Classifications

• • A—HUMAN NECESSITIES
  • A01—AGRICULTURE; FORESTRY; ANIMAL HUSBANDRY; HUNTING; TRAPPING; FISHING
  • A01G—HORTICULTURE; CULTIVATION OF VEGETABLES, FLOWERS, RICE, FRUIT, VINES, HOPS OR SEAWEED; FORESTRY; WATERING
  • A01G15/00—Devices or methods for influencing weather conditions

Definitions

• the invention relates to a composition suitable as protection against hail, which leads to the formation of ice crystal nuclei, crystallization centers.
• the clouds in the atmosphere are often in a colloidally unstable state.
• the water droplets forming the cloud are "supercooled", they are still in a liquid (supercooled) state even at temperatures below 0oC.
• the freezing process is facilitated by the presence of foreign particles. However, these particles are only present in the atmosphere in a concentration that is orders of magnitude lower than that in which the condensation of atmospheric water vapor takes place.
• the essence of the microphysical influence is precisely that missing natural crystal nuclei are replaced artificially; If there are too few crystal nuclei, only a few ice crystals form in the critical areas of the cloud, and these cause the formation of hailstones.
• the effectiveness of the artificially produced and brought into the cloud ice crystal forming germs depends to a large extent on their so-called activity threshold temperature.
• This threshold temperature is the highest temperature at which the respective particles can still trigger the phase change of the water drops.
• the best inorganic substance for forming ice crystal nuclei is silver iodide, the threshold temperature of which is -4.5 oC.
• the threshold temperature of the lead iodide used in Hungary to ward off hailstones is approximately -7oC.
• Hail damage can be prevented by the particles scattered into the atmosphere, because the particles increase the number of condensation nuclei and therefore only small, harmless ice granules are formed. These granules of ice melt as they fall through the atmosphere; they only reach the earth in the form of rain.
• the "freezing”, ie crystallizing properties of the most frequently used inorganic reagents are based on the fact that the crystal lattice of these substances is very similar to the crystal lattice of ice.
• the corresponding lattice constants of the ice crystals and the silver iodide crystals hardly differ by 1-2%.
• the difference between the lattice constants of ice and lead iodide is somewhat larger; therefore the lead iodide threshold temperature is below -6oC.
• Lead iodide is used in Hungary in an amount of about 2000 kg annually. This means an average lead iodide contamination of 200-250 g / ha, since the connection with the rainwater reaches the ground together and is then incorporated into plant and animal organisms.
• the object of the invention was to provide a crystal nucleating agent for ice which does not pollute the environment because it degrades naturally within a short time and which also has a threshold temperature and an activity spectrum around 0 ° C.
• bacterial mass obtained from cultures of Pseudomonas syringae, Erwinia herbicola and Pseudomonas fluorescens or mixtures thereof, or the cell membranes isolated therefrom or the supernatant of the culture is excellently suitable as an active ingredient for ice crystal-forming compositions.
• the liquid composition produced from the active ingredients obtained by fermentation can be distributed by spraying in the airspace; solid preparations containing the active ingredients can be applied as pyrotechnic mixtures.
• the liquid composition can be distributed on earth or in an airplane using generators. The former is less expensive; the particles distributed in the airspace reach the cloud level in the frequently occurring vertical air currents.
• the method has the disadvantage that it can only be used under certain meteorological or geographical conditions. It is much easier to get the particles in the right place in the right concentration by plane.
• the solid preparations can be brought to the desired location in the airspace with the aid of pyrotechnic cartridges attached to aircraft.
• the composition according to the invention has the following advantages over the known solutions:
• the microorganisms to be used in the sense of the invention are known. They are deposited in Great Britain under the following numbers: Pseudomonas syringae pv. Syringe van Hall NCPPB 2 507; Erwinia herbicola (Lohnis) dye NCPPB 2 281; Pseudomonas fluorescens migula NCPPB 1 598.
• Pseudomonas syringae, Erwinia herbicola or Pseudomonas fluorescens or mixtures of these bacteria in a number of 10-10 6 / ml are inoculated in nutrient solution which is sterilized in a manner known per se.
