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Theses (PG)

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2011 - 20192
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Author: SHIVALKAR YADAV, K × End date: 2021 ×
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    ThesisItemOpen Access
    PRODUCTION OF BIODEGRADABLE PLASTIC FROM BACTERIA OF DAIRY SEWAGE ORIGIN
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR – 585 226, 2019-06) SHIVALKAR YADAV, K; Dr. PRABHA R.
    Bacterial intracellular polyhydroxyalkanoates (PHAs), a potential substitute for synthetic plastic was extracted from bacteria of dairy sewage origin in the present study. The collected dairy sewage samples from dairies showed neutral pH with mean chemical and biological oxygen demand of 2566 and 1400 ppm respectively. On 2 % glucose enriched nutrient agar containing 0.3% lipophilic dye sudan black, black pin point colonies of viable PHA producing bacteria was 3.61 log10cfu/ml. Out of 26 PHA producers from dairy sewage samples, 24 were phenotyped as Bacillus licheniformis and 1 each as B. subtilis and B. thuringiensis. The highest PHA producer during screening was found to be B18 which was characterized as Bacillus licheniformis. Optimized medium for PHA production by B18 was found to be equal volumes of dairy sewage and nutrient broth containing 2 % glucose with peak production (78.8%) at 37οC/48 h from 9.46 log10cfu/ml. Extracted PHA from B18 and standard PHA showed stability at acidic, neutral and alkaline pH as well exhibited thermostability when subjected to batch pasteurization, boiling and sterilization temperatures through absorbance at 235 nm. Thin Layer Chromatography confirmed extracted compound from B18 as PHA, as retardation factor was similar to standard PHA. Fourier transform infrared spectroscopy revealed presence of CH, CO and OH groups in extracted and standard PHA. Liquid chromatography mass spectrometric analysis revealed molecular mass (m/z) of extracted PHA as 360 containing 3 monomers comparable with standard PHA. In biodegradability study of film made by incorporation of 1 % PHA with polypropylene had better weight loss of up to 79.9% in soil - nutrient broth extract at 26 οC at 90 days. Biodegradation of empty lassi stored bottles having similar composition of film in soil accounted for 88 % weight loss with viable bacterial count of 9.90 log10cfu/ml and yeast & molds of 8.50 log10cfu/ml, indicating microbial depolymerization of PHA and thus brittleness in bottles at the end of 180 days.
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    ThesisItemOpen Access
    CHARACTERIZATION OF PIGMENTS FROM WILD STRAINS OF RHODOTORULA
    (Karnataka Veterinary Animal And Fisheries Sciences University, Bidar, 2011) SHIVALKAR YADAV, K
    The development of foods with an attractive appearance is an important goal in the food industry