Salinity is one of the important environmental factors, which influence fertility and quality of ... more Salinity is one of the important environmental factors, which influence fertility and quality of the soil. In semiarid and arid regions of the world, salinity is the main constraint that is affecting productivity and yield of the crop plants. Many crop plants are very sensitive to high concentration of salinity. A recent concept of biochar application to soil is enhancing various physicochemical properties under acidic and saline conditions. Biochar is a carbonaceous compound and can be utilized as a better soil ameliorant in comparison to other organic amendments for improving the fertility of soil for an elongated time period. The present review chapter is based on the results of many research papers, showing that the application of biochar to soil is potentially suitable for highly weathered soils as it enhances physicochemical properties and reduces soil loss. Although the information on biochar for enhancing the soil chemical properties is well-known, information on physical properties' enhancement is scarce. Therefore, the main aim of the current chapter is to provide all the available literature and information on the role of biochar for the reclamation of soil by enhancing their physicochemical properties under saline conditions. Further, the present review examines and deliberates the investigations on the effect of biochar in reclamation and enhancing the properties of saltaffected soils.
International journal of scientific research, 2015
In the present investigation effect of various nutrient supplements iron, phosphate/potassium and... more In the present investigation effect of various nutrient supplements iron, phosphate/potassium and exogenous ni- trogen sources on growth and nitrogen fixing ability of cyanobacteria have been studied in terms of chlorophyll, carot - enoid and nitrogenase activity. The response was found to be species specific to K+/PO43- and Fe3+ and nutrient saturation occurred at dif- ferent concentration in term of photosynthetic pigment concentration. Amongst exogenous N-sources, nitrate alone had a stimulatory effect on chlorophyll of some strains while ammonium and amino acids tended to suppress the concentration of chlorophyll and other pigments. While exogenous nitrogen suppressed nitrogenase activity, the other nutrients significantly increased N2 fixing potential of the cyanobacteria.
International Journal of Environmental Science and Technology, 2017
In present investigation, consortia of two indigenous heterocystous cyanobacteria, Nostoc ellipso... more In present investigation, consortia of two indigenous heterocystous cyanobacteria, Nostoc ellipsosporum HH-205 and Nostoc punctiforme HH-206 isolated from a salt affected area of Hisar, Haryana (India) were used as biofertilizer in bioremediation of salt affected soils having high electrical conductivity (13.5 dS/m) and pH (8) with poor organic carbon (0.3%) as well as nitrogen content (0.008%). The experiments were conducted in a pot house for the period of 240 days. There was a significant (P \ 0.05) increase in carbon, phosphate, nitrogen, potassium, magnesium, cation exchange capacity, mean weight diameter and hydraulic conductivity of soil with biofertilizer treatment whereas sodium ion and electrical conductivity were found to be decreased. Improvement in soil aggregation and stability due to increased soil microbial activities (dehydrogenase, invertase and phosphomonoesterase) were also observed. Significant increase in growth and yield of pearl millet-wheat crop was observed in amended pots even under low water regime. Thus, the indigenous cyanobacterial species show promise in effective exploitation for phytoremediation and improved productivity of saline soils under semi-arid condition.
International Journal of Environmental Science and Technology, 2016
Microalgal lipids can be enhanced through varying nitrogen (N) content, and limited supply of nit... more Microalgal lipids can be enhanced through varying nitrogen (N) content, and limited supply of nitrogen source seems to be valuable approach for increased lipid accumulation in microalgae. In this study, Chlorella sp. IM-02 was observed under fluorescence microscope for increased number of lipid bodies under nitrogen scarcity. Fourier transform infrared spectroscopy was used to determine spectral changes due to varying lipid content under nitrogen-starved (N 0 , without sodium nitrate), nitrogen-limited (N 0.1 , N 0.25 , N 0.5 and N 1.0 representing 0.1, 0.25, 0.5 and 1.0 g/L of sodium nitrate, respectively) and nitrogen-sufficient (N 1.5 , i.e., 1.5 g/L sodium nitrate) setting. Chlorophyll content was also monitored under these conditions as growth indicator. Various biochemical components viz. total carbohydrates, total proteins and total lipids were also estimated under varying nitrogen levels spectrophotometrically. On fourth day itself, maximum lipid productivity was observed in case of N 0.5 , which is having one-third of nitrogen concentration present in original growth media, BG-11. This concludes N 0.5 as suitable nitrogen provision for better production of lipids in Chlorella sp. IM-02 without much compromising the biomass production as both growth and lipid quantity are key parameters affecting the lipid productivity of any microalgal strain.
