Unveiling the role of emerging metagenomics for the examination of hypersaline environments.

Hypersaline ecosystems are distributed all over the globe. They are subjected to poly-extreme stresses and are inhabited by halophilic microorganisms possessing multiple adaptations. The halophiles have many biotechnological applications such as nutrient supplements, antioxidant synthesis, salt tolerant enzyme production, osmolyte synthesis, biofuel production, electricity generation etc. However, halophiles are still underexplored in terms of complex ecological interactions and functions as compared to other niches. The advent of metagenomics and the recent advancement of next-generation sequencing tools have made it feasible to investigate the microflora of an ecosystem, its interactions and functions. Both target gene and shotgun metagenomic approaches are commonly employed for the taxonomic, phylogenetic, and functional analyses of the hypersaline microbial communities. This review discusses different types of hypersaline niches, their residential microflora, and an overview of the metagenomic approaches used to investigate them. Various applications, hurdles and the recent advancements in metagenomic approaches have also been focused on here for their better understanding and utilization in the study of hypersaline microbiome.

Role of psychrotrophic bacteria and cold-active enzymes in composting methods adopted in cold regions.

Temperature-dependent composting is a challenging task but is worthy if it is done in the right manner. Cold composting has been known to be practiced since ancient times but there were not enough advancements to overcome the long mesophilic phase and bring the compost maturation to a short period. The composting processes that have been well practiced are discussed and the role of psychrotrophic bacteria that produce cold tolerant hydrolytic enzymes has been highlighted. In this chapter, the mechanism of substrate degradation has been elaborated to better understand the need of specific bacteria for a specific kind of substrate allowing fast and efficient decomposition. This chapter attempts to pave an appropriate way and suggest the best-suited method of composting for efficient production of compost by the conservation of heat in cold regions.

Synergistic effect of fly ash in in-vessel composting of biomass and kitchen waste.

The present study aims to utilize coal fly ash for its property to adsorb heavy metals and thus reducing the bioavailability of the metals for plant uptake. Fly ash was incorporated into the in-vessel composting system along with organic waste. The in-vessel composting experiments were conducted in ten plastic vessels of 15 L capacity comprising varying proportions of biomass waste, kitchen waste and fly ash. In this study, maximum degradation of organic matter was observed in Vessel 3 having k value of 0.550 d-1. In vessel 10, 20% fly ash with a combination of 50% biomass waste and 30% kitchen waste along with the addition of 5% jaggery as an additive produced the best outcome with least organic matter (%C) loss and lowest value of rate constant (k).