Composition of isolated microorganisms and their use

Abstract

In a first aspect, the present invention relates to a composition of isolated microorganisms, wherein these are in the form of viable microorganisms of the following genera: Microcoleus, Nostoc, Scytonema. That is to say, the mixture comprises at least cyanobacteria, preferably as a mixture with microalgae. In a further aspect, the invention relates to a method for improving soils, comprising the application of the composition of isolated microorganisms according to the invention, in particular a method for improving the soil crust. Finally, the present invention relates to the use of the composition of isolated microorganisms according to the invention for improving soils, in particular for the (re)formation and improvement of soil crusts.

Description

In a first aspect, the present invention relates to a composition of isolated microorganisms which are in the form of viable microorganisms of the following genera: Microcleus, Nostoc, Scytonema. That is, the mixture comprises at least the cyanobacteria mentioned, preferably as a mixture with microalgae. In a further aspect, the invention relates to a method for improving soils, comprising applying the composition according to the invention of isolated microorganisms, in particular a method for improving the soil crust. Finally, the present invention is directed to the use of the composition of isolated microorganisms according to the invention for improving soils, in particular for reforming and improving soil crusts.Prior ArtBiological soil crusts are a complex community of photosynthetically active microorganisms including heterotrophic fungi, protozoa and bacteria as well as mosses and lichens forming the top layer of the soil. These organism community, in conjunction with soil particles and various proportions of extracellular polymers produced by these microorganisms, such as extracellularly deposited polysaccharides, form a micro-ecosystem whose ecological function is of importance above all in the pioneering of soils not covered or degraded by vegetation. Degraded soils are understood to mean that the soils can fulfil their ecosystem capacities to a certain extent or no longer at all. Soil degradation is understood to mean a deterioration of the ecosystem capacities of the soil, until their total loss. This floor crust, which can be understood as a three component system of microorganisms, earth particles and extracellular polymer matrix produced by these microorganisms, covers the floor surface as a continuous layer and usually has a thickness of a few millimeters. The soil crusts are given various important meanings and functions, such as nitrogen fixation, carbon fixation, water retention, stabilization of the soil particles and the provision of available nutrients for plants. Apart from in the tropical zones, soil crusts occur worldwide and different types of soil crusts can be differentiated on the basis of temperature, relative atmospheric humidity, sun intensity and the extent of deposition, it also being possible here to differentiate between the development of the soil crust and the subsequent processes. Thus, classification by Benap, et al., 2003 (Benap, J. and O. Lange (eds.) (2003) "Biological Soil Crystals: Structure, Function and Management" Ecological Studies 150, Analysis and Synthesis, Springer-Verlag Berlin Heidelberg GmbH), into various types: i) smooth soil crusts, ii) rough soil crusts, iii) rolling and spikey soil crusts) takes place. Furthermore, a distinction is often made between algae-fungus-dominated; light and dark algae-dominated crusts; lichens crusts, green algae lichens and cyanobacteria lichens-dominated crusts; and moss and moss lichens crusts.Biological soil encrustations can occur in climate zones on all types of soil. However, they are of particular importance in areas of low biological productivity due to extreme environmental conditions such as cold, heat or dryness. Especially in arid areas such as deserts, biological soil crusts are of great importance for the water balance, the coal blast and nitrogen circulation and as a basis for the further development and colonization of soils. Soil crusts can, by changing the soil surface on raw soils, accelerate and facilitate the colonization of the soils by vascular plants. The floor crusts are developed over various stages up to the floor crust with microorganisms, mosses and / or lichens. Soil crusts are important for various aspects, as already mentioned above. In particular, they increase the humidity of the soils to improve the colonization of mosses and lichens and, at a later time, of the vascular plants. They reduce soil erosion and thus the plugging and splashing of soils. They are therefore of particular importance in the arid fields.Various approaches for establishing soil crusts are described, in order in particular also to prevent the imminent reduction or degradation of the soil crust by the change in climate. An overview of biological soil crusts can be found, for example, in Antoninka A., et al., 2020, Restoration