Browsing by Author "Kumar, Punit"

Now showing 1 - 4 of 4
  • Thumbnail Image
    Item
    Enhanced production of lipstatin from mutant of Streptomyces toxytricini and fed‑batch strategies under submerged fermentation
    (3 Biotech, 2020) Khushboo; Pinki; Kumar, Punit; Dubey, Kashyap.Kumar; Luthra, Umesh
    Streptomyces toxytricini produces bioactive metabolite recognized as lipstatin and its intermediate orlistat. The main focus of this study is to enhance lipstatin production by strain improvement and precursor feeding. In this study, strain improvement to enhance the production of lipstatin was carried out by different doses (50, 100, 150, 200, and 250 Gy) of gamma radiation and precursors (Linoleic acid, Oleic acid, and l-Leucine). Screening showed that the highest yield of lipstatin (4.58 mg/g) was produced by mutant designated as SRN 7. The production of lipstatin (5.011 mg/g) increased significantly when the medium was supplemented with ratio 1:1.5 (linoleic acid + oleic acid). The addition of 1.5% l-Leucine leads to further increment in the production of lipstatin (5.765 mg/g). The addition of 10% soy flour in the culture medium resulted in the maximum production of lipstatin to 5.886 mg/g.
  • Thumbnail Image
    Item
    Extractive fermentation for process integration and amplified pullulan production by A. pullulans in aqueous two phase systems
    (Scientific Reports, 2019) Badhwar, Parul; Kumar, Punit; Dubey, Kashyap.Kumar
    Extractive fermentation technique or in situ product recovery process is a novel technique to segregate the desired product simultaneously in a fermentation process. For economic and high yield production of pullulan, Extractive fermentation process was applied fermentation process of A. pullulans. Aqueous Two Phase system (ATPS) systems were designed with various molecular mass of PEG (400, 600, 4000 and 6000) and dextran or mono/bi-sodium phosphate salts. Systems with short Tie Line length (TLL) 6.7 and 7.5% w/w for PEG-Salt and PEG-dextran respectively were chosen. Volume ratio for all the systems was kept constant at 1.0 and pH 7.0 for PEG-dextran and PEG-NaH2PO4 was maintained, whereas pH 9.0 was kept for PEG-Na2HPO4. A. pullulans, was found to be viable with PEG-NaH2PO4 and PEG-dextran systems. The biomass partitioned in the PEG rich top phase and the exopolysaccharide pullulan shown affinity towards the bottom phase. A maximum yield (36.47 g/L) was found with PEG 4000-Dextran 500 system of extractive fermentation process. The proposed process aptly integrates upstream and downstream process for continuous production and recovery of pullulan from the biomass, thus reducing the time quotient of the whole process
  • Thumbnail Image
    Item
    Implication of mutagenesis and precursor supplementation towards the enhancement of lipstatin (an antiobesity agent) biosynthesis through submerged fermentation using Streptomyces toxytricini
    (3 Biotech, 2018) Kumar, Punit; Dubey, Kashyap.Kumar
    In the present study, lipstatin production was studied from different mutants of Streptomyces toxytricini which were developed using ultraviolet radiation (exposure time 30 s, 1, 2, 5 and 10 min), ethyl methane sulfonte, methyl methane sulfonate (MMS) and N-methyl-N′-intro-N-nitrosoguanidine (NTG) treatments (50, 100, 200, 500, 1000 μM, respectively). Highest yielding mutants were provided precursor supplementation of citric acid, thiamine and biotin (each 1 g/L) at idiophase for further enhancement in the production of lipstatin. Screened mutants produced biomass in the range of 5.8–7.16 g/L which were lesser than control. Screened mutants also exhibited pellet morphology in submerged culture. Out of these mutants, NTG8 mutant produced highest amount of lipstatin (1383.25 mg/L) with 9.606 mg/L/h productivity. Precursor supplementation to this mutant further increased the production to 2387.81 mg/L. Mutant was validated in 5 L bioreactor and lipstatin production was enhanced to 2519.34 mg/L.
  • Thumbnail Image
    Item
    Improved pullulan production and process optimization using novel GA–ANN and GA–ANFIS hybrid statistical tools
    (Biomolecules, 2020) Budhwar, Parul; Kumar, Ashwani; Yadav, Ankush; Kumar, Punit; Siwach, Ritu; Chabra, Deepak; Dubey, Kashyap.Kumar
    Pullulan production from Aureobasidium pullulans was explored to increase yield. Non-linear hybrid mathematical tools for optimization of process variables as well as the pullulan yield were analyzed. The one variable at a time (OVAT) approach was used to optimize the maximum pullulan yield of 35.16 0.29 g/L. The tools predicted maximum pullulan yields of 39.4918 g/L (genetic algorithm coupled with artificial neural network (GA–ANN)) and 36.0788 g/L (GA coupled with adaptive network based fuzzy inference system (GA–ANFIS)). The best regression value (0.94799) of the Levenberg–Marquardt (LM) algorithm forANNand the epoch error (6.1055 10􀀀5) for GA–ANFIS point towards prediction precision and potentiality of data training models. The process parameters provided by both the tools corresponding to their predicted yield were revalidated by experiments. Among the two of them GA–ANFIS results were replicated with 98.82% accuracy. Thus GA–ANFIS predicted an optimum pullulan yield of 36.0788 g/L with a substrate concentration of 49.94 g/L, incubation period of 182.39 h, temperature of 27.41 C, pH of 6.99, and agitation speed of 190.08 rpm.