Thumbnail Image

Theses

Browse

2002 - 200932020 - 20221
Reset filters
Author: Satish Kumar × Start date: 2002 × Type: Thesis × Thesis Type: Ph.D ×
Reset filters

Search Results

Now showing 1 - 4 of 4
  • Thumbnail Image
    ThesisItemOpen Access
    Production, extraction and characterization of astaxanthin from microalgae
    (Chaudhary Charan Singh Haryana Agricultural University hisar, 2022-09) Satish Kumar; Satish Kumar; Rakesh Kumar; Rakesh Kumar
    In the present investigation, five microalgal isolates were retrieved from different regions of Himachal Pradesh and Haryana. Out of five, two isolates, PLM1 and PLM2, produced astaxanthin. Astaxanthin production potential of PLM1 was low; therefore, only PLM2 was selected for further studies. Based on molecular analysis, PLM1 and PLM2 were identified as novel species named Desmodesmus sp. nov. PLM1 and Desmodesmus sp. nov. PLM2. Optimized culture conditions include sodium nitrate (20 mM), glucose (3mM), potassium chloride (32mM), pH (7), incubation temperature (27°C), and 15 days of incubation time for the green and red stages. The media with optimized composition were re-named as Modified BG-11 or M-BG11 medium. After achieving maximum biomass yield, cells were harvested and inoculated in nitrogen, phosphorous limiting media supplemented with 0.2% NaCl and 4.4mM sodium acetate and incubated at 27℃ for 15 days under the illumination of the white light of intensity 3000 lux. After 15 days, microalgal red cyst cells from BG-11 and M-BG11 medium were harvested, lyophilized, stored, and directed for astaxanthin extraction using different solvents. Maximum astaxanthin extraction resulted from cells grown in M-BG-11 medium was 21.13 ppm using 4 M HCl. The extracted astaxanthin was confirmed for its presence using UHPLC, FTIR, and Raman spectroscopy. Astaxanthin extracted from Desmodesmus cells grown in two different media was evaluated for DPPH free radical scavenging activity. Maximum DPPH free radical scavenging activity (78.69%) and free hydroxyl radical activity (37.81%) were observed for astaxanthin extracted using 4M HCl. The lyophilized dried biomass was stored and evaluated for degradation at different temperatures, including -20°C, 4°C, 25°C, and room temperature. Maximum degradation (88%) was observed at room temperature after 20 weeks of storage for the BG11 medium. The red-light illumination enhanced the vegetative growth of Desmodesmus sp. PLM2, whereas blue-light illumination caused stress in Desmodesmus sp. PLM2, thereby triggering astaxanthin biosynthesis. The extracted astaxanthin was inhibiting the growth of Bacillus subtilis, Staphylococcus aureus, and E. coli.
  • Thumbnail Image
    ThesisItemOpen Access
    Role Of Earthworms In Relation To Conversion Of Soil Nutrients In Cultivated Soils
    (Chaudhary Charan Singh Haryana Agricultural University; Hisar, 2002) Satish Kumar; Sihag, R. C.
  • Thumbnail Image
    ThesisItemOpen Access
    Pathogenesis And Management Of Root Rot Disease Complex Of Okra [Abelmoschus Esculentus (L.) Moench]
    (Chaudhary Charan Singh Haryana Agricultural University;Hisar, 2002) Satish Kumar; Tripathi, N.N.
  • Thumbnail Image
    ThesisItemOpen Access
    Comparative Studies Of Mango Fruit Of Different Cultivars For Processing
    (Chaudhary Charan Singh Haryana Agricultural University; Hisar, 2008) Satish Kumar; Godara, R. K.