Honey bees (Apis cerana indica) play a crucial role in pollination and ecosystem stability, but their populations are increasingly threatened by pesticide exposure and environmental stressors. Lactic acid bacteria (LAB), particularly fructophilic LAB (FLAB), are key components of the honey bee gut microbiota, contributing to digestion, immune modulation, and pathogen resistance. This study investigates the diversity, phylogenetic relationships, and pesticide tolerance of LAB isolated from honey bee gut, pollen, and honey across four distinct agroecosystems in Tamil Nadu, India. A total of 41 LAB strains were identified using both morphological and molecular techniques, including Apilactobacillus kunkeei, Fructobacillus fructosus, A. apinorum, and Secundilactobacillus kimchicus. Notably, this study reports S. kimchicus in the honey bee gut for the first time, expanding the known microbiota diversity associated with honey bees. Phylogenetic analysis, based on molecular traits, revealed distinct clustering patterns, indicating regional adaptations and evolutionary divergence among isolates. Growth assays confirmed a strong preference for fructose-rich environments, consistent with their ecological niche in nectar and honey. Pesticide tolerance assays demonstrated that A. kunkeei exhibited the highest resilience to imidacloprid, dinotefuran, fipronil, and dimethoate, highlighting its potential role in mitigating pesticide-induced stress in honey bee colonies. These findings suggest the application of FLAB as probiotic candidates by degrading pesticides and enhance colony resilience by maintaining gut health. Future research should explore the functional mechanisms underlying pesticide detoxification and immune modulation to develop targeted probiotic formulations for sustainable apiculture.

Using probiotics, especially those containing lactic acid bacteria (LAB), to support honey bee health and alleviate the negative effects of pesticides represents a promising approach for sustainable beekeeping. Probiotics have shown their ability to boost honey bee immune systems, counteract pesticide impacts, and lower disease rates. Bacteria like Lactobacillus and Bifidobacterium have demonstrated their ability to degrade organophosphorus pesticides using phosphatase enzymes. Additionally, these bacteria are resistant to the harmful effects of pesticides and aid in detoxification. Furthermore, supplementing with LAB positively affects colony growth, resulting in increased honey production, improved pollen storage, and higher brood counts. Various methods of delivering probiotics, such as powdered supplements, sucrose syrup, and pollen patties, have been explored, each with its own set of challenges and considerations. Despite making significant progress, further study is still required to fully comprehend the precise interactions between probiotics and the physiology of honey bees, to improve delivery strategies, and to evaluate the wider ecological effects on hive microbiomes. By implementing probiotic strategies in beekeeping practices, we can create stronger and more resilient honey bee colonies that can thrive amidst environmental challenges, thus promoting the sustainability of pollination services.

The purpose of this study was to evaluate the impact of phyllosphere methylotrophic plant growth-promoting bacteria on drought stress mitigation in groundnut. The experiment included five treatments [T1-Control, T2-Methylobacterium populi TMV7-4, T3-Methylobacterium thio cyanatum VRI7-A4, T4-Pseudomonas psychrotolerans K-TMV7-6, and T5-microbial consortium (comprising M. populi TMV7-4 + M. thiocyanatum VRI7-A4 + P. psychrotolerans K-TMV7-6)] under three water regimes (75%, 45%, and 20% field capacity). Each treatment was replicated five times, and pots were arranged in a completely randomized design. Seeds were sown in containers and maintained under regular watering for 22 days before imposing water stress for an additional 6 days. Plant growth parameters, proline content, and ethylene emission were recorded at the end of the stress period. In addition, the expression of the ACC oxidase (ACCO) gene was analyzed using qRT-PCR. Results revealed that microbial inoculation improved plant growth compared to the control, irrespective of drought stress intensity. However, no significant differences were observed between single strains and the microbial consortium. Microbial inoculation alleviated drought stress by reducing stress-related ethylene and proline accumulation, indicating lowered stress levels in treated plants. Across all drought conditions, plants inoculated with methylotrophic bacteria exhibited significantly reduced ACCO gene expression compared to the control. These methylotrophic isolates hold potential for development into a drought-tolerant bio-inoculant for groundnut.