Ecology, 28 (S2, S3 to S8).In general, attempts are made either to form or to strengthen the floor crust by introducing solid constituents into the floor. In addition, various methods for restoring biological soil crusts are described, such as inoculation methods of the liquid or solid type or so-called mosaic methods.Various compositions for the formation of biological soil crusts have already been described in the literature. Thus, for example, Wu et al. (2013) (Wu, Y., et.al.;(2013), Plant Soil 370:115-124) or Peng et al. (2017) (Peng, C., et al., (2017) Journal of Applied Physiology, DOI 10.1007 / s10811-017-1061-2) describe inoculation with only 2 species: Microcleus vaginatus and Scytonema javanicum, in Wu et al. (2013) without specifying the mass ratio, in Peng 2017, the two species were used in a ratio of 4:3, but here only in Petri dishes in the laboratory, not in the field. Wang et al. (2013) specify a ratio of Microcoleus vaginateusand Scytonema javanicumof 10:1; the mixture was tested in a field experiment from 2003 to 2006 (Wang, W., et al. (2013) "Feasibility of cyanobacterial inoculation for biological soil crystals formation in dessert area" Soil Biology & Biochemistry 41: 926-929.)Hitherto, attempts have usually been made to form the soil crusts by local isolates of mixed cultures of natural soil crusts, and this is summarized in Lababpour (2016) (Lababpour, 2016, Int. J. Environm. Sci. Technol. 13:2521-2532) using mixed taxa for inoculation in most published studies.However, there is still a need to provide suitably suitable inocculates for the formation of biological soil crusts, which permits a rapid and progressive formation of the soil crusts with subsequent lichensation and / or moss colonization or other higher vegetation.Brief Description of the Present InventionIn a first aspect, in order to solve the above-mentioned problems, an isolated microorganism composition is provided which is particularly suitable for soil improvement by formation of soil crusts. This composition according to the invention comprises viable microorganisms of the following cyanobacteria genera: Microcleus, Nostoc, Scytonema. In one embodiment, the isolated microorganism composition of the invention further comprises green algae of the genus Klebsormidium.It has been found that the composition according to the invention permits effective formation of biological floor crusts and enables planar distribution on the floor surface. The composition according to the invention is one which is generally suitable for many different types of soil and continents.In a further aspect of the present invention, the use of the composition according to the invention of isolated microorganisms for improving the soil, in particular for building up soil crusts, is described.Finally, methods for improving soil crusts, in particular for building up and improving the soil crust, by application by incorporating a composition according to the invention of isolated microorganisms, are described.Brief Descriptions of the FiguresFigure 1a shows a gel-like polymer matrix in incident light microscope (magnification 4 times) formed by K. flaccidum on degraded soil of Burkina Faso. FIGS. 1 band 1 c show corresponding bottoms in reflected-light micrographs (magnified 4-fold). In Figure 1b, microorganisms of the species Microcleus, Nostoc, Scytonema and Scenedesmus were applied to the soil one day after application of K. flaccidum. Figure 1c is the control with application of said species without previous treatment with K. flaccidum. FIG. 2a shows the induction of the biological soil crust on soil from Burkina Faso with different degrees of decoration by inoculating the mix shown in Table 1 without the endemic isolates and rhizobacteria. FIG. 2 bshows the chlorophyll A contents determined after six months of the formulations shown in FIG. 2 a, wherein the individual test areas before and after treatment and the control are shown. FIG. 3 shows the effect of the additive calcite on the formation of the floor crust. FIG. 4 ashows the test areas in the field test 11 months after treatment, wherein the test areas 3 to 1 are shown with increasing degree of soil decoration.In Figure 4b, corresponding chlorophyll A determinations are made in the test areas before and after treatment. Figure 4c finally shows the total number of phototrophic colonies in the corresponding test areas before and after treatment.DETAILED DESCRIPTION OF THE PRESENT INVENTIONIn a first aspect, there is provided an isolated microorganism composition, particularly for soil improvement, comprising viable microorganisms of the following genera: a. Microcleus; b. Nostoc; c. Scytonema.This composition containing different species of cyanobacteria makes it possible to form biological floor crusts in different, climatically different areas. Depending on the target sites, different species of the same genus may be part of the composition. In particular, it is found that the selected genera of the microorganisms support each other reciprocally, e.g. with respect to sunscreen or the like.The term "isolated" as used herein describes that the microorganisms are not present as such a composition in natural environment, but are isolatedly mixed together.The term "viable" refers to the property of the microorganisms that they are present in the composition such that, after inoculation under suitable conditions, the microorganisms grow, in particular proliferate.The expression "soil improvement" or "improvement of the soil crust" is understood to mean that at least one of the following properties is improved in the soil introduced: a mechanical stabilization against wind and water erosion; an increase in water retention compared to soils not inoculated; an increase in the soil moisture, an increase in the organic C content in the soil, CO 2 fixation, an increase in the nitrogen content in the soil.In one embodiment, the isolated microorganism composition of the invention further comprises viable microorganisms of the genus Klebsormidium. It has been shown that these microalgae promote particularly well the growth and formation of the biological floor crust. In particular, this genus assists the planar spread on the soil surface by enhanced production of extracellular matrix in order to improve the binding of the soil particles and the further microorganisms. This positive effect has become evident particularly in soil textures with smaller particle size and low porosity. This enables the desired properties of water retention and mechanical stabilization against wind and water erosion and also the level of the floor moisture to be increased.Suitable types of Klebsormidiuminclude: flaccidum, sp.In one embodiment, the microorganisms of the genus Microcleus are those of the species steenstrupii, vagantus, chtonoplasts, sociatus.In one embodiment, the microorganisms of the genus Nostoc are those of the genus commune, punctiforme.In a further embodiment, the microorganisms of the Scytonema according to the invention are those of the type javanicum, hyainum, myochroous.In a further aspect, the composition according to the invention is one which comprises the still viable microorganisms of the genus Scenedesmus and / or Chlorella. These genera are green microalgae which in particular promote carbon fixation and have a high specific growth rate.Suitable species of the genus Scedesmus are, for example, Scedesmus vacuolatus. Suitable species of the genus Chlorella are, for example, Chlorella vulgarisor Chlorella ohadii.Furthermore, endemic isolates of viable microorganisms may also be present in the isolated microorganism composition of the invention. That is, these endemic isolates of viable microorganisms are isolates from soils representative of the environmental conditions of the target area to be treated. These allow to increase the biodiversity and the success of growing the floor crust to be formed. The endemic isolates have as high a number of different species as possible, usually endemic / local phototrophic species of microalgae and cyanobacteria, but also contain isolated rhizobacteria as nonphototrophic species. It is preferred that this local species has at least a 1% by weight proportion in the composition. These isolated endemic microorganisms, the phototrophic species of microalgae and cyanobacteria, and nonphototrophic species of rhizobacteria, improve the biodiversity and development of the soil crust as well as their adaptation to the environmental conditions.In one embodiment, the composition comprises at least 20 species of different isolated microorganisms.The composition according to the invention of isolated microorganisms can be present in various ways. Suitable compositions include those which are present as dried, usually particulate, mixtures. Lyophilized compositions are possible according to the invention. In addition, the compositions can be provided in liquid form, for example as a suspension of a wide variety of solid liquids. Furthermore, encapsulated forms of liquid or solid compositions according to the invention are possible. Thus, a suspension of microorganisms and medium may be present in suitable encapsulated form. The encapsulation may be, for example, a gel-like encapsulation, such as of alginate. Usually, the capsule materials are biodegradable materials.In a further embodiment, the composition of the isolated microorganisms is one which further comprises further components, additives, in particular additives or auxiliaries, such as biocompatible auxiliaries. Furthermore, the composition can contain additives, such as nutrients or media constituents. To improve the growth and formation of the floor crust, growth accelerators are possible as additives, but also fillers, such as clay. In addition biopolymers such as carboxymethylcellulose or alginates may be used. Optionally, the fillers or auxiliaries used may also be ground seed shells. These increase, for example, water retention and soil moisture. Sodium alginates as additive increase water retention and soil moisture, the alginate may be in particulate form in the mixture. Alternatively, the alginate can also be used to encapsulate the