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Open Access
Development of Acetobacter sp. consortia for acetous fermentation of banana (Musa paradisiaca) fruit waste
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-08) Joshi, Nisha; Tewari, Lakshmi
The present study was carried out for identification and characterization of potential ethanol and acetic acid producing bacteria. Native bacterial and yeast cultures were isolated from diverse fruit sources. Based on qualitative and quantitative screening for ethanol/ acetic acid production four ethanogenic and acetic acid bacteria were selected. All the cultures were also evaluated for their osmo-,thermo-, and ethano-tolerance limits. Finally yeast isolate YBP1 and S. cerevisae were selected for alcoholic fermentation and three potential acetic acid strains were selected for acetous fermentation. Then, these potential microbial strains in mono/co-cultures were screened for their alcohol and acetic acid producing efficacies using banana cellulosic and non-cellulosic waste. Bioconversion of banana fruit pulp and peel employing potential strains into bio-ethanol was carried out in batch cultures through SHF and SSF process and subsequent conversion of bio-ethanol into bio-acetic acid was carried out through acetous fermentation in batch cultures. Influence of fortification of substrate with carbon, nitrogen and phosphorous source on ethanol/ acetic acid production through both the fermentation was also studied and was found to significantly enhance ethanol and acetic acid production from banana fruit waste. Alcoholic fermentation of banana pulp using yeast YBP1 was found superior over S. cerevisae. Higher ethanol/ acetic acid production from cellulosic banana fruit waste (peel) was recorded during SHF fermentation process. Maximum acetic acid yield (9.63 g/100g) could be recorded with banana pulp using YBP1+ AAB-Consortium-II. The acid producing fermentation medium was identified through TLC technique.
Open Access
Biocontrol potential of indigenous fluorescent pseudomonads against banded leaf and sheath blight of maize incited by Rhizoctonia solani f.sp. sasakii
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-07) Brindhaa, N.T.; Sahgal, Manvika
Maize, the third most important cereal crop in the world is exposed to various abiotic and biotic stresses resulting in huge yield loss. The yield loss associated with fungal pathogens is estimated to be more than 10%. Of which, banded leaf and sheath blight (BL&SB) caused by Rhizoctonia solani f.sp.sasakii alone leads to 11-40 % yield loss. The aim of the study was to evaluate biocontrol potential of 22 indigenous (AS1-AS22) fluorescent pseudomonads (FLPs) (18 from Almora & 4 from Pithoragarh districts of Uttarakhand) against BL&SB. All the bacterial isolates were screened for in vitro antagonism against R.solani f.sp.sasakii coupled with hydrolytic enzyme production and plant growth promoting (PGP) traits. Out of these, two strains AS19 and AS21 showed the highest percent mycelial inhibition. The % mycelial inhibition with whole cell culture of AS19 and AS21 was 57.04 % & 54.07 respectively, whereas with cell free supernatant it was 67.41% & 65.74% respectively. Further, scanning electron micrographs revealed that hyphal cell wall at interaction zone of fungal mycelium with AS19 and AS21 was damaged. Both the FLP strains also inhibited the formation and germination of sclerotia in R.solani f.sp.sasakii and exhibited PGP traits like production of rhamnolipid, HCN, siderophore, IAA, ammonia and zinc and phosphate solubilization. They produced protease, chitinase, catalase, oxidase, gelatinase and H2S. Bacterial strains AS19 and AS21 were identified as Pseudomonas spp. through 16S rDNA sequence analysis with % similarity of 89.27 % and 86.62% respectively. The biocontrol efficacy of strains was evaluated in vivo through pot trial. The strains AS19 and AS21 significantly reduced the BL&SB disease incidence (DI). The reduction in DI ranged between 25-38.33%. Combined results of detached leaf assay and pot trial revealed that induced systemic resistance (ISR) was the mechanism of disease control. Foliar spray of two antagonistic isolates 48 hr before pathogen inoculation induced ISR and reduced the DI by half. The two strains AS19 and AS21 exhibited broad spectrum in vitro antifungal activity against Alternaria triticina, Bipolaris sorokiniana, Rhizoctonia maydis and Fusarium oxysporum f.sp.lentis. Future studies should focus on identification of the bacterial metabolite responsible for induced systemic resistance.
