Single step purification of asparaginase from endophytic bacteria Pseudomonas oryzihabitans exhibiting high potential to reduce acrylamide in processed potato chips

• Published in: Food and bioproducts processing 2016-07, Vol.99, p.222-230
• Main Authors: Bhagat, Jyoti, Kaur, Amarjeet, Chadha, Bhupinder Singh
• Format: Article
• Language: English
• Subjects: Acrylamide; Anticancer; Asparaginase; Endophytic bacteria; Hibiscus rosa-sinensis; Pseudomonas oryzihabitans
• ISSN: 0960-3085; 1744-3571
• DOI: 10.1016/j.fbp.2016.05.010

•Purification and characterization of asparaginase from endophytic Pseudomonas oryzihabitans.•The culture under optimized condition produced 4.3U/mL of asparaginase.•Single step purification was achieved using SP Sephadex ion exchange chromatography.•Purified asparaginase was found to be heterodimer.•Asparaginase reduced acrylamide by 90% and also exhibited anti-proliferative activity. This study reports the purification and characterization of extracellular asparaginase from an endophytic bacteria Pseudomonas oryzihabitans isolated from Hibiscus rosa-sinensis. Sixty endophytes isolated from medicinal plants H. rosa-sinensis, Withania somnifera and Ocimum sanctum were screened for their potential to produce asparaginase. Twenty seven isolates were found positive and exhibited asparaginase activity in the range of 0.6–2.3U/mL. Isolate Hib-3 produced maximal level of asparaginase (2.1U/mL) which was identified as P. oryzihabitans. The isolate under optimized culture conditions produced 4.3U/mL of asparaginase with productivity of 238.9U/L/h. Single step purification of asparaginase was achieved using SP sephadex cation exchange column. The purified asparaginase showed specific activity of 39μmolmin−1mgprotein−1 corresponding to 42 fold purification. Electrophoretic analysis indicated asparaginase to be heterodimer showing two bands of 54 and 50kDa on SDS-PAGE, whereas, single band of 208.7kDa was observed on Native-PAGE. Purified asparaginase was optimally active at pH 8.0 and 37–40°C. Addition of purified asparaginase (2.8U/g dried potato), reduced acrylamide (90%) in fried potatoes. In addition, the asparaginase was also found to exhibit anti-proliferative activity against MCF7-Breast and HeLa-Cervix carcinoma cell lines. This is the first report on purification of asparaginase from endophytic bacteria P. oryzihabitans isolated from H. rosa-sinensis.