Isolation, characterization, and fermentative pattern of a novel thermotolerant Prototheca zopfii var. hydrocarbonea strain producing ethanol and CO2 from glucose at 40 degrees C

作者：Ueno R; Urano N^*; Suzuki M; Kimura S

来源：Archives of Microbiology, 2002, 177(3): 244-250.

DOI：10.1007/s00203-001-0384-0

• Prototheca zopfii
• fermentation
• anaerobic metabolism
• thermotolerant
• ethanol
• CO2
• chlorella
• SSU rDNA sequence

A novel thermotolerant strain of the achlorophyllous micro-alga Prototheca was isolated from a hot spring. The isolate was found to produce an appreciable amount of ethanol and CO2 from glucose under anoxic conditions at both 25 and 40degreesC; this type of alcohol fermentation has not yet been reported in the genus Prototheca. Moreover, it also evolved gas from sucrose after a time lag at 40degreesC. Its taxonomic characteristics coincided with those of Prototheca zopfii var. hydrocarbonea, and phylogenetic analysis, based on a small-subunit (SSU) rDNA sequence, also revealed a close relationship between the two strains. D-lactic acid, ethanol, CO2 and a trace of acetic acid were produced from glucose, but L-lactic acid, formic acid, and H, were not. At 25degreesC, D-lactic acid and ethanol were produced in approximately equimolar amounts under N-2/H-2/CO2, whereas ethanol production was predominant under N-2. More ethanol was produced at 40degreesC than at 25degreesC irrespective of the gas composition in the atmosphere. This is the first report on gas production from glucose and on the changes in the fermentative patterns as a function of temperature for the genus Prototheca.

• 出版日期2002-3