composition.Further additives also include plant seeds of grasses or the like. - If the composition according to the invention is present in encapsulated form, this can be stored easily with high storage stability over a relatively long period of time and incorporated or applied to the raw soil.For example, should the composition be in suspension, calcite CaCO 3 may be used as an adjuvant to increase mechanical stability.The skilled person is familiar with suitable auxiliaries, in particular biocompatible auxiliaries, in particular for improving the shelf life and processability of the composition of the compositions according to the invention, but also as auxiliaries in the production of the compositions according to the invention in the desired administration form.The isolated microorganism composition of the invention, in one embodiment, comprises the endemic isolates of viable microorganisms at a mass fraction of at least 1%, such as at least 2%, and at most 15%, by mass, based on wet biomass. In one embodiment, the isolated microorganism composition of the invention comprises the endemic isolates of viable microorganisms at a mass fraction of 2% to 10%, such as 4% to 6%.The genus Klebsormidium is preferably present in a range from 20% to 40%, such as 25% to 35%, for example 30% by weight (w / w, weight per weight) based on moist biomass (cell wet weight).The genus Microcleus is present, for example, in a range from 35% to 55% by weight, based on moist biomass. The microorganisms of the genera Nostoc, Scytonemaand Scedesmusare in one embodiment present in the range of 4% to 15%, such as 5% to 10%, e.g. 7% by weight, based on moist biomass. The same applies to the genus Chlorella, which can likewise be present in the total composition in the corresponding mass fractions of 4% to 15%, such as 5% to 10%, for example 7% mass fraction, based on moist biomass, instead of the genus Scenedesmus.The total proportions of the respective species are correspondingly chosen such that the total mass makes up 100% mass proportion of the moist biomass. In addition to this 100% total mass, additives, including biocompatible auxiliaries, nutrients and fillers, but also biopolymers, can also be present.The isolated microorganism composition of the present invention may be provided as a composition. Alternatively, the composition may also be provided in several parts which are mixed together before use of the composition according to the invention to obtain an overall mix. If appropriate, suitable means for finishing the composition to be applied, for example dispersants, thick liquids, can also be used for producing the suspension to be applied, etc.Moreover, the isolated microorganisms can be stored as individual isolated microorganisms in separate storage devices to be then mixed together depending on the manner of application.The individual storage of the individual isolated microorganisms furthermore makes it possible to use individual mass fractions of the microorganisms on site in the composition according to the invention and optionally to provide, for example, a master mix with the microorganisms of the genus Microcleus, Nostoc and Scytonema, optionally also having microorganisms of the genus Klebsormidium and of the genus Scenedesmus or Chlorella, which are then mixed in the field of application with the endemic isolates before application.This master mix or standard mix correspondingly comprises the non-endemic isolates in one embodiment.The mass proportions of the respective genera of the microorganisms may be varied in the total composition to change desired properties and functions, for example, to improve nitrogen fixation, water retention or the like. For this purpose, the proportions of the microorganisms which are particularly suitable for this purpose are increased or the mass proportions of the others are decreased.The composition of the isolated microorganisms according to the invention can therefore be provided as a modular unit with in each case the individual isolated microorganisms set for producing the composition according to the invention.It is also possible that one part of the composition is present in liquid form, while another part is present in solid form and both are mixed with one another before use.In a further aspect, the present invention relates to the use of the composition according to the invention of isolated microorganisms for improving soil, as detailed and further illustrated in the examples below, the composition according to the invention allows the formation of soil crusts on raw soils and the development of soil crusts to be promoted. In particular, the use of the composition according to the invention of isolated microorganisms enables the task and functions of biocrusting to be established or improved, these including: mechanical stabilization against wind and water erosion; increase in water retention compared to uncovered soil; increase in soil moisture; increase in the organic C content in the soil by CO 2- fixation; and increase in the nitrogen content in the soil. In particular, therefore, the