Microbe Consortium Research Articles

Performance of salt‐bridge microbial fuel cell (SB‐MFC) with various microorganism cultures on the generation of electricity from tofu wastewater

A suitable wastewater treatment system is required due to the high organic compound content in tofu wastewater, which can harm the environment. Biological treatment methods are effective for treating tofu wastewater due to its characteristics. Microbial fuel cells (MFCs) represent one such biological treatment option, effectively removing organic contaminants while generating low‐power electricity through bioenergetic reactions. In MFCs, microorganisms are used as biocatalysts to degrade the organic compounds present in wastewater. This study aimed to assess the efficacy of Salt‐bridge microbial fuel cells (SB‐MFC) using various acclimatized microbe cultures for reducing organic compounds and generating energy from tofu wastewater. Tofu wastewater was sterilized prior to introduction into the reactor. Additional microbes, including the native microbe consortium from tofu wastewater, Escherichia coli, Saccharomycopsis fibuligera, and a mixed culture of E. coli and S. fibuligera, were then introduced as biocatalysts. Carbon electrodes were utilized as both the anode and cathode. The results indicate that the mixed culture of E. coli and S. fibuligera significantly reduced COD and BOD5 levels, with removal rates of 82.74% and 76.53%, respectively, after 48 h. Furthermore, the culture generated a voltage of 676 mV, a current of 2.53 mA, a power density of 428 mWatt/m2, and 4.789×10‐2 kWh of energy. This study contributes to the advancement of SB‐MFC by utilizing wastewater and a combination of bacteria and yeast as biocatalysts.

Engraftment of aging-related human gut microbiota and the effect of a seven-species consortium in a pre-clinical model

ABSTRACT Human aging is characterized by gut microbiome alteration and differential loss of gut commensal species associated with the onset of frailty. The administration of cultured commensal strains to replenish lost taxa could potentially promote healthy aging. To investigate the interaction of whole microbiomes and administered strains, we transplanted gut microbiota from a frail or healthy elderly subject into germ-free mice. We supplemented the frail-donor recipient group with a defined consortium of taxa (the “S7”) that we identified by analyzing healthy aging subjects in our previous studies and whose abundance correlated with health-promoting dietary intervention. Inoculation with a frail or a healthy donor microbiome resulted in differential microbiota compositions in murine recipients 5 weeks post-transplantation. Fecal acetate levels were significantly higher in healthy donor recipient mice than in frail donor recipient mice after 4 weeks. However, the frailty-related phenotype was not replicated in recipient mice with single-dose microbiota transplantation from a healthy and a frail donor. Five S7 species colonized successfully in germ-free mice, with a relatively high abundance of Barnesiella intestinihominis and Eubacterium rectale. The engraftment of five S7 species in germ-free mice increased fecal acetate levels and reduced colon permeability and plasma TNF-ɑ concentration. Supplementation with the S7 in frail-microbiota recipient mice did not increase alpha-diversity but significantly increased the abundance of Barnesiella intestinihominis. S7 supplementation showed the potential for improving spatial reference memory in frail-microbiota recipient mice. Collectively, these data highlight the challenge of elderly microbiota engraftment in the germ-free mouse model but show promise for modulating the gut microbiome of frail elderly subjects by administering an artificial gut microbe consortium associated with healthy aging.

Microbial consortium mediated acceleration of the defense response in potato against Alternaria solani through prodigious inflation in phenylpropanoid derivatives and redox homeostasis

The present study was carried out in a pot experiment to examine the bioefficacy of three biocontrol agents, viz., Trichoderma viride, Bacillus subtilis, and Pseudomonas fluorescens, either alone or in consortium, on plant growth promotion and activation of defense responses in potato against the early blight pathogen Alternaria solani. The results demonstrate significant enhancement in growth parameters in plants bioprimed with the triple-microbe consortium compared to other treatments. In potato, the disease incidence percentage was significantly reduced in plants treated with the triple-microbe consortium compared to untreated control plants challenged with A. solani. Potato tubers treated with the consortium and challenged with pathogen showed significant activation of defense-related enzymes such as peroxidase (PO) at 96 h after pathogen inoculation (hapi) while, both polyphenol oxidase (PPO), and phenylalanine ammonia-lyase (PAL) at 72 hapi, compared to the individual and dual microbial consortia-treated plants. The expression of antioxidant enzymes like superoxide dismutase (SOD) and catalase (CAT) and the accumulation of pathogenesis-related proteins such as chitinase and β-1,3-glucanase were observed to be highest at 72 hapi in the triple microbe consortium as compared to other treatments. HPLC analysis revealed significant induction in polyphenolic compounds in triple-consortium bioprimed plants compared to the control at 72 hapi. Histochemical analysis of hydrogen peroxide (H2O2) clearly showed maximum accumulation of H2O2 in pathogen-inoculated control plants, while the lowest was observed in triple-microbe consortium at 72 hapi. The findings of this study suggest that biopriming with a microbial consortium improved plant growth and triggered defense responses against A. solani through the induction of systemic resistance via modulation of the phenylpropanoid pathway and antioxidative network.

