Endophyte-mediated synthesis of silver nanoparticles and their biological applications

Valorization and Repurposing of Citrus limetta Fruit Waste for Fabrication of Multifunctional AgNPs and Their Diverse Nanomedicinal Applications

Herein we propose an ecofriendly process for the biofabrication of AgNPs by applying fruit waste of Citrus limetta. The aqueous extracts from the peels of the fruit were used as green chelating and stabilizing agents. Structural, optical, vibrational, morphological, and magnetic properties were established using UV-Vis (ultraviolet visible spectroscopy), XRD (X-rays diffraction), FTIR (Fourier transformed infrared spectroscopy), EDS (energy dispersive spectroscopy), SEM (scanning electron microscopy), ESR (electron spin resonance), and PPMS (physical property management system), while the thermal properties were established using TGA/DTG (thermal gravimetric analysis/derivative thermogravimetry). XRD pattern revealed intense peaks with single-phase purity, while the Debye-Scherrer approximation revealed an average crystallite size of 33.18 nm. The W-H plot revealed the size of 55.2 nm and strain 2.68 × 10-4. FTIR spectra revealed the involvement of different functional groups and major IR vibrations were observed at 2329 cm-1, 2092 cm-1, 1794 cm-1, 1268 cm-1, and 754 cm-1. TGA/DTG revealed major weight loss events at 240 °C and 360 °C. SEM revealed spherical or quasi-spherical morphology, while EDS confirmed the presence of elemental silver. The M-H behavior for all measurement temperature shows diamagnetic behavior. Electron spin resonance (ESR) revealed a high proportion of free electrons. Furthermore, the pharmacognostic and nanomedicinal potential CL-AgNPs was established using multiple in vitro and in vivo bioassays. The in vivo wound healing assays in mice revealed excellent healing potential which were similar to positive control. The percent wound healing is reported to be 93% on the 14th day of incision after application of CL-AgNPs. Bioassays were performed to assess enzyme inhibition potential of the CL-AgNPs for Alzheimer disease and antidiabetic applications. The AChE and BChE potential of the CL-AgNPs was highest at 1000 µg mL-1, i.e., 92% and 56%, respectively. The α-glucosidase inhibition potential for the CL-AgNPs was higher as compared to the α-glucosidase, while the DPPH free radical scavenging was reported to be 70% to 11% at varying concentrations between 1000 and 62.5 µg mL-1. Overall, our results indicate that the waste fruit peels can be a sustainable and eco-friendly resource of synthesis of the multifunctional nanoparticles.

Green synthesis of silver nanoparticles using Phlebopus portentosus polysaccharide and their antioxidant, antidiabetic, anticancer, and antimicrobial activities

Silver nanoparticles (AgNPs) by green synthesis from fungi polysaccharides are attracting increasing attention owing to their distinctive features and special applications in numerous fields. In this study, a cost-effective and environmentally friendly biosynthesizing AgNPs method with no toxic chemicals involved from the fruiting body polysaccharide of Phlebopus portentosus (PPP) was established and optimized by single factor experiment and response surface methodology. The optimum synthesis conditions of polysaccharide-AgNPs (PPP-AgNPs) were identified to be the reaction time of 140 min, reaction temperature of 94 °C, and the PPP: AgNO3 ratio of 1:11.5. Formation of PPP-AgNPs was indicated by visual detection of colour change from yellowish to yellowish brown. PPP-AgNPs were characterized by different methods and further evaluated for biological activities. That the Ultraviolet-visible (UV-Vis.) spectroscopy displayed a sharp absorption peak at 420 nm confirmed the formation of AgNPs. Fourier transform infrared (FTIR) analysis detected the presence of various functional groups. The lattice indices of (111), (200), (220), and (331), which indicated a faced-centered-cubic of the Ag crystal structure of PPP-AgNPs, was confirmed by X-ray diffraction (XRD) and the particles were found to be spherical through high resolution transmission electron microscopy (HRTEM). Energy dispersive X-ray spectroscopy (EDS) determined the presence of silver in PPP-AgNPs. The percentage relative composition of elements was determined as silver (Ag) 82.5 % and oxygen (O) 17.5 % for PPP-AgNPs, and did not exhibit any nitrogen peaks. The specific surface area of PPP-AgNPs was calculated to be 0.5750 m2/g with an average pore size of 24.33 nm by BET analysis. The zeta potential was -4.32 mV, which confirmed the stability and an average particle size of 64.5 nm was calculated through dynamic light scattering (DLS). PPP-AgNPs exhibited significant free radical scavenging activity against DPPH with an IC50 value of 0.1082 mg/mL. The MIC values of PPP-AgNPs for E. coli, S. aureus, C. albicans, C. glabrata, and C. parapsilosis are 0.05 mg/mL. The IC50 value of the inhibition of PPP-AgNPs against α-glucosidase was 11.1 μg/mL, while the IC50 values of PPP-AgNPs against HepG2 and MDA-MB-231 cell lines were calculated to be 14.36 ± 0.43 μg/mL and 40.05 ± 2.71 μg/mL, respectively. According to the evaluation, it can be concluded that these green-synthesized and eco-friendly PPP-AgNPs are helpful to improve therapeutics because of significant antioxidant, antimicrobial, antidiabetic, and anticancer properties to provide new possibilities for clinic applications.

