001. Sanjai Saxena. Department of Biotechnology, Thapar University, Patiala, Punjab, India. Microbial Enzymes and Their Industrial Applications. Applied Microbiology, 2015, Page: 121 - 154.

      Enzymes are biological catalysts produced in living cells. They are proteinaceous in nature, the exception being catalytic RNA, which are also referred to as ribozymes. The term en zyme‘ is derived from the Greek, meaning in sour dough‘. E. Buchner (1897) experimentally proved that cell-free extract from yeast could produce alcohol from sugars, and he referred to it as ―zymase‖. The unique characteristics that enzymes possess are that they (1) increase the rate of reaction they catalyze, without being consumed or lost; (2) act specifically with the substrate to produce the products; and (3) remain regulated from a state of low activity to high activity and vice versa. Enzymes have been grouped into six classes based on the types of reactions they catalyze. All cellular processes are controlled by a coordinated sequence of reactions that have specifically been catalyzed by a defined set of enzymes.

002. Muhammad Imran, David E. Crowley, Azeem Khalid, Sabir Hussain, Muhammad Waseem Mumtaz, Muhammad Arshad. Department of Environmental Sciences, University of Gujrat, Gujrat, 50700, Pakistan. Microbial biotechnology for decolorization of textile wastewaters. Reviews in Environmental Science and BioTechnology, 14(1), 2015, Page: 73- 92.

      Wastewater originating from the textile industry is one of the major sources of pollution for surface and groundwater bodies in countries where textiles and other dye-products are produced. Along with dyes, textile wastewaters also contain varying amounts of metals/metalloids, salts and organic pollutants. Moreover, these wastewaters have high temperatures and varying pH value. Various physicochemical and biological strategies have been devised to remove dye contaminants from such wastewaters. However, biotechnological approaches have attracted worldwide attention for their relative cost-effectiveness and environmentally friendly nature. Most biotechnological approaches rely on the use of microbes that have the potential to enzymatically degrade and decolorize dye-containing textile effluents. During recent years, several microbial cultures as well as microbial enzymes have been characterized and used for removal of dyes from simulated wastewaters having defined chemical compositions. However, there are still many challenges in scaling up microbial and enzymatic technologies for decolorization of raw textile wastewater that contain metals/metalloids, salts and other toxic compounds. The present review article summarizes the findings of recent studies conducted on decolorization of raw textile wastewaters. To the best of our knowledge, this is the only review reporting the biodegradation of azo dyes in raw textile effluents.

Keywords: Decolorization, Microbes, Textile effluents, Physico-chemical properties.