International Journal of Current Microbiology and Applied Sciences, 2016
The present study was undertaken to investigate the fungal associates of Rhododendron campanulatu... more The present study was undertaken to investigate the fungal associates of Rhododendron campanulatum D. Don from Churdhar region of District Shimla and Sirmaur in Himachal Pradesh. Studies revealed the presence of seven species of fungi belonging to six genera (Absidia, Aspergillus, Curvularia, Fusarium, Pythium and Trichoderma) from mycorrhizosphere soil of Rhododendron campanulatum. Fusarium was the most dominant genus among rhizosphere soil fungi. Twenty seven species of AM fungal spores belonging to eight genera (Acaulospora, Dentiscutata, Endogone, Entrophospora, Gigaspora, Glomus, Sclerocystis and Scutellospora) were isolated from the rhizosphere soil of Rhododendron campanulatum. Glomus was the most abundant genus recorded. Twenty species of endophytic fungi belonging to thirteen genera (Alternaria,
The study reports the effects of irrigation of a sodic soil with post methanation effluent (PME) ... more The study reports the effects of irrigation of a sodic soil with post methanation effluent (PME) of a distillery. Impact of long term effluent irrigation in the field (10 years) and short term effluent irrigation using different doses of PME in the laboratory (30 days) was studied in combination with three bioamendments i.e. farmyard manure, brassica residues and rice husk. Impact on various soil properties like EC, pH, total organic carbon (TOC), total Kjeldahl nitrogen (TKN), available phosphorus, exchangeable K, Na, Ca, Cl, microbial population and soil enzyme activities were studied. Long term application of PME proved useful in significantly increasing TOC, TKN, K, P and soil enzymatic activities in the soil but tended to build up harmful concentration of Na, that could be chelated by bioamendments. In short terms studies, application of 50% PME along with bioamendments proved to be the most useful in improving the properties of sodic soil and also favoured successful germination and improved seedling growth of pearl millet.
Multi-strain biofertilizer consisting of three indigenous cyanobacterial isolates was applied to ... more Multi-strain biofertilizer consisting of three indigenous cyanobacterial isolates was applied to an organically poor semi-arid clay-loam soil (pH 7; electrical conductivity, EC, 0.8 dSm − 1 ; total organic carbon, TOC, 0.34%; total Kjeldahl Nitrogen, TKN, 0.06%) in pot-house experiment. During the 240 d experiment under conditions of limited water regime (6-12% soil moisture), there was a significant (p b 0.05) increase in TOC, TKN and PO 4 3− P during the middle, which, however, diminished at later stages of the experiment. The biofertilizer (BF) improved carbon and nitrogen mineralization by promoting soil microbial activities and narrowed down C:N ratio. Effect of BF on cation exchange capacity of the soil became evident with time. Physical structure of the soil was influenced due to BF as indicated by significant (p b 0.01) decline in bulk density and increase in water holding capacity, hydraulic conductivity and mean weight diameter at the end of both pearl millet and wheat crop. Plant growth and yield of pearl millet-wheat sequence in the soil increased in response to cyanobacterial biofertilizer. Response of pearl millet to BF was more pronounced for certain parameters at the lower water level, W 2 (6% moisture). The native strains showed remarkable potential for improving structural stability, nutrient status and productivity of the soil under limited water regime.
