A novel thermotolerant Pediococcus acidilactici B-25 strain for color, COD, and BOD reduction of distillery effluent for end use applications

The present study was aimed to characterize physico-chemical and microbial population of distillery effluent and isolate a novel thermotolerant bacterium for color, COD, and BOD reduction of spentwash. The level of alkalinity, TSS, DO, COD, BOD, TN, ammonical nitrogen, nitrate nitrogen, phosphorous, potassium, chloride, and calcium of spentwash (SW), bioreactor effluent (BE), and secondary treated effluent (STE) were well above the permissible limits. The level of color, TS, and TDS were under the permissible limits for STE but not for SW and BE. The microbial population was higher in BE. The results revealed that effluent was highly polluted and require suitable treatment before discharge. A novel thermotolerant bacterium, identified as Pediococcus acidilactici, was isolated which exhibited maximum 79 % decolorization, 85 % COD, and 94 % BOD reduction at 45 °C using 0.1 %, glucose; 0.1 %, peptone; 0.05 %, MgSO4; 0.05 %, K₂HPO₄; pH 6.0 within 24 h under static condition. The ability of this strain to decolorize melanoidin at minimum carbon and nitrogen supplementation warrants its possible application for effluent treatment at industrial level. In addition, it is first instance when melanoidin decolorization was reported by P. acidilactici. This study could be an approach towards control of environmental pollution and health hazards of people in and around the effluent distillery unit.     

Poor efficacy of herbicides in biochar-amended soils as affected by their chemistry and mode of action

We evaluated wheat straw biochar produced at 450 °C for its ability to influence bioavailability and persistence of two commonly used herbicides (atrazine and trifluralin) with different modes of action (photosynthesis versus root tip mitosis inhibitors) in two contrasting soils. The biochar was added to soils at 0%, 0.5% and 1.0% (w/w) and the herbicides were applied to those soil-biochar mixes at nil, half, full, two times, and four times, the recommended dosage (H₄). Annual ryegrass (Lolium rigidum) was grown in biochar amended soils for 1 month. Biochar had a positive impact on ryegrass survival rate and above-ground biomass at most of the application rates, and particularly at H₄. Within any given biochar treatment, increasing herbicide application decreased the survival rate and fresh weight of above-ground biomass. Biomass production across the biochar treatment gradient significantly differed (p < 0.01) and was more pronounced in the case of atrazine than trifluralin. For example, the dose-response analysis showed that in the presence of 1% biochar in soil, the value of GR₅₀ (i.e. the dose required to reduce weed biomass by 50%) for atrazine increased by 3.5 times, whereas it increased only by a factor of 1.6 in the case of trifluralin. The combination of the chemical properties and the mode of action governed the extent of biochar-induced reduction in bioavailability of herbicides. The greater biomass of ryegrass in the soil containing the highest biochar (despite having the highest herbicide residues) demonstrates decreased bioavailability of the chemicals caused by the wheat straw biochar. This work clearly demonstrates decreased efficacy of herbicides in biochar amended soils. The role played by herbicide chemistry and mode of action will have major implications in choosing the appropriate application rates for biochar amended soils.     

Effect of compression ratio,nozzle opening pressure,engine load,and butanol addition on nanoparticle emissions from a non-road diesel engine

Currently, diesel engines are more preferred over gasoline engines due to their higher torque output and fuel economy. However, diesel engines confront major challenge of meeting the future stringent emission norms (especially soot particle emissions) while maintaining the same fuel economy. In this study, nanosize range soot particle emission characteristics of a stationary (non-road) diesel engine have been experimentally investigated. Experiments are conducted at a constant speed of 1500 rpm for three compression ratios and nozzle opening pressures at different engine loads. In-cylinder pressure history for 2000 consecutive engine cycles is recorded and averaged data is used for analysis of combustion characteristics. An electrical mobility-based fast particle sizer is used for analyzing particle size and mass distributions of engine exhaust particles at different test conditions. Soot particle distribution from 5 to 1000 nm was recorded. Results show that total particle concentration decreases with an increase in engine operating loads. Moreover, the addition of butanol in the diesel fuel leads to the reduction in soot particle concentration. Regression analysis was also conducted to derive a correlation between combustion parameters and particle number emissions for different compression ratios. Regression analysis shows a strong correlation between cylinder pressure-based combustion parameters and particle number emission.

     

Removal of toluene vapour from air stream using a biofilter packed with polyurethane foam

Biodegradation of toluene vapour was investigated for 168 days in a polyurethane packed biofilter inoculated with a mixed microbial population. Biofilter consisted of five square cross-section modular units each of size 0.16 m × 0.16 m × 0.20 m and filled with the polyurethane foam cubes up to a height of 0.15 m. Inlet concentration of toluene was varied from 0.04 to 2.5 g m^?3 and the volumetric flow rate of toluene loaded air from 0.06 to 0.90 m³ h^?1.Depending upon initial loading rates, removal efficiency ranging from 68.2 to 99.9% and elimination capacity ranging from 10.85 to 90.48 g h^?1 m^?3 were observed during steady state operations. More than 90% removal efficiency was observed up to an inlet loading rate of 76.3 g h^?1 m^?3. High carbon recovery (>90%) indicated effective biodegradation in the bed. Low variation of pH (7.2–8.8) and pressure drop (45.8–76.3 Pa) was observed. The stability of the biomass was evident from the fast response of the biofilter to shutdown and restartup.     

