Biochemical stress response in freshwater fish Channa punctatus induced by aqueous extracts of Euphorbia tirucalli plant

Piscicidal activities of aqueous extracts of Euphorbia tirucalli were very well established, but their ultimate mode of action on fish metabolism was not yet known. Exposure of fishes over 24h or 96h to sub-lethal doses (40% and 80% of LC(50)) of aqueous extract of E. tirucalli stem-bark and latex, significantly (P<0.05) altered the level of total protein, total free amino acids, nucleic acids, glycogen, pyruvate, lactate and activity of protease, alanine aminotransferase, aspartate aminotransferase, acetylcholinesterase and cytochrome oxidase enzyme in liver and muscle tissues of freshwater fish Channa punctatus. The alterations in all these biochemical parameters were significantly (P<0.05) time- and dose-dependent. After 7d of withdrawal of treatment of 80% of LC(50) of E. tirucalli extracts shows that there was a partial recovery in the levels of glycogen but nearly complete recovery in total protein, total free amino acids, pyruvate, lactate, nucleic acids level and activity of protease, aspartate aminotransferase, alanine aminotransferase, acetylcholinesterase and cytochrome oxidase enzyme in both the tissues of fish. Thus aqueous extracts of E. tirucalli adversely affect respiratory pathway of fish and cause energy crisis during stress by suppressing ATP production. The reversibility of the action of the aqueous extracts would be an additional advantage in their use.     

Significance of Bacillus subtilis strain SJ-101 as a bioinoculant for concurrent plant growth promotion and nickel accumulation in Brassica juncea

In this study, a nickel (Ni)-tolerant Bacillus subtilis strain SJ-101 was characterized based on the 16SrDNA homology and phylogenetic analysis. The role of this strain ascertained in facilitating Ni accumulation in the Indian mustard plant (Brassica juncea [L]. Czern and Coss) var. Pusa Bold (DIR-50), to elucidate the potential of Ni phytoremediation in combination with metal-tolerant rhizobacteria. The data revealed that the plants exposed to NiCl2 (1750 mg kg(-1)) in soil bioaugmented with strain SJ-101 have accumulated 0.147% Ni vis-à-vis 0.094% accumulation in dry biomass of the plants grown in uninoculated soil. The strain SJ-101 has also exhibited the capability of producing indole acetic acid (IAA) (55 microg ml(-1)), and solubilizing inorganic phosphate (90 microg ml(-1)) in specific culture media. The pot culture experiments clearly demonstrated the beneficial effects of bioinoculant strain SJ-101 with significant increase (p<0.05) in the plant growth attributes in untreated control soil. Furthermore, the protective effect of the strain SJ-101 against Ni phytotoxicity was evident in plants grown in soil treated with NiCl2 in concentration range of 250-1750 mg kg(-1). Thus, it is suggested that the strain SJ-101 owing to its intrinsic abilities of plant growth promotion, and attenuation of soil Ni by biosorption and bioaccumulation, could be exploited for bacteria-assisted phytoaccumulation of this toxic heavy metal from contaminated sites.     

Sustainable approach for the treatment of poultry manure and starchy wastewater by integrating dark fermentation and microalgal cultivation

Journal of Material Cycles and Waste Management - Dwindling fossil fuels, and the rise in energy demand have urged us to explore alternative renewable energy forms. An integrated process of dark...     

Impact of alkaline-hydrolyzed biosolids (Lystek) addition on the anaerobic digestibility of TWAS in lab – And full-scale anaerobic digesters

The effect of different Lystek biosolids doses on the anaerobic digestability of thickened waste activated sludge (TWAS) was evaluated in a lab- and full-scale anaerobic digester. The overall findings of this study emphasize the beneficial impact of Lystek addition to the lab- and full-scale anaerobic digesters in terms of enhanced biogas production and increased volatile suspended solids reduction (VSSR) efficiency. Lystek added at 4% by volume to TWAS increased the methane yield from 0.22 to 0.26 L CH₄/g VSS_added at an solids retention time (SRT) of 10 days, and from 0.27 to 0.29 L CH₄/g VSS_added at an SRT of 15 days. Furthermore, the VSSRs of 37% and 47% were observed for the TWAS, and the TWAS with 4% Lystek, while at an SRT of 15 days, the observed VSSR were 49% and 58%, respectively. The lab-scale study showed that the influence of Lystek addition on methane yield and solids destruction efficiencies was more pronounced at the shorter SRT, 20% enhancement (SRT of 10 d) vs. 9% enhancement (SRT of 15 d) for methane yield, and 27% (SRT of 10 d) vs. 22% (SRT of 15 d) for VSS destruction efficiency improvement. Furthermore, addition of 4% of Lystek to the feed of the full-scale anaerobic digester at St. Marys wastewater treatment plant (WWTP) resulted in a 50% increase in the average specific methanogenic activity and 23% increase in methane yield of the biochemical methane potential tests after eight months. The results showed that Lystek degradation kinetics were 40% faster than the TWAS, as reflected by first order kinetic coefficients of 0.053 d^?1 and 0.073 d^?1 for TWAS and Lystek at an SRT of 10 days.     