In the present study, the fungal associates of Rhododendron arboreum were investigated. Studies r... more In the present study, the fungal associates of Rhododendron arboreum were investigated. Studies revealed the presence of twelve species of endophytic fungi and fifteen species of rhizospheric fungi belonging to different genera (Aspergillus, Cladosporium, Fusarium, Penicillium, Rhizoctonia, Rhizopus, Stachybotrys, Trichoderma and a sterile mycelium) from the leaves, stem, bark, roots and rhizosphere soil of Rhododendron arboreum. Aspergillus was the most abundant genus among the endophytic and rhizospheric fungi and maximum number of fungi was observed during rainy season followed by winter and summer. Twenty two species of AM fungal spores belonging to five genera (Acaulospora, Dentiscutata, Entrophospora, Gigaspora and Glomus) were isolated from mycorrhizosphere soil samples of this plant. Glomus was found most abundant genus among the AM fungal spores. Maximum number of spores was observed during rainy season followed by summer and winter seasons respectively.
The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia... more The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia and Nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. Besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (VI) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. While phycobilins and carotenoids also increased in Nostoc linckia with total dissolved salts (TDS) as well as metal, a decline was observed in Nostoc spongiaeforme in the presence of Cr (VI). Relative algal biomass (as % of control) showed significantly higher values (123-239) in Nostoc linckia in the presence of salt, metal and combination of the two. In Nostoc spongiaeforme it declined in the presence of metal (72-81) but increased in the presence of salts (143-249) and also in the binary systems (121-440). The bi-algal consortium showed relatively less tolerance to salt and metal stress. Nostoc linckia (20 day culture) ...
The agriculture community is facing a great challenge to enhance the production. To meet the chal... more The agriculture community is facing a great challenge to enhance the production. To meet the challenge, the focus is on to reclaim the degraded land and understands the complexities and interactions of soil biological system and agro-ecosystem as a whole. Soil microorganisms play very important role in reclamation of such degraded lands and have important influence on soil fertility and plant health. The importance of AM association in restoration and improvement of revegetation of disturbed mined lands is well recognized. In the present studies, the indigenous species of fungal associates and vesicular arbuscular (VAM) fungi of Triticum aestivum plant were isolated from the disturbed field (cement mining area) and normal field (10 km from cement mining) in Darlaghat, Himachal Pradesh, India. Rhizospheric soil samples of Triticum aestivum revealed the presence of eighteen species of fungi. Aspergillus, Fusarium and Absidia were found to be the predominant genera and maximum genera i...
Effectof exopolysaccharides (EPS) produced by a consortium of cyanobacteria on germination of thr... more Effectof exopolysaccharides (EPS) produced by a consortium of cyanobacteria on germination of three crops wheat, maize and rice was studied at different salt concentrations. Production of EPS was found to be stimulated by salts, which in turn had a significant Na+ removal capability from aqueous solution. Seed germination, vigor index and mobilization efficiency in all the three crops remarkably improved when cyanobacterial EPS was applied. While germination improved significantly by 13 to 30%, mobilization efficiency increased marginally by 1.03 to 1.1 times and vigor index increased by 1.15 to 2.4 times in these crops in response to EPS under non-saline conditions. Salinity had an inhibitory effect on seed germination of all the species showing 18 to 54% reduction. However, in the presence of EPS, the salt induced inhibition diminished to 13 to 18%. Inhibitory effect of salt on chlorophyll concentration, vigor index and mobilization efficiency of the seedlings was much less in the...
In the present investigation, three strains of cyanobacteria isolated from agricultural fields ne... more In the present investigation, three strains of cyanobacteria isolated from agricultural fields near to salt mine were used as biofertilizer individually and in consortia. Farm yard manure was also used along with cyanobacterial biofertilizers to see the ameliorative effect on soil physical, chemical and biological properties. The algalization experiment was conducted in pots in the glass house of the department for 240 days. There was an improvement in carbon, nitrogen, phosphate, potassium, magnesium, calcium, zinc, iron, copper and manganese with biofertilizers treatment whereas sodium ion, EC and pH were found to be decreased. Soil microbial activities and plant growth parameters were found to be improved. Thus, the cyanobacterial species show promise in effective exploitation for phytoremediation and improved productivity of saline soils.
