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ThesisItem Open Access Isolation of heavy metal tolerant Lactobacilli from dairy products and their potential in detoxification of heavy metals(DEPARTMENT OF DAIRY MICROBIOLOGY, WARNER COLLEGE OF DAIRY TECHNOLOGY SAM HIGGINBOTTOM UNIVERSITY OF AGRICULTURE TECHNOLOGY AND SCIENCES, ALLAHABAD-211007, U.P, INDIA, 2018) PRASAD, NIVEDITAToxic metals remain a cause of concern as they are coming up with serious health issues. They are absorbed in human body through food chain. It was hypothesized that the gut microbiota plays a role in reducing toxic metals. Keeping this in view the present study was designed to isolate the heavy metal tolerant Lactobacillus species from dairy products and to study their potential in reduction of toxic heavy metals like Lead, Cadmium and Chromium. A total 250 samples of dairy products: raw buffalo, cow and goat milk, curd and paneer (50 each) were collected from the different regions of Allahabad city.Out of 293 bacterial isolates, 39 bacterial isolates were found to be tolerant to 100 mg/L concentration of Pb, Cd and Cr. These bacterial isolates were further screened for higher metal concentration and identification was done through morphological and biochemical tests.Only 6 bacterial isolates namely BM1, CM3, GM1, CD5, CD8 and PA4 were found to be potentially tolerant to all the three heavy metals (Pb, Cd and Cr).All the 6 species showed 100 % homology with the sequences found in (NCBI) (nttp://www.ncbi.nlm.nih.gov /BLAST/). L. fermentumSN_1 showed 100% homology with KR816163.1, L. fermentumSN_2 with KT159935.1, L. fermentumSN_3 with KF030760.1, L. fermentumSN_4 with KF030779.1, L. fermentumSN_5 with AB362616.1, L. rhamnosusSN_6 with KJ702504.1. Also, the study was conducted to detect heavy metals in raw milk and dairy product samples in which sample BM1 showed the maximum concentration of Lead (6.61mg/L) in buffalo milk collected from Mahewa east which was more than the permissible limit set by FSSAI and CODEX. Cadmium concentration in was highest in BM7 i.e., 0.65 mg/L which was above the permissible limitThe maximum fat, protein, ash, T.S., S.N.F. and lactose content among milk product (curd and paneer) samples was observed in paneerbut less moisture as compared to curd.Maximum bioaccumulation was observed at pH 6.0.L.fermentumSN_5 showed maximum bioaccumulation (62.20%) of lead while minimum was observed for L.rhamnosus_SN6 (36.85%). Plasmid curing studies were conducted to conclude whether heavy metal tolerance resistance characteristics were plasmid mediated or not. L.fermentumSN_1, L.fermentumSN_3, L.fermentumSN_4 showed best curing results at 98% for Pb, 725 for Cd and 80% for Cr respectively. The probiotics potential results for simulated gastric juices showed that all the isolates were resistant to simulated gastric juices at pH 2.0 and 3.0 at 0 hour. . However, the growth of culture was lesser at pH 2.0 as compared to pH 3.0. Moreover, cell survival was also assessed for 0-3 hours. The results showed that increase in time have an adverse effect on viable count of bacteria.Ox-bile tolerance was assayed at concentrations of 0.2, 0.3, 0.5 and 1.0% bile salts. All strains survived well more than 50 % in 0.2, 0.3 % 0.5 % and 1.0 % bile salt solution. The antimicrobial activity of Lactobacillus spp. was checked against pathogenic bacteria E. coli, B. cereus, S. typhimuriumandV. cholerae and it was observed that all the isolates showed poor antagonistic agent activity against the above pathogenic bacteria.The findings collectively suggest that Lactobacilli present a strong candidature to be used as potential probiotics.ThesisItem Open Access The prevalence and resistance to antimicrobial agents of Bacillus spp. isolates from dairy foods(WARNER SCHOOL OF FOOD AND DAIRY TECHNOLOGY SAM HIGGINBOTTOM INSTITUTE OF AGRICULTURE, TECHNOLOGY AND SCIENCES (DEEMED-TO-BE- UNIVERSITY) ALLAHABAD-211007, 2016) SINGH, VINAY KUMAR; Shukla, SangeetaStudies were conducted on 200 selected dairy sample 50 each of pasteurized milk, cream, butter and paneer. The samples were collected randomly from various shops from different zone of Allahabad and Student’s Dairy in Sam Higginbottom Institute of Agriculture, Technology and Sciences Deemed-to–be University Allahabad. The highest bacterial population was found in