Induction of Systemic Resistance in Maize and Antibiofilm Activity of Surfactin From Bacillus velezensis MS20

Abstract

Surfactin lipopeptide is an eco-friendly microbially synthesized bioproduct that holds considerable potential in therapeutics (antibiofilm) as well as in agriculture (antifungal). In the present study, production of surfactin by a marine strain Bacillus velezensis MS20 was carried out, followed by physico-chemical characterization, anti-biofilm activity, plant growth promotion, and quantitative Reverse Transcriptase—Polymerase Chain Reaction (q RT-PCR) studies. From the results, it was inferred that MS20 was found to produce biosurfactant (3,300 mg L–1) under optimized conditions. From the physicochemical characterization [Thin layer chromatography (TLC), Fourier Transform Infrared (FTIR) Spectroscopy, Liquid Chromatography/Mass Spectroscopy (LC/MS), and Polymerase Chain Reaction (PCR) amplification] it was revealed to be surfactin. From bio-assay and scanning electron microscope (SEM) images, it was observed that surfactin (MIC 50 μg Ml–1) has appreciable bacterial aggregation against clinical pathogens Pseudomonas aeruginosa MTCC424, Escherichia coli MTCC43, Klebsiella pneumoniae MTCC9751, and Methicillin resistant Staphylococcus aureus (MRSA) and mycelial condensation property against a fungal phytopathogen Rhizoctonia solani. In addition, the q-RTPCR studies revealed 8-fold upregulation (9.34 ± 0.11-fold) of srfA-A gene compared to controls. Further, treatment of maize crop (infected with R. solani) with surfactin and MS20 led to the production of defense enzymes. In conclusion, concentration and synergy of a carbon source with inorganic/mineral salts can ameliorate surfactin yield and, application wise, it has antibiofilm and antifungal activities. In addition, it induced systemic resistance in maize crop, which makes it a good candidate to be employed in sustainable agricultural practices.

Microbial surfactants: A journey from fundamentals to recent advances

“…A lipopeptide allegedly inhibited the anthracnose-causing pathogen Colletotrichum gloeosporioides in papaya leaves ( Kim et al, 2010 ). A surfactin was used to treat the Rhizoctonia solani infected maize crop which led the production of defense enzymes ( Ali et al, 2022b ). Such properties make biosurfactants useful in phytopathogenic control.…”

Pseudomonas aeruginosa inhibits quorum-sensing mechanisms of soft rot pathogen Lelliottia amnigena RCE to regulate its virulence factors and biofilm formation

“…These signal molecules freely diffuse to the cells and bind to their respective receptors, thus regulating various pathogenesis-related traits. The production of EPS (Ilyas et al, 2020 ; Sheikh et al, 2022 ), pigment (Polapally et al, 2022 ), toxins, formation of biofilm (Ali et al, 2022 ; Fazeli-Nasab et al, 2022 ), and secretion of cell wall degrading enzymes (Jadhav et al, 2020 ) are key traits expressed by the pathogen once sufficient cell density is achieved (Sibanda et al, 2018 ). This quorum-sensing guided virulence factor synthesis can be controlled by disturbing the QS system either by mimicking the signal molecules, which leads to competitive inhibition, or enzymatically hydrolyse the auto-inducers (N-Homoserine Lactone).…”

Harnessing the Potential of Biosurfactants for Biomedical and Pharmaceutical Applications

“…With ongoing research and advancements in biosurfactant production and formulation techniques, surface coating methods (such as physical adsorption, bulk incorporation or covalent grafting) have been proposed and used to attach these molecules on a wide range of materials. Moreover, biosurfactant-based coatings exhibit excellent biocompatibility and biodegradability, making them attractive alternatives to conventional synthetic coatings [ 48 , 49 , 50 ].…”