Cotton, a crucial commercial fibre crop, depends heavily on seed-associated characteristics like germination rate, vigour, and resistance to post-harvest deterioration for both production and lint quality. Serious cellular damage during post-harvest processes such as delinting, prolonged seedling emergence periods, decreased viability, increased susceptibility to infections, and lipid peroxidation during storage pose serious problems to seed quality. The performance of seeds and total crop productivity are adversely affected by these problems. Traditional methods of seed improvement, like physical scarification and seed priming, have demonstrated promise in raising cotton seed vigour and germination rates. Furthermore, modern approaches including plasma therapies, magnetic water treatments, and nanotechnology-based treatments have shown promise in improving seed quality and reducing environmental stresses. By offering sustainable substitutes for conventional approaches, these cutting-edge procedures lessen the need for fungicides and other agrochemicals that pollute the environment. This review explores various conventional and emerging strategies to address the detrimental factors impacting cotton seed quality. It emphasizes the importance of integrating classical and advanced approaches to enhance germination, ensure robust crop establishment, and achieve higher yields. In addition to promoting sustainable cotton production, this kind of integration helps preserve the ecosystem and create resilient farming methods.

Hemiptera insects, like mealybug (Pseudococcidae family), pose a significant threat to agriculture, as evidenced by their status as a major pest and the existence of over 2,000 described species and 290 genera. Their destructive feeding habits lead to significant reductions in quality and productivity. In attempts to mitigate this problem, farmers often prefer the widespread use of synthetic insecticides. However, this conventional approach carries substantial drawbacks, like threats to human and environmental health, biomagnifications, the depletion of natural enemies, and resistance to target pests. The situation is more aggravated when water-based pesticides and biological control agents are quickly becoming ineffective by their cryptic lifestyle, hydrophobic wax covering, and the presence of gut endosymbionts of mealybugs, which together make their management difficult at best. The presence of symbiotic microbes in the saliva of phloem-sucking hemipterans, including mealybugs, enables these insect pests to defeat host plant defences and detoxify insecticides. Gut endosymbionts, wax-degrading bacteria, and entomopathogenic fungi are other promising eco-friendly agents that can channel to suppress populations of this polyphagous insect pest. Here, we review the analysis of conventional approaches to control mealybug infestations. Further, we explore eco-friendly alternatives and unravel cryptic interactions between mealybugs and associated microbes that would protect crops from the relentless menace of this assertive agricultural insect pest.

Nano-bio-formulations for insect pest management.

Metal nanoparticles (MNPs) have gained considerable attention for their diverse applications across various fields, including medicine, electronics, and environmental remediation, agriculture and manufacturing. The relationship between metal nanoparticles and the microorganisms, highlighting the diverse mechanisms through which nanotoxicity manifests and influences microbial communities. Metal nanoparticles, owing to their unique physicochemical properties, can interact with the microbiome directly or indirectly, disrupting microbial homeostasis and functionality. The interactions are complex, involving mechanisms such as membrane disorganization, reactive oxygen species (ROS) generation, and oxidative Deoxyribonucleic acid (DNA) damage. Comprehending the different types of metal nanoparticles, their antimicrobial properties, and the mechanisms that underlie their nanotoxicity towards microorganisms is imperative for the secure advancement and implementation of nanotechnology, paving the way for innovative strategies to mitigate adverse effects and promote sustainable nanomaterial applications. Nanotechnology has witnessed remarkable advancements in various fields, yet concerns regarding its potential adverse effects on biological systems, particularly the microbiome, have emerged as a significant area of investigation. This abstract highlight the importance of interdisciplinary approaches encompassing nanoscience, microbiology, and toxicology to unravel the intricate dynamics of metal nanoparticle-microbes’ interactions and facilitate the design of safer nanoproducts for diverse applications. Overall, this study emphasizes the need for more investigation to clarify the complex dynamics of metal nanoparticles in microbial environments and their long-term effects on sustainability and environmental health.

