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      Supervivencia de Azotobacter y otros grupos microbianos en suelo seco almacenado Translated title: Survival of Azotobacter and other microbial group in dry soil by storage


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          Resumen En suelos secos la supervivencia del género y especies de Azotobacter, es paralela a la de otros grupos microbianos nativos como actinomicetos y hongos de ese ambiente, dependiente de la capacidad de adaptación genética de cada uno, en combinación con algunas de las propiedades fisicoquímicas del suelo, y de las condiciones ambientales de almacén. Los objetivos de este trabajo fueron: i) analizar la supervivencia de Azotobacter en suelo recién colectado y almacenado por 11 y 30 años ii) caracterizar bioquímicamente Azotobacter vinelandii aislado estos suelos iii) dinámica de supervivencia de actinomicetos, bacterias y hongos en los suelos. Para cual cada uno de los suelos se conservó por distinto periodo de tiempo en contenedores de vidrio estériles a temperatura ambiente, de ahí diluyeron para cuantificar cada grupo en: agar nutritivo para bacterias, agar de caseína almidón para actinomicetos, agar Rosa de Bengala para hongos y agar Burk para Azotobacter. Los resultados mostraron que el número de Azotobacter supervivientes en el suelo almacenado por 30 años fue de 12 x 106 UFC/g, de 52 x 106 UFC/g en suelo seco por 11 años y de 300 x 106 UFC/g de suelo seco recién colectado. En el suelo de 30, 11 años se detectó una densidad de Azotobacter spp., inferior al suelo seco recién colectado. Se encontró diferencia en los perfiles bioquímicos de A. vinelandii de suelo almacenado por 30 años, en comparación el mismo género y especie en el recién colectado. Lo que anterior indica que las propiedades fisicoquímicas del suelo, el periodo de desecación fue crítico en la supervivencia de Azotobacter y de los otros grupos de microorganismos nativos de ese ambiente.

          Translated abstract

          Abstract In dry soils, the survival of the genus and species of Azotobacter is parallel to that of other native microbial groups such as actinomycetes and fungi of that environment, depending on the genetic adaptation capacity of each one, in combination with some of the physicochemical properties of the soil. soil, and environmental storage conditions. The objectives of this work were: i) to analyze the survival of Azotobacter in soil recently collected and stored for 11 and 30 years ii) to biochemically characterize Azotobacter vinelandii isolated from these soils iii) survival dynamics of actinomycetes, bacteria and fungi in soils. For which each of the soils was kept for a different period of time in sterile glass containers at room temperature, from there they were diluted to quantify each group in: nutrient agar for bacteria, casein starch agar for actinomycetes, Rose Bengal agar for fungi and Burk agar for Azotobacter. The results showed that the number of surviving Azotobacter in soil stored for 30 years was 12 x106 CFU/g, 52 x 106 CFU/g in dry soil for 11 years, and 300 x106 CFU/g in freshly collected dry soil. In the soil of 30, 11 years, a density of Azotobacter was detected, lower than the dry soil recently collected. A difference was found in the biochemical profiles of A. vinelandii from soil stored for 30 years, compared to the same genus and species in the newly collected soil. The above indicates that the physicochemical properties of the soil, the drying period was critical in the survival of Azotobacter and other groups of microorganisms native to that environment.

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          Most cited references34

          • Record: found
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          Prokaryotes: The unseen majority

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            Responses of soil microbial communities to water stress: results from a meta-analysis.

            Soil heterotrophic respiration and nutrient mineralization are strongly affected by environmental conditions, in particular by moisture fluctuations triggered by rainfall events. When soil moisture decreases, so does decomposers' activity, with microfauna generally undergoing stress sooner than bacteria and fungi. Despite differences in the responses of individual decomposer groups to moisture availability (e.g., bacteria are typically more sensitive than fungi to water stress), we show that responses of decomposers at the community level are different in soils and surface litter, but similar across biomes and climates. This results in a nearly constant soil-moisture threshold corresponding to the point when biological activity ceases, at a water potential of about -14 MPa in mineral soils and -36 MPa in surface litter. This threshold is shown to be comparable to the soil moisture value where solute diffusion becomes strongly inhibited in soil, while in litter it is dehydration rather than diffusion that likely limits biological activity around the stress point. Because of these intrinsic constraints and lack of adaptation to different hydro-climatic regimes, changes in rainfall patterns (primary drivers of the soil moisture balance) may have dramatic impacts on soil carbon and nutrient cycling.
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              Effects of growth medium, inoculum size, and incubation time on culturability and isolation of soil bacteria.

              Soils are inhabited by many bacteria from phylogenetic groups that are poorly studied because representatives are rarely isolated in cultivation studies. Part of the reason for the failure to cultivate these bacteria is the low frequency with which bacterial cells in soil form visible colonies when inoculated onto standard microbiological media, resulting in low viable counts. We investigated the effects of three factors on viable counts, assessed as numbers of CFU on solid media, and on the phylogenetic groups to which the isolated colony-forming bacteria belong. These factors were inoculum size, growth medium, and incubation time. Decreasing the inoculum size resulted in significant increases in the viable count but did not appear to affect colony formation by members of rarely isolated groups. Some media that are traditionally used for soil microbiological studies returned low viable counts and did not result in the isolation of members of rarely isolated groups. Newly developed media, in contrast, resulted in high viable counts and in the isolation of many members of rarely isolated groups, regardless of the inoculum size. Increased incubation times of up to 3 months allowed the development of visible colonies of members of rarely isolated groups in conjunction with the use of appropriate media. Once isolated, pure cultures of members of rarely isolated groups took longer to form visible colonies than did members of commonly isolated groups. Using these new media and extended incubation times, we were able to isolate many members of the phyla Acidobacteria (subdivisions 1, 2, 3, and 4), Gemmatimonadetes, Chloroflexi, and Planctomycetes (including representatives of the previously uncultured WPS-1 lineage) as well as members of the subclasses Rubrobacteridae and Acidimicrobidae of the phylum Actinobacteria.

                Author and article information

                Journal of the Selva Andina Research Society
                J. Selva Andina Res. Soc.
                Órgano oficial de la:; SELVA ANDINA RESEARCH SOCIETY (La Paz, , Bolivia )
                : 13
                : 1
                : 3-15
                [4] Denton Texas orgnameUniversity of North Texas orgdiv1Department of Biological Sciences United States
                [1] Morelia Mich orgnameUniversidad Michoacana de San Nicolás de Hidalgo orgdiv1Instituto de Investigaciones Químico Biológicas Mexico
                [2] La Habana orgnameMinisterio de Agricultura de la República de Cuba orgdiv1Instituto de Investigaciones en Fruticultura Tropical (IIFT) Cuba
                [3] Caracas orgnameAcademia Militar de Medicina (AMMED) Venezuela
                S2072-92942022000100003 S2072-9294(22)01300100003

                This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

                : 01 August 2021
                : 01 December 2021
                Page count
                Figures: 0, Tables: 0, Equations: 0, References: 35, Pages: 13

                SciELO Bolivia

                ARTÍCULO ORIGINAL

                almacenaje,quistes,diversidad microbiana,Soil,storage,cysts,microbial diversity


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