Biosynthesis of Poly(3-hydroxybutyrate) from Cheese Whey by <Emphasis Type="Italic">Bacillus megaterium</Emphasis> NCIM 5472

Microbial polyhydroxyalkonate such as homopolyester of poly(3-hydroxybutyrate) (PHB) was produced from cheese whey by Bacillus megaterium NCIM 5472. Due to their numerous potential industrial applications, the focus was given to competently enhance the amount of PHB produced. The amount of PHB produced from whole cheese whey, and ultrafiltered cheese whey was first compared, and after observing a rise in PHB production by using ultrafiltered cheese whey, cheese whey permeate was chosen for further analysis. The presence of PHB was then confirmed by GCMS. Since the main aim of the study was to increase the amount of PHB produced through batch fermentation, various process parameters like time, pH, C/N ratio, etc. were optimized. After optimization, it was found that B. megaterium NCIM 5472 was capable of accumulating 75.5% of PHB of its dry weight and a PHB yield of 8.29 g/L. The chemical structure of the polymer was further analyzed by using FTIR and NMR spectroscopy methods. Also, the physical and thermal properties were studied by using Differential scanning calorimetry and Thermogravimetric analysis. It was found that the polymer produced had excellent thermal stability, thus allowing the possibility to exploit its properties for industrial purposes such as adhesives, packaging materials, etc.     

Studies on solvent extraction of iron(III) as a step for conversion of a waste effluent to a value added product

Solvent extraction of iron(III) from actual sulphate waste pickle liquor was investigated using trialkylphosphine oxide diluted with kerosene. The waste pickle liquor was procured from a local company which deals with the manufacturing of pipes and tubes made of iron and steel. Various parameters were studied to optimise a suitable condition for the maximum extraction of iron. The composition of the aqueous feed used in the experiment was 60.88 g/L Fe(III), 53 g/L acid with traces of Cu, Ni and Co. An ambient extraction at 30 °C yielded acceptable kinetics and loading efficiency for 40% trialkylphosphine oxide with a saturated loading capacity of 51.85 g/L in four contacts at O/A ratio of 1/1 in a multiple contact mode. Iron from the loaded organic was stripped using various strippants such as distilled water, H₂SO₄ and oxalic acid. Since only 32% of loaded Fe could be stripped with 2 M H₂SO₄ in five contacts, further stripping was done with 5% oxalic acid which showed a very promising result. It was found that almost 100% of Fe(III) could be stripped out with 5% oxalic acid at O/A of 1/1 in five contacts.     

Effect of water stress on carbon isotope discrimination and its relationship with transpiration efficiency and specific leaf area in Cenchrus species

Carbon isotope discrimination (CID) has been proposed in estimating transpiration efficiency (TE) in plants indirectly To identify variations for TE and specific leaf area (SLA) and their association with CID, a glasshouse experiment was conducted using six prominent species of Cenchrus. A significant increase in TE (3.50 to 3.87 g kg(-1)) and decrease in SLA (219.50 to 207.99 cm2 g(-1)) and CID (13.72 to 13.23% per hundred) was observed from well watered to stress condition. Results indicated a direct relationship of SLA with CID (r = 0.511* and 0.544*) and inverse relationship between TE and CID (r = -0.229 and -0.270) However the relationship of TE with CID was insignificant. A positive and significant relationship was visualized between TE and dry matter production in both control (r = 0.917**) and stress (0.718**) treatments. Relationships of total dry matter with SLA and CID were monitored insignificant and negative in control and positive in stress treatment indicated difference in dry matter production under two treatments. It seems that, in Cenchrus species, CID was influenced more by the photosynthetic capacity than by stomatal conductance, as indicated by its positive relationship with SLAin both control (r = 0.511) and stress (r = 0.544) conditions and negative relationship with root dry matter production under control (r = -0.921**) and stress (r = -0.919***) condition. Results showed good correspondence between CID and SLA, indicating that lines having high TE and biomass production can be exploited for their genetic improvement for drought.     