The application of chemical fertilizers and fungicides is causing harmful effects on the environment, such as soil acidification, water eutrophication, and air pollution. Thus, it is becoming crucial to achieve higher production through sustainable practices, avoiding or at least reducing the use of chemicals. Recently, a greater thrust has been given to the development of microbial products, since it consists of microbes of genetically diverse groups with different biochemical and physiological capabilities, which permit interactions among themselves and provide better management of diseases by way of synergistic effects and multiple modes of action. Plant probiotics are bacteria or a group of bacteria (PPBs) that, by their potential contribution to enhanced nutrient uptake and/or biocontrol activities, have the ability to support soil health, plant growth, and better tolerance or immunity to a variety of abiotic and biotic challenges. Methylotrophs are gram-negative, rod-shaped, and strictly aerobic microorganisms mostly abundant on the phylloplane of crop plants and are considered one of the PPBs. They belong to the classes of the Proteobacteria group, including alpha, beta, and gamma, and a few members of Verrucomicrobia, Firmicutes, Flavobacterium, and Actinobacteria. In this chapter, the nutritional mode of methylotrophs and their abundance, plant growth promotion mechanisms, and their role in sustainable agriculture are discussed in detail.

Abiotic stress poses a severe threat to agriculture because it negatively impacts cellular homeostasis and ultimately stunts plant growth. Abiotic stresses like drought, salinity, flood, and excessive heat are expected to occur more frequently in the future, which would reduce the yields of important crops and threaten the food security of human populations. Under stressful conditions, a range of characteristics, including physiological, biochemical, and molecular aspects of plants, are impacted. Only the plant-associated microbial community that supports plant growth and development under various abiotic stresses is a viable alternative. There is a developing paradigm that takes into account plant–microbiome linkages and interactions as a way to create novel techniques based on our present understanding of these interactions to mitigate plant stress. This chapter sheds light on current advancements in plant–microbe interactions for the alleviation of plant stress.

The utilization of various agrochemicals in crop production technology leads to soil health and fertility depletion. Multiple measures have been taken to revitalize the health of polluted soil. In this context, organic agriculture has increased over the past few years to overcome the detrimental effects of extensive modern agricultural practices. Several traditional organic formulations, such as panchagavya, jeevamurtha, beejamurtha, bokashi, etc., are vital in converting polluted farmlands into organic. Various countries have their own organic formulations to improve crop growth and yield. These formulations are rich sources of many macro and micronutrients, growth-promoting phytohormones, and provide resistance against biotic and abiotic stresses. Apart from these benefits, these formulations consist of several groups of beneficial microorganisms that belong to the phyla Proteobacteria, Firmicutes, Bacteroides, and Actinobacteria, while some of the novel groups of microorganisms were also reported from the ingredients used in the preparation of these organic formulations. These microorganisms can solubilize nutrients such as phosphorous and zinc, oxidize sulfur, reduce nitrate, and are also involved in the production of indole acetic acid, ethylene reduction enzyme (1-aminocyclopropane-1-carboxylic acid deaminase), and organic acids that promote plant growth and induce resistance in the plant system. Hence, the utilization of traditional organic formulations helps in the reclamation of environmental health without compromising crop yields. This review describes the importance of organic farming, the preparation and application of different types of traditional organic formulations in different countries, and the microbial composition and mechanism of growth promotion of different traditional organic formulations.

Flonicamid and dinotefuran are highly effective insecticides in paddy but residue persistence in crop and transmission into food and feed is unknown. This study aimed to examine initial deposits and dissipation kinetics of flonicamid and dinotefuran in paddy matrices and processed products including bran oil. The method was validated following acetonitrile extraction, dispersive solid phase clean-up and finally determination using liquid chromatography-mass spectrometry/mass spectrometry. Recoveries ranged from 76.6 to 109.7 percent for the paddy matrices tested. In a field experiment, flonicamid and dinotefuran were applied to paddy crops to study dissipation patterns. The half-lives of flonicamid and dinotefuran residues in paddy ranged from 2.0 to 3.0 days. However, at harvest time paddy grain and straw samples were found free from residues. Monitoring of residues in farm gate and market samples revealed that paddy products were not contaminated with flonicamid or dinotefuran residues.

