Exploration of green integrated approach for effluent treatment through mass culture and biofuel production from unicellular alga,Acutodesmus obliquus RDS01

Abstract

This study deals with the open pond (OP) pilot scale treatment of cassava effluent and enhancement of Ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) enzyme through CO₂ utilization by the microalga, Acutodesmus obliquus RDS01. The cassava effluent treatment (ET) revealed maximum reduction of ammonia (96.8%), calcium (94.6%), chloride (95.2%), chlorine (98.5%), inorganic phosphate (94.6%), magnesium (96.8%), nitrate (96.89%), organic carbon (95.9%), organic phosphorus (96.3%), potassium (97.9%), sodium (97.1%), and sulfate (95.4%) on 15^th day using A. obliquus. The microalga produced highest RuBisCO enzyme activity (90%), CO₂ utilization efficiency (95%), biomass (8.9 gL^?1), lipid (176.65?mg mL^?1), carbohydrate (96.78?mg mL^?1), biodiesel (4.1?mL g^?1), and bioethanol (3.7?mL g^?1) during OP treatment. The isolated RuBisCO gene (rbcL) was used to construct the protein model by homology modeling. The microalgal-lipid content was analyzed through thin layer chromatography, the biodiesel produced was analyzed using Fourier-transform infrared spectroscopy and gas chromatography mass spectrometry (GCMS). The bioethanol production was confirmed by high performance liquid chromatography and GCMS analyses. A. obliquus produced of 98.75% biodiesel and 96.83% bioethanol in the OP pilot scale treatment A. obliquus. Overall, the microalga A. obliquus could act as an effective CO₂ capturing and bioremediation agent in the cassava ET, and also for the biodiesel and bioethanol can be produced.     

Prey selection and food habits of three sympatric large carnivores in a tropical lowland forest of the Eastern Himalayan Biodiversity Hotspot

Prey selection and the feeding habits of tiger Panthera tigris, leopard Panthera pardus and Asiatic wild dog Cuon alpinus were investigated from June 2009 to December 2011 in Pakke Tiger Reserve, Arunachal Pradesh. A total of 422 scats were analyzed of which, 109 scats were of tigers, 150 were of leopard and 163 scats were of dholes. Multinomial Likelihood ratio test was used to estimate the prey selectivity of predators and Ivlev index, Pianka index were used to estimate prey preference and overlap respectively. Biomass consumption for three sympatric predators varied from 254.3 kg for dholes to 599.1 kg for tigers. Sambar, barking deer, wild pig were preyed more than their availability by all the predators. Ivlev index shows barking deer and sambar were preferred more than available prey for tiger where as leopard preferred sambar more than available and avoided barking deer. Dhole preferred more than available wild pig and barking deer. There was a high overlap between tiger–leopard (85.3%) and tiger–dhole (77.5%). To the best of our understanding, this study provides the first reliable information on prey selection and food habits of sympatric large carnivores in a protected area of Eastern Himalayan tropical rainforest.     

Host response profile of human brain proteome in toxoplasma encephalitis co-infected with HIV

Background

Toxoplasma encephalitis is caused by the opportunistic protozoan parasite Toxoplasma gondii. Primary infection with T. gondii in immunocompetent individuals remains largely asymptomatic. In contrast, in immunocompromised individuals, reactivation of the parasite results in severe complications and mortality. Molecular changes at the protein level in the host central nervous system and proteins associated with pathogenesis of toxoplasma encephalitis are largely unexplored. We used a global quantitative proteomic strategy to identify differentially regulated proteins and affected molecular networks in the human host during T. gondii infection with HIV co-infection.

Results

We identified 3,496 proteins out of which 607 proteins were differentially expressed (≥1.5-fold) when frontal lobe of the brain from patients diagnosed with toxoplasma encephalitis was compared to control brain tissues. We validated differential expression of 3 proteins through immunohistochemistry, which was confirmed to be consistent with mass spectrometry analysis. Pathway analysis of differentially expressed proteins indicated deregulation of several pathways involved in antigen processing, immune response, neuronal growth, neurotransmitter transport and energy metabolism.

Conclusions

Global quantitative proteomic approach adopted in this study generated a comparative proteome profile of brain tissues from toxoplasma encephalitis patients co-infected with HIV. Differentially expressed proteins include previously reported and several new proteins in the context of T. gondii and HIV infection, which can be further investigated. Molecular pathways identified to be associated with the disease should enhance our understanding of pathogenesis in toxoplasma encephalitis.