An overview of green synthesized silver nanoparticles towards bioactive antibacterial, antimicrobial and antifungal applications

Present review emphatically introduces the synthesis, biocompatibility, and applications of silver nanoparticles (AgNPs), including their antibacterial, antimicrobial, and antifungal properties. A comprehensive discussion of various synthesis methods for AgNPs, with a particular focus on green chemistry mediated by plant extracts has been made. Recent research has revealed that the optical properties of AgNPs, including surface plasmon resonance (SPR), depend on the particle size, as well as the synthesis methods, preparation synthesis parameters, and used reducing agents. The significant emphasis on the use of synthesized AgNPs as antibacterial, antimicrobial, and antifungal agents in various applications has been reviewed. Furthermore, the application areas have been thoroughly examined, providing a detailed discussion of the underlying mechanisms, which aids in determining the optimal control parameters during the synthesis process of AgNPs. Furthermore, the challenges encountered while utilizing AgNPs and the corresponding advancements to overcome them have also been addressed. This review not only summarizes the achievements and current status of plant-mediated green synthesis of AgNPs but also explores the future prospects of these materials and technology in diverse areas, including bioactive applications.

Harnessing the action mechanisms of microbial endophytes for enhancing plant performance and stress tolerance: current understanding and future perspectives

Microbial endophytes are microorganisms that reside within plant tissues without causing any harm to their hosts. These microorganisms have been found to confer a range of benefits to plants, including increased growth and stress tolerance. In this review, we summarize the recent advances in our understanding of the mechanisms by which microbial endophytes confer abiotic and biotic stress tolerance to their host plants. Specifically, we focus on the roles of endophytes in enhancing nutrient uptake, modulating plant hormones, producing secondary metabolites, and activating plant defence responses. We also discuss the challenges associated with developing microbial endophyte-based products for commercial use, including product refinement, toxicology analysis, and prototype formulation. Despite these challenges, there is growing interest in the potential applications of microbial endophytes in agriculture and environmental remediation. With further research and development, microbial endophyte-based products have the potential to play a significant role in sustainable agriculture and environmental management.

An insight into endophytic antimicrobial compounds: an updated analysis

Resistance in micro-organisms against antimicrobial compounds is an emerging phenomenon in the modern era as compared to the traditional world which brings new challenges to discover novel antimicrobial compounds from different available sources, such as, medicinal plants, various micro-organisms, like, bacteria, fungi, algae, actinomycetes, and endophytes. Endophytes reside inside the plants without exerting any harmful impact on the host plant along with providing ample of benefits. In addition, they are capable of producing diverse antimicrobial compounds similar to their host, allowing them to serve as useful micro-organism for a range of therapeutic purposes. In recent years, a large number of studies on the antimicrobial properties of endophytic fungi have been carried out globally. These antimicrobials have been used to treat various bacterial, fungal, and viral infections in humans. In this review, the potential of fungal endophytes to produce diverse antimicrobial compounds along with their various benefits to their host have been focused on. In addition, classification systems of endophytic fungi as well as the need for antimicrobial production with genetic involvement and some of the vital novel antimicrobial compounds of endophytic origin can further be utilized in the pharmaceutical industries for various formulations along with the role of nanoparticles as antimicrobial agents have been highlighted.