Utilization of agroindustrial waste, such as press mud from the sugar industry, presents a compelling opportunity to address both economic and environmental concerns. Press mud is obtained during sugarcane juice clarification, is rich in sugar, minerals, and nutrients, making it a valuable resource for various applications. Since it is rich in nutrient, primarily press mud is used as manure for crop growth such as rice, maize, and wheat especially sugarcane. It increases the higher quality, yield, shoot, and root length. Press mud is mixed with bioinoculants, inorganic fertilizer, and it also contains native inoculum. It reduces the usage of chemical fertilizer. In addition to fertilizer, press mud is also used as biofuel, with detailed exploration into its conversion into biogas, biocompressed natural gas, and hydrogen, providing renewable resource, cost effective, eco-friendly alternatives, and contributions. Press mud role as an animal feed is delved into showcasing its inclusion in diets for layers, swine, broilers, and lambs and demonstrating its potential to reduce expenses without compromising growth. The economic, energetic, and environmental feasibility of these processes are discussed, highlighting the potential of press mud to contribute significantly to sustainable energy solutions. Sugarcane press mud is positioned as a versatile and valuable resource through this comprehensive exploration, offering solutions to waste management, agricultural enhancement, and sustainable energy production. The widespread adoption of press mud utilization is advocated by the findings, promoting a holistic approach to address both agricultural and environmental challenges. In future days, press mud can be explored as potential bioinoculant, renewable sources, and viable alternative feed.

Black gram (Vigna mungo (L.) Hepper) is a significant pulse crop due to its nutritional value and productivity within the Indian subcontinent. Pulses possess the inherent ability to fix atmospheric nitrogen into the soil through a symbiotic association with the Rhizobium, a genus of essential soil microorganisms that facilitate nitrogen fixation in legumes. However, conventional biofertilizers encounter challenges related to limited shelf life, reduced cellular viability, and inefficacy of carriers. This research investigates the encapsulation of Rhizobium using starch nanoparticles and sodium alginate to mitigate these drawbacks. The nanoformulations was assessed, with a mean droplet size and polydispersity index of 292 nm and 0.056, respectively. FTIR analysis confirmed the successful incorporation of all functional components. SEM imaging illustrated a uniform distribution of the formulation over the seed coat. Release kinetics displayed an initial burst release, followed by controlled and sustained release phases. The nanoformulations effectively protects the cells from adverse conditions in soil with different pH levels. A pot culture experiment with Black gram was conducted to evaluate the efficacy of the nanoformulations. The findings indicated significant enhancements in growth parameters, nodulation, and yield characteristics compared to the control and conventional treatments. The highest dosage of nanoformulation at the rate of 15ml/8Kg (T6) consistently surpassed other treatments, demonstrating improved shoot and root lengths, chlorophyll content, soluble protein, and enzyme activities. Treatment T6 gains the highest nodule count (approx. 100/plant) and maximized yield parameters. This investigation highlights the potential of Rhizobium nanoformulations in promoting plant growth, nodulation, and yield in black gram. It offers a promising strategy for sustainable agricultural practices and addresses the limitations of traditional biofertilizers.

