Metagenomic Approach towards Bioprospection of Novel Biomolecule(s) and Environmental Bioremediation

Microorganisms have developed several physiological adaptations to survive within extreme ecological niches including environments contaminated with heavy metals, pesticides, polycyclic aromatic hydrocarbons, and nuclear wastes. Microorganisms in extreme habitat are potential source of “novel biomolecule(s)” such as whole microbial cells, extremozymes and extremolytes, significantly required for environmental, industrial, and red medical/pharmaceutical biotechnology. These novel biomolecule(s) are valuable resources and may help improve economic development. The scanty information about the factors governing the microbial growth within stressed environments is the major constraint in the recovery of novel biomolecule(s) from extreme habitats. Understanding the structure, metabolic capabilities, microbial physiology, and factors governing the composition and role of indigenous microorganism is the key to success of any study. In recent past the problems associated with classical cultivation techniques have been resolved by an emerging approach referred to as “metagenomics”. Metagenomic studies give an insight into details of the structure, metabolic and physiological capabilities of indigenous microbial communities. High-throughput sequencing technologies in conjunction with metagenomics has aided in the identification and characterization of novel culturable and uncultured microorganisms with unique capabilities. Metagenomic studies have been used for isolation and characterization of novel biomolecule(s) relevant for white, grey, and red biotechnologies. The major objective of this review is to discuss the applications of metagenomic approach for bioprospection of novel biomolecule(s) and environmental bioremediation.

Biotechnological applications of archaeal enzymes from extreme environments

To date, many industrial processes are performed using chemical compounds, which are harmful to nature. An alternative to overcome this problem is biocatalysis, which uses whole cells or enzymes to carry out chemical reactions in an environmentally friendly manner. Enzymes can be used as biocatalyst in food and feed, pharmaceutical, textile, detergent and beverage industries, among others. Since industrial processes require harsh reaction conditions to be performed, these enzymes must possess several characteristics that make them suitable for this purpose. Currently the best option is to use enzymes from extremophilic microorganisms, particularly archaea because of their special characteristics, such as stability to elevated temperatures, extremes of pH, organic solvents, and high ionic strength. Extremozymes, are being used in biotechnological industry and improved through modern technologies, such as protein engineering for best performance. Despite the wide distribution of archaea, exist only few reports about these microorganisms isolated from Antarctica and very little is known about thermophilic or hyperthermophilic archaeal enzymes particularly from Antarctica. This review summarizes current knowledge of archaeal enzymes with biotechnological applications, including two extremozymes from Antarctic archaea with potential industrial use, which are being studied in our laboratory. Both enzymes have been discovered through conventional screening and genome sequencing, respectively.