Application Potential of Lactic Acid Bacteria in Horticultural Production

Lactic acid bacteria (LAB) are found on the surface of some plants, forming their natural microbiome, and are especially common in fermented plant products. They are microorganisms capable of performing lactic fermentation, during which they utilize carbohydrates and produce lactic acid. They are considered probiotic microorganisms. LAB are characterized by strong antagonistic activity against other microorganisms. The mechanism of action of these bacteria is mainly based on the production of substances with strong antimicrobial activity. Some strains of LAB also inhibit the secretion of mycotoxins by mold fungi or have the ability to eliminate them from the environment. With the changing climate and the need for plants to adapt to new, often stressful climatic conditions, the use of LAB in crops may offer a promising solution. These bacteria stimulate plant resistance to abiotic factors, i.e., drought and extreme temperatures. Research has also shown the ability of LAB to extend the storage life of fruits and vegetables. These bacteria reduce the number of unfavorable microorganisms that contaminate plant products and cause their spoilage. They also have a negative effect on human pathogenic bacteria, which can contaminate plant products and cause food poisoning in humans. When applied as an edible coating on leaves or fruits, LAB protect vegetables and fruits from microbial contamination; moreover, these vegetables and fruits can be served as carriers of probiotic bacteria that benefit human health. The presented properties of LAB predispose them to practical use, especially as components of biological plant protection products, growth biostimulants, and microbial fertilizer products. They have great potential to replace some agrochemicals and can be used as a safe component of biofertilizers and plant protection formulations for increasing plant resilience, crop productivity, and quality. The use of LAB is in line with the aims and objectives of sustainable horticulture. However, there are some limitations and gaps which should be considered before application, particularly regarding efficient and effective formulations and transfer of antibiotic resistance.