Biofertilizers are broths containing beneficial
microorganisms that are applied to soils to enhance crop production and soil
fertility. The microbes in a biofertilizer enhance and drive natural processes
such as nutrient transformation and cycling, organic matter decomposition, and
gas emission. Environoc 401 manufactured by Biodyne-USA is described as an
agricultural soil enhancer that is comprised of a consortium of beneficial
microorganisms. Production of Environoc 401 is achieved by an incubation that
begins with a concentrated lyophilized microbial consortium. The focus of this
study is to try to understand the community dynamics that occur during the
incubation process to help predict the proportions of individual strains and
the overall metabolic activity of the microbial community in Environoc 401
under different conditions. In order to quantify individual strains in
Environoc 401, species-specific primers were developed for use in
quantitative-PCR. These primers were
then used to quantify target strains in Environoc 401 broth stored at 22
°C and 27 °C for 1 month and sampled at time 0, 1 week, and 1 month to evaluate
the effect of storage conditions on the microbial community. In general, Environoc
401 stored at 22 °C had greater substrate utilization richness compared to
Environoc 401 stored at 27 °C, but only after 1 month. The microbial community
within Environoc 401 stored at 27 °C after 1 month did not utilize any amines
or phenolic compounds, while the communities stored at 22 °C did use these
substrates. To evaluate the overall effect of Environoc 401 on plants and on
the microbial activity in potting medium, the product was used in the potting
soil of soybean plants grown in an environmental growth chamber. This study
contained five treatments upon unifoliate emergence: a no treatment control,
pesticide and chemical fertilizer, pesticide and biofertilizer (as Environoc 401),
biofertilizer only, and chemical fertilizer only. Soil medium samples were
collected from each treatment at the time of seed planting, 24 hrs before
application, 24 hrs after application, 2 weeks after application, and 1 month
after application. The soybean plants treated with Environoc 401 generally had
the highest average total plant height, average number of leaves, average dry
weight of leaves, stems, and roots, and the least acidic pH. Samples from both
studies were also used to inoculate Biolog EcoPlates to assess changes in
carbon-source utilization patterns for each condition and to generate
Community-Level Physiological Profiles (CLPPs). Principle Component Analysis
was performed on the CLPPs and diversity was also assessed using Shannon’s
diversity indices for samples from both studies. The CLPPs for the storage
samples clustered tightly after 1 week of storage, however, after 1 month of
storage the two temperatures diverged greatly. The CLPPS for the soybean plant treatment
samples clustered tightly 24 hours prior to treatment but varied greatly after
treatment application. <a>These results indicate that
treatment application, storage time, and temperature affect carbon utilization
within the microbial communities. These results are a reflection on the
activity and health of the microbial community and future studies should
explore changes taking place on a finer scale by targeting specific carbon
sources or conditions.</a>
| Identifer | oai:union.ndltd.org:purdue.edu/oai:figshare.com:article/12250016 |
| Date | 06 May 2020 |
| Creators | Shannon M Calder (8801099) |
| Source Sets | Purdue University |
| Detected Language | English |
| Type | Text, Thesis |
| Rights | CC BY 4.0 |
| Relation | https://figshare.com/articles/THE_EFFECT_OF_ENVIRONMENTAL_CONDITIONS_ON_THE_COMMUNITY_DYNAMICS_OF_BIOFERTILIZER_MICROORGANISMS/12250016 |
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