Promote plant growth by adding Bacillus subtilis to bio fertilizers

    Bacillus subtilis significantly improves the appearance quality, nutritional content, flavor, taste, and safety of agricultural products by regulating crop metabolism, optimizing nutrient absorption, enhancing stress resistance, and improving microecology through multiple mechanisms. The following are specific action paths and typical cases:

1、 Enhance nutrient accumulation

1. Promote photosynthetic efficiency and nutrient transport
Enhance photosynthesis
    By secreting cytokinins (CTK) and gibberellins (GA), it promotes chlorophyll synthesis in crop leaves (chlorophyll content can increase by 15%~30%), expands leaf area, and improves light energy capture efficiency. For example, spraying Bacillus subtilis during the grape flowering period can increase leaf photosynthetic rate by 22% and advance fruit swelling period by 5-7 days.

Optimize nutrient allocation
    Regulate the source sink relationship of crops and guide the transportation of photosynthetic products (such as sucrose and starch) to organs such as fruits and grains. Research has shown that after applying Bacillus subtilis to wheat, the expression level of the sucrose transporter gene (TaSUT1) in the flag leaf is upregulated by 40%, and the starch content in the grain increases by 8% to 12%.

2. Enrich minerals and functional components
    Improve the absorption of mineral elements
    By secreting iron carriers and organic acids (such as citric acid) to chelate trace elements (Fe, Zn, Mn, etc.) in soil, and activating root transport proteins (such as IRT1, ZIP family). For example, after applying Bacillus subtilis to spinach, the leaf iron content increased from 28 mg/kg to 45 mg/kg, reaching the standard for iron rich vegetables.

Promote the synthesis of secondary metabolites
    Inducing activation of the phenylpropane metabolic pathway, increasing the content of flavonoids (such as flavonols, anthocyanins), phenolic acids, and other antioxidant substances. The anthocyanin content in blueberry fruits can be increased by 30% to 50%, and the antioxidant activity (DPPH value) can be enhanced by 40%.
Regulating terpenoid metabolic pathways and increasing the content of fruit aroma compounds such as esters and aldehydes. After strawberry application, the aroma components such as ethyl caproate and ethyl butyrate in the fruit increased by 25%, and the flavor score increased by 1-2 points (out of 5 points).

2、 Improve the appearance and taste of agricultural products

1. Optimize fruit shape and color
Promote uniform growth
    By balancing endogenous hormones (such as reducing the content of ethylene precursor ACC) and reducing malformed fruits (such as tomato cracking and cucumber bending), the deformity rate can be reduced by 20% to 40%.

Enhance coloring intensity
    Inducing the expression of anthocyanin synthase (CHS, DFR) genes in fruit peels and promoting the accumulation of carotenoids such as lycopene and β - carotene. For example, the lycopene content in tomato fruit increased from 12 mg/100g to 18 mg/100g, the fruit color index (a */b * value) increased by 35%, and the marketability significantly improved.

2. Adjust the sugar acid ratio and taste
Increase soluble sugar content
    Promote the transport of photosynthetic products to fruits and convert them into soluble sugars such as glucose and fructose. After watermelon application, the central sugar content increased from 10.5 ° Brix to 12.5 ° Brix, and the edge sugar content difference decreased (from 2.0 ° Brix to 1.2 ° Brix), resulting in a more uniform taste.

Reduce the content of organic acids
    By promoting organic acid metabolism (such as converting citric acid to isocitric acid), reduce fruit sourness. The titratable acid content of grape fruit decreased from 0.65% to 0.48%, and the sugar acid ratio increased from 15:1 to 22:1, resulting in a richer flavor.

3、 Enhance resilience and safety
1. Reduce stress damage and pesticide residues
Anti stress preservation
    By inducing the activity of antioxidant enzyme systems (SOD, POD, CAT), the oxidative damage of fruits under stress such as drought and high temperature can be reduced, and the shelf life can be extended. For example, when strawberries are treated with Bacillus subtilis suspension after harvesting, the shelf life at room temperature is extended from 3 days to 7 days, and the decay rate is reduced by 50%.

Biodegradable pesticides
    Secreting cytochrome P450 enzymes, esterases, and other enzymes to degrade residual pesticides (such as imidacloprid and atrazine) in soil, resulting in pesticide residues in agricultural products below the national standard limit. After application in a certain tea garden, the residual amount of cypermethrin in tea decreased from 0.32 mg/kg to 0.08 mg/kg (national standard ≤ 0.5 mg/kg), meeting the green food standard.

2. Inhibit heavy metal absorption
    Fixed heavy metals (such as Cd ² ⁺ and Pb ² ⁺) in soil through extracellular polysaccharide adsorption and bacterial cell wall ion exchange, reducing their transport into crops. Rice pot experiments showed that after applying Bacillus subtilis, the cadmium content in grains decreased from 0.3 mg/kg (exceeding the standard) to 0.1 mg/kg (national standard ≤ 0.2 mg/kg), and the compliance rate increased from 50% to 100%.

4、 Typical application cases
1. Improvement of Apple Quality
Handling method
    Spray Bacillus subtilis bacterial agent once each during the flowering and young fruit stages (concentration 1 × 10 ⁹ CFU/mL).
effect
    The fruit hardness increased from 12.5 kg/cm ² to 14.2 kg/cm ² (enhanced storage and transportation resistance);
The soluble solids content increased from 13.2% to 15.1%, and the vitamin C content increased by 28%;
The incidence rate of bitter pox decreased from 18% to 5%, and the commercial fruit rate increased by 22%.

2. Improvement of Tea Quality
Handling method
    Apply a composite preparation of Bacillus subtilis and humic acid to the roots of spring tea before germination (bacterial count 5 × 10 ⁸ CFU/strain).
effect
    The content of tea polyphenols increased from 18.5% to 22.3%, and the content of amino acids increased from 3.2% to 4.1% (improving the freshness of tea soup);
    The leaf thickness increased by 15%, the fuzz density increased by 20%, and the dry tea color became more oily;
    Reduce aphid incidence by 40% and decrease the frequency of chemical pesticide use by 2-3 times.

3. Optimization of Rice Quality
Handling method
    Before sowing, mix the seeds with Bacillus subtilis bacterial agent (strain: B. subtilis BS-208, dosage 10 g/kg seeds).
effect
    The chalky grain rate decreased from 25% to 12%, and the whole grain rate increased from 58% to 65% (improvement in processing quality);
    The content of amylose was adjusted from 18.7% to 15.5%, and the viscosity was increased from 50 mm to 75 mm (the taste score was increased from 62 to 78 points, referring to the Japanese rice taste evaluation standards).
 

Key influencing factors and application recommendations
    Strain specificity: Select a multifunctional strain that combines * * growth promotion (such as IAA secretion), phosphorus solubilization (such as high phosphatase activity), and antioxidant production (such as glutathione synthesis) * *, such as B. subtilis WB600 (which has been proven to increase vitamin C content in strawberries).

Application period:
    Fruits and vegetables: applied during the flower bud differentiation and fruit expansion stages, with a focus on enhancing flavor compounds;
    Grains: Apply during the jointing and filling stages to promote nutrient transport to the grains.
    Synergistic effect enhancement: When combined with humic acid and seaweed extract, it can enhance the colonization ability of bacterial strains and supplement carbon sources. For example, Bacillus subtilis+humic acid treatment can increase grape anthocyanin content by more than 60%.

      By precisely regulating the metabolites of Bacillus subtilis and crop physiological responses, key quality indicators of different agricultural products can be targeted to meet the demands of the high-end market for "safety, nutrition, and flavor".