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Fipronil is a phenylpyrazole insecticide used in various agricultural, horticulture, and veterinary practices. Besides its wide range of applications, it also causes severe health hazards to the non-targeted organisms especially in developing countries. Fipronil showed hepatotoxic, nephrotoxic, neurotoxic, and altered reproductive development and endocrine system in humans and animals. Several methods have been already introduced for the removal of toxic fipronil including physicochemical and by the implementation of microorganisms. The microbial methods of fipronil degradation are the most promising and environmentally sustainable. The remediation of fipronil from the environment is an emerging task due to its enhanced residual concentration. Herein, we discuss the bioremediation potential of microbial strains in contaminated soil and water. It is shown that fipronil can be remediated from the environment using combined ecotechnologies. This review discusses the toxicity, different physico-chemical and biological methods, and sustainable developments in fipronil-contaminated agriculture and aquatic environments.

Chlorpyrifos is a broad-spectrum organophosphate pesticide and used frequently on different cropping systems to control phytopathogens. Being a hazardous substance, chlorpyrifos may affect human health as some unutilized pesticide percolates through soil and contaminates ground water. Present study was planned to establish an effective remediation method of chlorpyrifos using two fungal isolates (C1 and C3), recovered from the waste (soil) of a refrigeration industry. C1 and C3, identified as Byssochlamys spectabilis and Aspergillus fumigates respectively were able to tolerate 600 mg L− 1 of chlorpyrifos. “The Half-life of chlorpyrifos (control) was 231 days which could be reduced to 13.6 days” under in vitro condition in the presence of mixture of two fungi in Czapek dox medium (CDM). Consortium of the fungi showed 98.4 % degradation of chlorpyrifos within 30 days in CDM. Degradation of the pesticide was related to specific laccase activity of the fungi and the level of enzyme activity was better in consortium 9.09 and 10.29 U mL− 1 after 6 and 10 days respectively. Immobilized fungal enzymes also showed appreciable biodegradation of the pesticide by providing extra matrix for enzyme substrate reaction. Residual analysis of chlorpyrifos in the soil of onion (Allium cepa) in a phytoremediation experiment revealed a significant decrease in t1/2 value in the presence of fungi. Hence, it is concluded that chlorpyrifos biodegradation ability of fungal consortium reveals the potential of these isolates in biodegradation of toxic compounds from contaminated water and soil. However, further studies are needed to access the biodegradation of the pesticide in different soil types, crops and under varied environmental conditions at molecular level.

The large-scale application of organic pollutants (OPs) has contaminated the air, soil, and water. Persistent OPs enter the food supply chain and create several hazardous effects on living systems. Thus, there is a need to manage the environmental levels of these toxicants. Microbial glycoconjugates pave the way for the enhanced degradation of these toxic pollutants from the environment. Microbial glycoconjugates increase the bioavailability of these OPs by reducing surface tension and creating a solvent interface. To date, very little emphasis has been given to the scope of glycoconjugates in the biodegradation of OPs. Glycoconjugates create a bridge between microbes and OPs, which helps to accelerate degradation through microbial metabolism. This review provides an in-depth overview of glycoconjugates, their role in biofilm formation, and their applications in the bioremediation of OP-contaminated environments.

Purple blotch disease of onion, caused by Alternaria porri (Ellis) Cif., causes extensive damage to the bulb and seed crops. The present study was aimed to assess the morpho-cultural variations and genetic diversity in 14 isolates of A. porri by simple sequence repeat (SSR) markers (selected on the basis of polymorphism pattern). Most isolates showed white fluffy colony growth and yellow to light orange pigmentation with circular, irregular and smooth margin along with clear-cut zonation. During the study period, 36 loci were obtained and the average expected gene diversity was found in the range of 0.0531-0.3707. Shan cluster analysis and unweighted pair-group method with arithmetic averages (UPGMA) analysis revealed that the isolates ‘A.p.B4’ and ‘A.p.B1' had maximum similarity coefficient (0.9166667), while isolates ‘A.p.B12’ and ‘A.p.B13’ had distant similarity coefficient (0.6111111). The SSR primers D.N.alt4 (200-720 bp) and D.N.alt10 (300-600 bp) represented unique bands for all isolates which were used for the identification of isolates. The polymorphic information content (PIC) value for primer D.N.alt-4 and D.N.alt-10 was 0.0, with maximum and minimum PIC value for D.N.alt14 (0.2978) and D.N.alt-5 (0.0495), respectively, thus represented the discriminatory power of a locus. The study revealed that the nine SSR markers tested were helpful in the isolation and molecular characterization of A. porri on the basis of polymorphism or genetic diversity.