Journal of Environmental Chemical Engineering, 2016
Abstract The effect of chromium and its mixed salts on nitrogenase activity of various indigenous... more Abstract The effect of chromium and its mixed salts on nitrogenase activity of various indigenously isolated cyanobacterial strains using Acetylene Reduction Assay (ARA) has been studied. The studies have been performed at varying level of metal, chromium VI and chromium III (0–20 mg/L) and salts (0–2000 mg/L) concentrations in long term and short term duration. It has been observed that the nitrogenase activity of all the strains varied. Based on nitrogenase activity, a few strains have been identified showing positive behavior. Furthermore, depending on their response, the strains have been categorized into sensitive, tolerant and adapted ones. In monocomponent system, Nostoc puncitforme HH-19 has been found to adapt itself to both forms of chromium under long as well as short term stress conditions with increased nitrogenase activity possible due to defensive mechanism.
Various chemical and physical treatments have been applied to indigenously isolated cyanobacteria... more Various chemical and physical treatments have been applied to indigenously isolated cyanobacterial strain, Lyngbya putealis HH-15, to observe the effect on chromium removal capacity. Pretreatment with hydrochloric acid (99.1%) and nitric acid (98.5%) resulted in enhanced chromium removal as compared to untreated control biosorbent (98.1%). Pretreatment with acetic acid (97.9%), methanol (97.0%), calcium chloride (96.0%), hot water (95.2%), and sodium hydroxide (93.9%) did not improve the chromium removal capacity of biosorbent. Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) analysis identified changes in biomass functionality and availability after physical and chemical modification-the results of which were in agreement with metal removal studies. In conclusion, this acid-treated biosorbent represents a suitable candidate to replace conventional removal technologies for metal-bearing wastewaters.
Journal of environmental biology / Academy of Environmental Biology, India, 2008
The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia... more The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia and Nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. Besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (VI) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. While phycobilins and carotenoids also increased in Nostoc linckia with total dissolved salts (TDS) as well as metal, a decline was observed in Nostoc spongiaeforme in the presence of Cr (VI). Relative algal biomass (as % of control) showed significantly higher values (123-239) in Nostoc linckia in the presence of salt, metal and combination of the two. In Nostoc spongiaeforme it declined in the presence of metal (72-81) but increased in the presence of salts (143-249) and also in the binary systems (121-440). The bi-algal consortium showed relatively less tolerance to salt and metal stress. Nostoc linckia (20 day culture) ...
The present study was undertaken to explore the possibilities of antioxidant compounds present in... more The present study was undertaken to explore the possibilities of antioxidant compounds present in two halophilic cyanobacterial species Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 isolated from Drang salt mine of Distt. Mandi Himachal Pradesh. These compounds can be used by human to treat some diseases such as cancer, hypercholesterolemia and oxidative damage. Methanol extracts of Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 at 21 day of growth were prepared to study preliminary phytochemical screening, gas chromatography and mass spectrometry (GC-MS) analysis and antioxidant activity by DPPH free radical scavenging assay. Preliminary phytochemical screening of methanol extracts of Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 showed the presence of alkaloids, saponins and terpenoids and GC-MS analysis detected 9 and 24 compounds respectively. Phthalic acid (82.52%) and hexadecanoic acid methyl ester (15.67%) were the major compounds i...
Biosorption of Cr(VI) using native strains of cyanobacteria from metal contaminated soil in the p... more Biosorption of Cr(VI) using native strains of cyanobacteria from metal contaminated soil in the premises of textile mill has been reported in this paper. Biosorption was studied as a function of pH (1-5), contact time (5-180 min) and initial chromium ion concentration (5-20 mg/l) to find out the maximum biosorption capacity of alginate immobilized Nostoc calcicola HH-12 and Chroococcus sp. HH-11. The optimum conditions for Cr(VI) biosorption are almost same for the two strains (pH 3-4, contact time 30 min and initial chromium concentration of 20 mg/l) however, the biomass of Chroococcus sp. HH-11 was found to be more suitable for the development of an efficient biosorbent for the removal of Cr(VI) from wastewater, as it showed higher values of q m and K f , the Langmuir and Freundlich isotherm parameters. Both the isotherm models were suitable for describing the biosorption of Cr(VI) by the cyanobacterial biosorbents.