Monitoring of an Applied Beneficial Trichoderma Strain in Root-Associated Soil of Field-Grown Maize by MALDI-TOF MS.

The persistence of beneficial microorganisms in the rhizosphere or surrounding soil following their application is a prerequisite for the effective interaction with the plant or indigenous microbial communities in the respective habitats. The goal of the study was to analyze the establishment and persistence of the applied beneficial Trichoderma harzianum (OMG16) strain in the maize root-associated soil depending on agricultural practice (soil management practice, N-fertilizer intensity) in a field experiment. A rapid identification of the inoculated strain OMG16 is essential for its monitoring. We used a culture-based approach coupled to matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS) analysis for the rapid identification of the inoculated Trichoderma strain as part of the beneficial microbe consortium (BMc). We isolated 428 fungal isolates from eight treatments of the field experiment. Forty eight percent of the isolated fungi equivalent to 205 fungal isolates were identified as Trichoderma, of which 87% (=179 isolates) were obtained from the fields inoculated with BMc. Gene sequence analysis showed a high similarity of the MALDI-TOF MS-identified Trichoderma, with that of the inoculated Trichoderma harzianum OMG16 confirming the re-isolation of the added beneficial fungus. This study highlighted the use of MALDI-TOF MS analysis as a quick, cost-effective detection and efficient monitoring tool for microbial-based bioinoculants in the field.

Lipid degrading microbe consortium driving micro-ecological evolvement of activated sludge for cooking wastewater treatment

In this study, a lipid degrading microbe consortium (LDMC) was assembled to improve the performance of activated sludge (AS) on cooking wastewater purification. LDMC can rapidly degrade high-level oil (efficiency beyond 93.0% at 5.0 g/L) as sole carbon source under various environmental conditions (10.0–45.0 °C, pH 2.0–12.0). With LDMC inoculation, AS' water treatment performance was significantly enhanced, which removed 36.10 and 48.93% more chemical oxygen demand (COD) and ammonia nitrogen from wastewater than control. A better settling property and smaller bulking risk were found with LDMC inoculation, indicated by a lower SV30 and SVI index but a higher MLSS. By GC/MS analysis, a gradual degradation on the end of the fatty acid chain was suggested. LDMC inoculation significantly changed AS's microbial community structure, improved its stability, decreased the microbial community diversity, facilitated the enrichment of lipid degraders and functional genes related to lipid bio-degradation. Lipid degraders including Nakamurella sp. and Stenotrophomona sp., etc. played a crucial role during oil degradation. Sludge structure maintainers such as Kineosphaera sp. contributed largely to the stability of AS under exogenous stress. This study provided an efficient approach for cooking wastewater treatment along with the underlying mechanism exploration, which should give insights into oil-containing environmental remediation.

Mechanism study of Chromium influenced soil remediated by an uptake-detoxification system using hyperaccumulator, resistant microbe consortium, and nano iron complex

A soil heavy metal decontamination system was developed based on the immobilization of bioavailable metal fraction by iron-biochar nano-complex (BC@Fe3O4) and the uptake by Chromium (Cr) hyperaccumulator Leersia hexandra (L. hexandra) under the assistance of metal resistant microbe consortium (MC). In this system, L. hexandra was able to accumulate 485.1–785.0 mg kg−1 in root and 147.5–297.2 mg kg−1 of Cr in its aerial part. With MC assistance, more Cr could be translocated to the aerial part of L. hexandra, which dramatically improved its remediation potential. Meanwhile, BC@Fe3O4 application decreased bioavailable Cr in soil and reduced soil toxicity, which contributed to soil microbial community adaption and L. hexandra performance under high level of Cr concentration (elevated microbial activity, decreased plant stress response, enhanced L. hexandra growth and accumulation) without negative influence on accumulation efficiency. Moreover, details of the possible mechanistic insight into metal removal were discussed, which indicated a negative correlation of the extractable Cr with soil microecology and hyperaccumulator performance. Furthermore, the resistant bacteria successfully altered soil microbial community, enhanced its diversity, which was in favor of the soil quality improvement.

