so. This percentage doubled during Saharan dust intrusions, which had practically no influence on INP−10. Overall, the results suggest that aerosolised epiphytic microorganisms, or parts thereof, are responsible for the majority of primary ice formation in moderately supercooled clouds above western Europe.

General characteristics and taxonomic composition of epiphytic microflora of plants

Main problem: Microbial-plant relationships, including epiphytic microflora, are the subject of attention of many scientists. Numerous works confirm the high interest of researchers and the relevance of studying this topic. Despite many years of research, some questions concerning the characteristics of the epiphytic microflora still remain open. It is already a well-known fact that the epiphytic microflora is directly related to the physiological development of the plant, including yield. This is due to the close interaction of the plant with the microorganisms living on its surface throughout the entire growing season. It is also proved that epiphytic microflora has the ability to change characteristics under the influence of environmental factors (temperature, humidity, soil contamination, sunlight, etc.). In this regard, the study of this topic is one of the important areas of biological and agricultural sciences and is of high importance. It should be noted that a significant role in the development of agriculture in the Republic of Kazakhstan and the Pavlodar region is played by representatives of vegetable crops, including tomatoes and potatoes belonging to the Solanaceae family, which indicates the high importance of the plants selected for the study. The combination of the above arguments determines the need to study the epiphytic microflora of plants and establish the regularities of its influence on the adaptive properties of the studied plants of the Solanaceae family, as well as on their productivity. In turn, the study of epiphytic microflora can also contribute to the search for new ways to increase the yield of plants and their resistance to various diseases. Purpose: The article is devoted to the study of the properties and characteristics of the epiphytic microflora of the surface of various organs of plants of the Solanaceae family (on the example of tomato and potato). The variability of the composition and number of epiphytic microorganisms in seasonal dynamics is shown. Methods: bacterioscopic method, fingerprint method, flushing method, Gram staining method. Results and their significance: The characteristics and properties of representatives of epiphytic microorganisms of aboveground (leaf, fruit, flower) and underground (potato fruit) plant organs were studied. The role of the influence of environmental factors on the variability of epiphytic microflora is determined on the example of plants Lycopersicon esculentum Mill. (common tomato) and Solanum tuberosum L. (tuberous nightshade). The differences in the microflora of different plant organs in different periods of vegetation are shown.

Characteristics of epiphytic microorganisms of wheat plants antagonists of phytopathogenic fungi

Epiphytic microbiological complex of the surface of spring wheat plants of the Saratov 70 variety was studied. Among of the selected epiphyte cultures, strains of fungicide producers were screened for the genera Alternaria, Aspergillus and Fusarium.

A New RoVe Method to Purify Endophytic Fungi from Medicinal Plants Western Ghats of Karnataka India

Endophytic fungi from medicinal plants were hardly ever reported as compared to those from soil and marine sources. The present results associate the presence of endophytic fungi in medicinal plants by isolating them from three medicinal plants i.e. Bombax ceiba, Aloe vera, and Ximenia americana. In the present research investigation, surface sterilization method and media were standardized, and 32 endophytic fungi were isolated from three medicinal plants. We assessed the competence of three different surface sterilization methods and four media for isolation of endophytic fungi. The RoVe method used was more effective in eliminating epiphytic microorganisms. Therefore by using new method we have isolated total of 32 fungal endophytes and those were belongs to Aspergillus nomius (63.20%), Aspergillus niger (41.60%), Thielaviopsis basicola (38.33%), Fusarium oxysporum (33.20%), Pestalotiopsis inflexa (27.20%), Nigrospora sphaerica (20%), Alternaria alternata (15.30%) and Phomopsis archeri (20%). This is the first report of successful isolation of endophytic fungi from the said medicinal plants, for using newly formulated surface sterilization method.

AN EFFECT OF STORAGE AND TRANSPORTATION TEMPERATURE ON QUANTITATIVE AND QUALITATIVE COMPOSITION OF MICROFLORA OF PLANT PRODUCTS

The results of the study on changes in the composition and quantity of epiphytic and endophytic microorganisms of plant products during storage and transportation are presented. For the investigation, the authors took apple fruits and leafy spicy green products that had biological peculiarities and allowed investigating processes of the long-term and short-term main stages (cold storage, transportation by refrigerated transport, presales storage) of the continuous cold chain on the way to a consumer. Apple fruits were placed in storage in cold chambers with the temperature regimes of plus (2–3)°C and minus (1–2)°C, where they were stored for 90 days. The vegetative organs of dill and parsley were transported during 8 hours by a refrigerated truck and placed in the commercial refrigeration equipment at two temperature regimes (4–5) C and (0–1) C for 72 hours for presales storage. The results of the microbiological analysis showed that the number of endophytic microorganisms (bacteria, yeasts and molds) was lower by 1–3 orders of magnitude in apple fruits and by 2–3 times in green vegetables compared to the number of epiphytic microorganisms. It was established that the regime of storage at negative temperatures completely inhibited the development of epiphytic bacteria on fruits, significantly delayed the multiplication of epiphytic yeasts and molds; while at a positive temperature the number of bacteria increased approximately by 10–17 times, yeasts by 180 times and molds by 3 times. The dynamics of changes in the number of endophytic microorganisms during storage showed the same trend that was observed for epiphytic microorganisms. Analysis of the microbial quantity after transportation of green products showed an increase in abundance of the revealed groups of epiphytes and endophytes by 1.5–3 times upon absolute prevalence of bacteria. After short-term storage, a significant growth of the revealed microbial groups was found; with that, their quantity was 1.5–6.5 times higher at (4–5) C than at (0–1) C. The authors experimentally confirmed the conclusion that with respect to reduction of losses due to microbiological spoilage and extension of shelf life, the cold storage regime of the studied plant products at near-zero temperatures is preferable compared to the regimes of storage at higher positive temperatures.