Salinity is one of the important environmental factors, which influence fertility and quality of ... more Salinity is one of the important environmental factors, which influence fertility and quality of the soil. In semiarid and arid regions of the world, salinity is the main constraint that is affecting productivity and yield of the crop plants. Many crop plants are very sensitive to high concentration of salinity. A recent concept of biochar application to soil is enhancing various physicochemical properties under acidic and saline conditions. Biochar is a carbonaceous compound and can be utilized as a better soil ameliorant in comparison to other organic amendments for improving the fertility of soil for an elongated time period. The present review chapter is based on the results of many research papers, showing that the application of biochar to soil is potentially suitable for highly weathered soils as it enhances physicochemical properties and reduces soil loss. Although the information on biochar for enhancing the soil chemical properties is well-known, information on physical properties' enhancement is scarce. Therefore, the main aim of the current chapter is to provide all the available literature and information on the role of biochar for the reclamation of soil by enhancing their physicochemical properties under saline conditions. Further, the present review examines and deliberates the investigations on the effect of biochar in reclamation and enhancing the properties of saltaffected soils.
International journal of scientific research, 2015
In the present investigation effect of various nutrient supplements iron, phosphate/potassium and... more In the present investigation effect of various nutrient supplements iron, phosphate/potassium and exogenous ni- trogen sources on growth and nitrogen fixing ability of cyanobacteria have been studied in terms of chlorophyll, carot - enoid and nitrogenase activity. The response was found to be species specific to K+/PO43- and Fe3+ and nutrient saturation occurred at dif- ferent concentration in term of photosynthetic pigment concentration. Amongst exogenous N-sources, nitrate alone had a stimulatory effect on chlorophyll of some strains while ammonium and amino acids tended to suppress the concentration of chlorophyll and other pigments. While exogenous nitrogen suppressed nitrogenase activity, the other nutrients significantly increased N2 fixing potential of the cyanobacteria.
International Journal of Environmental Science and Technology, 2017
In present investigation, consortia of two indigenous heterocystous cyanobacteria, Nostoc ellipso... more In present investigation, consortia of two indigenous heterocystous cyanobacteria, Nostoc ellipsosporum HH-205 and Nostoc punctiforme HH-206 isolated from a salt affected area of Hisar, Haryana (India) were used as biofertilizer in bioremediation of salt affected soils having high electrical conductivity (13.5 dS/m) and pH (8) with poor organic carbon (0.3%) as well as nitrogen content (0.008%). The experiments were conducted in a pot house for the period of 240 days. There was a significant (P \ 0.05) increase in carbon, phosphate, nitrogen, potassium, magnesium, cation exchange capacity, mean weight diameter and hydraulic conductivity of soil with biofertilizer treatment whereas sodium ion and electrical conductivity were found to be decreased. Improvement in soil aggregation and stability due to increased soil microbial activities (dehydrogenase, invertase and phosphomonoesterase) were also observed. Significant increase in growth and yield of pearl millet-wheat crop was observed in amended pots even under low water regime. Thus, the indigenous cyanobacterial species show promise in effective exploitation for phytoremediation and improved productivity of saline soils under semi-arid condition.
International Journal of Environmental Science and Technology, 2016
Microalgal lipids can be enhanced through varying nitrogen (N) content, and limited supply of nit... more Microalgal lipids can be enhanced through varying nitrogen (N) content, and limited supply of nitrogen source seems to be valuable approach for increased lipid accumulation in microalgae. In this study, Chlorella sp. IM-02 was observed under fluorescence microscope for increased number of lipid bodies under nitrogen scarcity. Fourier transform infrared spectroscopy was used to determine spectral changes due to varying lipid content under nitrogen-starved (N 0 , without sodium nitrate), nitrogen-limited (N 0.1 , N 0.25 , N 0.5 and N 1.0 representing 0.1, 0.25, 0.5 and 1.0 g/L of sodium nitrate, respectively) and nitrogen-sufficient (N 1.5 , i.e., 1.5 g/L sodium nitrate) setting. Chlorophyll content was also monitored under these conditions as growth indicator. Various biochemical components viz. total carbohydrates, total proteins and total lipids were also estimated under varying nitrogen levels spectrophotometrically. On fourth day itself, maximum lipid productivity was observed in case of N 0.5 , which is having one-third of nitrogen concentration present in original growth media, BG-11. This concludes N 0.5 as suitable nitrogen provision for better production of lipids in Chlorella sp. IM-02 without much compromising the biomass production as both growth and lipid quantity are key parameters affecting the lipid productivity of any microalgal strain.