butter samples ranged from 3.8 – 6.6 x 106 cfu/gm and least bacterial population was found in pasteurized milk samples ranged from 4.1 - 6.65 x 104 cfu/ml. The present study was conducted on the basis of cultural, morphological and biochemical tests. Eight Bacillus spp., were identified viz Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Bacillus pumilus, Bacillus sphaericus, Bacillus circulans, Bacillus coagulans and Bacillus licheniformis. Bacillus spp. were observed as g+ve, single rods, producing endospore with creamy, white colour, undulate colonies on nutrient agar, catalase positive, Indole negative and oxidase and nitrate positive or negative. Most of Bacillus spp. generated acid from glucose, sucrose, dextrose, lactose, mannitol and arabinose. The present study was conducted 96(48%) Bacillus species were isolated. The highest incidence of Bacillus spp. was found in Paneer Samples (76%) followed by pasteurized milk (50%), Cream (46%) and Butter (20%). Out of 96 Bacillus species (39.58%) found in Paneer was followed by (26.04%) in Pasteurized milk, (23.95%) in Cream and (10.41%) in Butter, respectively. Among Bacillus spp. higher incidence was of Bacillus subtilis (19.79%) and least wae of Bacillus sphaericus (7.29%). Bacillus isolates were tested to determine their susceptibilities to antibiotics total 5 (5.2%) strains of Bacillus spp. were resistant to chloramphenicol, 2 (2.08%) strains were resistant to gentamicin, 3 (3.1%) strains was resistant to cephalothin and 7 (7.2%) strains was resistant to tetracyclineThesisItem Open Access PRODUCTION AND QUALITY EVALUATION OF HERBAL YOGURT(Sam Higginbottom Institute of Agriculture, Technology & Sciences (SHIATS), 2014) Yadav, Keerti; Shukla, SangeetaMedicinal herbs are widely used in culinary and as therapeutic herbs in traditional medicine. Herbal yogurt was fermented with yogurt culture, contain Lactobacillus delbrueckii ssp. bulgaricus (NCDC009) and Streptococcus thermophilus (NCDC 0074) were incubated at 41ºC and storage at 4ºC for 7 days. Control yogurt contain milk fat 3.5%, SNF 11% (Solid not fat), Skim milk powder (2%).The experimental yogurt contain 0.5%, 1%, 1.5% of each herbs. Cinnamon yogurts treatment (0.5%, 1%, 1.5%) reduces pH from 4.6 to 4.25, for Tulsi yogurt pH value reduces from 4.43 to 4.40 and for Green tea yogurt pH range from 4.31-4.34 between 1 to 7 days of storage life. The total titrable acidity for herbal yogurt increases during storage life (0.88-1.24). physico-chemical analysis was done for estimating (fat, acidity, moisture ,protein, total solid ,ash respectively). The herbal yogurt viable bacterial count of L.bulgaricus (80.36×10-4 to 103.46×10-4) and S.thermophilus (20.40×104to 69.20×104) increases during storage life at 4ºC. All the herbal yogurt show the good antioxidant activity than plain yogurt. The highest antioxidant activity shown in green tea (75.56%to 78.22%) at different treatment level (0.5%,1% and 1.5%) between 1- 7 days of storage. The MIC was recorded against 3 pathogens (E.coli, S.aureus and P.aeruginosa). The highest MIC was recorded for E.coli is for Green tea and Cinnamon yogurt (T1Ci3, T3Ca3,) at dilution 10-3, for S.aureus , highest MIC was recorded for T3Ca3, T1Ci3 at dilution 10-3, 10-4 μl/ml and for P.aeruginosa Green tea yogurts show MIC at dilution 107μl/ml. The product was analyzed for organoleptic attributes like flavour and taste, body and texture, colour and appearance and overall acceptability. Cinnamon yogurt was most desirable yogurt among the entire herbal yogurt.ThesisItem Open Access Isolation, screening and characterization of bacteriocin producing Lactobacilli and their application as food preservative(Sam Higginbottom Institute of Agriculture, Technology & Sciences (SHIATS), 2015) Samuel, Sarah S.; Shukla, Dr. SangeetaThe present study entitled as “Isolation, screening and characterization of bacteriocin producing Lactobacilli and their application as food preservative” was conducted with the following objectives: 1. To isolate, screen and identify the Lactobacillus spp. from food and dairy products. 2. To extract, purify and evaluate the antagonistic effect of bacteriocins. 3. To characterize the effect of conditions on the antagonistic activity of bacteriocin. 4. To evaluate the effect of application of bacteriocin for preservation of food products.