The present study was planned with the objective to isolate and characterize a carbendazim-degrading Achromobacter sp. strain GB61 from the contaminated agriculture field. Optimized carbendazim biodegradation (76.2%) by Achromobacter sp. strain GB61 was observed at 30 °C, pH 7.0, and 120 rpm within 20 days of incubation and was determined using response surface methodology. The degradation kinetics revealed the half-life (t1/2) of 7.3 days, and correlation coefficient (R2) 0.0882 and degradation constant (K) 0.095 respectively. Maximum specific degradation rate (qmax), half-saturation constant (Ks) and inhibition constant (Ki) were determined to be 0.122 d−1, 0.724 mg L−1 and 271.71 mg L−1, respectively. Intermediate metabolites of carbendazim biodegradation confirming the formation of dihydroxybenzimidazole, 2-aminobenzimidazole and benzimidazole as intermediates. The results of the experiments suggested that the strain GB61 could be used for large-scale bioremediation of carbendazim contaminated environments.

Evolution is mainly driven by environmental stresses. Among all the living beings, microorganisms have elaborated a wide range of physiological responses to survive in different ecosystems. Variations in the environment allow microorganisms to acquire new gene(s) through different processes and to lose preexisting genes by the processes like mutation or deletion. Our environment is heavily contaminated by indiscriminate and wide spread use of polythene, paints, petroleum products, industrial dyes, toxic chemicals and pesticides etc. Indiscriminate use of these chemicals/polymers adversely affects the environment and ultimately human beings and other living systems. Microbial evolution/ adaptation is the key of formation of a fully functional catabolic pathway enabling them to use toxic compound(s) as a source of carbon and energy. Physical and chemical methods are applicable in a modified matrix or help in converting the pollutants from one phase to another but the microbial degradation process to detoxify the pollutants can be effectively used to overcome the pollution problem.

The present study aimed to give insights into the binding interactions of the laccases and peroxidase for the degradation of the lignin. The active site of the applied enzymes contains the amino acids that are playing an essential role in lignin degradation. The binding pocket amino acids have interacted with the lignin via the hydrogen, alkyl and van der Waal bonds. The mutagenesis in the active sites of these enzymes predicted the increasing and decreasing performance of the lignin-degrading enzymes. Ramachandran plot analysis of the Laccase and peroxidases determined the active conformation of the lignin-degrading enzymes. Phylogenetic study of the Laccase, lignin peroxidase, versatile peroxidase and manganese peroxidase suggested each of the enzymes belong to the separate protein cluster. The present study reveals the binding potential of the various lignin-degrading enzymes that could increase our understanding of the application of plant biomass large scales.

Secondary metabolites of microbial origin are structurally diverse and functionally versatile compounds that offer selective advantages to the producing organism. Production of these compounds is low under natural conditions and requires elicitation for large-scale production. Omic sciences provide a major breakthrough in the discovery of novel compounds and indicate efficiency of microorganisms to produce a diverse array of chemical entities more than those known today. Synthetic biology in particular, has remarkably changed the outlook to explore natural products by unravelling hidden potential of the microorganisms. In silico studies pave a path to investigate new secondary metabolic compounds by the fusion of genetics, chemistry, and computer science, which expand their diversity and lead to generation of new analogs. Genes involved in secondary metabolite biosynthesis, regulation and transport in microorganisms are organized into clusters known as Biosynthetic gene clusters (BGCs). Application of sophisticated tools helps to get more information on newer BGCs leading to novel bioactive compound discovery. Experimental verification and structural elucidation are still the bottleneck in the discovery of a new product, but in silico tools help to speed up the process of product prediction and its identification. They also help in optimizing strains for stable and optimal production during scale up process for an economic output. In the present study, we have described microbial secondary metabolites with special mention of polyketides (PKS) and non-ribosomal polypeptides (NRPS) along with some of the strategies employed to induce their production, providing the main emphasis on in silico methods and tools used in their study and analysis to date.