Open Access
Combined effect of nanochitosan and potential bioinoculant on maize plant and its rhizosphere
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-07) Agri, Upasana; Sharma, Anita
Present study focuses on the application of agriusable nanochitosan along with potential plant growth promoting rhizobacteria on maize plants under pot experiment. PC1 and PC4 were selected on the basis of their plant growth promoting properties and identified as Pseudomonas taiwanensis and Pantoea agglomerans with accession number MK106029 and MK106024 respectively. They were found compatible with each other and along with nanochitosan (40ppm) which was further supported by SEM results showing no inhibitory effect of Nch on bacterial cultures. Percent seed germination was significantly higher upto 98% in the combined treatment of nanochitosan and PGPR under pot experiment. Application of Nch and bioinoculants enhanced plant growth parameters. A significant increase (>1.5 fold) in carotenoid, total sugar, total phenol was observed in seedlings treated with nanochitosan and bacterial cultures after 30 days in comparison to control. Total catalase and peroxidase activity was found maximum in PC1+PC4+Nch treatment which accounted for 16.25 and 43.67 μmol/min/mg protein after 30 days of pot trial. Enhancement in total fluorescein diacetate and alkaline phosphatases enzyme activity was observed in PC1+PC4+Nch treated soil with (>1.6 fold increase) in comparison to control. Low level of dehydrogenase activity was found in Nch treated soils. physiochemical properties like oxidizable organic carbon, available phosphorus, and potassium and ammonical nitrogen were higher in Nch treated soil as compared to control. Improvement in soil health was observed in all treatments after 30 days in comparison to control. 1.5- 2 fold increase in total microbial population was observed in soil treated with Nanochitosan and bacterial cultures. Population based metagenomics analysis revealed no negative impact of nanochitosan on microbial population in total. It can be concluded from our findings that application of nanocompound along with bacterial treatments improved plantbacterial interaction, promoted plant parameters, increased microbial diversity and increased the level of soil health indicator enzymes.
Open Access
Effect of nanosilicon dioxide on maize and its rhizosphere under the influence of indigenous bioinoculant
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-07) Bharti; Sharma, Anita
Nanotechnology is a science that has wide application in almost all the developing fields including chemical, manufacturing, medical and agriculture sector. Nanoparticles are atomic or molecular aggregates of 1 to 100 nm in size. Two bacterial isolates (PC1 and PC4) were selected on the basis of their plant growth promoting properties and used as bioinoculant along with/without nanosilicon dioxide in a pot experiment on maize. Based on molecular analysis PC1 and PC4 showed homology with Pseudomonas taiwanensis and Pantoea agglomerans respectively and were allotted with accession number MK106029 and MK106024 respectively. Amplification of acdS (ACC deaminase) gene was observed in PC1 and PC4 isolates with amplicon size of 500bp and 600bp respectively. Scanning electron microscopy and biocompatibility assay on nutrient agar plate revealed the compatibility of both the isolates with each other. PC1 and PC4 produced 44% and 25% siderophore unit, solubilised 3.49mg/l and 3.63mg/l zinc and 382.2μg/ml and 361.9μg/ml phosphate respectively while consortium of the two (PC1+PC4) produced 31% siderophore unit, solubilised 3.70 mg/l zinc and 478.6μg/ml phosphate. Combined application of bacterial consortium (PC1+PC4) and nSiO2 showed enhancement in agronomic parameters of maize plants. Average plant height and number of leaves were increased by 1.38 and 1.28 folds over control respectively after 30 days. Values of total chlorophyll (3.32mg/g), carotenoid (0.326mg/g), total sugar (50.47mg/g) and total soluble protein (18.42 mg/g) in maize plant were also high in PC1+PC4+nSiO2 treatment. Total phenol and flavonoid content was 2.75 mg/g and 0.544mg/g respectively on 30th day when treated with PC1+PC4+nSiO2. Level of antioxidant enzymes (catalase and peroxidise) were found to be maximum in treatment (PC1+PC4+nSiO2) which accounts for 15.09μmol/min/mg protein and 60.92μmol/min/mg protein respectively on 30th day. Total bacterial count and population of K and P solublizers was maximum in of the soil treated with PC1+PC4+ nSiO2. Enhancement of 70.6% in total bacterial count in PC1+PC4+ nSiO2 treatment over control was reported. An increase of 2.14, 1.57 and 1.43 times over control in the activity of FDA, dehydrogenase and alkaline phosphatase respectively was observed in PC1+PC4+nSiO2 treatment. Population based metagenomics analysis revealed no negative impact of nanosilicon dioxide on microbial population in total. Thus, our study with PGPR and nanosilicon dioxide treated maize plants revealed that inoculation of beneficial microorganism in combination with nanocompounds is an effective method for enhancing the growth of maize and maintaining the soil health.
