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Open Access
Comparative study on phosphate solubilization potential of bacteria in wheat under agroforestry vs open cultivation systems
(G. B. Pant University of Agriculture and Technology, Pantnagar, 2022-10) Hedi, Anjali; Sahgal, Manvika
To fulfill the rising need for food, chemical fertilizers and pesticides have been used excessively, which has surely resulted in pollution and significant harm to soil fertility. The use of bio fertilizers, an environmentally benign agricultural input that is also more affordable than chemical fertilizers, significantly increases soil fertility over time. Phosphate solubilizing bacteria associated with plant increase the plant available phosphorus in soil thereby promoting the plant growth as well as yield. The current study examined the plant growth promoting potential of two PSB Pseudomonas strains on wheat through a field trial in open cultivation system and agroforestry system. Both the strains were previously isolated from the Dalbergia sissoo forest in the North-western Himalayan region of India and tested for their ability to serve as bio fertilizer using an integrative approach that included field trial with recommended dose of NPK. They were identified as Pseudomonas paralactis L3 (NCBI Gen Bank Accession number MG966341), Culture Accession number NAIMCC-B-03170 and Pseudomonas aeroginosa P2 (NCBI Gen Bank Accession number MG966347), Culture Accession number NAIMCC-B-03171). The field trial was conducted in two experimental setup i.e. open cultivar with Randomized Block Design (RBD) having three replicates per treatment and in all three treatments,P2, L3 individual and in consortium, CNS (L3+P2). At 60DPI and 120DPI in open field cultivation, CNS showed the best result in all agronomic parameters, GY, BY, HI and 1000 grain weight, photosynthetic pigments, microbial count and soil enzymatic activities and were significantly higher than untreated control at p<0.05. Whereas in agroforestry system P2 showed the best result. At 120DPI the highest GY (14.37qha-1), BY(16.27qha-1), HI (88.29) and1000grain yield (36g) was observed in P2 strain in agroforestry system. Whereas in open cultivation system GY (13.27qha-1), BY(15.06qha-1), HI (88.1) and 1000grain yield (33.33g) was shown by CNS. The highest NPKcontent in soil during open field cultivation was observed in CNS (37.30%,0.44% and 1.63%) and in agroforestry system the maximum response was observed in P2 (38.09%, 0.482% and 1.69%) as compared to uninoculated control. In open system the highest protein and carbohydrates content were found in CNS10.82% and 2.603% whereas in agroforestry system P2 showed the highest response 12.52% and 2.93%. To assess the impact of PSB on wheat seed germination the in vivo seed germination assay was performed in which P2 treated seeds showed significantly higher seed shoot length (SL) crawling as compared to untreated wheat seedling. Overall while comparing both the systems the best results were obtained in agroforestry system as compared to open field cultivation.