Remediation of hexavalent chromium contaminated soil by nano-FeS coated humic acid complex in combination with Cr-resistant microflora.

A novel nano-composite material (CMC-FeS@HA) combining the advantages of humic acid (HA) and FeS was synthesized to remediate hexavalent chromium (Cr(VI)) contaminated soil along with chromium (Cr) resistant microflora. The characteristic analysis confirmed the successful synthesis of the nano-composite, which provided further mechanism evidence of its detoxification effect on polluted soil. Energy Dispersive System analysis proved the adsorption of the microbe consortium (MC) for Cr. After remediation, Cr(VI) in all treatments was dramatically reduced and the leachable Cr in soil treated by CMC-FeS@HA and MC decreased 89.14% compared with control. The result of BCR sequential extraction showed that Cr was stabilized, whose form changed to oxidizable and residual from HOAC-extractable. Besides, CMC-FeS@HA, as a sustained-release acid with high biocompatibility, could continuously decrease the pH of strongly alkaline soil and created a suitable micro-ecological environment for soil microorganisms. Moreover, CMC-FeS@HA dramatically improved soil physicochemical property, soil microbial activity (dehydrogenase, hydrolase, urease, and invertase activities), and soil microecological diversity. In total, this study provided a useful technology for soil remediation, which innovatively combined chemical remediation and microbial-remediation with a positive effect on soil quality, providing a good approach for the multiple technology combination in the environmental cause.

Potential Application of Consortium Microbe from Sea Cucumber Intestinal Symbiont as Preservatives for Vaname Shrimp

Vaname shrimp is one of the most profitable export commodities in Indonesia. However, the shrimp meat undergoes rapid quality degradation when shipped without any preservatives. This is an issue since the preservatives commonly found on the market are formalin-based. This study aims to discover a natural preservative solution by utilizing microbes. The objective of the study is to discover natural preservatives made of symbiont microbe in sea cucumber's intestinal organ by antimicrobial activity screening. Sea cucumber samples were collected from Bandengan waters of Jepara. There are 3 symbiotic microbe form intestinal cucumber that can inhibit the growth from Bacillus cereus and Pseudomonas aeruginosa. These three microbes are Listeria sp., Staphylococcus sp., and Rothia sp. Consequently, tested microbial samples were prepared into a consortium microbe and were tested further as a preservative agent for shrimp with a positive control parameter (cooling). The observations conducted in this study include organoleptic properties, acidity, total colony, proximate test (protein, water, ash, fat, and carbohydrate contents), and Total Volatile Base-Nitrogen (TVBN). The results found 3 active isolates are synergic one to each other as a bacterial consortium. Acidity test of sample extract treatment measured a pH of 7.44, compared to the non-treatment result of 7.14. Organoleptic test results of the shrimp indicated that the shrimp was acceptable for consumption. Proximate test of the treatment did not show a significant difference compared to the positive control treatment. Total colony and TVBN test on treated samples resulted in 48 x 105 CFU/ml and 39.62 mgN% respectively, whereas a similar test on non-treatment sample showed 119 x 105 CFU/ml and 45.31 mgN% respectively. It was concluded that the extract of sea cucumber symbiont microbe consortium showed potency in preventing meat quality degradation in shrimp, although treatment by freezing still produces a better result.

The Effect of Biofertilizer and Inorganic Fertilizer Toward The Nutrient Uptake in Maize Plant (Zea mays l.)

