Background

Overview of Agricultural Strains Optimization

The development of agriculture is closely related to global population growth, limited arable land resources, environmental protection needs, the pursuit of improved crop yields and quality, and strategies to reduce dependence on chemical pesticides and fertilizers. As the population continues to grow, the demand for food and agricultural products is also rising, which requires us to improve agricultural production efficiency on limited arable land. At the same time, the excessive use of chemical fertilizers and pesticides in traditional agricultural production methods has caused serious pollution and damage to the environment. Therefore, developing sustainable agriculture and reducing negative impacts on the environment has become an urgent global need.

In this context, the optimization of bacterial strains for agricultural use is particularly important. By using beneficial microbial strains, crops can improve their nutrient uptake efficiency and disease resistance, thereby reducing reliance on chemical fertilizers and pesticides. These optimized strains can provide necessary nutrients to crops through biological control and biofertilizers, while improving soil structure and ecological environment and reducing chemical pollution.

In addition, with the continuous advancement of biotechnology, the application of modern technologies such as gene editing and synthetic biology has provided new means for the screening and improvement of agricultural strains. These technologies have significantly improved the efficiency of strain screening and ushered in new opportunities for the development of the agricultural microbial industry. At the same time, large-scale and precise identification and evaluation of microbial resources will help discover more new resources and functional genes that meet the needs of modern agricultural development.

Fig. 1. Schematic presentation of phosphate solubilization by phosphate-solubilizing microorganisms. (Pang, et al., 2024)

Classifications of Agricultural Strains

Agricultural strains are classified according to their specific applications in agricultural production, including but not limited to biocontrol, plant growth promotion, decomposition processes, bioremediation, and as biofertilizers. The following is an overview of the classification of agricultural strains according to different applications:

• Biocontrol strains: These strains are mainly used to control crop diseases. For example, Trichoderma spp. is widely used in agriculture for their biocontrol mechanisms, where they inhibit the growth of pathogenic fungi, thereby reducing crop diseases. Also, the genetic diversity of different strains of Ralstonia solanacearum, a pathogenic bacterium that causes bacterial wilt in plants, has been studied to understand their pathogenicity.
• Plant growth promoting strains: These strains promote plant growth and increase crop yields. For example, Trichoderma spp. not only acts as biocontrol agent, but also as plant growth promoter, stimulating plant growth by producing plant hormones and other beneficial substances.
• Bioremediation strains: These strains are used to remediate contaminated soil or water bodies and improve environmental quality by degrading organic pollutants. Trichoderma spp. is also studied for their use in bioremediation because of their ability to break down harmful substances in the soil.
• Biofertilizer strains: Biofertilizer strains are used to provide plant nutrients and improve soil quality. For example, biofertilizers containing Rhizobium sp. have been sold on the agricultural market for more than 100 years to improve nitrogen supply to plants.

Creative BioMart Microbe, with its expertise and experience, is committed to optimizing agricultural strains, improving crop yields and quality, and achieving sustainable agricultural development. Please feel free to contact us for more information.

Service Procedure

Service Details

Nitrogen-fixing Microbes Optimization

Nitrogen-fixing microorganisms improve soil fertility and crop yields, and can also reduce environmental pollution. We offer more than 1,000 strains with nitrogen fixation related genes and also provide customers with strain construction and screening services. Using high-throughput in vitro nitrogen fixation assays and ammonia and acetylene reduction assays combined with early response plant growth chamber and N-stress greenhouse (e.g. V4, V6, V10) assays, we can evaluate and optimize strain competitiveness. The aim is to screen out the best nitrogen-fixing microorganisms in cereal crops and legume crops.

Phosphate-solubilizing Microbes Optimization

Phosphate- solubilizing microbes can convert insoluble phosphates in the soil into a form that can be absorbed by plants, thereby improving the soil's phosphorus efficiency and benefiting environmental protection. We isolate these microbes from various environments such as soil, rhizosphere, or plant tissues and use environmental perturbation and propagation to enhance the phosphate solubilization activity of microbial communities. A series of functional tests including comprehensive silica and in vitro mode of action assays, root architecture assays and phosphorus deficiency assays are carried out to ensure the effectiveness of the microorganisms.

Carbon Sequestration Function Optimization

Carbon-fixing microorganisms fix carbon dioxide in the atmosphere into organic matter, increasing the organic carbon content in the soil, thereby improving soil structure and increasing soil fertility. They also promote plant growth and enhance soil moisture retention capacity. Through genetic engineering, we can improve the efficiency of improved strains in utilizing organic carbon sources, enhance the resistance of strains to environmental stresses (such as drought, high temperature, pH changes, etc.), improve their carbon fixation capacity under different environmental conditions, or improve the metabolic pathways of microorganisms. Using stable isotope labeling and biomarker monomer 13C analysis technology, we can quantitatively evaluate the accumulation efficiency of microbial residues, thereby optimizing the carbon fixation function of strains.