A potential pesticide degrading bacterial isolate (2D), showing maximum tolerance (450 mg∙L-1) for cypermethrin, fipronil, imidacloprid and sulfosulfuron was recovered from a pesticide contaminated agricultural field. The isolate degraded cypermethrin, imidacloprid, fipronil and sulfosulfuron in minimal salt medium with 94, 91, 89 and 86% respectively as revealed by high performance liquid chromatography (HPLC) and gas chromatography (GC) analysis after 15 days of incubation. Presence of cyclobutane, pyrrolidine, chloroacetic acid, formic acid and decyl ester as major intermediate metabolites of cypermethrin biodegradation was observed in gas chromatography mass spectrometry (GC-MS) analysis. Results based on 16S rDNA sequencing, and phylogenetic analysis showed maximum similarity of 2D with Bacillus cereus (Accession ID: MH341691). Stress responsive and catabolic/pesticide degrading proteins were over expressed in the presence of cypermethrin in bacteria. Enzymatic kinetics of laccase was deduced in the test isolate under normal and pesticide stress conditions which suggested that the production of enzyme was induced significantly in pesticide stress (163 μg.μL-1) as compare to normal conditions(29 μg.μL-1) while the Km value was decreased in pesticides stress condition (Km = 10.57 mM) and increases in normal condition (Km = 14.33 mM).Amplification of laccase gene showed a major band of 1200bp. The present study highlights on the potential of 2D bacterial strain i.e., high tolerance level of pesticide, effective biodegradation rate, and presence of laccase gene in bacterial strain 2D, could become a potential biological agent for large-scale treatment of mixture of pesticide (cypermethrin, fipronil, imidacloprid and sulfosulfuron) in natural environment (soil and water).

During bacterial growth an increased mRNA level is usually linked with higher rate of metabolism related to biodegradation of an unusual compound. In this study, quantitative gene expression data d...

A potential pesticide degrading bacterial isolate (2D), showing maximum tolerance (450 ppm) for cypermethrin, fipronil, imidacloprid and sulfosulfuron was recovered from a pesticide contaminated agricultural field. The isolate degraded cypermethrin, imidacloprid, fipronil and sulfosulfuron in minimal salt medium with 94, 91, 89 and 86 % respectively as revealed by HPLC and GC analysis after 15 days of incubation. Presence of cyclobutane, pyrrolidine, chloroacetic acid, formic acid and decyl ester as major intermediate metabolites of cypermethrin biodegradation was observed in GC-MS analysis. Results based on 16S rDNA sequencing, and phylogenetic analysis showed maximum similarity of 2D with Bacillus cereus (MH341691). Stress responsive and catabolic/ pesticide degrading proteins were over expressed in the presence of cypermethrin in bacteria. Enzyme kinetics of laccase was deduced in the test isolate under normal and pesticide stress conditions. Amplification of laccase gene showed a major band of 1200bp. Maximum copy number of 16S rDNA was seenin uncontaminated soil as compared to pesticide contaminated soil using qRT-PCR. The metagenome sequencing revealed reduction in the population of proteobacteria in contaminated soil as compared to uncontaminated soil but showed dominance of actinobacteria, firmicutes and bacteriodates in pesticide spiked soil. Presence of some new phyla like chloroflexi, planctomycetes, verrucomicrobia was observed followed by extinction of acidobacteria and crenarchaeota in spiked soil. The present study highlights on the potential of 2D bacterial strain i.e., high tolerance level of pesticide, effective biodegradation rate, and presence of laccase gene in bacterial strain 2D, could become a potential biological agent for large-scale treatment of mixture of pesticide (cypermethrin, fipronil, imidacloprid and sulfosulfuron) in natural environment (soil and water).