International Journal of Current Microbiology and Applied Sciences, 2016
The present study was undertaken to investigate the fungal associates of Rhododendron campanulatu... more The present study was undertaken to investigate the fungal associates of Rhododendron campanulatum D. Don from Churdhar region of District Shimla and Sirmaur in Himachal Pradesh. Studies revealed the presence of seven species of fungi belonging to six genera (Absidia, Aspergillus, Curvularia, Fusarium, Pythium and Trichoderma) from mycorrhizosphere soil of Rhododendron campanulatum. Fusarium was the most dominant genus among rhizosphere soil fungi. Twenty seven species of AM fungal spores belonging to eight genera (Acaulospora, Dentiscutata, Endogone, Entrophospora, Gigaspora, Glomus, Sclerocystis and Scutellospora) were isolated from the rhizosphere soil of Rhododendron campanulatum. Glomus was the most abundant genus recorded. Twenty species of endophytic fungi belonging to thirteen genera (Alternaria,
The study reports the effects of irrigation of a sodic soil with post methanation effluent (PME) ... more The study reports the effects of irrigation of a sodic soil with post methanation effluent (PME) of a distillery. Impact of long term effluent irrigation in the field (10 years) and short term effluent irrigation using different doses of PME in the laboratory (30 days) was studied in combination with three bioamendments i.e. farmyard manure, brassica residues and rice husk. Impact on various soil properties like EC, pH, total organic carbon (TOC), total Kjeldahl nitrogen (TKN), available phosphorus, exchangeable K, Na, Ca, Cl, microbial population and soil enzyme activities were studied. Long term application of PME proved useful in significantly increasing TOC, TKN, K, P and soil enzymatic activities in the soil but tended to build up harmful concentration of Na, that could be chelated by bioamendments. In short terms studies, application of 50% PME along with bioamendments proved to be the most useful in improving the properties of sodic soil and also favoured successful germination and improved seedling growth of pearl millet.
Multi-strain biofertilizer consisting of three indigenous cyanobacterial isolates was applied to ... more Multi-strain biofertilizer consisting of three indigenous cyanobacterial isolates was applied to an organically poor semi-arid clay-loam soil (pH 7; electrical conductivity, EC, 0.8 dSm − 1 ; total organic carbon, TOC, 0.34%; total Kjeldahl Nitrogen, TKN, 0.06%) in pot-house experiment. During the 240 d experiment under conditions of limited water regime (6-12% soil moisture), there was a significant (p b 0.05) increase in TOC, TKN and PO 4 3− P during the middle, which, however, diminished at later stages of the experiment. The biofertilizer (BF) improved carbon and nitrogen mineralization by promoting soil microbial activities and narrowed down C:N ratio. Effect of BF on cation exchange capacity of the soil became evident with time. Physical structure of the soil was influenced due to BF as indicated by significant (p b 0.01) decline in bulk density and increase in water holding capacity, hydraulic conductivity and mean weight diameter at the end of both pearl millet and wheat crop. Plant growth and yield of pearl millet-wheat sequence in the soil increased in response to cyanobacterial biofertilizer. Response of pearl millet to BF was more pronounced for certain parameters at the lower water level, W 2 (6% moisture). The native strains showed remarkable potential for improving structural stability, nutrient status and productivity of the soil under limited water regime.
In the present study, the fungal associates of Rhododendron arboreum were investigated. Studies r... more In the present study, the fungal associates of Rhododendron arboreum were investigated. Studies revealed the presence of twelve species of endophytic fungi and fifteen species of rhizospheric fungi belonging to different genera (Aspergillus, Cladosporium, Fusarium, Penicillium, Rhizoctonia, Rhizopus, Stachybotrys, Trichoderma and a sterile mycelium) from the leaves, stem, bark, roots and rhizosphere soil of Rhododendron arboreum. Aspergillus was the most abundant genus among the endophytic and rhizospheric fungi and maximum number of fungi was observed during rainy season followed by winter and summer. Twenty two species of AM fungal spores belonging to five genera (Acaulospora, Dentiscutata, Entrophospora, Gigaspora and Glomus) were isolated from mycorrhizosphere soil samples of this plant. Glomus was found most abundant genus among the AM fungal spores. Maximum number of spores was observed during rainy season followed by summer and winter seasons respectively.
