Research output: Contribution to Journal/Magazine › Journal article › peer-review
Research output: Contribution to Journal/Magazine › Journal article › peer-review
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TY - JOUR
T1 - Carbohydrate and amino acid metabolism of the diplomonad parasite Spironucleus vortens
AU - Millet, Coralie
AU - Lloyd, David
AU - Coogan, Michael
AU - Rumsey, Joanna
AU - Cable, Joanne
PY - 2011
Y1 - 2011
N2 - The metabolism of Spironucleus vortens, a parasitic, diplomonad flagellate related to Giardia intestinalis, was investigated using a combination of membrane inlet mass spectrometry, 1H NMR, 13C NMR, bioscreen continuous growth monitoring, and ion exchange chromatography. The products of glucose-fuelled and endogenous metabolism were identified by 1H NMR and 13C NMR as ethanol, acetate, alanine and lactate. Mass spectrometric monitoring of gas metabolism in buffered cell suspensions showed that glucose and ethanol could be used by S. vortens as energy-generating substrates, but bioscreen automated monitoring of growth in culture medium, as well as NMR analyses, suggested that neither of these compounds are the substrates of choice for this organism. Ion-exchange chromatographic analyses of free amino-acid and amino-acid hydrolysate of growth medium revealed that, despite the availability of large pools of free amino-acids in the medium, S. vortens hydrolysed large amounts of proteins during growth. The organism produced alanine and aspartate, and utilised lysine, arginine, leucine, cysteine and urea. However, mass spectrometric and bioscreen investigations showed that addition of the utilised amino acids to diluted culture medium did not induce any significant increase in metabolic or growth rates. Moreover, as no significant amounts of ornithine were produced, and addition of arginine under aerobic conditions did not generate NO production, there was no evidence of the presence of an energy-generating, arginine dihydrolase pathway in S. vortens under in vitro conditions.
AB - The metabolism of Spironucleus vortens, a parasitic, diplomonad flagellate related to Giardia intestinalis, was investigated using a combination of membrane inlet mass spectrometry, 1H NMR, 13C NMR, bioscreen continuous growth monitoring, and ion exchange chromatography. The products of glucose-fuelled and endogenous metabolism were identified by 1H NMR and 13C NMR as ethanol, acetate, alanine and lactate. Mass spectrometric monitoring of gas metabolism in buffered cell suspensions showed that glucose and ethanol could be used by S. vortens as energy-generating substrates, but bioscreen automated monitoring of growth in culture medium, as well as NMR analyses, suggested that neither of these compounds are the substrates of choice for this organism. Ion-exchange chromatographic analyses of free amino-acid and amino-acid hydrolysate of growth medium revealed that, despite the availability of large pools of free amino-acids in the medium, S. vortens hydrolysed large amounts of proteins during growth. The organism produced alanine and aspartate, and utilised lysine, arginine, leucine, cysteine and urea. However, mass spectrometric and bioscreen investigations showed that addition of the utilised amino acids to diluted culture medium did not induce any significant increase in metabolic or growth rates. Moreover, as no significant amounts of ornithine were produced, and addition of arginine under aerobic conditions did not generate NO production, there was no evidence of the presence of an energy-generating, arginine dihydrolase pathway in S. vortens under in vitro conditions.
KW - Diplomonad
KW - Spironucleus
KW - Carbohydrate
KW - Amino acid
KW - Mass spectrometry
KW - NMR
U2 - 10.1016/j.exppara.2011.05.025
DO - 10.1016/j.exppara.2011.05.025
M3 - Journal article
VL - 129
SP - 17
EP - 26
JO - Experimental Parasitology
JF - Experimental Parasitology
SN - 0014-4894
IS - 1
ER -