Open Access
Evaluation of salt tolerant bacterial consortia on growth of green gram (Vigna radiata) under saline and non-saline conditions
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-12) Negi, Riya; Singh, Ajay Veer
Salinity is one of the most crucial problems for sustainable agriculture which is severely affecting crop growth and decreasing the food production. On the other side, the world's growing population necessitates increased food production. So, there is a need of hours to increase agricultural production from salt affected soils by adopting cost-effective and environment friendly approaches. Use of salt tolerant plant growth promoting rhizobacteria (PGPR) could be a promising option to enhance the production of crops in salt affected soils and reduce the negative impacts of salt stress in soil. In this regard, the present study was conducted with 7 Plant growth promoting bacteria, which were further rescreened for salt tolerance capacity at different NaCl concentrations. These Plant growth promoting bacteria were capable to tolerate 15-20% of NaCl concentrations. Further, On the basis of biocompatibility assay, 3 Consortia i.e. Consortium1 (SRK14 and MRCII6), Consortium C2 (RRCI5 and SRP9II1) and Consortium C3 (CP17 and CP20) were prepared. All the bacterial isolates and consortia were screened for different plant growth promoting traits such as indole-3- acetic acid (IAA), Siderophore production, K solubilization, P solubilization, Zinc solubilization, Ammonia production, N2 fixation and exopolysaccharide production. Based on these results, bacterial consortia showed better PGPs traits as compare to single bacterial isolates. Therefore further selected for towel paper assay and pot experiment on green gram (Vigna radiata var. PM9) under saline and non-saline conditions. In paper towel assay, a significant enhancement of root length, shoot length, standard germination, first count, plant fresh weight, dry weight, seedling vigour index I, seedling vigour index II, relative growth index, germination value, mean daily germination and peak value were recorded in plants inoculated with bacterial consortia under both saline and non saline conditions over uninoculated plants. Similarly, in pot trial assay, at elevated concentrations of NaCl, the adverse effects on plant height, no. of nodules, chlorophyll content, carotenoid content, no. of pods per plant, no. of seeds per pod, 100 grains weight along with yield attributing characteristics were recorded in uninoculated (only NaCl) plants. However, in similar conditions inoculation of bacterial consortia showed positive adaption and improve growth performance of green gram compared to uninoculated. Hence, the results suggested that plant inoculated with Consortium 1(SRK14 and MRCII6) under non saline conditions and under saline conditions Consortium C3 (CP17 and CP20) showed better results over uninoculated control. Therefore, Consortium C1 (SRK14 and MRCII6) under non saline conditions is a potential consortium for promoting plant growth attributes in green gram and Consortium C3 (CP17 and CP20) under saline conditions is a potential salt tolerant consortium to mitigate the deleterious effects of salinity in green gram.
Open Access
Isolation of cellulose degrading microorganisms from biogas slurry and their application in rice straw degradation
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Deorari, Pinki; Sahgal, Manvika
Rice is one of the major food grain crops in the world. Besides grain, it also produces large amount of waste in the form of rice straw. Present study explores the biogas slurry microorganisms in the biodegradation of rice straw. Efforts were also made to identify potential cellulase producing microbial cultures from biogas slurry that play an important role in the hydrolysis of lignocellulosic biomass. 45 bacterial and fungal cultures were isolated from biogas slurry. These isolates were screened for cellulase and xylanase enzyme activities both qualitatively and quantitatively. The potential fungal isolate SSF4 exhibiting maximum FPase (0.315 U/mL) activity on CMC minimal salt medium, fungal isolate SSF1 showing highest β-glucosidase (0.552 U/mL) activity on CMC minimal salt medium and SSF1 showed maximum xylanase (0.510 U/mL) activity on wheat bran minimal salt medium were selected for biodegradation of rice straw. Based on the morphological characterization and microscopic observation of selected strain revealed that SSF1 culture was identified as Aspergillus genus and SSF4 culture as Trichderma genus. The consortium of these two strains with biogas slurry was effective in biodegradation of rice straw. The rice straw was first subjected to alkaline pretreatment for removal of lignin content from rice straw. For biological treatment, the alkaline pretreated rice straw was treated with selected fungal isolates and biogas slurry. The pretreated and biologically treated rice straw was monitored through FTIR analysis to reveal the chemical changes in the lignocellulosic biomass of rice straw. The future research should be focus on the study this consortium at the biochemical level and optimization would be needed for higher production of enzyme to improve biodegradation of rice straw.