Estimation of Heavy Metals in Different Berberis Species and Its Market Samples

Popularity of herbal drugs is increasing all over the world because of lesser side effects as compared to synthetic drugs. Besides, it costs less and easily available to poor people particularly in developing countries. But quality assurance of herbal drugs is very necessary prior to its use. Because in today's polluted environment, even herbal drugs are not safe. Berberis spp. is very important medicinal plant, having various medicinal properties. It is also included in Indian and British pharmacopoeias. Its demand is quite high in herbal drug market. So, to check the quality of market samples of this drug, ten different samples were procured from different drug markets of India for heavy metal estimation. Besides, genuine samples of four species of Berberis viz. B. aristata, B. chitria, B. lycium, B. asiatica were also collected from natural habitats to compare heavy metal concentration in both market and genuine samples. It was found that market samples were much more contaminated than genuine samples. Lead (Pb) concentration is far beyond from WHO permissible limit (10 ppm) for herbal drugs, reaching to maximum 49.75 ppm in Amritsar market sample. Likewise, concentration of all other metals like Cd, Cr and Ni were also very high in market samples as compared to genuine samples.     

Intracellular cyanobiont Richelia intracellularis: ultrastructure and immuno-localisation of phycoerythrin,nitrogenase, Rubisco and glutamine synthetase

In marine tropical or subtropical plankton the filamentous, heterocyst-forming cyanobacterium Richelia intracellularis forms a symbiosis with the diatom Rhizosolenia clevei. An ultrastructural analysis of the apex of Rhizosolenia clevei showed that the cytoplasm in that particular part of the cell was present only where the cyanobiont was located. The cyanobiont was, however, always outside the host cytoplasm. Vegetative cells as well as the heterocysts of the cyanobiont were devoid of gas vesicles and cyanophycin granules, while carboxysomes and large glycogen granules were common. The cyanobacterial cell wall apparently remained intact in both vegetative and heterocyst cells. In green excitation light the heterocysts and vegetative cells emitted a bright yellow fluorescence, indicating that both cell types possessed high concentrations of the pigment phycoerythrin (PE) commonly associated with photosystem (PS) II. The presence of this pigment in both cell types was verified by immunogold localisation. Using the same technique, the nitrogenase (dinitrogenase reductase) enzyme was shown to be exclusively present in the heterocysts, while Rubisco was localised primarily to the carboxy-somes, which were only detected in vegetative cells. Using an antiserum against the ammonia assimilating enzyme glutamine synthetase (GS), we could demonstrate very low levels of this enzyme, indicating repression of GS in the cyanobiont.     

Modeling a wetland system: The case of Keoladeo National Park (KNP), India

A model for the wetland part of KNP is presented and analyzed. Two-dimensional parameter scans suggest that this minimal model possesses dynamical complexities. Per capita availability of water to “bad” biomass (W₁) is one of the most vital parameters. One can ensure good health of the park by restricting the par capita availability of water to low values. Getting the “bad” biomass removed by granting permits to villagers should go hand in hand with water management and conservation activities. The model presented in this paper may be helpful in designing the timing and nature of human interventions in the form of implementation of well worked out policies in future.     

Investigation on Miscibility of Sodium Alginate/Pullulan Blends

Miscibility studies of Sodium alginate (NaAlg)/Pullulan have been carried out in different percentage of blend components. The ultrasonic velocity, viscosity, density and refractive index were measured at 30 and 40 °C. Further the blend films of NaAlg and Pullulan were prepared by solution casting method and characterized by differential scanning calorimetric (DSC), fourier transition infrared spectroscopic (FTIR), and scanning electron microscopic (SEM) methods. Using the viscosity data, interaction parameters were computed to determine the miscibility. The data suggest that the blend is miscible in the entire composition range. The change in temperature had no significant effect on the miscibility of NaAlg/Pullulan blends. The miscibility is confirmed by SEM, DSC, ultrasonic velocity, density, and refractive index methods. The specific interactions of hydrogen bonding type of the blends were investigated by FTIR.     

Impact of rhizobacteria on growth and chromium accumulation in Scirpus lacustris L. grown under chromium supplementation

Four chromate tolerant rhizobacterial strains viz., RZB-01, RZB-02, RZB-03 and RZB-04 were isolated from rhizosphere of Scirpus lacustris collected from Cr-contaminated area. These strains characterized at morphological and biochemical levels. The most efficient chromate tolerant strain RZB-03 was inoculated to fresh plant of S. lacustris and grown in 2 microg ml(-1) and 5 microg ml(-1) of Cr+6 supplemented nutrient solution under controlled laboratory condition. The effects of rhizobacterial inoculation on growth and chromium accumulation in S. lacustris were evaluated. The inoculation of rhizobacteria increased biomass by 59 and 104%, while total chlorophyll content by 1.76 and 15.3% and protein content increased by 23 and 138% under 2 microg ml(-1) and 5 microg ml(-1) concentrations of Cr+6, respectively after 14 d as compared to non-inoculated plant. Similarly, the Cr accumulation also increased by 97 and 75% in shoot and 114 and 68% in root of inoculated plants as compared to non inoculated plants at 2 microg ml(-1) and 5 microg ml(-1) Cr+6 concentrations, respectively after 14 d. The chromate tolerant rhizobacteria which play an important role in chromium uptake and growth promotion in plant may be useful in development of microbes assisted phytoremediation system for decontamination of chromium polluted sites.