Moisture stress poses a significant threat to global agriculture, compromising crop yields and food security. In the quest for sustainable solutions, endophytic microorganisms have emerged as promising candidates for enhancing plant resilience to drought. The study's primary goal was to analyse the significance of bacterial endophytes, both rhizobial and passenger endophytes, in alleviating the effects of moisture stress. Here, PEG 6000 was used to test the drought endurance of the ten identified rhizobial and passenger endophytes. Rhizobium pusense S6R2, Enterobacter cloacae S23 and Bacillus tequilensis NBB13 were selected as best performing endophytes as they showed high tolerance of poly ethylene glycol (PEG) and maximum plant growth promoting traits like Indole Acetic Acid, exopolysaccharide production, biofilm formation, 1-aminocyclopropane1-carboxylate (ACC) deaminase activity, siderophore, zinc and phosphorous solubilisation even in PEG induced moisture stress condition. Metabolite analysis revealed that twenty-four significant compounds mostly belong to fatty acyls, amino acids, peptides, polyketides, and benzenoids were found in the root exudates of groundnut treated with endophytes. The best-performing endophytes were used in a pot culture experiment, with groundnut as the test crop. The current study found that co-inoculation of Rhizobium pusense S6R2 and Enterobacter cloacae S23 significantly increased nodule number, growth, photosynthetic pigment, anti-oxidant enzymes, and osmolyte under moisture stressed conditions when compared to other treatments. As a result, co-inoculation of Rhizobium and entophytic bacteria may be recommended as a bio-inoculant for groundnut for moisture stress alleviation after confirming the results in field evaluation.

Aim This study aims to reveal the passenger endophytic bacterium Enterobacter cloacae S23 isolated from groundnut nodules and to underpin the molecular mechanism and genes responsible for abiotic stress tolerance. Background A variety of microorganisms that contribute to nodulation and encourage plant development activity in addition to the nodulating Rhizobium. Passenger endophytes (PE) are endophytes that accidentally penetrate the plant without any selective pressure keeping them in the interior tissue of the plant. PE possesses characteristics that encourage plant development and boost output while reducing pathogen infection and improving biotic and abiotic stress tolerance. However, there is a lack of molecular evidence on the passenger endophyte-mediated alleviation of abiotic stresses. Objective This study was formulated to reveal the draft genome sequence of Enterobacter cloacae S23, as well as genes and characteristics involved in plant growth promotion and stress tolerance. Method The data were submitted to PATRIC and the TORMES-1.0 Unicyclker tools were used to conduct a complete genome study of Enterobacter cloacae S23. The TORMES-1.0 platform was used to process the reads. RAST tool kit (RASTtk) was used to annotate the S23 sequence. The plant growth-promoting traits such as indole acetic acid production, siderophore secretion, production of extracellular polysaccharides, biofilm formation, phosphate solubilization, and accumulation of osmolytes were examined under normal, 7% NaCl and 30% polyethylene glycol amended conditions to determine their ability to withstand salt and moisture stressed conditions, respectively. Result We report the size of Enterobacter cloacae S23 is 4.82Mb which contains 4511 protein-coding sequences, 71 transfer RNA genes, and 3 ribosomal RNA with a G+C content of DNA is 55.10%. Functional analysis revealed that most of the genes are involved in the metabolism of amino acids, cofactors, vitamins, stress response, nutrient solubilization (kdp, pho, pst), biofilm formation (pga) IAA production (trp), siderophore production (luc, fhu, fep, ent, ybd), defense, and virulence. The result revealed that E. cloacae S23 exhibited multiple plant growth-promoting traits under abiotic stress conditions. Conclusion Our research suggested that the discovery of anticipated genes and metabolic pathways might characterise this bacterium as an environmentally friendly bioresource to support groundnut growth through several mechanisms of action under multi-stresses.

Plant microbiomes encompass different communities of microorganisms either as epiphytic regions such as phyllosphere, or rhizosphere regions and as endophytes in different plant tissues, which showed saprophytic, symbiotic, or pathogenic nature. Quorum sensing (QS) is a gene regulatory mechanism that controls crucial bacterial biological processes, including a variety of virulence characteristics. The concentration of chemical signal molecules known as autoinducers, which are produced and released by quorum-sensing bacteria, rises with cell density. A change in gene expression results from the observation of a minimal threshold stimulatory concentration of an autoinducer. Bacteria of both the Gram-positive and Gram-negative types use quorum-sensing communication circuits to control a wide range of physiological processes. Symbiosis, pathogenicity, competence, conjugation, generation of antibiotics, motility, sporulation, and biofilm development are some of these processes. This chapter covered numerous QS molecules’ methods for detection as well as diverse disease control strategies.