use of the composition according to the invention for improving soil encrustations is envisaged. The term "improvement of soil crusts" includes that the soil crust is also newly formed, for example on raw soils, and further the development of the bioruscrustings, wherein the use according to the invention can accelerate the formation of the bioruscrus.Finally, the present invention describes a method for improving soils, in particular raw soils without biocrusting. The method comprises the step of applying and / or introducing a composition according to the invention of isolated microorganisms onto the soil and / or into the soil. The composition according to the invention can be incorporated or inoculated onto and / or into the soils by customary methods. The application and / or introduction can take place here as a liquid composition or as a solid composition or else mixed, a part liquid, a part solid. Suitable methods for application and / or introduction are known to the skilled person. In one embodiment, it is a method of applying the composition of the invention. The method is in particular one for improving the floor crust or for forming and accelerating development and accelerated formation of floor crust.The application and / or introduction can be effected in an amount of 5 to 1000 g / m 2 such as in an amount of 10 to 500 g / m 2, e.g. 40 to 300 g / m 2, in particular in a range of 100 to 200 g / m 2 based on the wet biomass.Furthermore, the additives or auxiliaries can be introduced and / or added accordingly. The additives can be added in amounts of 1 to 1000 g / m 2, such as in an amount of 5 to 500 g / m 2, e.g. 15 to 300 g / m 2, in particular in a range of 25 to 100 g / m 2.The application and / or introduction can be effected in such a way that the composition as a whole is applied and / or introduced, or that individual components of the composition are applied and / or introduced, for example offset in time. In one embodiment, microorganisms of the genus Klebsomodum, for example, are introduced and / or introduced and the further microorganisms of the composition are then introduced at a later point in time.The additives or auxiliaries can be introduced and / or introduced separately. This can take place before and / or after application and / or introduction of the composition.The present subject matter is further illustrated by means of examples, without being limited thereto.Example:A composition according to the invention is shown, for example, in Table 1:1Kleb'sormidium flaccidumor Kleb'sormidium sp.30%2Microcleus steenstrupii or Microcleus vaginatus or Microcleus chtonoplasts45%3Nostoc commune or Nostoc punctiforme7%4Scytonema javanicum or Scytonema hyalineum7%5aaScenedesmus vacuolalus7%5bbChlorella vulgaris(such as 5a)or Chlorella ohadii6Endemic isolations (cyanobacteria, microalgae) and rhizobacteria (see Table 2)4% (min. 1%)7Mineral salts (media constituents as remainder of biomass production)< 1%8Additives such as Na alginate, calcite CaCO 3, fillers etc.Optionally, the method is further further optionallyThe endemic isolations listed in Table 1 are presented in Table 2 below:1Klebsormidium flaccidumMA, filamentous source: SAG; SAG 23072Microcleus steenstruppiiCB, filamentous source: SAG; SAG 22123Nostoc communeCB, source: SAG; SAG 1453-34Scytonema javanicumCB, filamentous source: SAG; SAG 39.905Scenedesmus vacuolalusMA, single source: SAG; SAG211-11 m6Chlorella sp. ArM0029BMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso7Chlorella sorokinianaMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso8Auxenochlorella pyrenoidosaMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso9Ettlia oleoabundansMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso10Chlorella vulgarisMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso11Chlorella variabilisMA mixed culture, isolation 4, source: local soil crust, Koudougou, Burkina Faso12Desmonostoc PCC-7422CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso13Nostoc PCC-7107CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso14Tolypotrix PCC-7601CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso15Nostocaceae cyanobacterium CENA369CB Mixed Culture, Isolation 6,Source: local soil crust, Koudougou, Burkina Faso16Fischerella CENA298,CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso17Nostoc ellipsospora CCAP 1453 / .2CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso18Notoc PCC-73102CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso19Nostoc punctiforme SAG 60.79CB mixed culture, isolation 6, source: local scale, Koudougou, Burkina Faso20Chloromonas perforataMA / RB mixed culture, isolation 7, also in isolation 8 source: local soil crust, Koudougou, Burkina Faso21Dunaliella tertiolectaMA / RB mixed culture, isolation 7, also in isolation 8 source: local soil crust, Koudougou, Burkina Faso22Rhizobium halotoleransMA / RB mixed culture, isolation 7 source: local soil crust, Koudougou, Burkina Faso23Rhizobiales, Beijerinckiaceae uncuulated, uncuulated bacteriumAs yet, not certain local RB species of mixed MA / RB