The productivity of land and plants have decreased slowly, due to the use of inorganic fertilizers continuously. Efforts to improve productivity are reducing inorganic fertilizers and returning organic matter to the soil. The aim of this research are (1) to identify the chemical characteristics of biofertilizer with an indigenous microorganism as bioactivators and (2) to study the effect of biofertilizer on nutrient uptake of maize plant. The research was conducted at Laboratory, Greenhouse, and Experimental Field of Politeknik Pertanian Negeri Payakumbuh, West Sumatra Indonesia. The first step experiment in the Laboratory was produced indigenous microorganism from banana humps. The second step of making bio-fertilizers in Greenhouse used a Completely Randomized Design with four treatments of indigenous microorganism (IMO) level 0%, 10%, 20%, 30% in biofertilizer with five replications. The third step of biofertilizer application on the Experimental Field used Randomized Block Design Factorial arranged with two factors and three replications, the first factor IMO level in biofertilizer (M) 0%, 10%, 20%, 30% and the second factor was the dosage of inorganic fertilizer (P) 0%, 50%, 100% of the recommended dosage, 12 combinations of treatments were obtained. Results showed that microbe consortium (Enterobacter cloacae, Bacillus subtilis, Pseudomonas fluorescens, Aspergillus niger, and Trichoderma asperellum) in biofertilizers with different levels would affect the chemical characteristics of biofertilizer. Biofertilizers influences nutrient uptake of P and K maize plant, while inorganic fertilizer influences nutrient uptake of N and P maize plant.

Plant-microbiome assisted and biochar-amended remediation of heavy metals and polyaromatic compounds ─ a microcosmic study

The study has been carried out to develop a plant-microbes assisted remediation technology to accelerate polyaromatic hydrocarbons (PAHs) degradation and heavy metals (HMs) removal in a microcosmic experiment. The quaternary mixture of PAHs (phenanthrene, anthracene, pyrene, and benzo[a] pyrene) and metals (Cr, Ni, and Pb) spiked the soil, constructing a microcosm; the microcosms were bioaugmented with newly developed plant bacterial consortia (Cpm1 and Cpm2). The microcosms were amended with biochar (sieved particle size 0.5–2 mm) as redox regulators to reduce oxidative stress of plant-microbe systems. To formulate the two plant-bacterial consortia, plant species were collected and bacteria were isolated from oil spill soil. The bacterial strains used in two formulated consortia includes ─ Cpm1 (Enterobacter cloacae HS32, Brevibacillus reuszeri HS37, and Stenotrophomonas sp. HS16) and Cpm2 (Acinetobacter junii HS29, Enterobacter aerogenes HS39 and Enterobacter asburiae HS22). The PAHs degradation and metal removal efficacy of the consortia (Cpm1 and Cpm2) were studied after 24 weeks of trial. The physicochemical properties of microcosm's soil (M2 and M3) were assessed after experimentation, which resulted in the finding that the soil exhibits dropped in pH from basic to neutral after application of the plant microbe's consortium. The electrical conductivity was lower in M2 and M3 soils, with a range between 1.60 and 1.80 mS/cm after the treatment. The Gas Chromatography/Mass Spectrometry (GC/MS) results illustrate how metabolites with the different molecular weight (M.W) were found in M2 and M3 soils (184─446), as a result of the plant-microbes mediated rhizodegradation of four spiked PAHs. The metals in microcosm's soil are very low in concentration after 24 weeks of trial when compared to control(M1). The Cr, Ni and Pb removal percentages were found in 45.79, 42.19 and 44.85 in M2. However, the removal percentages were found to be 45.41, 41.47 and 44.25 respectively for these same HMs in M3 soil. Both the consortia that were newly developed showed similar trends of metals removal and PAHs degradation. This study provides a breakthrough in the area of rhizosphere engineering with the goal of maintaining a sustainable application of plant-microbes in ecosystem services.

A novel microbe consortium, nano-visible light photocatalyst and microcapsule system to degrade PAHs

In this study, a MI-MC-photocatalyst compound system (MCS) was prepared for multi-PAHs degradation. Briefly, a high-efficient degradation microbe consortium (MC) was suspended in microcapsule (MI) interior space and nano-visible light photocatalyst Ag3PO4@Fe3O4 was anchored on the membrane of MI. The structure of MCS was investigated through various characteristic analysis methods. Its photocatalytic and biologic degradation potential for PAHs in soil were studied, which confirmed splendid visible light photocatalytic activity of Ag3PO4@Fe3O4 and good inhabitation of MC. Biocompatibility test showed that Ag3PO4@Fe3O4 influenced soil microbe activity slightly (no significant difference compared with CK). With MCS implement, 944.1 mg kg−1 PAHs was removed in 30 days under visible light (49.83% higher than CK). Besides, MCS dramatically improved soil micro-ecology and decreased micro-ecological stress (enhanced microbe counts, activities of dehydrogenase, hydrolase etc. and decreased catalase activity). The soil eco-toxicity decreased sharply testified by seed germinability and reduction of carcinogenic risk assessment (RCRA). Different PAHs reduction in treatments applied with different combination of MC, MI and Ag3PO4@Fe3O4 further proved that the decrement of low and high molecular weight PAHs was mainly contributed by biodegradation of MC and photocatalysis of Ag3PO4@Fe3O4, respectively. To sum up, this system provided a novel perspective for the combined utility of photochemistry and microbiology technology which could potentially facilitate the development of many environmental biotechnology products.