• the culture is fermented at 20-30 ° C for 24-36 hours.
• the bacterial mass is separated from the liquid supernatant.
• the bacterial mass can be diluted with 50-100 mass% of a 0.1-2 mass percent buffer solution, preferably an alkali dihydrogen phosphate with a pH of 6.5-7, and then with Be treated with ultrasound.
• the disrupted cells are dewatered, preferably by lyophilization.
• the bacterial mass can also be stirred with a glucose solution with a concentration of 10-80 mass% and the active substance can then be separated off by centrifugation or by chromatography.
• the bacterial mass can also be treated with ultrasound and the undestroyed cells separated by centrifugation with 20,000 to 40,000 g; the cell membranes obtained in this way are washed and then separated from the washing liquid.
• composition according to the invention preferably contains the active ingredient in concentrations of 0.001-95% by mass, in particular 0.5-90% by mass, in addition liquid carriers and extenders, preferably 0.1-1% by mass alkali metal chloride solution or 0.1-2% by mass alkali metal hydrogen phosphate solution , or solid supports, preferably silica, silica gel, zeolite or polymers. Culture media of known composition or nutrient solutions with special additives can be used to cultivate the bacteria.
• DIFCO Nutrient, pH 7.1
• the deposited bacterial mass (25 g / l culture) is taken up in 25 ml of 20 mM phosphate buffer (KH 2 PO 4 , pH 7.0). Both the bacterial mass and the cell-free supernatant are used to produce the composition which forms ice crystal nuclei according to the invention.
• Example 3 The procedure described in Example 1 is followed, with the difference that the nutrient medium is inoculated with Pseudomonas fluorescens.
• Example 4 The procedure described in Example 1 is followed, with the difference that the nutrient medium is inoculated with Pseudomonas fluorescens.
• Bacterial mass produced according to example 1 is treated with ultrasound (power of the device: 250 W).
• the duration of the treatment is 20 seconds, followed by a 20 second break, followed by another 20 seconds of sound, ten times in total.
• the vessel is cooled with ice water from the outside because heating the material can damage the organic substances.
• the suspension containing the disrupted cells is poured into a round bottom flask and cooled with liquid air in a New Brunswick brand and lyophilized at +4 ° C. and 2.6 kPa (20 torr) pressure.
• a series of dilutions is made from the lyophilisate with 10 mM phosphate buffer in the range from 0.05 to 3 mg / l.
• the samples and also 0.5 ml of buffer are placed in the tubes of an Ependorf centrifuge. The
• the bacterial mass prepared according to Example 1 is diluted 1: 1 at room temperature with a two molar glucose solution and homogenized for 25-30 minutes.
• the solid substance is centrifuged off and the centrifugate on a DEAE Sephadex
• Example 6 Having concentration corresponds to the NaCl content of the test solutions.
• the test solutions freeze at -5.8 to -6.0 ° C, while the controls freeze at -9.8 to -12.3 ° C.
• the experiment shows that the substance treated with glucose is able to form crystal nuclei.
• Example 4 The procedure is as described in Example 4, but the method of Example 2 is used Bacteria mass. The results of the freeze tests agree with the exercises described in Example 4.
• Example 5 The procedure described in Example 5 is followed, except that the one prepared according to Example 3 is used
• the cell membrane is isolated from the bacterial mass prepared in accordance with Example 1 in order to determine whether or not the cell membrane has a nucleating effect.
• the mass isolated from 3 liters of culture liquid is suspended in 80 ml of 10 mM phosphate buffer (pH 7.0) containing 0.14 mass% of mercaptoethanol.
• the cells are treated with ultrasound (power of the device: 250 W) for 30 seconds. After a minute's break, the treatment is repeated, a total of fifteen times. The digestion is about 70%.
• the undestroyed cells are centrifuged at 1500 g. The supernatant is at 0 ° C with 30 000 g
• Example 9 Centrifuge for 40 minutes. The sediment containing the cell membranes is washed twice with the phosphate buffer mentioned, then centrifuged and finally suspended in the buffer. After determining the solids content, a series of dilutions is prepared from the substance according to Example 4. Each link in this row freezes between -4.0 and -4.3 ° C under the conditions described in Example 4. The 10 mM phosphate buffer used as a control freezes at -10.8 ° C. Example 9