The role of plant growth-promoting rhizobacteria along with nanochitosan on maize productivity remains unexplored. In the present study we report the effect of nanochitosan and PGPR on growth, productivity and mechanism(s) involved in defence response in Zea mays under field conditions. Application of nanochitosan (50 mg L−1) along with plant growth-promoting rhizobacteria enhanced seed germination, plant height, root length, leaf area, fresh and dry weight of shoot and root, chlorophyll, carotenoids, total sugar and protein content upto 1.5–2 fold over control in maize after 60 days of the field experiment. Treated maize plants also showed enhanced level of defence-related biomolecules like phenolic compounds (103%), catalase (60.09%), peroxidase (81.57%) and superoxide dismutase (76.50%) over control. Level of phenols and sugar content in maize plants enhanced which was analysed by GC–MS (Gas chromatography–mass spectrometry). Significant increase in cob length, cob weight/plot, grain yield/plot and 100 grain weight was observed in treated maize plants over control. As per the results, the combination of nanochitosan and plant growth-promoting rhizobacteria was reported to improve the health and yield of maize. The interaction can be further studied in field trials for improvement in agriculture production.

Zinc-solubilizing bacteria, namely Burkholderia cepacia and Acinetobacter baumannii (H1 and H3, respectively), able to grow in liquid basal medium supplemented with ZnO, Zn3 (PO4)2, and ZnSO4·7H2O (0.1%), showed plant growth promoting properties. The treatment of Acinetobacter baumannii (H3) solubilizes the ZnO (1.42 ppm), Zn3 (PO4)2 (1.15 ppm), and ZnSO4·7H2O (1.44 ppm).The maximum solubilization of ZnSO4·7H2O (1.42 ppm) was observed in Burkholderia cepacia (H1) after 15 days. Organic acids produced by the bacteria decreased the pH of the medium and helped in Zn solubilization. In pot experiment on maize, Burkholderia cepacia (H1) treatment significantly enhanced plant height and root length in the presence of ZnO (2%) added in 10 mL of inoculum in each pot. High-performance liquid chromatography (HPLC) analysis of maize root extract showed the presence of oxalic, maleic, tartaric, and fumaric acid after 60 days of the experiment. Bacterial treatments enhanced sugar and protein level in maize plants and were 55.2 and 42.55 µg/mL plant extract, respectively, under mixture of bacterial treatment. Hence, isolates H1 and H3 expressed highest potential throughout the experiments, as zinc solubilizers and plant growth-promoting strains. This study demonstrated that meticulous use of Zn-solubilizing bacterial strains could aid in enhanced plant growth and can be the potential bio-inoculants for biofortification of maize to overcome the problems of malnutrition.

The large-scale application of xenobiotics adversely affects the environment. The genes that are present in the chromosome of the bacteria are considered nonmobile, whereas the genes present on the plasmids are considered mobile genetic elements. Plasmids are considered indispensable for xenobiotic degradation into the contaminated environment. In the contaminated sites, bacteria with plasmids can transfer the mobile genetic element into another strain. This mechanism helps in spreading the catabolic genes into the bacterial population at the contaminated sites. The indigenous microbial strains with such degradative plasmids are important for the bioremediation of xenobiotics. Environmental factors play a critical role in the conjugation efficiency, which is involved in the bioremediation of the xenobiotics at the contaminated sites. However, there is still a need for more research to fill in the gaps regarding plasmids and their impact on bioremediation. This review explores the role of bacterial plasmids in the bioremediation of xenobiotics from contaminated environments.

