What is Bacillus polymyxa?
Bacillus polymyxa, now more commonly known as Paenibacillus polymyxa, is a soil-dwelling, spore-forming bacterium known for producing antibiotics, promoting plant growth, and acting as a natural biocontrol agent.
How does B. polymyxa fight harmful microbes?
It produces antimicrobial substances including polymyxins and other heat-stable compounds that can inhibit the growth of bacteria, fungi, and yeasts (Rosado & Seldin, 1993).
What are polymyxins and how do they work?
Polymyxins are antibiotics produced by B. polymyxa that target Gram-negative bacteria by disrupting their cell membranes, leading to cell death (Vasantha et al., 1980).
Does B. polymyxa have agricultural benefits?
Yes, it is used as a biofertilizer and biocontrol agent. It promotes plant growth by fixing nitrogen, solubilizing phosphate, and producing phytohormones and antifungal compounds like fusaricidin (Padda et al., 2017).
Can B. polymyxa produce enzymes?
Yes, it produces enzymes such as amylases and proteases that can break down complex carbohydrates and proteins. These enzymes are useful in industrial applications and soil nutrient cycling (Robyt & French, 1964).
How is antibiotic production linked to sporulation?
Polymyxin production and spore formation are interconnected. The presence of polymyxins can regulate when the bacterium forms spores, indicating a dual role in defense and development (Nefelova et al., 1980).
Where is B. polymyxa commonly found?
It is found in diverse environments including soil, plant roots, and marine sediments. Its ability to adapt and colonize various habitats contributes to its usefulness in ecological and agricultural applications.