Impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH by Sclerotinia sclerotiorum.
Sclerotinia sclerotiorum D-E7 was studied to determine the impact of nutritional supplements and monosaccharides on growth, oxalate accumulation, and culture pH in broth media (initial pH c. 5). Cultures with 0.1% nutritional supplement (tryptone, yeast extract, or soytone) yielded minimal growth, 2-3 mM oxalate, and a final culture pH of 4.2-4.8. In contrast, cultures with 0.1% nutritional supplement and 25 mM glucose yielded significant growth, minimal oxalate (<1 mM), and a final culture pH of 2.8-3.7. Similar trends were observed when glucose in 0.1% soytone cultures was replaced with 25 mM d-mannose, l-arabinose, or d-xylose. With 1% soytone-25 mM glucose cultures, growth and oxalate accumulation ( approximately 21 mM) occurred with little change in initial pH. This was not the case with 1% soytone-250 mM glucose cultures; increased glucose levels resulted in a decrease in oxalate accumulation ( approximately 7 mM) and in final culture pH (3.4). Time-course studies with these cultures revealed that oxalate accumulation was suppressed during growth when the culture pH dropped to <4. Overall, these results indicate that (1) the decrease in external pH (i.e. acidification) was independent of oxalate accumulation and (2) acidification coupled to glucose-dependent growth regulated oxalate accumulation by Sclerotinia sclerotiorum.
Culbertson
Bryan J
BJ
Department of Chemistry, Eastern Illinois University, Charleston, IL 61920, USA. sldaniel@eiu.edu
Furumo
Norbert C
NC
Daniel
Steven L
SL
D001203:Ascomycota / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D003470:Culture Media / Q000494:pharmacology; D005947:Glucose / Q000494:pharmacology; D006863:Hydrogen-Ion Concentration; D009005:Monosaccharides / Q000494:pharmacology*; D010070:Oxalates / Q000378:metabolism*; D013997:Time Factors
D003470:Culture Media; D009005:Monosaccharides; D010070:Oxalates; D005947:Glucose