Plant pathogens cause various crop plant diseases and are considered one of the biotic stresses, accounting for 20–40% of economic losses. Chemical-based treatments are currently believed to be an effective and reliable agricultural management technique for disease control. Agrochemicals are highly effective and easy to use, yet they pose a danger to the ecosystem. The use of microbial agents to combat plant diseases is a good alternative to the use of chemicals, which are harmful to the environment and human health. Members of the Bacillus and Streptomyces genera are two of the most frequently used biocontrol agents to suppress plant diseases. Plant growth-promoting (PGP) characteristics are shared by both bacterial species. This chapter comprehensively reports the mechanisms used by Bacillus and Streptomyces in their behavior as biocontrol and PGP agents. Also discussed are the various commercial formulations made from these genera. The application of biocontrol agents made from viable microbial strains to the field bodes well for successful management of the disease for sustainable agriculture.

The rapid increase in soil salinization has impacted agricultural output and poses a threat to food security. There is an urgent need to focus on improving soil fertility and agricultural yield, both of which are severely influenced by abiotic variables such as soil salinity and sodicity. Abiotic forces have rendered one-third of the overall land unproductive. Microbes are the primary answer to the majority of agricultural production’s above- and below-ground problems. In stressful conditions, proper communication between plants and beneficial microbes is critical for avoiding plant cell damage. Many chemical substances such as proteins and metabolites synthesized by bacteria and plants mediate communication and stress reduction. Metabolites such as amino acids, fatty acids, carbohydrates, vitamins, and lipids as well as proteins such as aquaporins and antioxidant enzymes play important roles in plant stress tolerance. Plant beneficial bacteria have an important role in stress reduction through protein and metabolite synthesis under salt stress. Proper genomic, proteomic and metabolomics characterization of proteins and metabolites’ roles in salt stress mitigation aids scientists in discovering a profitable avenue for increasing crop output. This review critically examines recent findings on proteins and metabolites produced during plant-bacteria interaction essential for the development of plant salt stress tolerance.

The present study aimed to isolate Bacillus and Streptomyces species to control Macrophomina phaseolina and Fusarium oxysporum f. sp. udum that cause root rot and wilt diseases in pulses in general and pigeon pea, respectively. Bacillus subtilis BRBac4-1, B. subtilis BRBac24-2 and Bacillus siamensis BRBac21-1, Streptomyces cavourensis BRAcB10-1 and Streptomyces griseofuscus BRAcB11-2 showed potential antagonistic activity against Macrophomina phaseolina and Fusarium oxysporum f. sp. udum, in a dual culture assay. These rhizobacteria were found to possess multiple plant growth-promoting traits besides producing -lytic enzymes, non-volatile metabolites (iturin and surfactin), and volatile organic carbon compounds (disulphide, azithromycin, 1-butanol, 2-methyl, and dimethyl disulphide) with antifungal activities which were detected in culture filtrate through GC-MS and LC-MS analyses. A pot culture experiment was conducted to test plant growth promotion and disease suppression capacity of the selected rhizobacteria in green gram, black gram, and red gram. In a pot culture experiment, combined inoculation of B. siamensis BRBac21-1 plus S. cavourensis BRAcB10-1 rendered the plant more resistant to fungal infection and further development through the induction of systemic defense in host tissue by improving the status of different defense enzymes (phenylalanine ammonia lyase, polyphenol oxidase, and peroxidase). Furthermore, these two bacteria significantly reduced disease severity, and, promoted shoot and root growth in all the tested crops. In conclusion, B. siamensis BRBac21-1 and S. cavourensis BRAcB10-1 displayed the potential antifungal activities and promoted plant growth and the combined bio-formulation of these two rhizobacteria may be used to manage wilt and root rot pathogens in pulses after field evaluation.