Open Access
Bioremediation of polluted Kalyani river water using immobilized microbial consortia
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Rawal, Himanshu; Tewari, Lakshmi
The pollution of rivers and other water bodies has become one of major concern for the entire world especially for the developing nations like India. The effluents of various industries, loaded with synthetic dyes in large amount, are great threat for the ecosystem and their native flora and fauna. Therefore, the present investigation was carried out for the bioremediation of several toxic industrial azo dyes (Congo red, Direct brown and Diazo black) and wastewater from Kalyani river, Rudrapur, Uttarakhand, using eighteen microbial cultures (fungi, microalgae and cyanobacteria). 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 three azo dyes. Five fungal cultures, (WRTP2, WRTP3, WRTP4, BS1 and WRFP1) were able to decolorize all the three azo dyes in 1-4d. The microbial consortia were developed using the potential microbial monocultures (fungi, microalgae and cyanobacteria) to increase the extent of dye removal for the three azo dyes (Congo red, Direct brown and Diazo black). The consortia were more efficient and showed complete decolorization of the liquid cultures in lesser time (within 48h). The effect of dye concentration and pH of the medium were also found to have significant impact and the developed microbial consortia (WRTP3+Syn) and (BS1+ Syn) were able to grow and decolorize the azo dyes (Congo red and Direct brown) upto a conc. of 1200 mgL-1. The immobilized co-cultures (on stainless steel sponge and cotton plugs) showed rapid decolorization of dye direct brown and were able to decolorize 100 mgL-1 and 200 mgL-1 of dye in 14h and 20h respectively. The extent of dye decolorization during microbial decolorization process was monitored by UV-visible spectroscopy, FT-IR and SEM analysis. The Kalyani river water was analysed for its physio-chemical parameters. Reduction in the values of BOD, COD, electrical conductivity, pH, colour and turbidity in the microbially treated wastewater sample was also recorded.
Open Access
Bioconversion of pretreated paddy biomass into sugar using combined chemical and microbial approach
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-10) Solanki, Anjali; Tewari, Lakshmi
Rice is the major staple food of our county and most part of the world.. Rice waste generation and their open field burning is major problem, resulting in nutrient losses as well as major air quality issues that threaten human health and safety. Therefore the present investigation was carried for the conversion of these paddy waste into valuable fermentable sugar. For this study 17 fungal and 5 bacterial microbial cultures were isolated from Crop research centre, Pantnagar, Uttarakhand and some cultures were collected from Department of Microbiology. Then, the selected isolates were further screened qualitatively and quantitavely for their extracellular enzyme activities i.e. cellulase, laccase, silicase with the aim to select cultures of best enzyme activities for removal of lignin and silica content from rice straw biomass and their conversion into fermentable sugar. In this study, various pretreatments such as chemical and biological were given to remove silica and lignin content from rice straw. Microbial culture RSFP3 was found to give maximum FPase enzymatic activity (0.108U/ml) after 7th day of incubation period which was isolated from rice stem. Fungal culture RSFP1 give maximum silicase enzyme activity (276.62mg/L) after 10th day of incubation period. Fungal cultures BS6 reported to give maximum laccase enzyme activity (115.40U/ml) after 12th day of incubation period. On the basis of given results microbial cultures RSFP1 and BS6 were selected for further study to remove silica and lignin content from rice straw. Consortium of fungal isolate (RSFP1+BS6) remove the lignin content from 14.65% to 9.3% and % silicon solubilisation by using these consortium is 92.79mg/L. After the pretreatments treated biomass was further used for conversion into fermentable sugar by using fungal culture PPCF.
