Publications by authors named "Jayita Chopra"

2 Publications

  • Page 1 of 1

Production, partial purification and characterization of a proteoglycan bioemulsifier from an oleaginous yeast.

Bioprocess Biosyst Eng 2020 Oct 14;43(10):1747-1759. Epub 2020 May 14.

Department of Biotechnology, Indian Institute of Technology Kharagpur, West Bengal, Kharagpur, 721302, India.

In this study, Meyerozyma caribbica, an indigenously isolated oleaginous yeast, produced in media containing glucose a bioemulsifier that was partially characterized as a proteoglycan based on preliminary analysis. Optimization of carbon:nitrogen (C:N) ratio revealed 30:1 as the suitable ratio for enhanced production. Apart from higher emulsification activity (E: 70-80%), this molecule showed strong emulsion stability over a wide range of pH (2.0-9.0), salinity (0.05%-10%, w/v) and temperature (- 80 °C to + 50 °C). The current study emphasizes on the determination of critical media parameters for improved and stable bioemulsifier production coupled with partial characterization and identification of the molecule. Thus, a proteoglycan-based bioemulsifier with such a stable emulsifying property can serve as a versatile and potential component in food, cosmetics and pharmaceutical formulations.
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http://dx.doi.org/10.1007/s00449-020-02361-1DOI Listing
October 2020

Process optimization involving critical evaluation of oxygen transfer, oxygen uptake and nitrogen limitation for enhanced biomass and lipid production by oleaginous yeast for biofuel application.

Bioprocess Biosyst Eng 2018 Aug 20;41(8):1103-1113. Epub 2018 Apr 20.

Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal, 721302, India.

Lipid accumulation in oleaginous yeast is generally induced by nitrogen starvation, while oxygen saturation can influence biomass growth. Systematic shake flask studies that help in identifying the right nitrogen source and relate its uptake kinetics to lipid biosynthesis under varying oxygen saturation conditions are very essential for addressing the bioprocessing-related issues, which are envisaged to occur in the fermenter scale production. In the present study, lipid bioaccumulation by P. guilliermondii at varying C:N ratios and oxygen transfer conditions (assessed in terms of ka) was investigated in shake flasks using a pre-optimized N-source and a two-stage inoculum formulated in a hybrid medium. A maximum lipid concentration of 10.8 ± 0.5 g L was obtained in shake flask study at the optimal condition with an initial C:N and ka of 60:1 and 0.6 min, respectively, at a biomass specific growth rate of 0.11 h. Translating these optimal shake flask conditions to a 3.7 L stirred tank reactor resulted in biomass and lipid concentrations of 16.74 ± 0.8 and 8 ± 0.4 g L. The fatty acid methyl ester (FAME) profile of lipids obtained by gas chromatography was found to be suitable for biodiesel application. We strongly believe that the rationalistic approach-based design of experiments adopted in the study would help in achieving high cell density with improved lipid accumulation and also minimize the efforts towards process optimization during bioreactor level operations, consequently reducing the research and development-associated costs.
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http://dx.doi.org/10.1007/s00449-018-1939-7DOI Listing
August 2018
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