Faculty Publications
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Item Partial purification and characterization of L-asparaginase from an endophytic Talaromyces pinophilus isolated from the rhizomes of Curcuma amada(Elsevier, 2016) Krishnapura, P.R.; Belur, P.D.l-Asparaginase is a commercially significant enzyme. There exists a demand for a broad variety of microbial l-asparaginases with characteristics compatible with its different applications. Endophytic microorganisms, in particular are emerging as potential sources of l-asparaginases. The current work involves partial purification and characterization of l-asparaginase from Talaromyces pinophilus, an endophytic fungus isolated from the rhizomes of Curcuma amada. Maximum enzyme activity could be achieved at pH 8.0 and with temperature 28 °C. The enzyme Exhibits 95 % and 98% of its total activity at physiological pH and temperature, respectively. The enzyme activity is largely unhindered in the presence of metal ions such as Ca2+, Cu2+, Fe2+, Mg2+, Mn2+, Zn2+. Increase in the enzyme activity in the presence of thiol groups and reduction in the same upon addition of thiol blockers indicates the involvement of cysteine in the enzyme's catalytic activity. The enzyme is a heterodimer of 62 kDa and 39 kDa. The enzyme has a Km of 6.4 mM, its turnover number towards l-asparagine is 286.3 s-1. The enzyme has 16% glutaminase activity; its Km towards glutamine is 13.3 mM and turnover number is 54.6 s-1. Our results highlight that l-asparaginase from endophytic Talaromyces pinophilus could be considered as potential candidate for clinical and industrial trials, owing to its efficiency and biochemical properties. To the best of our knowledge, this is the first report on partial purification and characterization of L-asparaginase from an endophyte. © 2015 Elsevier B.V. All rights reserved.Item L-asparaginase production using solid-state fermentation by an endophytic talaromyces pinophilus isolated from rhizomes of curcuma amada(Journal of Pure and Applied Microbiology micro_drkhan@yahoo.com 54, Near Post Office, Thana Street, Shahjahanabad Bhopal 462 001, 2020) Krishnapura, P.R.; Belur, P.D.In recent times, exploration of endophytes for L-asparaginase production is gradually gaining momentum. This work deals with studies on the production of L-asparaginase from Talaromyces pinophilus, an endophytic fungus isolated from the rhizomes of Curcuma amada. L-asparaginase production was carried out by Submerged Fermentation (SmF) followed by Solid-state Fermentation (SSF). A liquid medium was designed and optimized using Plackett-Burman Design and Response Surface Methodology (RSM), under SmF. Additionally, optimal concentrations of various metal salts were incorporated in the optimized liquid medium, by one-factor-at-a-time experiments. To further enhance L-asparaginase production, SSF was carried out using Polyurethane Foam (PUF) as inert support impregnated with the optimized liquid medium. Effects of PUF cube volume, mass of PUF, moisture content, initial medium pH, and incubation temperature on the enzyme production in SSF were optimized by one-factor-at-a-time approach.L-asparaginase production enhanced from 80.8 U/mL in the unoptimized medium to 94.4 U/mL in the optimized medium under SmF. Enzyme production further increased to 120.3 U/mL under SSF by using PUF soaked in the optimized liquid medium. This study highlights the benefits of carrying out SSF with PUF, using the same liquid medium optimized for SmF - a novel approach to enhance the enzyme yield (in our case an increase of about 27% was observed). To the best of our knowledge, this is the first report on the production of L-asparaginase by both SmF and SSF, from an endophyte Talaromyces pinophilus isolated from the rhizomes of Curcuma amada. © The Author(s) 2020. Open Access. This article is distributed under the terms of the Creative Commons Attribution 4.0 International License which permits unrestricted use, sharing, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.Item Development of stable and functional encapsulated chrysin using casein–polysaccharide complexes for food applications(John Wiley and Sons Inc, 2023) Parappa, K.; Krishnapura, P.R.; Iyyaswami, R.; Belur, P.D.Chrysin is a hydrophobic flavonoid with multiple health benefits. The various applications of chrysin are challenged by its poor solubility, instability and loss of bioactivity. Casein–chrysin complex and casein–polysaccharide–chrysin complexes have developed to overcome these limitations. Very high encapsulation efficiency of 98.23 ± 0.22% was achieved with casein–inulin–chrysin complex. The chrysin was able to form a stable casein–polysaccharide–chrysin complex suspension with a hydrodynamic diameter of 382.3 nm, zeta potential value of −12.3 mV and a Polydispersity Index (PDI) of 27.7. The antioxidant activity of chrysin increased about threefold after encapsulation. The release of chrysin from its encapsulated complexes to different buffers in the pH range of 3 to 10 was studied at 1:10 ratio. At the end of 48 h, only 6%–8% of chrysin was released in the pH range 3–4, 33%–58% at pH 5–9 and 62% at pH 10. The chrysin encapsulated in casein–inulin–chrysin complex was able to overcome the rapid release of chrysin from the casein–chrysin complex. The results indicate the successful development of a stable encapsulated chrysin complex which can overcome the various limitations of chrysin in its potential applications. © 2023 Institute of Food, Science and Technology (IFSTTF).