Production, Purification and Characterization of Exoglucanase by Aspergillus Sp. Isolated from Mirpur Azad Kashmir

Abstract

Every organism in this world interacts with the biological environment and also with a biological environment. This interaction depends upon the physical and physiological properties of an organism under which it is restrained to a particular habitat. In that particular habitat an organism not only interacts with the other population of the same species but also with the other species in terms of reproduction, competition, predation etc.  In the present study, the main concern was to understand or probe those ideal conditions under which an organism thrive and shows its maximum potential. In biological studies it is always an advantage for the researcher to have a better understanding of organism’s life cycle and its optimized conditions. In our current study, different parameters were used to understand the maximum productivity of Aspergillus niger. The optimum growth of Aspergillus niger was observed on different temperatures, varying pH levels, size of inoculum and also the different concentration of carbon nitrogen sources. After wards the growth was correlated by the enzyme (exoglucanase) it produced. Obvious reason behind this was that at optimum growth the enzyme produced was also optimum. The enzyme exoglucanase was taken under observation because of high economic value of fungi in our daily life not only their uses in our industries but also because of its notorious nature in deteriorating our crops, lumber and human and plant diseases. There after enzyme was further purified and its activity was observed by using different parameters so that it’s characterization could be done. Maximum activity of exoglucanase was observed at 80 percent moisture level (2.26 IU/mL/min, 6.0 pH (8.19 IU/mL/min), 37 ⁰C growth temperature (3.15 IU/mL/min) and 1 ml inoculum size (1.266 IU/mL/min). Addition of 0.3 percent fructose as a carbon source and glucose gave maximum activity (3.10 IU/mL/min).The exoglucanase produced by Aspergillus niger under optimum conditions was partially purified using ammonium sulphate precipitation method. The maximum exoglucanase (3.46 IU/mL/min) was obtained by adding 0.2 percent ammonium sulphate. Partially purified enzyme was further purified by gel filtration chromatography using 5 percent silica gel. The maximum exoglucanase activity (1.604 IU/mL/min) was observed in elution number 23. There was 1.106-fold purification observed after ammonium sulphate purification and 1.066 fold after gel filtration chromatography.