Endosulfan is a broadly applied cyclodiene insecticide which has been in use across 80 countries since last 5 decades. Owing to its recalcitrant nature, endosulfan residues have been reported from air, water and soil causing toxicity to various non-target organisms. Microbial decontamination of endosulfan has been reported previously by several authors. In the current study, we have evaluated the pathways of endosulfan degradation and its hazardous impact on other living beings including insects, humans, plants, aquatic life and environment by in-silico methods. For establishment of the endosulfan metabolism in different ecosystems, cell designer was employed. The established model was thereafter assessed and simulated to understand the biochemical and physiological metabolism of the endosulfan in various systems of the network. Topological investigation analysis of the endosulfan metabolism validated the presence of 207 nodes and 274 edges in the network. We have concluded that biomagnification of the endosulfan generally occurs in the various elements of the ecosystem. Dynamics study of endosulfan degrading enzymes suggested the important role of monooxygenase I, II and hydrolase in endosulfan bioremediation. Endosulfan shows toxicity in human beings, fishes and plants, however it is biodegraded by the microbes. To date, there are no reports of in- silico analysis of bioremediation of endosulfan and its hazardous effects on the environment. Thus, this report can be important in terms of modelling and simulation of biodegradation network of endosulfan and similar compounds and their impact on several other systems. Communicated by Ramaswamy H. Sarma

The world population is increasing at an alarming rate, and to feed such a huge population from an exhausted arable land with depleted water resources would be a great concern and challenge in near future for agriculture scientists. Present agricultural practices are dependent on seed quality, irrigation facilities, and chemical fertilizers that affect the fertility of soil significantly. To overcome from this problem, some alternative methods must be employed. The use of several rhizospheric bacteria and fungi as bioinoculant with plant growth-promoting ability is under practice by some farmers, forming the base of upcoming green revolution. Plant growth-promoting microbes (PGPM) are usually present around the root zone, rhizosphere, and inside the plants and found responsible for enhanced plant growth by way of providing essential nutrition and hormones and controlling pathogens by producing antifungal and antimicrobial compounds. Soil is the most important component of a terrestrial ecosystem and essentially required to establish, support, and enhance plant growth by providing nutrition and water. The cross signaling between the plants and rhizobacteria for mutual benefits is possible because of the involvement of different types of root exudates, genes, and several known and unknown factors which make a network for a better functioning of plant and bacteria. Conservation of biogeochemical cycles consisting of carbon, nitrogen, phosphorus, and sulfur in relation to recycling of essential nutrients in an ecosystem is only possible by the involvement of numerous soil microbes. Biological activity of a soil or soil health must be known to get good agriculture produce. In this chapter, we have undertaken various aspects of rhizospheric microbes including their involvement in higher food production and maintenance of soil and plant health.

Bio-inoculants play an important role for sustainable agriculture. Application of nanocompounds in the agriculture sector provides strength and is reported to enhance crop production but the combined effect of nanocompounds and plant growth-promoting rhizobacteria on plants has not been studied much. Therefore, the present study was planned to observe the effect of two plant growth promotory Bacillus spp. along with nanozeolite on maize under field conditions using a randomized block design. Combined treatment of nanozeolite and bio-inoculants promoted plant height, root length, fresh and dry weight of shoot and root, chlorophyll, carotenoids, total sugar, protein and phenol contents in maize significantly over control. Enhanced level of catalase, peroxidase, superoxide dismutase, phenols, alcohols and acid-esters in treated plants over control showed their role in stress management. An increase of 29.80% in maize productivity over control was reported in the combined treatment of Bacillus sp. and nanozeolite. Our results indicate that the application of bio-inoculants with nanozeolite showed a positive response on the health and productivity of maize plants. Hence, these may be used to enhance the productivity of different crops.