Correlating emissions with time and temperature to predict worst-case emissions from open liquid area sources

The two primary factors influencing ambient air pollutant concentrations are emission rate and dispersion rate. Gaussian dispersion modeling studies for odors, and often other air pollutants, vary dispersion rates using hourly meteorological data. However, emission rates are typically held constant, based on one measured value. Using constant emission rates can be especially inaccurate for open liquid area sources, like wastewater treatment plant units, which have greater emissions during warmer weather, when volatilization and biological activity increase. If emission rates for a wastewater odor study are measured on a cooler day and input directly into a dispersion model as constant values, odor impact will likely be underestimated. Unfortunately, because of project schedules, not all emissions sampling from open liquid area sources can be conducted under worst-case summertime conditions. To address this problem, this paper presents a method of varying emission rates based on temperature and time of the day to predict worst-case emissions. Emissions are varied as a linear function of temperature, according to Henry's law, and a tenth order polynomial function of time. Equation coefficients are developed for a specific area source using concentration and temperature measurements, captured over a multiday period using a data-logging monitor. As a test case, time/temperature concentration correlation coefficients were estimated from field measurements of hydrogen sulfide (H2S) at the Rowlett Creek Wastewater Treatment Plant in Garland, TX. The correlations were then used to scale a flux chamber emission rate measurement according to hourly readings of time and temperature, to create an hourly emission rate file for input to the dispersion model ISCST3. ISCST3 was then used to predict hourly atmospheric concentrations of H2S. With emission rates varying hourly, ISCST3 predicted 384 acres of odor impact, compared with 103 acres for constant emissions. Because field sampling had been conducted on relatively cool days (85-90 degrees F), the constant emission rate underestimated odor impact significantly (by 73%).     

Errors in representing regional acid deposition with spatially sparse monitoring: Case studies of the eastern US using model predictions

The current study uses case studies of model-predicted regional precipitation and wet ion deposition over 5-year periods to estimate errors in corresponding regional values derived from the means of site-specific values within regions of interest located in the eastern US. The mean of model-predicted site-specific values for sites within each region was found generally to overestimate the corresponding model-predicted regional wet ion deposition. On an annual basis across four regions in the eastern US, these overestimates of regional wet ion deposition were typically between 5 and 25% and may be more exaggerated for individual seasons. Corresponding overestimates of regional precipitation were typically <5%, but may be more exaggerated for individual seasons. Period-to-period relative changes determined from the mean of site-based model-predicted wet deposition for the current regional ensembles of sites generally estimated larger beneficial effects of pollutant emissions reductions in comparison to changes based on model-predicted regional wet deposition. On an annual basis site-based relative changes were generally biased low compared to regional relative changes: differences were typically <7%, but they may also be more exaggerated for individual seasons. Spatial heterogeneities of the wet ion deposition fields with respect to the sparse monitoring site locations prevented the monitoring sites considered in the current study from providing regionally representative results. Monitoring site locations considered in the current study over-represent the geographical areas subject to both high emissions and high wet ion deposition and under-represent the geographical areas subject to low emissions and low wet deposition. Since the current case studies consider only those eastern US site locations that have supported concurrent wet and dry deposition monitoring, similar errors may be expected for dry and total deposition using results from the same monitoring site locations. Current case study results illustrate the approximate range of potential errors and suggest caution when inferring regional acid deposition from a network of sparse monitoring sites.     

Engineering of mono-dispersed mesoporous TiO2 over 1-D nanorods for water purification under visible light irradiation

Environmental Science and Pollution Research - Herein we synthesized a novel structure of mesoporous TiO2 decorated on 1D ZnO nanorods for environmental remediation. The effect of mesoporous TiO2...     