culture, isolation 7 source: local soil crust, Koudougou, Burkina Faso24Chlorogonium capillatumMA mixed culture, isolation 8 source: local soil crust, Koudougou, Burkina Faso25Chlorella sp. SUN-2MA mixed culture, isolation 8 source: local soil crust, Koudougou, Burkina Faso26Chlorella sp. SUN-3MA mixed culture, isolation 8 source: local soil crust, Koudougou, Burkina Faso27Coelastrella sp. M60MA mixed culture, isolation 8 source: local soil crust, Koudougou, Burkina FasoSeries of Experiments 1:Functionality Klebsormidium flaccidum:In a first batch, K. flaccidumwas applied in an amount of 60 g / m 2 to degraded soil of Burkina Faso and developed for one day at 30° C. (incubation conditions: T=30° C., photon flux density of 100 μE / (m 2 s) in the day-night rhythm 12 h / 12 h).Figure 1a shows the formation of gel-like polymer matrix after incubation with K. flaccidum.In Figures 1b and c, the other four microorganisms as mentioned in Table 1 except for the endemic isolates were then applied as a mixture. Application was effected in an amount of 200 g wet biomass per m 2( or of 140 g / m 2 for the batch with specification of K. flaccidum) with a mixing ratio of the microorganisms of (70:10:10:10 for Microcoleus:Nostoc:Scytonma:Scenedesmus), and incubation was then continued. Figure 1b shows the experimental batch in which K. flaccidumwas applied to the soil in advance and incubated for one day, Figure 1c shows a corresponding comparison without prior application of K. flaccidum. The improved formation of the gel-like polymer matrix is clearly visible. K. flaccidum appropriately promotes the growth of the microorganisms. This was also shown by an increased biomass content in the soil as determined by chlorophyll A (not shown).The base mixture shown in Table 1 without the endemic isolates is thus suitable for forming corresponding to the soil crusts.Series of Experiments 2:Induction of biological soil crusts with a mixture of five species.The microorganisms mentioned in Table 1, except for the endemic isolates and rhizobacteria, were applied to soils from Burkina Faso, these soils having a different degree of soil degeneration. Test area 1 showed the strongest degeneration, and test area 3 the smallest. The samples were incubated for six months at 30°C and a PFD of 50 μE(m 2 s), 16 / 8 day / night. 100 g wet biomass / m 2 soil were used.FIG. 2a shows the corresponding formation of the floor crusts. The chlorophyll A contents of these samples were determined after six month incubation, see Fig. 2b. FIG. 2 bshows the chlorophyll A contents per gram of soil of the soils of the three test areas shown with different degradation states from Burkina Faso before and after the six month treatment. A control of a natural biocrusce of the type dark cyanobacteria microalgae dominated crust from Burkina Faso is shown as a comparison. The chlorophyll A contents are clearly increased as a measure of the biomass content in the soil.It was also found that water retention in these soils is improved (not shown).Series of Experiments 3:The influence of the additive calcite on the formation of the floor crust was investigated, for which purpose an artificial sand was incubated with a mixture listed in Table 2 for four weeks at room temperature. The amount here was 200 g / m 2 Burkina Faso Mix. In addition, in the lower series of experiments, calcite was added as an additive in an amount of 25 g / m 2. As shown, when the additive was added, a thicker scale of the soil was found after four weeks of incubation.Series of Experiments 4: 4Field TestOn a soil corresponding to test areas 1 to 3 described above, the formation of biological soil crusts was examined in a field test within a period of 11 months after treatment. As in the above series of experiments, test area 1 has a high degree of soil degradation, test area 2 has a medium and test area 3 has no soil degradation. Accordingly, FIG. 4a shows areas after 11 months of treatment. The treatment was carried out in such a way that the compositions according to Table 2 were applied and the surfaces were subsequently treated by watering and nutrition. On the surfaces of the high degradation, the floor crusts are more pronounced than the crusts of the test surface 2, and the test surface 3 without appreciable degradation showed little or no further formation of the floor crust, since there was a higher vegetation in the form of grasses and shoots. The surface with high floor degradation, on the other hand, showed the formation of the floor crust with almost complete coverage.The formation of the soil crust is also confirmed in the determination of the chlorophyll A content shown in FIG. 2a before and after treatment of the test areas. Whereas the chlorophyll A content has remained constant or has decreased somewhat after treatment in test areas 2 and 3, the chlorophyll A content per gram of soil has increased greatly on the test areas 1 and is now comparable to the chlorophyll A content of a naturally grown biological soil crust from the test area. The low chlorophyll A content of the test areas 2 and 3 can be