The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia... more The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia and Nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. Besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (VI) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. While phycobilins and carotenoids also increased in Nostoc linckia with total dissolved salts (TDS) as well as metal, a decline was observed in Nostoc spongiaeforme in the presence of Cr (VI). Relative algal biomass (as % of control) showed significantly higher values (123-239) in Nostoc linckia in the presence of salt, metal and combination of the two. In Nostoc spongiaeforme it declined in the presence of metal (72-81) but increased in the presence of salts (143-249) and also in the binary systems (121-440). The bi-algal consortium showed relatively less tolerance to salt and metal stress. Nostoc linckia (20 day culture) ...
The agriculture community is facing a great challenge to enhance the production. To meet the chal... more The agriculture community is facing a great challenge to enhance the production. To meet the challenge, the focus is on to reclaim the degraded land and understands the complexities and interactions of soil biological system and agro-ecosystem as a whole. Soil microorganisms play very important role in reclamation of such degraded lands and have important influence on soil fertility and plant health. The importance of AM association in restoration and improvement of revegetation of disturbed mined lands is well recognized. In the present studies, the indigenous species of fungal associates and vesicular arbuscular (VAM) fungi of Triticum aestivum plant were isolated from the disturbed field (cement mining area) and normal field (10 km from cement mining) in Darlaghat, Himachal Pradesh, India. Rhizospheric soil samples of Triticum aestivum revealed the presence of eighteen species of fungi. Aspergillus, Fusarium and Absidia were found to be the predominant genera and maximum genera i...
Effectof exopolysaccharides (EPS) produced by a consortium of cyanobacteria on germination of thr... more Effectof exopolysaccharides (EPS) produced by a consortium of cyanobacteria on germination of three crops wheat, maize and rice was studied at different salt concentrations. Production of EPS was found to be stimulated by salts, which in turn had a significant Na+ removal capability from aqueous solution. Seed germination, vigor index and mobilization efficiency in all the three crops remarkably improved when cyanobacterial EPS was applied. While germination improved significantly by 13 to 30%, mobilization efficiency increased marginally by 1.03 to 1.1 times and vigor index increased by 1.15 to 2.4 times in these crops in response to EPS under non-saline conditions. Salinity had an inhibitory effect on seed germination of all the species showing 18 to 54% reduction. However, in the presence of EPS, the salt induced inhibition diminished to 13 to 18%. Inhibitory effect of salt on chlorophyll concentration, vigor index and mobilization efficiency of the seedlings was much less in the...
In the present investigation, three strains of cyanobacteria isolated from agricultural fields ne... more In the present investigation, three strains of cyanobacteria isolated from agricultural fields near to salt mine were used as biofertilizer individually and in consortia. Farm yard manure was also used along with cyanobacterial biofertilizers to see the ameliorative effect on soil physical, chemical and biological properties. The algalization experiment was conducted in pots in the glass house of the department for 240 days. There was an improvement in carbon, nitrogen, phosphate, potassium, magnesium, calcium, zinc, iron, copper and manganese with biofertilizers treatment whereas sodium ion, EC and pH were found to be decreased. Soil microbial activities and plant growth parameters were found to be improved. Thus, the cyanobacterial species show promise in effective exploitation for phytoremediation and improved productivity of saline soils.
Journal of Environmental Chemical Engineering, 2016
Abstract The effect of chromium and its mixed salts on nitrogenase activity of various indigenous... more Abstract The effect of chromium and its mixed salts on nitrogenase activity of various indigenously isolated cyanobacterial strains using Acetylene Reduction Assay (ARA) has been studied. The studies have been performed at varying level of metal, chromium VI and chromium III (0–20 mg/L) and salts (0–2000 mg/L) concentrations in long term and short term duration. It has been observed that the nitrogenase activity of all the strains varied. Based on nitrogenase activity, a few strains have been identified showing positive behavior. Furthermore, depending on their response, the strains have been categorized into sensitive, tolerant and adapted ones. In monocomponent system, Nostoc puncitforme HH-19 has been found to adapt itself to both forms of chromium under long as well as short term stress conditions with increased nitrogenase activity possible due to defensive mechanism.
