• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 1
  • Tagged with
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

A STUDY ON THE GROWTH AND METABOLIC ACTIVITY OF STREPTOMYCES VENEZUELAE

MacIntosh, Andrew John 19 August 2010 (has links)
The bacteria Streptomyces venezuelae produce the novel antibiotic jadomycin. The study of growth characteristics and metabolic behavior of the bacteria are necessary to scale up antibiotic production and facilitate further research. In this study, a method for producing consistent inoculum was developed that showed good repeatability when used in growth trials. The rod shaped spores of Streptomyces venezuelae were determined to be approximately 0.8 x 0.2 ?m with a smooth surface type. The effects of temperature and pH on bacterial growth and substrate consumption were examined in a 7 L bioreactor. Of the range of parameters tested (28, 32, 36 °C, and media pH of 5, 7 and 9), 32 °C with a media pH of 7 yielded the highest rate of growth (µmax of 1.43 hours-1 with a lag time of 7.7 hours). The results of all trials showed that free glucose was consumed before the maltose, which was the major sugar substrate in the media. The initiation of exponential bacterial growth occurred after rapid consumption of free glucose. A heat balance analysis was also performed over the bioreactor to identify the heat generated through agitation, losses over the vessel and the heat of metabolism from Streptomyces venezuelae. Under normal operating parameters 33 - 24 % of the heat generated through mixing was lost with the exhaust gas, while 56 - 64 % was lost through the bioreactor wall. The heat of mixing was calculated to be 1.62 J•s-1 while the maximum amount of heat generated by Streptomyces venezuelae metabolism and activity during a growth trial was 2.28 J•s-1 for 60 x 109 CFU?mL-1.

Page generated in 0.0678 seconds