Team:Nanjing high school/Implementation
Hardware
Living bacteria agents refer to the viable preparation made by the target microorganism (effective bacterium) after industrial production and propagation. Appropriate use of agricultural microbial agents can increase the yield of agricultural products, improve the quality of agricultural products, reduce the amount of fertilizer, reduce the cost, improve the soil, protect the ecological environment. In our project, we’d like to design two forms of products made by our engineered Tatumella Citrea such as fertilizer adjuvant and living bacteria agent kit to promote phosphate solubilizing. We will show more details below.
1. Fertilizer adjuvant
Design
In order to practice our concept, we designed a fertilizer adjuvant that contains genetically engineered Tatumella Citrea. We researched for some forms of adjuvant in fertilizer market, and found that dry powder is the most common form. According to the description of Tatumella Citrea, they are non-motile and non-spore-forming (Kageyama et al. 1992). We devised an alternative form, which is a living bacteria agent. The bacteria must be placed in a culture medium and 2 mmol/L salicylic acid environment, so they can survive, which is the bacteria agent. It will contain extra Sodium Salicylate and culture medium that will be necessary in the future to produce 2mmol/L salicylate culture solution as an extra agent.
User Manuals
Users
We’d like to produce this product for farmers, orchardists or people who need to increase crop yield.
Conditions of usage:
Absorbing the fermentation liquid of the bacterium to make living bacteria agents be used for seed dressing or root dipping.
If the adjuvant is not used, the bacteria agent should be stored properly in the refrigerator.
Time of usage:
Before the product is used, immerse the bacteria in the salicylic acid for 15-22 hours, to reach the maximum effectiveness.
Use the bacteria agent with the phosphorus fertilizer:
Before the fertilizing, mix salicylic acid solution medium (2mmol/L configured from the extra agent provided) with the bacteria agent, and put them in 25°C environment overnight. After fertilizing, apply the mixture twice a day in 2-3 successive days, or more frequently if the weather is dry. This is for planting the bacteria deeper into the rhizosphere by the solution.
Steps
Prepare the mixture of bacteria agent and the salicylic acid solution culture medium, and place in 25°C environment overnight
Use the phosphate fertilizer
Apply the prepared solution to the rhizosphere of the plants.
In the successive 2 or 3 days, add extra agent twice a day, to help the bacteria survive.
Prototype
2. Living Bacteria Agent kit
Design
In the agent kit, we will provide bacteria expressed both pTrc99k-nahR plasmid and pMW118-PsaI-GFP plasmids, in the form of dry powder with the Sodium Salicylate using porous material as adsorbent (such as peat and vermiculite). This is an expansion of our project because users can utilize this mechanism by adding a gene into pMW119 vector. We used GADPH, they can change to genes they need to control genes expression or repression, to achieve the restriction of nutrients.
User Manuals
Users
We’d like to produce this product for farmers, orchardists or people who need to increase crop yield or researchers to do bacteria reconstruction.
Conditions of usage:
It can be used even when plowing or after manuring.
Must be stored in the refrigerator if not used.
The insertion of different genes depend on the gene’s condition and processes are different.
Prototype
3. Challenges
Since the bactericidal agent is mostly used in the outdoor places, and the outdoor environment, such as precipitation, temperature and pH of the soil, which may affect the effect of living bacteria agents. So specific investigation and analysis are needed, and the composition of living bacteria agent should be adjusted according to different situations.
4. Notice
Cross-contamination and environmental pollution caused by excessive dosage should be avoided during the use of both of the bacteria agents.
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