Reevaluation of Disaccharide-Induced Osmoprotection in Sinorhizobium meliloti 1021

Publication Year



Bacteria Osmoprotection Disaccharide Rhizobia Hyperosmotic




This investigation sought to reevaluate disaccharide induced osmoprotection in the soil bacteria, Sinorhizobium meliloti 1021. Soil bacteria frequently encounter salt-induced hyperosmotic environments and must be able to respond to osmotic stress. Many forms of soil bacteria respond to osmotic stress through the synthesis or accumulation of compatible solutes (osmoprotectants). Previous research has established the unique ability by S. meliloti to use disaccharide sugars as osmoprotectants. My investigation reevaluated the osmoprotective ability of the disaccharides sucrose and cellobiose by comparing their growth in osmotically stressed environments under varying media conditions. Growth curves were created and compared by growing the bacterial cultures in 16 mm test tubes and checking their absorbances at 600 nm using a UV Spectrophotometer over a period of time. The results indicate that both sucrose and cellobiose confer osmoprotective abilities. Growth curves using the same method were also used for several mutant strains of S. meliloti in order to determine metabolic requirements for the use of disaccharide osmoprotectants. Further research is required to confirm these findings and broaden understanding of disaccharide induced osmoprotection in mutant strains of S. meliloti.

Department 1 Awarding Honors Status

Biochemistry and Molecular Biology

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