Pesticides are widely used in agriculture, households, and industries; however, they have caused severe negative effects on the environment and human health. To clean up pesticide contaminated sites, various technological strategies, i.e. physicochemical and biological, are currently being used throughout the world. Biological approaches have proven to be a viable method for decontaminating pesticide-contaminated soils and water environments. The biological process eliminates contaminants by utilizing microorganisms' catabolic ability. Pesticide degradation rates are influenced by a variety of factors, including the pesticide's structure, concentration, solubility in water, soil type, land use pattern, and microbial activity in the soil. There is currently a knowledge gap in this field of study because researchers are unable to gather collective information on the factors affecting microbial growth, metabolic pathways, optimal conditions for degradation, and genomic, transcriptomic, and proteomic changes caused by pesticide stress on the microbial communities. The use of advanced tools and omics technology in research can bridge the existing gap in our knowledge regarding the bioremediation of pesticides. This review provides new insights on the research gaps and offers potential solutions for pesticide removal from the environment through the use of various microbe-mediated technologies.

Nanotechnology is the art and science of manipulating material at atomic scale. It can also be defined as the designing, characterization, production and application of structures, devices and systems by controlling shape and size at the nanoscale. The present investigation was carried out to assess the effect of Gold-nanoparticle treatment on vegetative and flowering attributes of Calendula. Experiment consisted of four treatments (5, 10, 15, 20 ppm Goldnanoparticle), along with control and was laid out in Randomized block design. Among the various treatments, application of 10 ppm of Gold-nanoparticle (T2 ) was found best for most of the parameters viz., plant height (73.95 cm), plant spread (54.62 cm), number of branches (25.15), number of leaves (127.55), number of flower (131.30), flower diameter (7.06 cm), flower weight (4.31), minimum days to flower bud initiation (30.85 days) and Flowering duration (105.15 days over the rest treatments. Treatment T4 (20 ppm Gold-nanoparticle) showed poor growth in most of the recorded parameters due to the toxicity of Gold-nanoparticle at higher concentration. Nanoparticles when applied to the plants can help them to cope up the adverse condition by releasing the ROS enzyme (Reverse Oxygen Species). During stress conditions ROS enzyme releases and antioxidant defense system of plant gets activated to maintain the normal equilibrium. As a result additional amount of proteins, carbohydrates and DNAs are formed. These additional molecules enhance plant growth and improve yield.

This study investigates the potential role of Bacillus sp. FA4 for the bioremediation of fipronil in a contaminated environment and resource recovery from natural sites. The degradation parameters for fipronil were optimized using response surface methodology (RSM): pH - 7.0, temperature - 32 °C, inocula - 6.0 × 108 CFU mL−1, and fipronil concentration - 50 mg L−1. Degradation of fipronil was confirmed in the mineral salt medium (MSM), soil, immobilized agar discs, and sodium alginate beads. The significant reduction of the half-life of fipronil suggested that the strain FA4 could be used for the treatment of large-scale fipronil degradation from contaminated environments. The kinetic parameters, such as qmax, Ks, and Ki for fipronil degradation with strain FA4, were 0.698 day−1, 12.08 mg L−1, and 479.35 mg L−1, respectively. Immobilized FA4 cells with sodium alginate and agar disc beads showed enhanced degradation with reductions in half-life at 7.83 and 7.34 days, respectively. The biodegradation in soil further confirmed the degradation potential of strain FA4 with a half-life of 7.40 days as compared to the sterilized soil control’s 169.02 days. The application of the strain FA4 on fipronil degradation, under different in vitro conditions, showed that the strain could be used for bioremediation and resource recovery of contaminated wastewater and soil in natural contaminated sites.

Zinc-solubilizing bacteria, namely Burkholderia cepacia and Acinetobacter baumannii (H1 and H3, respectively), able to grow in liquid basal medium supplemented with ZnO, Zn

