The Effects of Starvation on The Ruminal Bacteria Megasphaera Elsdenii and Selenomonas Ruminantium

The ruminal bacteria, Megasphaera elsdenii and Selenomonas ruminantium, were subjected to total organic nutrient starvation after growth in batch and/or continuous culture. Both organisms exhibited a very limited survival capacity in comparison to other bacteria reported in the literature. This capacity appears to have been at least partially influenced by pre-starvation growth conditions and levels of cell constituents. Because these conditions were constantly changing during batch culture growth, continuous culture growth was found to be more suitable as a basis for starvation studies. Depending on pre-starvation growth conditions, both M. elsdenii and S. ruminantium appeared to break down carbohydrate, RNA and/or DNA preferentially during starvation, suggesting that a degradation of carbohydrate storage material, excess ribosomes and/or extra genomes may have taken place. The role of protein degradation in survival of these organisms, if any, is unclear. Cellular RNA levels always exhibited relatively rapid decreases and were accompanied by either catabolism or excretion from the cell of the RNA or its components, depending on the organism and pre-starvation growth conditions. Those populations that did appear to catabolize these substrates tended to have a better survival capacity. However, no positive correlation could be found between survival ability and level of any single constituent.

Name thesis:degree_name

Ph.D.

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Dairy Science

Grantor

University of Illinois at Urbana-Champaign

Year dc:date

2014

Author dc:creator

• Mink, Ronald William

• Biology, Microbiology

Language dc:language

eng

Identifier

(UMI)AAI8127648

OAI identifier oai:identifier

oai:www.ideals.illinois.edu:2142/68561