Mycosynthesis of Metal-Containing Nanoparticles-Fungal Metal Resistance and Mechanisms of Synthesis

In the 21st century, nanomaterials play an increasingly important role in our lives with applications in many sectors, including agriculture, biomedicine, and biosensors. Over the last two decades, extensive research has been conducted to find ways to synthesise nanoparticles (NPs) via mediation with fungi or fungal extracts. Mycosynthesis can potentially be an energy-efficient, highly adjustable, environmentally benign alternative to conventional physico-chemical procedures. This review investigates the role of metal toxicity in fungi on cell growth and biochemical levels, and how their strategies of resistance, i.e., metal chelation, biomineral formation, biosorption, bioaccumulation, compartmentalisation, and efflux of metals from cells, contribute to the synthesis of metal-containing NPs used in different applications, e.g., biomedical, antimicrobial, catalytic, biosensing, and precision agriculture. The role of different synthesis conditions, including that of fungal biomolecules serving as nucleation centres or templates for NP synthesis, reducing agents, or capping agents in the synthesis process, is also discussed. The authors believe that future studies need to focus on the mechanism of NP synthesis, as well as on the influence of such conditions as pH, temperature, biomass, the concentration of the precursors, and volume of the fungal extracts on the efficiency of the mycosynthesis of NPs.

Microbes-mediated synthesis strategies of metal nanoparticles and their potential role in cancer therapeutics

Past few years have seen a paradigm shift towards ecofriendly, green and biological fabrication of metal nanoparticles (MNPs) for diverse nanomedicinal applications especially in cancer nanotheranostics. Besides, the well-known green synthesis methods of plant materials, the potential of the microbial world (bacteria, fungi, alga, etc.) in biofabrication is equally realized. Biomolecules and enzymes in the microbial cells are capable of catalyzing the biosynthesis process. These microbial derived inorganic nanoparticles have been frequently evaluated as potential agents in cancer therapies revealing exciting results. Through, cellular and molecular pathways, these microbial derived nanoparticles are capable of killing the cancer cells. Considering the recent developments in the anticancer applications of microbial derived inorganic MNPs, a dire need was felt to bring the available information to a single document. This manuscript reviews not only the mechanistic aspects of the microbial derived MNPs but also include the diverse mechanisms that governs their anticancer potential. Besides, an updated literature review is presented that includes studies of 2019-onwards.

Biological Synthesis of Silver Nanoparticles and Prospects in Plant Disease Management

Exploration of nanoparticles (NPs) for various biological and environmental applications has become one of the most important attributes of nanotechnology. Due to remarkable physicochemical properties, silver nanoparticles (AgNPs) are the most explored and used NPs in wide-ranging applications. Also, they have proven to be of high commercial use since they possess great chemical stability, conductivity, catalytic activity, and antimicrobial potential. Though several methods including chemical and physical methods have been devised, biological approaches using organisms such as bacteria, fungi, and plants have emerged as economical, safe, and effective alternatives for the biosynthesis of AgNPs. Recent studies highlight the potential of AgNPs in modern agricultural practices to control the growth and spread of infectious pathogenic microorganisms since the introduction of AgNPs effectively reduces plant diseases caused by a spectrum of bacteria and fungi. In this review, we highlight the biosynthesis of AgNPs and discuss their applications in plant disease management with recent examples. It is proposed that AgNPs are prospective NPs for the successful inhibition of pathogen growth and plant disease management. This review gives a better understanding of new biological approaches for AgNP synthesis and modes of their optimized applications that could contribute to sustainable agriculture.

Antimicrobial, antibiofilm, and anticancer potential of silver nanoparticles synthesized using pigment-producing Micromonospora sp. SH121

