Biosurfactant based formulation of Pseudomonas guariconensis LE3 with multifarious plant growth promoting traits controls charcoal rot disease in Helianthus annus

Liquid Bioformulation: A Trending Approach Towards Achieving Sustainable Agriculture

The human population is expanding at an exponential rate, and has created a great surge in the demand for food production. To intensify the rate of crop production, there is a tremendous usage of chemical pesticides and fertilizers. The practice of using these chemicals to enhance crop productivity has resulted in the degradation of soil fertility, leading to the depletion of native soil microflora. The constant application of these hazardous chemicals in the soil possesses major threat to humans and animals thereby impacting the agroecosystem severely. Hence, it is very important to hunt for certain new alternatives for enhancing crop productivity in an eco-friendly manner by using the microbial bioformulations. Microbial bioformulations can be mainly divided into two types: solid and liquid. There is a lot of information available on the subject of solid bioformulation, but the concept of liquid bioformulation is largely ignored. This article focuses on the diverse spectrum of liquid bioformulation pertaining to the market capture, its different types, potency of the product, mode of usage, and the limitations encountered. Also the authors have tried to include all the strategies required for sensitizing and making liquid bioformulation approach cost effective and as a greener strategy to succeed in developing countries.

Lignin/Surfactin Coacervate as an Eco-Friendly Pesticide Carrier and Antifungal Agent against Phytopathogen

Excessive usage of biologically toxic fungicides and their matrix materials poses a serious threat to public health. Leveraging fungicide carriers with inherent pathogen inhibition properties is highly promising for enhancing fungicide efficacy and reducing required dosage. Herein, a series of coacervates have been crafted with lignin and surfactin, both of which are naturally derived and demonstrate substantial antifungal properties. This hierarchically assembled carrier not only effectively loads fungicides with a maximum encapsulation efficiency of 95% but also stably deposits on hydrophobic leaves for high-speed impacting droplets. Intriguingly, these coacervates exhibit broad spectrum fungicidal activity against eight ubiquitous phytopathogens and even act as a standalone biofungicide to replace fungicides. This performance can significantly reduce the fungicide usage and be further strengthened by an encapsulated fungicide. The inhibition rate reaches 87.0% when 0.30 mM pyraclostrobin (Pyr) is encapsulated within this coacervate, comparable to the effectiveness of 0.80 mM Pyr alone. Additionally, the preventive effects against tomato gray mold reached 53%, significantly surpassing those of commercial adjuvants. Thus, it demonstrates that utilizing biosurfactants and biomass with intrinsic antifungal activity to fabricate fully biobased coacervates can synergistically combine the functions of a fungicide carrier and antifungal agent against phytopathogens and guarantee environmental friendliness. This pioneering approach provides deeper insights into synergistically enhancing the effectiveness of agrochemicals from multiple aspects, including fungicide encapsulation, cooperative antifungal action, and droplet deposition.

Promoting Seed Germination of Some Plant Species by Rhamnolipid Produced by Pseudomonas aeruginosa

With growing environmental concerns and a growing world population, there is an interest in developing cheap, efficient, and environmentally friendly substances that benefit humanity. Microbial surfactants are nontoxic, biodegradable bioproducts that provide sustainable solutions in agricultural applications due to their many benefits over their synthetic counterparts. Hence the crucial importance of scientific research to understand the effect of microbial surfactants on plant development. The present study aimed to assess the effect of rhamnolipid produced by Pseudomonas aeruginosa on seed germination of wheat (Triticum aestivum), barley (Hordeum vulgare), okra (Abelmoschus esculentus), onion (Allium cepa), and lettuce (Lactuca sativa) under laboratory conditions. The results showed that P. aeruginosa was capable of producing 3.83 g/L of viscous, honey-colored rhamnolipid, which was capable of lowering the surface tension to 30 ± 0.33 mN/m. Different concentrations of rhamnolipid ranging from 0.25 to 1.00 g/L were assessed, with distilled water acting as a control. After treatment of seeds, results showed that applying 0.25 g/L of rhamnolipid can significantly increase seed germination to 100% on the fourth day of sowing okra and lettuce, and on the fifth day of sowing onion seeds, compared to control groups that recorded 60%, 50%, and 55%, respectively. In wheat and barley seeds, applying rhamnolipid can protect seeds from pathogenic fungi while delaying their germination to 60% and 70% on the third day of sowing, while 90% and 100% have been reported in the control groups. Thus, this biological molecule demonstrates promising results in enhancing seed germination of the studied species by protecting them from phytopathogens and then aiding plant growth.