established by the fact that these test areas are predominantly covered with grasses and strands and therefore less biological soil crust with a concentration of chlorophyll A is present in the uppermost soil layers.Figure 4c shows the phototrophic colonies in the top soil layer as evidence of the live biomass concentration of the photosynthetic crust component, as well as the number of different phototrophic species and thus biodiversity. The improvements after treatment are clearly evident.On all degraded test areas (test areas 1) it was possible to observe formation of biological soil crusts 11 months after treatment. These biological soil crusts have a comparable content of chlorophyll A as their natural variants in the test area. In addition, the biodiversity of the phototrophic soil organisms in the corresponding layers after treatment could be increased.Determination of chlorophyll A content was carried out as follows:The determination of the chlorophyll A content was carried out according to Park et al 2015 (Park, Chan-Ho; Li, Xinrong; Jia, Rong Liang; Hur, Jae-Seoun (2015): Effects of superabsorbent polymer on Cyanobacterial Biological Soil Crust Formation in Laboratory. In Arid Land Research and Management 29 (1), pp. 55-71. DOI: 10.1080 / 15324982.2014.928835.) At least 2 g of the soil sample (or biocrusted sample) are treated with 5 ml 99.8% (v / v) ethanol in a 50 ml Falcon tube, mixed three times by inversion and then incubated in a water bath at 80° C. for 5 min. After inversion again three times, the samples are cooled at room temperature for 30 min. After centrifugation for 5 min at 4° C. and 4000 rpm, the supernatant is measured in a UV-Vis spectrophotometer against 99.8% ethanol as zero value. The absorbance is measured at a wavelength of 665 nm. The Chl a concentration per g of soil is calculated according to a formula by Ritchie (2006) (Ritchie, Raymond J. (2006): Consistent sets of spectrophotometric chlorophyll equations for acetone, methanol and ethanol solvents. In Photosynthesis Research 89(1), pp. 27-41. DOI: 10.1007 / s11120-006-9065-9.): Chl a: chlorophyll A content [μg / g soil] A 665: absorption at 665 nm [AU] V: volume ethanol [mL] m S: weight soil sample, initial weight [g] d: layer thickness cuvette [cm], 1 cm ε, 665: specific extinction coefficient of chlorophyll A in ethanol [μg×cm / Au×mL]The total number of photochromic colonies was determined as follows:1 g of the biocrusce is mixed in 10 ml each of Butterfield's buffer in a suitably large Falcon vessel. The falcon vessel (or optionally a sufficiently large petri dish) is incubated for 7 days under low photon flux density of 40-50 μE / (m 2 s) and natural day / night rhythm at room temperature.The suspensions of slurried biocrusted are subsequently diluted 1 / 10 and 1 / 100 with the aid of Butterfield's buffer and spread on suitable nutrient medium agar plates (e.g. BG11, BG11 0 and BBM medium). The coated agar plates are then incubated for at least one week under the same conditions under illumination. The grown phototrophic colonies are subsequently determined by enumeration.Individual components can be varied in the abovementioned mixtures according to the invention. This may be for various reasons, for example, alternatively to Kleb'sormidium flaccidumor Kleb'sormidiumsp., another way may be used to address geographical peculiarities. Microcleus specific species such as Microcleus steenstruppii at higher temperatures, Microcleus vaginatus at temperatures of the temperate zone or Microcleus chtonoplasts at salty soils, Microcleus sociatus at sandy soils can be selected accordingly based on the local circumstances. Scytonema javanicum or Scytonema hyainum can also be selected for geographic adaptation. The same applies when selecting the type of Scenedesmus vacuolatus or Chlorella vulgaris or Chlorella ohadii (very high temperature and solar radiation). Depending on the desired results, the above-mentioned mix may also be used in its proportions to influence, for example, C-fixation, N-fixation, etc. N-fixation can be achieved by increasing the proportions of generally the genus Notoc, for example. Nostoc commune, or from Scytonema. The water outflow can be changed by increasing the proportions of scytonema, which leads to influencing of the water outflow (due to its specific morphology, which causes an increased surface structuring).The compositions according to the invention may likewise comprise further additives as mentioned in the description.It has been shown that the compositions according to the invention promote the formation and development of soil crusts. The compositions according to the invention are thus suitable for use in improving the soil, in particular in the formation of soil crusts on raw soils and in preventing blocking or splashing.References included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Cited Non-Patent LiteratureBenap, J. and O. Lange (eds.) (2003 ) "Biological Soil Crystals: Structure, Function and Management" Ecological Studies 150, Analysis and Synthesis, Springer-Verlag Berlin Heidelberg GmbH