Silver nanoparticles (AgNPs) have gained interest as an alternative pharmaceutical agent because of antimicrobial resistance and drug toxicity. Considering the increasing request, eco-friendly, sustainable, and cost-effective synthesis of versatile AgNPs has become necessary. In this study, green-made AgNPs were successfully synthesized using Micromonospora sp. SH121 (Mm-AgNPs). Synthesis was verified by surface plasmon resonance (SPR) peak at 402 nm wavelength in the UV-Visible (UV-Vis) absorption spectrum. Scanning electron microscopy (SEM) analysis depicted that Mm-AgNPs were in the size range of 10-30 nm and spherical. Fourier transform infrared spectroscopy (FTIR) confirmed the existence of bioactive molecules on the surface of nanoparticles. The X-ray diffraction (XRD) analysis revealed the face-centered cubic (fcc) structure of the Mm-AgNPs. Their polydispersity index (PDI) and zeta potential were 0. 284 and -35.3 mV, respectively. Mm-AgNPs (4-32 µg/mL) exhibited strong antimicrobial activity against Bacillus cereus, Enterococcus faecalis, Enterococcus hirae, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas putida, Staphylococcus epidermidis, Streptococcus pneumoniae, and Aspergillus flavus. Mm-AgNPs partially inhibited the biofilm formation in Acinetobacter baumannii, E. coli, K. pneumoniae, and Pseudomonas aeruginosa. Furthermore, results showed that low concentrations of Mm-AgNPs (1 and 10 µg/mL) caused higher cytotoxicity and apoptosis in DU 145 cells than human fibroblast cells. Based on the results, Mm-AgNPs have an excellent potential for treating infectious diseases and prostate cancer.

Catalytic potential of endophytes facilitates synthesis of biometallic zinc oxide nanoparticles for agricultural application

Recent advances fascinated the use of biological resources in combination with metals to obtain high quality biometals and apply its advantages in different fields. Endophytic mediated Zinc oxide nanoparticles (ZnO-NPs) is an economical and ecofriendly way for farmers to avoid Zn deficiency in rice crop and obtain high yield. Here we synthesized ZnO-NPs utilizing endophytic bacterial strain of Enterobacter hormaechei (E. hormaechei). The physiochemical properties of the prepared NPs were determined through UV-Vis spectroscopy, XRD, FT-IR, SEM and TEM. The prepared NPs revealed surface plasmon resonance (SPR) at 320 nm (nm) and crystalline structure with 21 nm average crystalline size. FT-IR spectra showed the presence of carboxylic, alcohol and amine functional groups, which confirm the biometallic assembling of the ZnO and endophytic bacterial functional groups. SEM showed pyramidal symmetry whereas TEM revealed poly dispersed spherical shape with particle size distribution 18-48 nm. Our results showed that prepared NPs possess significant antifungal, antibacterial and antioxidant potential at 25, 50 and 100 µg/mL concentrations. Moreover, Cytotoxic and hemolytic assay showed significant results (less % viability and hemolysis activity) at 50 and 100 µg/mL (ZnO-NP's) concentrations as compared to control. The prepared ZnO-NPs were used as bio fertilizer in various concentrations as a foliar spray, which showed significant enhancement of the rice plant growth, along with chlorophyll, proteins and carotenoid contents. These results recommend that endophytic mediated ZnO-NPs are biocompatible and possess significant potential for agricultural applications.

Biosynthesis and characterization of silver nanoparticles from symbiotic bacteria Xenorhabdus nematophila and testing its insecticidal efficacy on Spodoptera litura larvae

Spodoptera litura, one of the polyphagous pests, causes huge economical lose and use of chemical pesticide causes impact to the environmental. The present study deals with the use of cell- free supernatant of bacteria Xenorhabdus nematophila NP-1 strain for synthesizing silver nanoparticles and analyzing its larvicidal ability against Spodoptera litura. Color change from yellow to dark brown specifies the synthesis of AgNPs. UV-Vis spec indicates the presences of AgNPs at 440 nm λ_max and functional groups; alcohols, carboxylic acids, aromatics, alkylhalides, ethers and phenols were confirmed by FTIR. SEM revealed the synthesized AgNPs is in spherical shape, EDaX confirms the elemental composition and the crystalline nature were observed using XRD. GC-MS analysis showed presence of Benzencepropanoic acid, 1, 3, 5 Trichloropent-2-ene, 1,1-Dichloro-2,3- dicmethycycloprone and 1,2-benzenedicarboxylic acid bioactive compounds some of which may be responsible for insecticidal and antibacterial activity. The antibacterial activity against S. aureus, B. subtilis and K. pneumoniae showed maximum zone of inhibition at 100 µL/mL. Larvicidal activity of S. litura shows highest mortality at 48 h. In potted plant experiment, AgNPs treated plants showed less damage, with less leaf consumption by S. litura larvae. Further, the synthesis of AgNPs were targeted to zebrafish embryos (non- target organism) and it didn't exhibit any toxic effect even at higher concentration. Our experiment concludes that, AgNPs synthesized using NP-1 strain has highest antimicrobial and insecticidal activity, which can be used in biomedical and biopesticides.