Bioformulation of Bacillus proteolyticus MITWPUB1 and its biosurfactant to control the growth of phytopathogen Sclerotium rolfsii for the crop Brassica juncea var local, as a sustainable approach

Bacillus proteolyticus MITWPUB1 is a potential producer of biosurfactants (BSs), and the organism is also found to be a producer of plant growth promoting traits, such as hydrogen cyanide and indole acetic acid (IAA), and a solubilizer of phosphate. The BSs were reportedly a blend of two classes, namely glycolipids and lipopeptides, as found by thin layer chromatography and Fourier-transform infrared spectroscopy analysis. Furthermore, semi-targeted metabolite profiling via liquid chromatography mass spectroscopy revealed the presence of phospholipids, lipopeptides, polyamines, IAA derivatives, and carotenoids. The BS showed dose-dependent antagonistic activity against Sclerotium rolfsii; scanning electron microscopy showed the effects of the BS on S. rolfsii in terms of mycelial deformations and reduced branching patterns. In vitro studies showed that the application of B. proteolyticus MITWPUB1 and its biosurfactant to seeds of Brassica juncea var local enhanced the seed germination rate. However, sawdust-carrier-based bioformulation with B. proteolyticus MITWPUB1 and its BS showed increased growth parameters for B. juncea var L. This study highlights a unique bioformulation combination that controls the growth of the phytopathogen S. rolfsii and enhances the plant growth of B. juncea var L. Bacillus proteolyticus MITWPUB1 was also shown for the first time to be a prominent BS producer with the ability to control the growth of the phytopathogen S. rolfsii.

Sustainable biosurfactant production from secondary feedstock-recent advances, process optimization and perspectives

Biosurfactants have garnered increased attention lately due to their superiority of their properties over fossil-derived counterparts. While the cost of production remains a significant hurdle to surpass synthetic surfactants, biosurfactants have been anticipated to gain a larger market share in the coming decades. Among these, glycolipids, a type of low-molecular-weight biosurfactant, stand out for their efficacy in reducing surface and interfacial tension, which made them highly sought-after for various surfactant-related applications. Glycolipids are composed of hydrophilic carbohydrate moieties linked to hydrophobic fatty acid chains through ester bonds that mainly include rhamnolipids, trehalose lipids, sophorolipids, and mannosylerythritol lipids. This review highlights the current landscape of glycolipids and covers specific glycolipid productivity and the diverse range of products found in the global market. Applications such as bioremediation, food processing, petroleum refining, biomedical uses, and increasing agriculture output have been discussed. Additionally, the latest advancements in production cost reduction for glycolipid and the challenges of utilizing second-generation feedstocks for sustainable production are also thoroughly examined. Overall, this review proposes a balance between environmental advantages, economic viability, and societal benefits through the optimized integration of secondary feedstocks in biosurfactant production.