• Example 10 The liquid supernatant, which is obtained by centrifuging off the bacterial mass prepared according to Example 1, is lyophilized in the manner described there. The white powder obtained is weighed. Then, according to Example 4, a series of dilutions prepares. All links in the dilution series freeze at -4.2 ° C. Culture medium and the lyophilized supernatant of a culture of Pseudomonas syringae ice- are used as controls (this manipulated Pseudomonas does not cause frost damage); the controls freeze at -10.2oC and -10.3oC, respectively. The experiment proves that the supernatant also contains substances that form crystal nuclei of the ice. Example 10 The supernatant of those obtained in Example 2
• a sprayable formulation is produced from the moist bacterial mass prepared according to Example 1.
• 0.01 kg of the bacterial mass is mixed with 1 kg of 0.1% NaCl solution.
• the liquid mixture is sprayed.
• Example 12 In a stirrer, 0.5 kg of the bacterial mass obtained according to Example 2 is mixed with 0.1 kg 0.1% NaCl solution.
• the mixture is mixed with 0.5 kg of Aerosil (SiO 2 ), then homogenized and finally dried at room temperature.
• the Preparation can be delayed by pyrotechnic means in the air.
• Example 12 The procedure is as described in Example 12, but 0.7 kg of synthetic zeolite is used as the solid filler. This preparation can also be applied pyrotechnically.
• Example 11 The procedure is as described in Example 11, but the mass of bacteria is mixed with 2 kg of 50% by weight aqueous cellulose acetate solution.
• Solutions of a concentration of 0.1, 0.2 or 1.0 g / 1 are prepared from the bacterial mass isolated according to Example 1 with 0.1% NaCl solution by weight. Droplets with an average diameter of 1.2 mm are formed from these solutions.
• the freezing properties of the droplets are studied in a diffusion chamber. In the chamber, the droplets are applied to a surface cooled with Peltier elements and treated with silicone grease. The temperature of the surface, which because of the considerable difference in mass essentially corresponds to the temperature of the drops, is measured with a platinum resistance thermometer and read off from a digital display with an accuracy of 0.1 degrees.
• the cooling rate of the chamber and thus that of the drops can be regulated. In the range below 0 oC, which is important for the measurement, the cooling rate can be regulated within the range of 1-3 degrees / min.
• the temperature t 50 is measured, ie the temperature at which half of the drops are frozen. This temperature is lower for the three samples different concentrations at -3.2 oC, -3.6 oC and
• a NaCl solution with a concentration of 0.1 g / l is prepared as a control with distilled water. Half of the 4 mm diameter drops formed from this solution are frozen at -12 ° C. The entire freezing process starts at -10 ° C and ends at -14 ° C.
• the composition according to the invention accordingly causes an increase in melting point of approximately 10 ° C.
• a solution with a concentration of 0.1 g / l is prepared from the bacterial mass according to Example 1 using NaCl solution with a concentration of 0.1% by mass.
• a dispersion of 0.1 g / l concentration is prepared from silver iodide and 0.1% NaCl solution.
• the freezing behavior of the batches is investigated in the diffusion chamber described in Example 15.
• the cooling rate used is 2 degrees / min in the range below 0 ° C. Drops of an average size of 1.2 mm are applied to the cooling surface.
• the t 50 temperatures were: composition according to the invention -3.2 ° C, silver iodide: -4.9 ° C.
• the experiment shows that the threshold temperature of the compositio ⁇ invention is closer to 0 ° C, that is, the composition rather prevents hypothermia.

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• Life Sciences & Earth Sciences (AREA)
• Atmospheric Sciences (AREA)
• Environmental Sciences (AREA)
• Micro-Organisms Or Cultivation Processes Thereof (AREA)
• Preparation Of Compounds By Using Micro-Organisms (AREA)

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• 1985
  • 1985-10-23 HU HU408085A patent/HU192370B/hu unknown
• 1986
  • 1986-10-21 JP JP61505654A patent/JPS63501643A/ja active Pending
  • 1986-10-21 EP EP19860906422 patent/EP0243437A1/de not_active Withdrawn
  • 1986-10-21 WO PCT/HU1986/000055 patent/WO1987002691A1/de not_active Ceased
  • 1986-10-21 YU YU179786A patent/YU45801B/sh unknown
  • 1986-10-22 CS CS764186A patent/CS273622B2/cs unknown
• 1987
  • 1987-06-19 SU SU874202765A patent/SU1593574A3/ru active

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