Bacillus Subtilis as a Soil Probiotic

It is well known that number of beneficial soil microorganisms, like Bacillus subtilis, act as soil probiotics. This is also called synergistic plant promotion.

Bacillus subtilis was one of the first soil microbes discovered. It is sometimes known as  the hay bacillus or grass bacillus. It is a spore producing bacteria. Because it produces these tough spores, it is widely used as a commercial biofertilizer.

B. subtilis produces plant hormones and solubilizes insoluble forms of phosphates. This makes the phosphate, a necessary chemical in plant growth, available to the plant.

Bacillus subtilis produces Auxins

One of the ways that B.subtilis promotes plant growth is by the production (biosynthesis) of plant hormones such as auxins. Auxin was derived from the greek word auxein which means to grow.

Auxins were the first plant hormones discovered. Auxins have a number of effects on plants including:

• Stimulates cell elongation
• Delays fruit ripening
• Auxin is required for fruit formation
• Stimulates the xylem and phloem
• Auxin promotes root initiation and formation.

By producing auxins, B. subtilis helps the plant grow and develop. Since both the plant and the soil microorganism benefit, this relationship is called synergistic or sometimes the term probiotic is used. Either way, the soil microorganisms perform an invaluable service to the plant.

Bacillus subtilis solubilizes insoluble phosphate

The second major reason for the phrase Bacillus subtilis plant growth promoter is the ability to solubilize phosphate. Insoluble phosphate is generally inaccessible to the plant. The root system simply cannot absorb it. B. subtilis, however, solubilizes the phosphate making it accessible to the plant.

Soil microorganisms, such as B. subtilis, are essential to plant health and plant growth. The synergistic relationship between the soil bacteria and the plant roots is a vital one for both parties.

Commercial Products containing B. Subtilis

Custom Biologicals manufactures three agricultural products that contain B. subtilis.

• Custom B5 – Liquid concentrate, contains 5 species of beneficial soil bacteria
• Custom B5 Fizzytabs – an effervescent tablet containing 5 species of beneficial soil microbes.
• Biota Max™ – Great for home gardens. Biota Max contains both beneficial soil bacteria and beneficial soil Trichoderma fungi.

Custom Biologicals is expert in the use of beneficial soil bacteria such as B. subtilis, sometimes called B. Sub or B. Sub bacteria.

Custom manufactures a wide variety of biological products including soil amendments. Contact Custom Biologicals at (561) 797-3008 or via email at Bill@Custombio.biz. Distributor inquiries are welcome. Private labeling and customized formulations are available.