Open Access
Effect of plant growth promoting rhizobacterial consortia with nanoparticle and plasma treated seeds under abiotic stress conditions in wheat
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-06) Kaviya, N.; Singh, Ajay Veer
The plants existing in natural environmental conditions are being continuously exposed to different biotic and abiotic stresses that results in reduced plant growth and development. In this aspects, the present study was accomplished with the implementation of drought tolerant plant growth promoting rhizobacteria (PGPR) along with two different nanoparticles namely nano zinc-oxide and nanochitosan under drought stress conditions and with plasma treated seeds under heat stress conditions. For this study six drought tolerant bacterial isolates were retrieved from departmental culture collection. Those cultures were tested for their drought tolerant ability and further analyzed for several PGP traits (siderophore production, zinc solubilization, phosphate solubilization, IAA production, etc.) and based on the compatibility test the cultures were choosen to make consortia. This developed consortium was also tested for different PGP traits. Furthermore, two microbial consortia was choosen based on PGP traits and used for seed treatment of wheat (Triticum aestivum L.) along with nano zinc-oxide and nano chitosan treated seeds to be evaluated under drought stress conditions and with plasma treated seeds to be evaluated under heat stress conditions in field conditions. The results of this experiment showed that the treatment of Nano zinc-oxide, Nano chitosan and Microbial Consortia 1 (Zn+C+MC1) from drought stress conditions and the treatment of Plasma and Microbial Consortia 1 (P+MC1) from heat stress conditions showed significant improvement in several physiological and biochemical characters of leaf like chlorophyll and carotenoid content, antioxidant enzymes like catalase (CAT), ascorbate peroxidase (APX) and superoxide dismutase (SOD), protein content, proline content, malondialdehyde content and relative water content when compared with their respective control. The agronomical and yield parameters as well as the zinc and iron micronutrient content in soil and grain; Bacterial dynamics in soil was also significantly higher in Nano zinc-oxide, Nano chitosan and Microbial Consortia 1 (Zn+C+MC1) treatment under drought stress conditions and Plasma and Microbial Consortia 1 (P+MC1) treatment under heat stress conditions. The shelf life of consortia was also evaluated and the results demonstrated that the shelf life life of Microbial Consortia (MC1) at 4°C was significantly better compared to Microbial Consortia 2 (MC2) and storage at room temperature. Therefore, the application of Microbial Consortia 1 (MC1) along with nanoparticles and plasma could be a novel strategy to improve crop production under abiotic stress conditions to maintain the agricultural sustainability.