Evaluation of kepok banana corm fermented with Saccharomyces cerevisiae and Aspergillus niger as feeds

This study evaluated the nutritional and tannin contents of cooked Kepok banana corm, fermented with Saccharomyces cerevisiae and Aspergillus niger. Corm meal was pretreated by steam for 1 hour at 102 0C before fermenting. The pretreated corms were inoculated with 10% (w/v) inoculum dose with additional nutrient mono-culture or co-culture. A completely randomized design with a 3 x 3 factorial arrangement was used to investigate two main factors: microbial strains and incubation time, with three subfactors each, resulting in nine treatment combinations and three replications. The microbial strain and incubation time significantly (P>0.01) affected the nutrient content of fermented Kepok banana corms. The highest dry matter content (91.84%) was achieved by incubation with S. cerevisiae for 48 h, while 89.61% organic matter was obtained by fermentation with both S. cerevisiae + A. niger for 48 h. The highest crude protein content was 5.81%, which resulted from treatment with S. cerevisiae for 96 h, increasing the crude protein by 61% compared to the control (3.58% crude protein). Fermentation by the microbe consortium (S. cerevisiae + A. niger) for 72 h, produced maximum starch (35.54 g/100 g) and energy (3511 Kcal/kg) values. Thus, the fermented products are a potential source of energy, to be used as feed ingredients.

Investigation, expression, and molecular modeling of ORF2, a metagenomic lipolytic enzyme.

One clone exhibiting lipolytic activity was selected among 30 positives from a metagenomic library of a microbe consortium specialized in petroleum hydrocarbon degradation. From this clone, a sublibrary was constructed and a metagenome contig was assembled and analyzed using the ORF Finder; thus, it was possible to identify a potential ORF that encodes a lipolytic enzyme, denoted ORF2. This ORF is composed of 1035-bp 345 amino acids and displayed 98 % identity with an alpha/beta hydrolase from Pseudomonas nitroreducens (accession number WP024765380.1). When analyzed against a metagenome database, ORF2 also showed 76 % of sequence identity with a hypothetical protein from a marine metagenome (accession number ECT55726.1). The ProtParam analyses indicated that the recombinant protein ORF2 has a molecular mass approximately 39 kDa, as expected from its amino acid sequence, and based on phylogenetic analysis and molecular modeling, it was possible to suggest that ORF2 is a new member from family V. This enzyme exhibits the catalytic triad and conserved motifs typical from this family, wherein the serine residue is located in the central position of the conserved motif GASMGG. The orf2 gene was cloned in the expression vector pET28a, and the recombinant protein was superexpressed in Escherichia coli BL21(DE3) cells. The lipolytic activity of protein bands presented in a SDS-PAGE gel was confirmed by zymogram analyses, indicating ORF2 activity. These discoveries raise the possibility of employing this protein in biotechnological applications, such as bioremediation.

Biological management of Sclerotinia sclerotiorum in pea using plant growth promoting microbial consortium.

The beneficial plant-microbe interactions play crucial roles in protection against large number of plant pathogens causing disease. The present study aims to investigate the growth promoting traits induced by beneficial microbes namely Pseudomonas aeruginosa PJHU15, Trichoderma harzianum TNHU27, and Bacillus subtilis BHHU100 treated singly and in combinations under greenhouse and field conditions to control Sclerotinia sclerotiorum. Plants treated with three microbe consortium enhanced plant growth maximally both in the presence and absence of the pathogen. Increase in plant length, total biomass, number of leaves, nodules and secondary roots, total chlorophyll and carotenoid content, and yield were recorded in plants treated with microbial consortia. Also, a decrease in plant mortality was observed in plants treated with microbial consortia in comparison to untreated control plants challenged with S. sclerotiorum. Furthermore, the decrease in disease of all the treatments can be associated with differential improvement of growth induced in pea.

