Next Generation High Throughput Sequencing to Assess Microbial Communities: An Application Based on Water Quality.

Traditional techniques to identify different contaminants (biological or chemical) in the waters are slow, laborious, and can require specialized expertise. Hence, the rapid determination of water quality using more sensitive and reliable metagenomic based approaches attains special importance. Metagenomics deals with the study of genetic material that is recovered from microbial communities present in environmental samples. In traditional techniques cultivation-based methodologies were used to describe the diversity of microorganisms in environmental samples. It has failed to function as a robust marker because of limited taxonomic and phylogenetic implications. In this backdrop, high-throughput DNA sequencing approaches have proven very powerful in microbial source tracking because of investigating the full variety of genome-based analysis such as microbial genetic diversity and population structure played by them. Next generation sequencing technologies can reveal a greater proportion of microbial communities that have not been reported earlier by traditional techniques. The present review highlights the shift from traditional techniques for the basic study of community composition to next-generation sequencing (NGS) platforms and their potential applications to the biomonitoring of water quality in relation to human health.

Ecological restoration of habitats invaded by Leucanthemum vulgare that alters key ecosystem functions.

Precise assessment of the impacts of invasive alien species (IAS) on ecosystem structure and functions is paramount for implementing appropriate management and restoration strategies. Here we investigated the impacts of Leucanthemum vulgare (ox-eye daisy), an aggressive invader in Kashmir Himalaya, on species diversity and primary productivity. We also evaluated bunch of strategies for the ecological restoration of the habitats invaded by this species. We found that uninvaded plots harbored on an average of 6.11 (±2.92) more species per 1m2 of quadrat than invaded plots. At multivariate scale, the ordination (nMDS) and ANOSIM exhibited significant differences between invaded and uninvaded plots with R = 0.7889 and p < 0.001. The decrease in diversity indices in invaded as compared to uninvaded plots was associated with more productive plant communities due to Leucanthemum invasion. Higher altitude Gulmarg site was more affected by Leucanthemum invasion than lower altitude Drung site. We tested different approaches for restoration and management of invaded habitats that include herbicide treatment at seedling stage, herbicide treatment before and after flowering stage, mowing and herbicide treatment together, joint mowing, digging and herbicide treatment and Leucanthemum uprooting. Among these treatments, uprooting and combined digging, mowing and herbicide treatment proved to be most effective in controlling Leucanthemum invasion. The implications of these results for effective management of ecologically sensitive and socio-culturally important landscapes are discussed.

Differential Bioaccumulation of Select Heavy Metals from Wastewater by Lemna minor.

The capacity of Lemna minor to remediate toxic heavy metals from wastewater is reasonably well documented. In view of the pivotal role of this species in the environmental clean-up, here we evaluated the bioaccumulation potential of L. minor for cadmium (Cd), lead (Pb), and nickel (Ni) through a controlled experiment. L. minor tolerated the metals Cd, Ni, and Pb up to 0.5, 5, and 8 mg/L, respectively, and beyond these concentrations the toxicity symptoms appeared. Bio-concentration factor varied at different concentrations of heavy metals tested. Overall, L. minor showed good phytoremediation potential for all the three tested heavy metals (Cd, Ni, and Pb), though in relative terms it was more effective in extracting Ni and Cd, as compared to Pb, both in single and mixed concentrations. In view of the growing pollution in Kashmir Himalayan aquatic habitats the phytoremediation by invasive species such as L. minor promises to be one of the best choices than other native plants for cleaning up of polluted soils/water because of its fast growth rate, high abundance, easy handling, and wide distribution in Kashmir Himalayan aquatic ecosystems.