The environment is contaminated by synthetic contaminants owing to their extensive applications globally. Hence, the removal of synthetic pollutants (SPs) from the environment has received widespread attention. Different remediation technologies have been investigated for their abilities to eliminate SPs from the ecosystem; these include photocatalysis, sonochemical techniques, nanoremediation, and bioremediation. SPs, which can be organic or inorganic, can be degraded by microbial metabolism at contaminated sites. Owing to their diverse metabolisms, microbes can adapt to a wide variety of environments. Several microbial strains have been reported for their bioremediation potential concerning synthetic chemical compounds. The selection of potential strains for large-scale removal of organic pollutants is an important research priority. Additionally, novel microbial consortia have been found to be capable of efficient degradation owing to their combined and co-metabolic activities. Microbial engineering is one of the most prominent and promising techniques for providing new opportunities to develop proficient microorganisms for various biological processes; here, we have targeted the SP-degrading mechanisms of microorganisms. This review provides an in-depth discussion of microbial engineering techniques that are used to enhance the removal of both organic and inorganic pollutants from different contaminated environments and under different conditions. The degradation of these pollutants is investigated using abiotic and biotic approaches; interestingly, biotic approaches based on microbial methods are preferable owing to their high potential for pollutant removal and cost-effectiveness.

The role of plant growth-promoting rhizobacteria along with nanochitosan on maize productivity remains unexplored. In the present study we report the effect of nanochitosan and PGPR on growth, productivity and mechanism(s) involved in defence response in Zea mays under field conditions. Application of nanochitosan (50 mg L(−1)) along with plant growth-promoting rhizobacteria enhanced seed germination, plant height, root length, leaf area, fresh and dry weight of shoot and root, chlorophyll, carotenoids, total sugar and protein content upto 1.5–2 fold over control in maize after 60 days of the field experiment. Treated maize plants also showed enhanced level of defence-related biomolecules like phenolic compounds (103%), catalase (60.09%), peroxidase (81.57%) and superoxide dismutase (76.50%) over control. Level of phenols and sugar content in maize plants enhanced which was analysed by GC–MS (Gas chromatography–mass spectrometry). Significant increase in cob length, cob weight/plot, grain yield/plot and 100 grain weight was observed in treated maize plants over control. As per the results, the combination of nanochitosan and plant growth-promoting rhizobacteria was reported to improve the health and yield of maize. The interaction can be further studied in field trials for improvement in agriculture production. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-021-02790-z.

Bio-inoculants play an important role for sustainable agriculture. Application of nanocompounds in the agriculture sector provides strength and is reported to enhance crop production but the combined effect of nanocompounds and plant growth-promoting rhizobacteria on plants has not been studied much. Therefore, the present study was planned to observe the effect of two plant growth promotory Bacillus spp. along with nanozeolite on maize under field conditions using a randomized block design. Combined treatment of nanozeolite and bio-inoculants promoted plant height, root length, fresh and dry weight of shoot and root, chlorophyll, carotenoids, total sugar, protein and phenol contents in maize significantly over control. Enhanced level of catalase, peroxidase, superoxide dismutase, phenols, alcohols and acid-esters in treated plants over control showed their role in stress management. An increase of 29.80% in maize productivity over control was reported in the combined treatment of Bacillus sp. and nanozeolite. Our results indicate that the application of bio-inoculants with nanozeolite showed a positive response on the health and productivity of maize plants. Hence, these may be used to enhance the productivity of different crops. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s13205-020-02561-2.

Atrazine is the most commonly used herbicide worldwide in the agricultural system. The increased environmental concentration of the atrazine showed the toxic effects on the non-target living species. Biodegradation of the atrazine is possible with the bacterial systems. The present study investigated biodegradation potential of atrazine degrading bacteria and the impact of atrazine on environmental systems. Model of atrazine fate in ecological systems constructed using the cell designer. The used model further analyzed and simulated to know the biochemistry and physiology of the atrazine in different cellular networks. Topological analysis of the atrazine degradation confirmed the 289 nodes and 300 edges. Our results showed that the overall biomagnification of the atrazine in the different environmental systems. Atrazine is showing toxic effects on humans and plants, whereas degraded by the bacterial systems. To date, no one has analyzed the complete degradation and poisonous effects of the atrazine in the environment. Therefore, this study is useful for overall system biology based modeling and simulation analysis of atrazine in living systems. Communicated by Ramaswamy H. Sarma.