Plant Growth Regulators Strains Screening

We have a microbial library with over 14,000 strains in which we've identified some candidate strains with a range of known plant growth-promoting modes of action, including promoting nutrient absorption, enhancing plant disease resistance and increasing plant tolerance to environmental stress. The mutagenic or rational strain engineering techniques coupled with ultra-high-throughput screening can enhance the performance and stability of wild type strains. Utilizing our proprietary chassis strains, we can further produce specific plant hormones through fermentation on a commercial scale.

Biofungicides Strains Screening

Microbes, used in biofungicides, can reduce the use of pesticides while inhibiting and eliminating harmful pathogens through multiple mechanisms such as competing for nutrients and space, producing antibiotics, inducing plant defense mechanisms, and parasitizing pathogens. In order to obtain microorganisms with potential antibacterial activity, samples can be collected from different environments such as soil, water, plant rhizosphere, etc., and the performance of the isolated microorganisms can be tested to evaluate their antibacterial activity. These functional strains can be further used for high-throughput in vitro growth inhibition tests and plant root rot and leaf rot analysis.

Our Advantages

• Over 14,000 strains in microbial library. Such as Bacillus amyloliquefaciens, Bacillus subtilis, Paenibacillus polymyxa, Pseudomonas fluorescens, Bacillus cereus, Methyltrophic bacillus, Trichoderma hartzii, Marine bacillus, etc.
• High-throughput screening platform.
• Industrial sized scale-up.
• Rapid development time.
• High success rate.

Case Study

Case Study 1: Bacillus velezensis SQR9 with the ResDE system has superior ROS tolerance in plant defense interactions.

Efficient root colonization by plant growth-promoting rhizobacteria is essential for their beneficial effects, yet the mechanisms to bypass plant immunity are not fully understood. This study reveals that Bacillus velezensis SQR9, with a flg22 homolog (flg22SQR9), induces oxidative bursts in cucumber and Arabidopsis, indicating a complex interaction with plant defenses. Unlike Pseudomonas, B. velezensis SQR9 withstands higher H2O2 levels and suppresses flg22-induced oxidative bursts, suggesting a superior ROS tolerance mechanism involving the ResDE system, which aids in root colonization. These findings highlight the need for further exploration of rhizobacteria-plant immunity interactions.

Fig. 2. Colonization of B. velezensis SQR9 and ∆resE on the roots of Arabidopsis rbohD and rbohF mutants. (Zhang, et al., 2021)

Case Study 2: Beneficial microbe Trichoderma erinaceum activates tomato defense genes and antioxidant response.

This study explored the plant defense mechanisms activated by beneficial microbes like Trichoderma erinaceum in tomato plants. We focused on the expression of WRKY genes and observed significant upregulation of SlWRKY31 and SlWRKY37 in bioprimed plants, while SlWRKY4 was downregulated. PR protein expression and antioxidative enzyme activity increased in response to the treatment, correlating with reduced H2O2 production and enhanced lignification in the stem tissues.

Fig. 3. Morphological growth characteristic of the T. erinaceum bioprimed and unprimed plants at two different intervals 15 and 45 days. (Aamir, et al., 2019)

Case Study 3: Production of bio-fungicide from sugarcane bagasse using Pichia membranifaciens yeast.

In this study, antagonistic yeast Pichia membranifaciens was used to produce a bio-fungicide from hydrolyzed sugarcane bagasse, a low-cost carbon source. In optimized conditions, including specific concentrations of nitrogen sources and salts, along with Triton X100 surfactant, the yeast produced 3,782 mg/L of bio-fungicide. This product was effective against post-harvest fungi like Aspergillus niger, Penicillium digitatum, and Phytophthora capsici, with minimum biocidal and inhibitory concentrations of 378.2 and 37.82 mg/L, respectively. These findings suggest the bio-fungicide's potential for preserving agricultural products in storage.

Fig. 4. The growth ability of pathogenic fungi in cultures with different concentrations of bio-fungicide. (Ahmadi, et al., 2020)

FAQs

References:

1. Zhang H.; et al. Bacillus velezensis tolerance to the induced oxidative stress in root colonization contributed by the two-component regulatory system sensor ResE. Plant Cell Environ. 2021;44(9):3094-3102.
2. Pang F.; et al. Soil phosphorus transformation and plant uptake driven by phosphate-solubilizing microorganisms. Front Microbiol. 2024;15:1383813.
3. Aamir M.; et al. Trichoderma erinaceum bio-priming modulates the WRKYs defense programming in tomato against the fusarium oxysporum lycopersici (Fol) challenged condition. Front Plant Sci. 2019;10:911.
4. Ahmadi F, Najafpour G D, Mohammadi M. Production of bio-fungicide from sugarcane bagasse using Pichia membranifaciens yeast and its activity against post-harvest pathogenic fungi. Biointerface Res. Appl. Chem. 2020;11:10435-10445.