Endophytic Microorganisms From the Tropics as Biofactories for the Synthesis of Metal-Based Nanoparticles: Healthcare Applications

Nanoparticles (NPs) have gained great attention in recent years due to their extensive and innovative applications in the field of medicine. However, conventional physicochemical approaches for the synthesis of NPs may be limited and costly, and the reaction by-products are potentially toxic for human health and the environment. Bio-mediated synthesis of NPs exploiting microorganisms as nanofactories has emerged as an alternative to traditional methods, as it provides economic and environmental benefits. Tropical ecosystems harbor a high diversity of endophytes, which have a diverse array of metabolic pathways that confer habitat adaptation and survival and that can be used to produce novel bioactive compounds with a variety of biological properties. Endophytic bacteria and fungi cultivated under optimum conditions have potential for use in biogenic synthesis of NPs with different characteristics and desired activities for medical applications, such as antimicrobial, antitumoral, antioxidant and anti-inflammatory properties. The bio-mediated synthesis of metal-based NPs can be favored because endophytic microorganisms may tolerate and/or adsorb metals and produce enzymes used as reducing agents. To our knowledge, this is the first review that brings together exclusively current research highlighting on the potential of endophytic bacteria and fungi isolated from native plants or adapted to tropical ecosystems and tropical macroalgae as nanofactories for the synthesis of NPs of silver, gold, copper, iron, zinc and other most studied metals, in addition to showing their potential use in human health.

Recent Developments in Metallic Nanomaterials for Cancer Therapy, Diagnosing and Imaging Applications

Cancer continues to represent a global health concern, imposing an ongoing need to research for better treatment alternatives. In this context, nanomedicine seems to be the solution to existing problems, bringing unprecedented results in various biomedical applications, including cancer therapy, diagnosing, and imaging. As numerous studies have uncovered the advantageous properties of various nanoscale metals, this review aims to present metal-based nanoparticles that are most frequently employed for cancer applications. This paper follows the description of relevant nanoparticles made of metals, metal derivatives, hybrids, and alloys, further discussing in more detail their potential applications in cancer management, ranging from the delivery of chemotherapeutics, vaccines, and genes to ablative hyperthermia therapies and theranostic platforms.

Synthesis and characterization of polystyrene with embedded silver nanoparticle nanofibers to utilize as antibacterial and wound healing biomaterial

Herein, silver nanoparticles (Ag) embedded in polystyrene (PS) nanofiber composites have been prepared by an electrospinning technique using N, N-dimethylformamide (DMF) as a solvent and safe reducing agent. Electrospinning of polystyrene (PS) solutions is conducted using different electrospinning parameters such as polymer concentration in the electrospinning solution; solution feed rate, and electrical field strength. Then silver nanoparticles (AgNPs) were embedded into PS nanofibers to obtain an AgNPs-PS nanofiber composite as a powerful, cheap, and nontoxic bioactive material. PS nanofibers and AgNPs-PS nanofibers composite were characterized by using thermogravimetric analysis (TGA), X-ray diffraction, and scanning electron microscopy (SEM). Also, AgNPs were characterized by UV-vis spectroscopy, transmission electron microscopy (TEM), and EDX analysis. Results showed that PS nanofibers were obtained with concentrations ranging from 10–30 wt.% in DMF solvent. Also, an AgNPs-PS nanofiber composite has been produced from its solutions by using DMF at the optimum value. The prepared AgNPs have a 21–40 nm particle size and a semi-spherical shape. In addition, the antibacterial activity of AgNPs-PS nanofibers towards both Gram-positive and Gram-negative bacteria has been increased. Therefore, this nanocomposite can be used as a powerful bioactive material in biomedical fields.

