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2018 - 20205
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Subject: Dairy Microbiology × End date: 2020 × Start date: 2010 × Type: Thesis × Thesis Type: M.Tech. ×
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    ThesisItemOpen Access
    INCIDENCE OF LISTERIA SPECIES FROM DAIRY ENVIRONMENTAL SAMPLES
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2020-08-01) CHAITHRA S.; PRABHA R.
    In present study, Listeria count in soil, fodder, dung and feed samples collected from university dairy farm ranged from 2.30 to 3.14 log10cfu/g. Udder swab, pail rinse, pail milk and can milk had Listeria count of 0.30 log count while 0.60 log count observed in chilled milk whereas water, swabs of hand, udder and equipment, pail and can rinses, aseptic milk and pasteurized milk did not show the presence of Listeria. Among 23 isolates of Listeria obtained from dairy environmental samples, Listeria monocytogenes predominated (56.50) followed by Listeria innocua (17.39), Listeria ivanovii (8.70); Listeria seeligeri (4.35) and 13.06 per cent of unidentified Listeria sp. All the 23 Listeria isolates, except L. monocytogenes L16 grew well at 5 C indicating psychrotrophic nature of the isolates. At deep freeze temperature (-18 C), only 9 out of 23 Listeria isolates showed growth indicating the psychrophilic nature of isolates. Among 23 Listeria isolates, 14 numbers of Listeria spp. showed haemolysis, phospholipase and coagulase activities indicating pathogenic nature. Listeria monocytogenes L10 showed highest DMC of 8.95 log10/ml among 23 isolates and used in further studies. Initial viable log count of Listeria monocytogenes L10 in sterile milk 5.95 reached to 8.98 with per cents of 0.30 LA; protein of 1.00, oleic acid of 1.86 and haemolysin of 10 mm diameter at 24 h of incubation at 37 C. L. monocytognes L10 at 3, 4, 5 and 6 viable log counts inoculated into sterile whole milk and stored at 5 C the raise on an average viable log count was by 4, 3, 2 and 1.5 with storage period of 30, 20, 12 and 9 days, respectively based on the curdling of milk. During storage, the percent mean acidity of 0.23, protein reduction by 1.25, developed oleic acid was 1.40. Haemolysin production in L. monocytognes L10 started on half of storage period that reached peak on last day of storage at 5 C.
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    ThesisItemOpen Access
    ANTIBACTERIAL AND ANTIOXIDANT PROPERTIES OF CHAKKA WHEY BASED BEVERAGE
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2019-08-01) THUPAKULA SARASWATHI; RAMACHADRA, B.
    The present study was aimed to utilization of chakka whey obtained from chakka using Lactococcus lactis ssp. lactis, yoghurt culture Streptococcus thermophilus and Lactobacillus delbreuckii ssp. bulgaricus, Befidobacterium sp. These cultures were used separately and in combination for the preparation of chakka. The chakka whey beverages added with different levels of sugar at 5, 7.5 and 10 per cent. At the 7.5 per cent sugar level, the chakka whey beverage prepared from chakka whey obtained from chakka using yoghurt culture was found to be best among the other cultures. In case of antibacterial activity of chakka whey and its beverage, there was no antibacterial activity against E.coli and Salmonella sp. But, the antibacterial activity against the test organism Stap.aureus were 11.78 , 12.10, 13.0 and 12.5 sq.mm for chakka whey beverage prepared from chakka whey obtained from chakka using Lactococcus lactis ssp. lactis, yoghurt culture, Bifidobacterium sp. and in the combined cultures respectively. The antioxidant activity (% DPPH) of chakka whey, beverage and their fractions of supernatant and CFE obtained using Lactococcus lactis ssp. lactis were 18.03, 24.03, and 43.8. Similarly chakka whey beverage, their fractions of supernatant and CFE obtained using yoghurt culture, Bifidobacterium sp. were 61.72, 47.36, 70.49 and 61.41, 53.06, 61.40 respectively, whereas in case of chakka whey beverage prepared from chakka whey obtained from chakka using combined cultures it was 35.2, 35, 54.30. The effect of heating on antioxidant activity (% DPPH) of chakka whey beverages at control, pasteurization, 85oC/30 min, boiling and sterilization temperatures showed 70.49, 49.33, 32.85, 19.1 and negative values respectively. The altered pH values of chakka whey beverages at control 2, 3, 4, 5, 6, 8 and 9 had 70.49, 84.5, 80.5, 60.5, 58, 20, 13, 11 and 8.0 (% DPPH) antioxidant activity respectively. The characterized crude whey protein obtained on dialysis of whey beverage had 4.9 pH, 0.20 acidity (Lactic acid) per cent, Further, heating of whey proteins at 80oC for 5 min had lost 20 per cent whey proteins. And the antioxidant activity of dialysed whey proteins at 1:10 dilution was 36.8 (% DPPH), 12.5 Sq.mm antibacterial activity against the Stap.aureus. The optimized chakka whey beverages prepared from whey obtained from chakka using yoghurt culture was stored at refrigeration temperature (7±1oC) and was found acceptable till 12th day at refrigeration temperature respectively.
