Biosurfactants’ multifarious functional potential for sustainable agricultural practices

Abstract

Increasing food demand by the ever-growing population imposes an extra burden on the agricultural and food industries. Chemical-based pesticides, fungicides, fertilizers, and high-breeding crop varieties are typically employed to enhance crop productivity. Overexploitation of chemicals and their persistence in the environment, however, has detrimental effects on soil, water, and air which consequently disturb the food chain and the ecosystem. The lower aqueous solubility and higher hydrophobicity of agrochemicals, pesticides, metals, and hydrocarbons allow them to adhere to soil particles and, therefore, continue in the environment. Chemical pesticides, viz., organophosphate, organochlorine, and carbamate, are used regularly to protect agriculture produce. Hydrophobic pollutants strongly adhered to soil particles can be solubilized or desorbed through the usage of biosurfactant/s (BSs) or BS-producing and pesticide-degrading microorganisms. Among different types of BSs, rhamnolipids (RL), surfactin, mannosylerythritol lipids (MELs), and sophorolipids (SL) have been explored extensively due to their broad-spectrum antimicrobial activities against several phytopathogens. Different isoforms of lipopeptide, viz., iturin, fengycin, and surfactin, have also been reported against phytopathogens. The key role of BSs in designing and developing biopesticide formulations is to protect crops and our environment. Various functional properties such as wetting, spreading, penetration ability, and retention period are improved in surfactant-based formulations. This review emphasizes the use of diverse types of BSs and their source microorganisms to challenge phytopathogens. Extensive efforts seem to be focused on discovering the innovative antimicrobial potential of BSs to combat phytopathogens. We discussed the effectiveness of BSs in solubilizing pesticides to reduce their toxicity and contamination effects in the soil environment. Thus, we have shed some light on the use of BSs as an alternative to chemical pesticides and other agrochemicals as sparse literature discusses their interactions with pesticides. Life cycle assessment (LCA) and life cycle sustainability analysis (LCSA) quantifying their impact on human activities/interventions are also included. Nanoencapsulation of pesticide formulations is an innovative approach in minimizing pesticide doses and ultimately reducing their direct exposures to humans and animals. Some of the established big players and new entrants in the global BS market are providing promising solutions for agricultural practices. In conclusion, a better understanding of the role of BSs in pesticide solubilization and/or degradation by microorganisms represents a valuable approach to reducing their negative impact and maintaining sustainable agricultural practices.

Use of biosurfactants produced by Bacillus subtilis H1 and Pseudomonas aeruginosa PAO1 as a disinfectant and plant growth stimulation

“…Fungal phytopathogens carried by seeds can significantly reduce seed germination and affect plant yields [19]. A detailed study of the functional potentials of biosurfactants showed that various biosurfactants have antimicrobial and fungicidal properties [20] [21][22][23][24]. This work also shows the ability of biosurfactants derived from bacteria to inhibit the growth of fungal mycelia.…”

Biosurfactants: Promising Biomolecules for Agricultural Applications

“…The process of obtaining biopesticides using biosurfactants involves several steps, which may vary according to the source of biosurfactants and the type of biopesticide to be produced. Some of the most common steps are: (i) Selection of the best biosurfactant source, with microorganisms able to sporulate being usually the most suitable, (ii) Biosurfactant isolation from the selected source and its purification for further use, which involves growing the source under conditions suitable for biosurfactant production and separating it from cells and other cellular components, (iii) Biopesticide formulation, which may involve mixing of the isolated biosurfactant with other components such as preservatives and adjuvants to enhance the effectiveness of the product, (iv) Efficacy tests using the formulated biopesticide against pests or diseases to be controlled, which are usually performed both in lab-scale and in the field to assess its effectiveness under actual growing conditions, (v) Large-scale production, in case the efficacy tests were successful, of both the biosurfactant and biopesticide formulation, and (vi) Biopesticide registration and regulation by the competent authorities, which implies providing product safety and efficacy data, as well as compliance with environmental and food safety regulations [3,59,104,111,152].…”

Natural surfactant mediated bioremediation approaches for contaminated soil

“…In order to advance our knowledge of the mechanistic action of biosurfactants for the degradation of hydrophobic contaminants, additional research is actually needed to comprehend the actual interaction of biosurfactants with cells. 96 4.2 Biosurfactants used for the bioremediation of heavy metals from soil Metals can be readily accumulated in the soil media and thereby easily enter into the soil-food chain, 97 which becomes a matter of concern to the entire environmentalist community and all other divisions of research. Soil microorganisms have a remarkable role on remediating these metallic toxins.…”

“…In order to advance our knowledge of the mechanistic action of biosurfactants for the degradation of hydrophobic contaminants, additional research is actually needed to comprehend the actual interaction of biosurfactants with cells. 96 …”