Pharmacological properties of biogenically synthesized silver nanoparticles using endophyte Bacillus cereus extract of Berberis lyceum against oxidative stress and pathogenic multidrug-resistant bacteria

The emergence of multidrug resistance in pathogenic bacteria limits the utilization of available antibiotics. The development of alternate options to treat infectious diseases is the need of the day.The present study was aimed to synthesize, characterize and evaluate the bioactive properties of silver nanoparticles. Endophytic bacterium Bacillus cereus (MT193718) isolated from Berberis lycium was used to synthesize biocompatible silver nanoparticles. Antibacterial properties of AgNPs were evaluated against clinically isolated multidrug-resistant strains of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter baumannii and Klebsiella pneumoniae. AgNPs indicated significant antibacterial activity against S. aureus and K. pneumoniae fwith a zone of inhibition of 17 and 18 mm at a concentration of 1000 µg/ mL with minimum inhibitory concentration of 15.6 and 62.5 µg/mL respectively. Significant antioxidant activity with an IC50 value of 9.5 µg/mL was recorded. Biosynthesized AgNPs were found compatible with red blood cells at a concentration of 31.5 µg/ml with no clumping of erythrocytes. The study suggested that AgNPs synthesized by the endophytic bacterium Bacillus cereus are biologically active and can be used as antioxidant and antibacterial agents against drug-resistant bacteria.

Harnessing Bacterial Endophytes for Promotion of Plant Growth and Biotechnological Applications: An Overview

Endophytic bacteria colonize plants and live inside them for part of or throughout their life without causing any harm or disease to their hosts. The symbiotic relationship improves the physiology, fitness, and metabolite profile of the plants, while the plants provide food and shelter for the bacteria. The bacteria-induced alterations of the plants offer many possibilities for biotechnological, medicinal, and agricultural applications. The endophytes promote plant growth and fitness through the production of phytohormones or biofertilizers, or by alleviating abiotic and biotic stress tolerance. Strengthening of the plant immune system and suppression of disease are associated with the production of novel antibiotics, secondary metabolites, siderophores, and fertilizers such as nitrogenous or other industrially interesting chemical compounds. Endophytic bacteria can be used for phytoremediation of environmental pollutants or the control of fungal diseases by the production of lytic enzymes such as chitinases and cellulases, and their huge host range allows a broad spectrum of applications to agriculturally and pharmaceutically interesting plant species. More recently, endophytic bacteria have also been used to produce nanoparticles for medical and industrial applications. This review highlights the biotechnological possibilities for bacterial endophyte applications and proposes future goals for their application.

Applications of endophytic microbes in agriculture, biotechnology, medicine, and beyond

Endophytes are emerging as integral components of plant microbiomes. Some of them play pivotal roles in plant development and plant responses to pathogens and abiotic stresses, whereas others produce useful and/or interesting secondary metabolites. The appreciation of their abilities to affect plant phenotypes and produce useful compounds via genetic and molecular interactions has paved the way for these abilities to be exploited for health and welfare of plants, humans and ecosystems. Here we comprehensively review current and potential applications of endophytes in the agricultural, pharmaceutical, and industrial sectors. In addition, we briefly discuss the research objectives that should be focused upon in the coming years in order for endophytes and their metabolites to be fully harnessed for potential use in diverse areas.

Bacillus Spp.: Efficient Biotic Strategy to Control Postharvest Diseases of Fruits and Vegetables

: Postharvest diseases significantly reduce the shelf-life of harvested fruits/vegetables worldwide. Bacillus spp. are considered to be an eco-friendly and bio-safe alternative to traditional chemical fungicides/bactericides due to their intrinsic ability to induce native anti-stress pathways in plants. This review compiles information from multiple scientific databases (Scopus, ScienceDirect, GoogleScholar, ResearchGate, etc.) using the keywords "postharvest diseases", "Bacillus", "Bacillus subtilis", "biocontrol", "storage", "losses", and "fruits/vegetables". To date, numerous examples of successful Bacillus spp. application in controlling various postharvest-emerged pathogens of different fruits/vegetables during handling, transportation, and storage have been described in the literature. The mechanism/s of such action is/are still largely unknown; however, it is suggested that they include: i) competition for space/nutrients with pathogens; ii) production of various bio-active substances with antibiotic activity and cell wall-degrading compounds; and iii) induction of systemic resistance. With that, Bacillus efficiency may depend on various factors including strain characteristics (epiphytes or endophytes), application methods (before or after harvest/storage), type of pathogens/hosts, etc. Endophytic B. subtilis-based products can be more effective because they colonize internal plant tissues and are less dependent on external environmental factors while protecting cells inside. Nevertheless, the mechanism/s of Bacillus action on harvested fruits/vegetables is largely unknown and requires further detailed investigations to fully realize their potential in agricultural/food industries.