Exploring the Application Potential of Aquaculture Sewage Treatment of Pseudomonas chengduensis Strain WD211 Based on Its Complete Genome

Pseudomonas chengduensis is a new species of Pseudomonas discovered in 2014, and currently, there is a scarcity of research on this bacterium. The P. chengduensis strain WD211 was isolated from a fish pond. This study investigated the purification capability and environmental adaptability of strain WD211 in wastewater and described the basic features and functional genes of its complete genome. According to the results, the sewage treated with strain WD211 showed a decrease in concentration of 18.12% in total nitrogen, 89.39% in NH4+, 62.16% in NO3-, 79.97% in total phosphorus, and 71.41% in COD after 24 h. Strain WD211 is able to survive in a pH range of 6-11. It shows resistance to 7% sodium chloride and different types of antibiotics. Genomic analysis showed that strain WD211 may remove nitrogen and phosphorus through the metabolic pathway of nitrogen assimilation and phosphorus accumulation, and that it can promote organic decomposition through oxygenase. Strain WD211 possesses genes for producing betaine, trehalose, and sodium ion transport, which provide it with salt tolerance. It also has genes for antibiotic efflux and multiple oxidases, which give it antibiotic resistance. This study contributes to the understanding of the sewage treatment ability and potential applications of P. chengduensis.

Biosurfactants' multifarious functional potential for sustainable agricultural practices

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.

Mannosylerythritol lipids: production, downstream processing, and potential applications

Mannosylerythritol lipids (MELs) are biosurfactants produced by various fungal species. Depending on the degree of acetylation and further chemical modifications, these glycolipids can show remarkable biological properties, including the increase of water retention in the stratum corneum suppression of melanogenic enzymes tyrosinase-1 and -2, reversion of UV-A radiation-induced aquaporin-3 suppression, skin whitening, and anti-aging effects. These applications of MELs require high purity, which is usually reached by liquid-liquid extraction followed by chromatography, obtaining ≥95% purity. This worked aimed to critically discuss the current state of the art and trends on the production of MELs, including post-production treatment as enzymatic conversion. In addition, their application as skincare or pharmaceutical agents and agricultural biostimulants.

Bacillus thuringiensis PM25 ameliorates oxidative damage of salinity stress in maize via regulating growth, leaf pigments, antioxidant defense system, and stress responsive gene expression

Soil salinity is the major abiotic stress that disrupts nutrient uptake, hinders plant growth, and threatens agricultural production. Plant growth-promoting rhizobacteria (PGPR) are the most promising eco-friendly beneficial microorganisms that can be used to improve plant responses against biotic and abiotic stresses. In this study, a previously identified B. thuringiensis PM25 showed tolerance to salinity stress up to 3 M NaCl. The Halo-tolerant Bacillus thuringiensis PM25 demonstrated distinct salinity tolerance and enhance plant growth-promoting activities under salinity stress. Antibiotic-resistant Iturin C (ItuC) and bio-surfactant-producing (sfp and srfAA) genes that confer biotic and abiotic stresses were also amplified in B. thuringiensis PM25. Under salinity stress, the physiological and molecular processes were followed by the over-expression of stress-related genes (APX and SOD) in B. thuringiensis PM25. The results detected that B. thuringiensis PM25 inoculation substantially improved phenotypic traits, chlorophyll content, radical scavenging capability, and relative water content under salinity stress. Under salinity stress, the inoculation of B. thuringiensis PM25 significantly increased antioxidant enzyme levels in inoculated maize as compared to uninoculated plants. In addition, B. thuringiensis PM25-inoculation dramatically increased soluble sugars, proteins, total phenols, and flavonoids in maize as compared to uninoculated plants. The inoculation of B. thuringiensis PM25 significantly reduced oxidative burst in inoculated maize under salinity stress, compared to uninoculated plants. Furthermore, B. thuringiensis PM25-inoculated plants had higher levels of compatible solutes than uninoculated controls. The current results demonstrated that B. thuringiensis PM25 plays an important role in reducing salinity stress by influencing antioxidant defense systems and abiotic stress-related genes. These findings also suggest that multi-stress tolerant B. thuringiensis PM25 could enhance plant growth by mitigating salt stress, which might be used as an innovative tool for enhancing plant yield and productivity.