Abstract:
Gundruk is a non-salted fermented and acidic vegetable product indigenous to the Nepal. The main objective of this study was to determine the microorganisms found in Gundruk sample collected from leaves of Brassica napus. A total of 30 samples of Gundruk were collected from different places of Sunsari district, Nepal and were analyzed for microbial counts using standard microbial techniques. The colonies grown were identified by conventional methods as described by Bergey’s manual of determinative bacteriology. The antimicrobial susceptibility test and antimicrobial test were also performed by using Mueller Hinton Agar (MHA). No yeast and mold were detected. In order to identify the predominating organisms, a total of 98 strains were isolated. The phenotypic characteristics of these strains were determined by using Gram’s stain, biochemical tests, Carbohydrate fermentation test and capacity to grow on different temperature, pH and different concentration of NaCl. The major representatives of the LAB involved in Gundruk were identified as Lactobacillus plantarum and Pediococus pentasaccus. No pathogenic bacteria were found in gundruk sample collected from different places of Sunsari. No any P-solubilizing bacteria were detected. All isolates were susceptible to most of common antibiotics except Vancomycin. This result suggested that LAB isolated from gundruk have very good potential to be used as probiotics. Antimicrobial activity of gundruk sample was also determined. All gundruk samples were able to inhibit most of the indicator pathogens tested except Salmonella spp and Vibrio cholera. Attempts were made to produce gundruk using mixed starter culture of LAB previously isolated under lab-respective products. The product prepared under lab condition has scored higher sensory ranking comparable to market products.
Description:
A
Dissertation
Submitted to the Department of Microbiology, Central Campus of Technology, Tribhuvan University, Dharan, Nepal, in partial Fulfillment of the Requirements for the Award of Degree of Master of Science in Microbiology
(Environment and Public Health)