Arsenic toxicity in mice and its possible amelioration

Oral administration of arsenic trioxide(3 and 6 mg/kg body weight/d) for 30 d caused, as compared with vehicle control, dose-dependent significant reductions in body weight, absolute weight, protein, glycogen, as well as, total, dehydro and reduced ascorbic acid contents both in the liver and kidney of arsenic-treated mice. Succinic dehydrogenase(SDH) and phosphorylase only in the liver activities were significantly reduced in a dose-dependent manner. Acid phosphatase activity was significantly decreased in the liver of low dose arsenic-treated animals;however, significant rise in its activity was observed in high dose group. As compared with vehicle control, treatment also caused significant dose-dependent reductions in SDH, alkaline phosphatase and acid phosphatase activities in the kidney of mice. Vitamin E cotreatment as well as, 30 d withdrawal of arsenic trioxide treatment with or without vitamin E caused significant amelioration in arsenic-induced toxicity in mice. Administration of vitamin E during withdrawal of treatment also caused significant amelioration as compared from only withdrawal of the treatment. It is concluded that vitamin E ameliorates arsenic-induced toxicities in the liver and kidney of mice.     

Methane oxidation and abundance of methane oxidizers in tropical agricultural soil (vertisol) in response to CuO and ZnO nanoparticles contamination

There is worldwide concern over the increase use of nanoparticles (NPs) and their ecotoxicological effect. It is not known if the annual production of tons of industrial nanoparticles (NPs) has the potential to impact terrestrial microbial communities, which are so necessary for ecosystem functioning. Here, we have examined the consequences of adding the NPs particularly the metal oxide (CuO, ZnO) on CH₄ oxidation activity in vertisol and the abundance of heterotrophs, methane oxidizers, and ammonium oxidizers. Soil samples collected from the agricultural field located at Madhya Pradesh, India, were incubated with either CuO and ZnO NPs or ionic heavy metals (CuCl₂, ZnCl₂) separately at 0, 10, and 20 μg g^?1 soil. CH₄ oxidation activity in the soil samples was estimated at 60 and 100 % moisture holding capacity (MHC) in order to link soil moisture regime with impact of NPs. NPs amended to soil were highly toxic for the microbial-mediated CH₄ oxidation, compared with the ionic form. The trend of inhibition was Zn 20?>?Zn 10?>?Cu 20?>?Cu 10. NPs delayed the lag phase of CH₄ oxidation to a maximum of 4-fold and also decreased the apparent rate constant k up to 50 % over control. ANOVA and Pearson correlation analysis (α?=?0.01) revealed significant impact of NPs on the CH₄ oxidation activity and microbial abundance (p?<?0.0001, and high F statistics). Principal component analysis (PCA) revealed that PC1 (metal concentration) rendered 76.06 % of the total variance, while 18.17 % of variance accounted by second component (MHC). Biplot indicated negative impact of NPs on CH₄ oxidation and microbial abundance. Our result also confirmed that higher soil moisture regime alleviates toxicity of NPs and opens new avenues of research to manage ecotoxicity and environmental hazard of NPs.     

Response of ammonia-oxidizing archaea and bacteria to long-term industrial effluent-polluted soils,Gujarat, Western India

Soil nitrifiers have been showing an important role in assessing environmental pollution as sensitive biomarkers. In this study, the abundance and diversity of ammonia-oxidizing archaea (AOA) and ammonia-oxidizing bacteria (AOB) were investigated in long-term industrial waste effluent (IWE) polluted soils. Three different IWE polluted soils characterized as uncontaminated (R1), moderately contaminated (R2), and highly contaminated (R3) were collected in triplicate along Mahi River basin, Gujarat, Western India. Quantitative numbers of ammonia monooxygenase α-subunit (amoA) genes as well as 16S rRNA genes indicated apparent deleterious effect of IWE on abundance of soil AOA, AOB, bacteria, and archaeal populations. Relatively, AOB was more abundant than AOA in the highly contaminated soil R3, while predominance of AOA was noticed in uncontaminated (R1) and moderately contaminated (R2) soils. Soil potential nitrification rate (PNR) significantly (P?<?0.05) decreased in polluted soils R2 and R3. Reduced diversity accompanied by apparent community shifts of both AOB and AOA populations was detected in R2 and R3 soils. AOB were dominated with Nitrosospira-like sequences, whereas AOA were dominated by Thaumarchaeal “group 1.1b (Nitrososphaera clusters).” We suggest that the significant reduction in abundance and diversity AOA and AOB could serve as relevant bioindicators for soil quality monitoring of polluted sites. These results could be further useful for better understanding of AOB and AOA communities in polluted soils.