Electronic supplementary material

The online version of this article (doi:10.1186/1559-0275-11-39) contains supplementary material, which is available to authorized users.     

A new fluorescent chemosensor for cadmium(II) based on a pyrene‐appended piperidone derivative and its β‐cyclodextrin complex

We report, in this article, a piperidin‐4‐one derivative carrying pyrenyl fluorescent reporter groups which acts as a Cd²⁺ ion sensor. The compound is synthesized and characterized using IR and NMR spectral techniques. The compound forms an inclusion complex with β‐cyclodextrin. It selectively binds to Cd²⁺ ions in water and aqueous β‐cyclodextrin media. The stoichiometry of the host–guest complex of the compound with β‐cyclodextrin is 1:2. The ligand–metal ion binding stoichiometry is 1:1 both in water and in β‐cyclodextrin. The linear concentration range of detection of the metal ion is reported. Cyclodextrin complex formation does not affect the metal ion selectivity of the compound.     

Body Composition Percentiles in Urban South Indian Children and Adolescents

Objective

This study aimed to generate age‐ and sex‐specific percentiles for body composition indices in children and to assess the variability in these indices, in relation to BMI.

Methods

Anthropometry and body fat were measured with the BOD POD (Cosmed; Rome, Italy) in 9,702 children from Bangalore, India. Smoothed percentile curves using the lambda‐mu‐sigma method were obtained for BMI, fat‐free mass index (FFMI), fat mass index (FMI), and body fat percentage (% BF).

Results

Percentile curves for % BF and FMI in boys increased from 6 to 12 years and declined from 13 years on, while in girls, it increased until 15 years. The FFMI percentile curves increased with age in both sexes. The mean FMI declined from 12 years on in boys, corresponding to a large increase in FFMI from that age, while in girls, both FMI and FFMI continued to increase. The 75th percentile of % BF and FMI had greater sensitivity to identify children with obesity.

Conclusions

This study developed smoothed percentile curves for body composition in Indian children and suggests FMI and FFMI as good indicators of growth in children.

     

Localization and characterization of prolipoprotein diacylglyceryl transferase (Lgt) critical in bacterial lipoprotein biosynthesis

Lipid modification of proteins is an essential post-translational event that can be targeted for protein engineering and pharmaceutical applications. In this regard, the unique and ubiquitous bacterial N-terminal lipid modification (N-acyl S-diacylglyceryl modification of N-terminal cysteine) is particularly attractive. It is initiated by phosphatidylglycerol:prolipoprotein diacylglyceryl transferase (Lgt) and therefore its properties, which remain uninvestigated, largely define the specifics of the modification. A synthetic peptide-substrate (MKATKSAVGSTLAGCSSHHHHHH) with a short hydrophilic h-region, unlike that of the prototypical substrate used so far, demonstrated lack of enzyme's substrate preference based on hydrophobicity, perhaps accounting for a significant number of lipoproteins possessing hydrophilic signal peptides. Solubilization experiments revealed a peripheral and possibly reversible hydrophobic association of Lgt with the inner-membrane on the cytosolic side contradicting its deduced transmembrane topology. Except for heat stability, the soluble enzyme was indistinguishable from the membrane-bound enzyme in kinetic behaviour, indicating that the committed first step of bacterial lipid modification may be aqueous compatible. The direct, more accurate, precise and easier paper electrophoretic assay, designed anew, and Lgt's ready extraction with water or low ionic strength solutions from inverted vesicles could aid better understanding and exploitation of the enzyme and bacterial lipid modification.     

Investigation of DNA binding mechanism, photoinduced cleavage activity, electrochemical properties and biological functions of mixed ligand copper(II) complexes with benzimidazole derivatives: synthesis and spectral characterization

The benzimidazole derivative Schiff bases and their copper(II) (Cu(II)) mixed-polypyridyl complexes (1-4) have been synthesized and characterized by the spectral and analytical techniques. DNA binding/cleavage studies indicate a stronger binding capability for the complex 4 which is confirmed by the absorbance, viscometric and gel-electrophoresis studies. The photocleavage of plasmid pBR322 DNA reveals that hydroxyl radical (OH(?)) and singlet oxygen ((1)O(2)) are likely to be the reactive species. Analysis of the growth activity shows that the antimicrobial effect of these Schiff bases on Gram-negative bacteria is higher than that on Gram-positive. Furthermore, the complexes having nitro group show an increased antimicrobial effect.