Open Access
Validation of biocontrol efficacy of a microbial consortium against Sclerotinia rot of tomato under field conditions of tarai and hilly region of Kumaun
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-08) Aravindharaja, S.T. M; Sharma, Anita
Present study revealed the biocontrol potential of a microbial consortium against a tomato pathogen viz., Sclerotinia sclerotiorum under laboratory and field condition at two locations. Bacterial consortium (consisted of MN8, MA13, AA17 and AA12) @ 1% dose effectively influenced and outperformed with individual bacterial isolates to promote the growth of tomato seedling in a biopriming experiment. Three fungicides namely carbendazim, mancozeb and hexaconazole effectively checked mycelial growth of Sclerotinia sclerotiorum at 500 ppm concentration. Bacterial consortium tolerated all the fungicides up to 500 ppm concentration. Outcome of the compatibility experiment of microbial consortium and fungicides was used to control Sclerotinia fungus using integrated disease management strategy. Percent disease incidence of Sclerotinia stem rot recorded in consortium treated tomato (T2) plants was 34.66 and 37.80%, whereas negative control (T5) showed disease incidence in the range of 60.93 and 65.64% in tarai and hilly regions of Kumaun after 30 days of disease induction. Application of bacterial consortium + carbendazim (T3) recorded 31.88 and 33.92% disease incidence. Two treatments (T2 and T3) showed nearly equal disease incidence as observed under carbendazim (T4) treatment (alone). Under biotic stress, bacterial consortium (T2) has played an effective role in number of growth parameters than consortium + carbendazim (T3), carbendazim (T4) treated and untreated control (T6) at tarai and hilly regions. Bacterial consortium (T2) treated tomato plants showed 1.30, 1.58 and 1.34-fold increase in plant height, number of leaves and leaf area in tarai and in hilly region values and were found in the range of 1.3, 1.49, 1.29 fold greater than control after 30 days of the induction. Above data mentioned, in tarai region bacterial consortium (T2) resulted least % disease incidence and high promotory activity of plant growth than hilly region of Kumaun, Uttarakhand.
Open Access
Biocontrol of banded leaf & sheath blight of maize caused by Rhizoctonia solani f.sp. sasakii using Pseudomonas strains AS19 & AS21
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-02) Kabdwal, Manisha; Sahgal, Manvika
Maize is the third most important cereal crop which provides food and nutritional security in the country. Banded leaf and sheath blight (BL &SB) caused by Rhizoctonia solani f.sp.sasakii is responsible for 10 to 40% yield loss in maize. Considering the harmful effects of chemical pesticides on human health and environment, biological control gains importance. The present study was undertaken to evaluate the field efficacy of two Pseudomonas strains AS19 (Culture Accession No. NAIMCC-B-02303) and AS21 (Culture Accession No. NAIMCC-B-02304) against Rhizoctonia solani f.sp.sasakii causing BL&SB in maize. The cell-free supernatant and whole-cell culture of both the strains inhibited fungal mycelium significantly under in vitro conditions. The percent mycelial inhibition with cell-free supernatant of AS19 (58.03%) and AS21 (62.56%) was higher than whole-cell culture of AS19 (48.43%) and AS21 (52.2%). Both Pseudomonas strains (AS19 and AS21) were positive for hydrolytic enzyme production (chitinase, β1-3 glucanase, protease, amylase, and gelatinase) and plant growth promoting traits (siderophore, ammonia, IAA, HCN, and phosphate solubilization). Subsequently, these two Pseudomonas strains were selected for field trial to evaluate their in vivo biocontrol potential and elucidate mechanism of control. The significant effect on disease control and plant growth were observed for field inoculated with AS21 with 29.19 % disease control and 17.76 % reduction in avoidable yield loss. A separate trial was conducted to elucidate the biocontrol mechanism, the seed plus soil formulation of BCAs resulted in higher disease reduction and enhanced growth. Inoculation of Pseudomonas strains resulted in enhanced level of defense responses like total phenol, protein content and reactive oxygen species(ROS) enzymes (superoxide dismutase, catalase, phenylalanine ammonia-lyase, peroxidase and polyphenol oxidase). Overall from above results, it is concluded that inoculation of bacterial biocontrol agent (BCAs) induced plant immunity against R.solani f.sp. sasakii and showed induced systemic resistance (ISR) as a mechanism of disease control. Therefore, the two antagonistic Pseudomonas species can be exploited as a commercial biocontrol agent against banded leaf and sheath blight disease in maize.