Pyrolysis of jute dust: effect of reaction parameters and analysis of products

Biowastes are becoming potential feedstocks for direct utilization or conversion to solid, liquid and gaseous fuels via various thermochemical routes. In this regard, jute dust which is a major agro-industrial waste in jute mills was pyrolysed in a fixed-bed reactor with an aim to study the product distribution and their characterization and to identify the optimum condition for bio-oil yield. The investigated process variables were temperature (400–700 °C), heating rate (10 and 40 °C/min) and nitrogen gas flow rate (50–250 ml/min). The yield of bio-oil is found to be maximum at 500 °C with a heating rate of 40 °C/min. However, further increase in temperature leads to decrease in bio-oil yield. Chemical compositions of the bio-oils were investigated using chromatographic and spectroscopic techniques such as ¹H NMR, FTIR and GC–MS. The heating value of the bio-oil is 26.71 MJ/kg. The study shows that jute dust have potential for conversion to bio-oil through the process of pyrolysis to supplement the petro-derived liquid fuel for heating and transportation applications after upgrading. The biochar produced as a co-product of jute dust pyrolysis can be a potential soil amendment with multiple benefits including increased soil fertility and C-sequestration.     

Denaturing gradient gel electrophoresis profiling of bacterial communities composition in Arabian Sea

Denaturing gradient gel electrophoresis (DGGE) was used to elucidate spatial and temporal variations in bacterial community composition (BCC) from four locations along the central west coast of India. DNA extracts from 36 water samples collected from surface, mid-depth (-10 m) and dose to bottom (-20 m) during premonsoon, postmonsoon, monsoon were analyzed by PCRfor amplifying variable region of 16S rRNAgene and subsequently through DGGE. Prominent bands were excised, cloned and sequenced indicated the preponderance of gammaproteobacteria, bacteroidetes and cyanobacteria. Non-metric dimensional scaling of the DGGE gels indicated that the spatial variations in BCC were prominent among the sampling locations. Temporal variations in the BCC appear to be influenced by monsoonal processes. The canonical correspondence analyses suggest that the concentration of chlorophyll a and nitrate are two important environmental factors for both spatial and temporal variations in BCC. Chlorophyll a seems to be impart a top-down control of BCC while nitrate, the bottom-up control. Our results also suggest that BCC can vary over a small geographic distance in highly dynamic, seasonally predisposed tropical coastal waters.     

Comparative study on the effect of chemicals on Alternaria blight in Indian mustard--a multi-location study in India

High severity of Altemaria blight disease is a major constraint in production of rapeseed-mustard in India. The aim of this study was to investigate the suppressive potential of chemicals viz., zinc sulphate, borax, sulphur, potash and calcium sulphate, aqueous extracts viz., Eucalyptus globosus (50 g l-1) leaf extract and garlic (Allium sativum) bulb (20 g l-1) extract, cow urine and bio-agents Trichoderma harzianum, Pseudomonas fluorescence in comparison with the recommended chemical fungicide (mancozeb), against foliar disease Alternaria blight of Indian mustard [Brassica juncea (L.) Czern. and Coss] under five different geographical locations of India. Mancozeb recorded the lowest mean severity (leaf: 33.1%; pod: 26.3%) of Alternaria blight with efficacy of garlic bulb extract alone (leaf = 34.4%; pod = 27.3%) or in combination with cow urine (leaf = 34.2%; pod = 28.6%) being statistically at par with the recommended chemical fungicide. Chemicals also proved effective in reducing Alternaria blight severity on leaves and pods of Indian mustard (leaf = 36.3-37.9%; pod = 27.5-30.1%). The effective treatments besides providing significant reduction in disease severity also enabled increase in dry seed yield of the crop (mancozeb = 2052 kg ha-1; garlic = 2006 kg ha-1; control = 1561 kg ha-1).     

Survey of nitrogen use pattern in rice in the irrigated rice-wheat cropping system of Haryana, India

Seeing the sustainability of rice-wheat cropping system (RWCS) of the Indo-Gangetic Plain, adequate crop nutrition in general and nitrogen (N) in particular holds the key to sound crop management. The excessive application or insufficient management of N means an economic loss to the farmer and may lead to yield penalties and environmental problems. Improving N management in consonance with other nutrients is much important to break yield plateaus as breeding for high yielding is not happening in recent years. Findings from farm survey are used to evaluate the on-farm N management practices in rice crop of the study area. The crop management practices (especially time of sowing/transplanting and irrigation requirement) and resource base of the farmers decided the N use pattern of the farmers. The N(Physical optimum) and N(economic optimum) exceeding the recommended levels revealed the apparent need for the revalidation of the existing recommendations. Paddy yield increased significantly within different rice types. This study generated comprehensive data on N use pattern in rice in the study area.