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    ThesisItemOpen Access
    INCIDENCE OF LISTERIA SPECIES FROM DAIRY ENVIRONMENTAL SAMPLES
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2020-08) CHAITHRA S.; Dr. PRABHA R.
    In present study, Listeria count in soil, fodder, dung and feed samples collected from university dairy farm ranged from 2.30 to 3.14 log10cfu/g. Udder swab, pail rinse, pail milk and can milk had Listeria count of 0.30 log count while 0.60 log count observed in chilled milk whereas water, swabs of hand, udder and equipment, pail and can rinses, aseptic milk and pasteurized milk did not show the presence of Listeria. Among 23 isolates of Listeria obtained from dairy environmental samples, Listeria monocytogenes predominated (56.50) followed by Listeria innocua (17.39), Listeria ivanovii (8.70); Listeria seeligeri (4.35) and 13.06 per cent of unidentified Listeria sp. All the 23 Listeria isolates, except L. monocytogenes L16 grew well at 5 °C indicating psychrotrophic nature of the isolates. At deep freeze temperature (-18 °C), only 9 out of 23 Listeria isolates showed growth indicating the psychrophilic nature of isolates. Among 23 Listeria isolates, 14 numbers of Listeria spp. showed haemolysis, phospholipase and coagulase activities indicating pathogenic nature. Listeria monocytogenes L10 showed highest DMC of 8.95 log10/ml among 23 isolates and used in further studies. Initial viable log count of Listeria monocytogenes L10 in sterile milk 5.95 reached to 8.98 with per cents of 0.30 LA; protein of 1.00, oleic acid of 1.86 and haemolysin of 10 mm diameter at 24 h of incubation at 37 °C. L. monocytognes L10 at 3, 4, 5 and 6 viable log counts inoculated into sterile whole milk and stored at 5 °C the raise on an average viable log count was by 4, 3, 2 and 1.5 with storage period of 30, 20, 12 and 9 days, respectively based on the curdling of milk. During storage, the percent mean acidity of 0.23, protein reduction by 1.25, developed oleic acid was 1.40. Haemolysin production in L. monocytognes L10 started on half of storage period that reached peak on last day of storage at 5 °C
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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
    MICROBIOLOGICAL CHARACTERISTICS OF KUMISS PRODUCED FROM COW’S MILK
    (KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR, 2018-07) SHIVARAJ SHIVASHIMPAR; Dr. RAMACHANDRA, B.
    Kumiss is an effervescent acidic, alcoholic fermented, milky white or greyish liquid made primarily from mare’s milk. Kumiss has health benefits as it contains prebiotics like inulin. It is limited to the places like central Asia, Russia, Eastern Europe etc. due to its limited technological information and unavailability of mare’s milk and Kumiss as a product itself in certain parts of the world. In the present study an attempt was made to prepare Kumiss from cow’s milk. The lactic isolates like lactococcus lactis ssp. lactis, Leuconostoc mesenteroides ssp. mesenteroides, Lactobacillus delbreuckii ssp. bulgaricus, Streptococcus thermophilus and yeast Kluveromyces lactis were isolated from the domestic dahi samples. During the preparation of Kumiss parameters like types of milk, lactose content of cow’s milk, heat treatments, inoculum levels and incubation periods were studied. Finally, cow’s milk was made enriched with lactose to the level of 6.1% to simulate mare’s milk lactose composition as lactose is a crucial component for the acid and alcohol production. The milk was heated to 900 C/5 min and inoculated with 10% LAB + 20% LFY separately for a period of 48 h. at 300C in an orbital shaking incubator for better alcohol production. A final cow’s milk Kumiss was produced with 0.89% alcohol and 0.85% LA. The stored cow’s milk Kumiss had 4 days shelf-life at room temperature (27±10C) with the acidity of (1.35% LA), alcohol (0.70%), viable count (6.72 log10cfu/ml) and 9 days shelf life at refrigeration temperature (6±10C) with the acidity (0.94%LA), alcohol (0.74%), viable count (6.1 log10cfu/ml) respectively.