Various chemical and physical treatments have been applied to indigenously isolated cyanobacteria... more Various chemical and physical treatments have been applied to indigenously isolated cyanobacterial strain, Lyngbya putealis HH-15, to observe the effect on chromium removal capacity. Pretreatment with hydrochloric acid (99.1%) and nitric acid (98.5%) resulted in enhanced chromium removal as compared to untreated control biosorbent (98.1%). Pretreatment with acetic acid (97.9%), methanol (97.0%), calcium chloride (96.0%), hot water (95.2%), and sodium hydroxide (93.9%) did not improve the chromium removal capacity of biosorbent. Fourier transform infrared spectrometry (FTIR) and scanning electron microscopy (SEM) analysis identified changes in biomass functionality and availability after physical and chemical modification-the results of which were in agreement with metal removal studies. In conclusion, this acid-treated biosorbent represents a suitable candidate to replace conventional removal technologies for metal-bearing wastewaters.
Journal of environmental biology / Academy of Environmental Biology, India, 2008
The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia... more The present study reports on chromium (VI) tolerance of two cyanobacterial strains Nostoc linckia and Nostoc spongiaeforme isolated from salt affected soils using uni-algal and bi-algal systems. Besides distinct halophilism, the two strains exhibited remarkable tolerance to chromium (VI) and revealed 1.2 to 2.8 times more chlorophyll in the presence of the metal. While phycobilins and carotenoids also increased in Nostoc linckia with total dissolved salts (TDS) as well as metal, a decline was observed in Nostoc spongiaeforme in the presence of Cr (VI). Relative algal biomass (as % of control) showed significantly higher values (123-239) in Nostoc linckia in the presence of salt, metal and combination of the two. In Nostoc spongiaeforme it declined in the presence of metal (72-81) but increased in the presence of salts (143-249) and also in the binary systems (121-440). The bi-algal consortium showed relatively less tolerance to salt and metal stress. Nostoc linckia (20 day culture) ...
The present study was undertaken to explore the possibilities of antioxidant compounds present in... more The present study was undertaken to explore the possibilities of antioxidant compounds present in two halophilic cyanobacterial species Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 isolated from Drang salt mine of Distt. Mandi Himachal Pradesh. These compounds can be used by human to treat some diseases such as cancer, hypercholesterolemia and oxidative damage. Methanol extracts of Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 at 21 day of growth were prepared to study preliminary phytochemical screening, gas chromatography and mass spectrometry (GC-MS) analysis and antioxidant activity by DPPH free radical scavenging assay. Preliminary phytochemical screening of methanol extracts of Cylindrospermum muscicola HPUSD12 and Phormidium sp. HPUSD13 showed the presence of alkaloids, saponins and terpenoids and GC-MS analysis detected 9 and 24 compounds respectively. Phthalic acid (82.52%) and hexadecanoic acid methyl ester (15.67%) were the major compounds i...
Biosorption of Cr(VI) using native strains of cyanobacteria from metal contaminated soil in the p... more Biosorption of Cr(VI) using native strains of cyanobacteria from metal contaminated soil in the premises of textile mill has been reported in this paper. Biosorption was studied as a function of pH (1-5), contact time (5-180 min) and initial chromium ion concentration (5-20 mg/l) to find out the maximum biosorption capacity of alginate immobilized Nostoc calcicola HH-12 and Chroococcus sp. HH-11. The optimum conditions for Cr(VI) biosorption are almost same for the two strains (pH 3-4, contact time 30 min and initial chromium concentration of 20 mg/l) however, the biomass of Chroococcus sp. HH-11 was found to be more suitable for the development of an efficient biosorbent for the removal of Cr(VI) from wastewater, as it showed higher values of q m and K f , the Langmuir and Freundlich isotherm parameters. Both the isotherm models were suitable for describing the biosorption of Cr(VI) by the cyanobacterial biosorbents.
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Papers by Nisha Rani