Identification and functional characterization of Est16, an esterase isolated from a metagenomic library of microbe consortium specialized in diesel oil degradation

Universidade Estadual Paulista, Departamento de Tecnologia, Faculdade de Ciencias Agrarias e Veterinarias de Jaboticabal

バイオフィルター用テーラーメイド細孔構造を有する 窒化ケイ素多孔体の開発 V. 微生物コンソーシアム形成の確認

バイオフィルター用テーラーメイド細孔構造を有する 窒化ケイ素多孔体の開発 V. 微生物コンソーシアム形成の確認

Rhizosphere microbes facilitate redox homeostasis in Cicer arietinum against biotic stress

AbstractThe aim of this study was to evaluate the potentiality of three compatible rhizosphere microbes, viz. fluorescent Pseudomonas aeruginosa (PHU094), Trichoderma harzianum (THU0816) and Mesorhizobium sp. (RL091), in community to mobilise antioxidant mechanisms in chickpea under the challenge of Sclerotium rolfsii. The microbes were applied as seed treatment in different combinations in two sets and the pathogen was inoculated in one of the sets after 3 weeks of sowing. A comparative study was conducted on the effect of the microbial combinations on host antioxidant mechanisms between the two sets. In pathogen challenged plants host defence responses included higher accumulation of hydrogen peroxide (H2O2) at petiolar and interveinal regions of leaf and high activities of catalase (CAT), glutathione reductase (GR) and guaiacol peroxidase (GPx) compared to unchallenged plants. The antioxidant enzyme activities increased 1.8‐3.3 and 1.9‐3.1 folds at 48 and 72 h, respectively, in the triple microbe treated challenged plants compared to unchallenged ones. Although, ascorbate peroxidase (APX) activity was significantly low, ascorbic acid (AA) and chitinase accumulation was high in the pathogen challenged plants. Antioxidant flavonols associated with host defence namely myricetin, quercetin and kaempferol also accumulated in high amounts in pathogen challenged plants. Among the microbial treatments, the triple microbe combination induced the highest response in all parameters as compared to dual or single application of the same microbes. The triple microbe consortium modulated the chickpea antioxidant mechanisms more efficiently and modulation of oxidative stress was directly correlated with lower plant mortality, thus demonstrating the synergistic behaviour of the microbes in protecting chickpea from the pathogen.

Development of Silicon Nitride Porous Bodies with Micro-Macro Complex Pore Structure for the Application of the ‘Bio-Filter’

In order to develop the ‘Bio-filter’, Si3N4 porous bodies with micro-macro complex pore structure were fabricated. The micro-pores were successfully introduced by inserting PE meshes between the green tapes. Micro-pore size was controlled by adding a small amount of the β-Si3N4 ‘seed’ particles to the α-Si3N4 raw powder. It is expected that the aerobic microbes colonize along the micro-pores consuming dissolved oxygen, which makes the anaerobic ones colonized within the micro-pores to develop the microbe consortium. In this study, this concept was verified by using the S. cerevisiae and B. bifidum as the aerobic and anaerobic microbes, respectively.

Compatible rhizosphere microbes mediated alleviation of biotic stress in chickpea through enhanced antioxidant and phenylpropanoid activities

The study was conducted to examine efficacy of a rhizospheric microbial consortium comprising of a fluorescent Pseudomonas (PHU094), Trichoderma (THU0816) and Rhizobium (RL091) strain on activation of physiological defense responses in chickpea against biotic stress caused by the collar rot pathogen Sclerotium rolfsii. Results of individual microbes were compared with dual and triple strain mixture treatments with reduced microbial load (1/2 and 1/3rd, respectively, of individual microbial load compared to single microbe application) in the mixtures. Periodical studies revealed maximum activities of phenylalanine ammonia lyase [E.C. 4.1.3.5] and polyphenol oxidase [E.C. 1.14.18.1] and accumulation of total phenol content in chickpea in the triple microbe consortium treated plants challenged with the pathogen compared to the single microbe and dual microbial consortia. Similarly, the expression of the antioxidant enzymes superoxide dismutase [E.C.1.15.1.1] and peroxidase [E.C.1.11.1.7] was also highest in the triple microbial consortium which was correlated with lesser lipid peroxidation in chickpea under the biotic stress. Histochemical staining clearly showed maximum and uniform lignification in vascular bundles of chickpea stem sections treated with the triple microbes. The physiological responses were directly correlated with the mortality rate as least plant mortality was recorded in the triple microbe consortium treated plants. The results thus suggest an augmented elicitation of stress response in chickpea under S. rolfsii stress by the triple microbial consortium in a synergistic manner under reduced microbial load.