[0002] Antoninka A., et al., 2020, Restoration Ecology, 28 (S2, S3 to S8

[0004] Wu, Y., et.al.;(2013 ), Plant Soil 370:115-124

[0006] Peng, C., et al., (2017) Journal of Applied Physiology, DOI 10.1007 / s10811-017-1061-2

[0006] Wang, W., et al. (2013) "Feasibility of cyanobacterial inoculation for biological soil crystals formation in dessert area" Soil Biology & Biochemistry 41:926-929

[0006] Lababpour, 2016, Int. J. Environm. Sci. Technol. 13: 2521-2532

[0007] Park, Chan-Ho; Li, Xinrong; Jia, Rong Liang; Hur, Jae-Seoun (2015): Effects of Superabsorbent Polymer on Cyanobacterial Biological Soil Crust Formation in Laboratory. In Arid Land Research and Management 29 (1), pp. 55-71. DOI: 10.1080 / 15324982.2014.928835

[0065] Ritchie, Raymond J. (2006): Consistent sets of spectrophotometric chlorophyll equations for acetone, methanol and ethanol solvents. In Photosynthesis Research 89(1), pp. 27-41. DOI: 10.1007 / s11120-006-9065-9

[0065]

Claims

Composition of isolated microorganisms, in particular for soil improvement, comprising viable microorganisms of the following genera: a. Microcleus; b. Nostoc; c. Scytonema.The isolated microorganism composition of claim 1, further comprising viable microorganisms of the genus Klebsormidium.The isolated microorganism composition of claim 1 or 2, further comprising viable microorganisms of the genus Scedesmus or Chlorella.An isolated microorganism composition according to any one of the preceding claims comprising endemic isolates of viable microorganisms from soils on which the isolated microorganism mixture according to any one of claims 1 to 3 is introduced.Isolated microorganism composition according to any one of the preceding claims, wherein this composition is in the form of a suspension, dried particles, lyophilized composition, granules, or capsules, in particular capsules containing liquid suspension.The isolated microorganism composition according to any one of the preceding claims, further comprising further, in particular biocompatible, excipients, in particular nutrients including sugars, such as trehalose or sucrose, medium constituents, growth accelerators, fillers, such as clay, biolpolymers or plant seeds of grasses.The isolated microorganism composition of any preceding claim, wherein the ratios of the microorganisms are as follows:Microcleus35% - 55%;Notoc4% - 15%;Scytonema4% - 15%;Klebsormidium20% - 40%;Senedsm and / or Chlorella4% - 15%;EndMic Isolations>1% by weight;with the total mass of 100% based on total wet biomass, optionally further comprising additives.The isolated microorganism composition of any preceding claim, wherein said mixture comprises at least twenty species of different isolated microorganisms.Use of an isolated microorganism composition according to any one of claims 1 to 8 for soil improvement.Use of the isolated microorganism composition according to claim 9 for improving soil encrustations.A method for improving soil comprising the step of applying an isolated microorganism composition according to any one of claims 1 to 9.The method for improving soils according to claim 11, wherein it is a method for improving soil crust.

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