Open Access
Evaluation of microbial consortia on paddy grown under organic, inorganic and integrated production system
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-01) Joshi, Manisha; Singh, Ajay Veer
The farmers and researchers are trying various combination of organic as well as inorganic fertilizers in agriculture to gain maximum produce without damage of soil health to fulfill the food demands of surging population across the globe. Plant growth promoting rhizobacteria (PGPRs) play an important role in sustainable agriculture through the improvement of plant growth via different processes like biological nitrogen fixation, phosphate solubilization, potassium solubilization, zinc solubilization, siderophore production and phytohormone synthesis. The use of PGPR is potentially increased in sustainable farming due to its eco-friendly and efficient nature. The present study is accomplished with implementation of potential plant growth promoting rhizobacteria (PGPRs) in different production systems i.e., organic, inorganic and integrated production system to compare and screen out the best combination for maximum yield. For this study, four bacterial isolates were retrieved from departmental culture collection and tested for various biochemical tests including carbohydrate utilization for various sources and antibiotic sensitivity assay. All the selected bacterial isolates were utilized for preparation of consortia on the basis of biocompatibility assay. Afterwards, bacterial isolates and their two consortia (C1 & C2) were tested for PGP traits like IAA production, phosphate solubilization, zinc solubilization, siderophore production, potassium solubilization, nitrogen fixation etc. On the basis of plant growth promoting traits analysis, consortium 1(SRK 14, MRC II 6) was selected for field experiment. The consortia 1 treated paddy seedlings were evaluated for growth and yield under different treatments of organic, inorganic and integrated production system. The results of the present study showed that treatment of microbial consortium (C1) was able to enhance the total chlorophyll content, carotenoid content, plant height, number of tillers, root length, root volume, panicle length, grain weight per panicle, thousand grain weight, effective tillers/m2, grain yield and total biological yield in all treatments. However, the maximum results for all parameters were recorded in treatment 6 (T6) under integrated I production system having combination of 50% organic fertilizers + 50% inorganic fertilizers + microbial consortia. Along with integrated production system, the use of consortium (C1) gave maximum results in organic as well as inorganic production systems indicating its promising potential. Hence, developed microbial consortia can be used as plant growth promoting biofertilizer to enhance plant growth and yield of paddy under field system in sustainable manner.
Open Access
Analysis of dye decolourization efficiency of a Bacillus Spp.
(G.B. Pant University of Agriculture and Technology, Pantnagar - 263145 (Uttarakhand), 2021-01) Singh, Shivani; Sharma, Anita
Dyes released from various industries show negative effect on ecology and human health (immune suppressions, acute poisoning, allergy and reproductive failure). Biodegradation of synthetic dyes (Toluidine blue, Methylene blue, Bromocresol green, Congo red and Rose Bengal) by using bacteria is a rapid, cost effective and ecofriendly approach. Present study was performed under laboratory conditions by using four bacterial isolates which were screened qualitatively for their in- vitro dye decolourization potential. SG2D identified as Bacillus cereus was selected for quantification of dye decolorization potential in minimal salt medium supplemented with different concentrations of dyes (5,10, 15 and 20 ppm) using free and immobilized culture. Maximum dye removal efficiency was obtained as 94.92, 25.56, 91.18, 47.58 and 23.63% for Methylene blue, Bromocresol green, Toluidine blue, Congo red and Rose Bengal respectively in the presence of free bacterial culture of SG2D. However, removal efficiency by immobilized SG2D was 94.92, 17.74, 93.62, 57.88 and 59. 78 % for Methylene blue, Bromocresol green, Toluidine blue, Congo red and Rose Bengal respectively. The optimum concentration of Methylene blue, Bromocresol green, Toluidine blue, Congo red and Rose Bengal removal was found to be 15, 10, 5, 20 and 15 ppm by free SG2D and 15, 20, 20, 20 and 10ppm by immobilized SG2D of respective dyes. Immobilized SG2D showed rapid decolourization as compared to free SG2D. The extent of decolorization and biodegradation of each dye was monitored using UV-Visible and FT-IR spectroscopy. Appearance and disappearance of peaks in the treated dye samples and stretching of bonds at various wave numbers as compared to control were correlated with the dye decolourization efficiency of the bacterial isolates.

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