Zinc oxide phytase nanocomposites as contributory tools to improved thermostability and shelflife

Abstract

The current study suggests the utility of ZnO nanoparticles to increase the thermotolerance of phytase enzymes; thereby aiding their effective utilization to provide better phosphate uptake when applied in animal feeds. Microbial isolates with predominant phytase activity were isolated from industrial wastewater to obtain a promising thermotolerant isolate of Penicillium decumbens. The purified phytase showed activities at mash preparatory temperature (32.59 ± 0.045 Uml−1 min−1 at 55 °C), animal feed pelletising temperature (37.83 ± 0.127 Uml−1 min−1 at 80 °C) and steam sterilization temperature (18.56 ± 0.027 Uml−1 min−1 at 100 °C) of animal feeds as per standard phytase assays. The supplementation of ZnO nanoparticles found to increase thermostability of phytase from 18.56 Uml−1 min−1 to 30.5 Uml−1 min−1 at 100 °C. The antibacterial role of the nanocomposites was checked against human pathogens to obtain satisfactory results against standard antibiotics. Thus the incorporation of ZnO nanoparticles in combination with phytase provided a dual benefit of increasing its thermostability and antimicrobial property thereby increasing its shelflife.