Open Access
Biochemical and functional characterization of psychrotolerant Pseudomonas helmanticensis AB-04
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2019-03) Joshi, Anurag; Goel, Reeta
To meet the requirement of increasing population, current agronomical practices are mainly focused on huge production of pulse crops in more sustainable manner. However, rigorous cropping patterns, rampant application of chemical fertilizers, and other environmental factors resulted into reduced crop productivity and adversely affect the soil fertility. Using plant growth promoting bioinoculants is a prominent and environment friendly alternative strategy for improved growth of plants. Therefore, the present study was performed for evaluating the impact of previously characterized Pseudomonas helmanticensis AB 04 on seedling germination of four native pulses viz. Pea (Pisum sativum L. var. Arkel), Mungbean (Vigna radiata L. var. Pant Mung 4), Urad (Vigna mungo, L. var. PU 31) and Chickpea (Cicer arietrinum L. var. PG-186), and further promotional effect on the seed vigour of selected crop. Outcomes of the biochemical tests revealed that the bacterial strain showed variability in utilizing different carbohydrate sources, and as well exhibited variant patterns of sensitivity and resistance against antibiotics. AB-04 strain showed improvement in seed germination percent for all the crops. The highest germination percent was reported for Urad (Vigna mungo, L. var. PU 31) upon bacterial treatment when compared with other three pulses and therefore, was selected for further analysis. The study also revealed the positive influence of AB 04 strain on seedling vigour of Urad (Vigna mungo L. var. PU 31). Therefore, this study confers an insight on exploring P. helmanticensis AB 04 strain as effective bioinoculant for native pulse crops under sustainable agricultural plans.
Open Access
Evaluation of endophytic bacteria for growth and stress tolerance of Trigonella Foenum-Graecum (Fenugreek) under saline stress conditions
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Naveen, K.; Tiwari, Lakshmi
Salt- affected soils are becoming greatest hindrance to crop production worldwide; the rate at which the arable land is lost every year due to these problems is imposing a greatest challenge to agricultural production. Hence in order to ameliorate the stress imposed by these soils on the crop plants, microbial mediated approach is selected and the present study is conducted to address this issue. Twenty seven indigenous endophytic bacteria were isolated from underutilized medicinal weed plant Phyllanthus sp and screened for in vitro pH (7.0-11.0) stress tolerance. Eleven alkalo-tolerant isolates were selected and further screened for in vitro salt tolerance(using NaCl concentration 0-12%) and plant growth promoting traits. The four superior isolates(PSBeP-8,PSBeP-11) showing higher stress tolerance and PGP properties were selected. The isolate PRBeP-10 was found to be most akalo-tolerant showing growth up to pH 10.0 while the isolate PSBeP-8 most salt tolerant with growth up to 10% NaCl concentration. Under normal conditions (pH 7.0;NaCl 0%) all the isolates showed P- solublization and siderophore production which was adversely affected with increasing salt and pH conditions. The isolate PRBeP-10 showed higher phosphate solublization under pH/salt stress conditions as compared to other cultures showing phosphate concentration of 61.18 μg/mL at pH 10.0 and 38.4 μg/mL at 10% NaCl concentration. Siderophore production at highly alkaline pH(pH 10.0) was shown by the isolate PRBeP-10(46.58% sid units in 72 h while at highly saline condition(10% NaCl) 28.3% sid units were recorded for PSBeP-8 in the same time. Thus the isolates PSBeP-8 and PRBeP-10 were found most halo-alkalo-tolerant retaining their p-solubilizing and siderophore producing abilities under pH and salt stress conditions. Both the isolates were evaluated for their in vitro and in vivo growth enhancing capabilities under normal and saline/alkaline conditions. Germination of fenugreek seeds was increased under salt and pH stress conditions due to inoculation with bacterial endophytes. During pot culture experiment, the mono-cultures of PRBeP-10 and PSBeP-8 and their co- culture inoculation enhanced the leafy biomass yield of fenugreek plants over their corresponding un treated controls grown in saline soil(of pH 9.0).Based on various morphological, biochemical traits and 16S rRNA gene sequence analysis, the isolate PRBeP-10 and PSBeP-8 were identified as Sphingobacterium sp PRBeP-10 and Pseudomonas aeruginosa PSBeP-8.
