Microbial and plant derived biomass for removal of heavy metals from wastewater

Discharge of heavy metals from metal processing industries is known to have adverse effects on the environment. Conventional treatment technologies for removal of heavy metals from aqueous solution are not economical and generate huge quantity of toxic chemical sludge. Biosorption of heavy metals by metabolically inactive non-living biomass of microbial or plant origin is an innovative and alternative technology for removal of these pollutants from aqueous solution. Due to unique chemical composition biomass sequesters metal ions by forming metal complexes from solution and obviates the necessity to maintain special growth-supporting conditions. Biomass of Aspergillus niger, Penicillium chrysogenum, Rhizopus nigricans, Ascophyllum nodosum, Sargassum natans, Chlorella fusca, Oscillatoria anguistissima, Bacillus firmus and Streptomyces sp. have highest metal adsorption capacities ranging from 5 to 641 mg g(-1) mainly for Pb, Zn, Cd, Cr, Cu and Ni. Biomass generated as a by-product of fermentative processes offers great potential for adopting an economical metal-recovery system. The purpose of this paper is to review the available information on various attributes of utilization of microbial and plant derived biomass and explores the possibility of exploiting them for heavy metal remediation.     

Occurrence of rhizobia in the gut of the higher termite Nasutitermes nigriceps

Wood-eating termites feed on a diet highly deficient in nitrogen. They must complement their diet with the aid of nitrogen-fixing bacteria. Nitrogen fixation in the gut has been demonstrated, but information about nitrogen-fixing bacteria in pure culture is scarce. From the higher termite Nasutitermes nigriceps the symbiotic bacterial strain M3A was isolated, which thrives in the hindgut contents. The Gram-negative strain exhibited similarities to the species of the genus Ensifer (including Sinorhizobium) on the basis of morphological and physiological/biochemical features. The 16S rRNA gene analysis showed the highest sequence similarity of the isolate M3A to Ensifer adhaerens (>99%; ATCC 33499). The DNA-DNA hybridization revealed a similarity of 66% with E. adhaerens (NCIMB12342(T)). In contrast to the type strain the isolate M3A possesses the capacity to nodulate plant roots. This is the first report on the detailed identification of a rhizobia-related strain from the intestinal tract of animals. Strain M3A has been deposited with two culture collections (DSM10169; ATCC BAA-396).     

Mineral proximity influences mechanical response of proteins in biological mineral-protein hybrid systems

The organic phase of nacre, which is composed primarily of proteins, has an extremely high elastic modulus as compared to that of bulk proteins, and also undergoes large deformation before failure. One reason for this unusually high modulus could be the mineral-organic interactions. In this work, we elucidate the specific role of mineral proximity on the structural response of proteins in biological structural composites such as nacre through molecular modeling. The "glycine-serine" domain of a nacre protein Lustrin A has been used as a model system. It is found that the amount of work needed to unfold is significantly higher when the GS domain is pulled in the proximity of aragonite. These results indicate that the proximity of aragonite has a significant effect on the unfolding mechanisms of proteins when pulled. These results will provide very useful information in designing synthetic biocomposites, as well as further our understanding of mechanical response in structural composites in nature.     

Induction and submerged cultivation of Valeriana jatamansi adventitious root cultures for production of valerenic acids and its derivatives

Plant Cell, Tissue and Organ Culture (PCTOC) - In vitro adventitious roots were induced from leaves of Valeriana jatamansi to assess their potential as a sustainable alternative to extract...     

Comparative liver transcriptome analysis of duck reveals potential genes associated with egg production

Molecular Biology Reports - Molecular studies on egg production in ducks were mostly focused on brain and ovaries as they are directly involved in egg production. Liver plays a vital role in...     

Mass rearing of Spalgis epius (Lepidoptera: Lycaenidae), a potential predator of mealybugs (Hemiptera: Pseudococcidae)

Spalgis epius (Lepidoptera: Lycaenidae) has been recorded as a potential predator of various species of mealybug crop pests worldwide. We describe the mass rearing of S. epius, as no information on this topic is available. Outdoor nylon tent cages of different dimensions were provided to achieve mating and oviposition as S. epius adults did not mate in the laboratory cages. Adults mated only in the tent cage (6×6×10 m) placed over a native tree (9 m height). The presence of a tree canopy inside the cage is essential to achieve courtship and mating. Gravid females of S. epius deposited eggs on the mealybug-infested pumpkins inside the different sized nylon cages with or without a bush/tree. Spalgis epius eggs were maintained on mealybug-infested pumpkins in the laboratory and developmental stages of the predator were reared. Adults fed on various diets laid significantly higher number of eggs than those of starved individuals. Spalgis epius with a life cycle completed in 21.2 days and 55.7 larvae, could be reared on a single mealybug-infested pumpkin.