Open Access
Plant growth promotory effect of PGPR and their consortia on wheat under drought stress conditions
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Lohani, Swati; Singh, Ajay Veer
Plants under natural environmental conditions experience various kinds of abiotic and biotic stresses, results as severe deterioration in plant growth and development. According to this perspective, the present study was accomplished with the implementation of drought tolerant plant growth promoting rhizobacteria (PGPR) in wheat. For this study, total twenty bacterial isolates were retrieved from departmental culture collection. Drought tolerant twelve bacterial isolates were selected on the basis of growth present on tryptic soy broth medium supplemented with 8% poly ethylene glycol. These drought tolerant isolates were further analyzed for plant growth promoting activities (siderophore production, zinc solubilization, phosphate solubilization IAA production etc.) and five potent bacterial isolates were screened and further used for consortia development. These consortia along with single bacterial isolates were analyzed for plant growth promoting traits such as siderophore production, zinc solubilization, phosphate solubilization and ammonia production. Furthermore, an in situ greenhouse pot experiment was designed under drought stress to evaluate the potential of drought tolerant plant growth promoting bacteria along with their consortia isolates on wheat (Triticum aestivum var. PBW373). Results of greenhouse pot experiment confirmed that all bacterial isolates and their consortia were significantly able to improve plant growth and productivity in terms of agronomical parameters such as root length and plant height. Among all treatments, two bacterial isolates i.e. WRPa4 and SRK14 and two consortia CIII and CV proved as more potent for drought tolerance and plant growth. To determine the shelf life of consortia under different temperature conditions such as room temperature (25 °C), 4°C and outdoor conditions, a talc based bioformulation was prepared. Result of shelf life determination demonstrated that all consortia were able to survive for three months in all defined condition. The bioformulation these consortia CIII and CVand bacterial isolate SRK14 and WRPa4 could be used as bio protective and biofertilizer agent after further examination, at commercial scale in field under stressed conditions.
Open Access
Development of immobilized microbial consortia for decolorization of synthetic industrial dyes
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2018-08) Shalu Priya; Tewari, Lakshmi
Industrial application of different types of synthetic toxic dyes in huge amount is of major concern with regard to environment and human health. Due to their carcinogenic and mutagenic properties these dyes are damaging the ecosystem and their natural flora and fauna. Therefore, the present investigation was carried out for the efficient bioremediation of seven toxic synthetic industrial dyes (direct brown, diazo black, congo red, direct black, turquoise blue, malachite green and brilliant green), which are widely used in different industries, using fourteen microbial (bacteria, fungi, yeast, microalgae and cyanobacteria) cultures. All the microbial cultures were initially screened for their in vitro dye decolorization efficiencies. Then, the selected isolates were further evaluated spectrophotometrically for the quantification of dye decolorization for all the dyes. Four fungal cultures, (PMF2, WFPN1, WDP2 and PPS1) showed maximum decolorization for most of the azo dyes, where as the microalgae (PASM, PHSM and PRSM) and the cyanobacteria (Synechococcus sp.) showed maximum decolorization for the dyes malachite green and brilliant green only in 4-7d. The microbial cocultures (consortia) were developed using the potential microbial monocultures to increase the extent of dye removal for the four selected dyes (congo red, direct black, malachite green and brilliant green). The decolorizing efficiencies shown by the selected fungal consortia for the azo dyes (congo red, direct black) and triaryl methane dyes (malachite green, brilliant green) were significantly higher than that for their monocultures. The consortia showed complete decolorization of the liquid cultures in lesser time (3-4d and upto 2d, respectively). The effect of certain factors such as concentration of dye and pH of the medium were also found to have a great impact on microbial dye decolorization. The developed microbial consortia (PHSM + Synechococcus) was able to grow and decolorize the synthetic dye (malachite green) upto a conc. of 1000 mgL-1 and could also tolerate high alkaline pH range decolorizing the dye upto pH 11. Reduction in the values of BOD, COD, electrical conductivity and pH of the treated samples as compared to their uninoculated control counterparts was also recorded. The immobilization of the co-cultures of microalgae and cyanobacteria was done on corn cob. The immobilized co-cultures showed rapid decolorization of the dye malachite green with better dye decolorizing efficacy. The extent of dye decolorization during microbial decolorization process was monitored by UV-visible spectroscopy, FTIR and SEM analysis.

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