Pectin utilization by the methylotrophic yeast Pichia methanolica.
The methylotrophic yeast Pichia methanolica was able to grow on pectic compounds, pectin and polygalacturonate, as sole carbon sources. Under the growth conditions used, P. methanolica exhibited increased levels of pectin methylesterase, and pectin-depolymerizing and methanol-metabolizing enzyme activities. On the other hand, P. methanolica has two alcohol oxidase (AOD) genes, MOD1 and MOD2. On growth on pectin, the P. methanolica mod1Delta and mod1Deltamod2Delta strains showed a severe defect in the growth yield, although the mod2Delta strain could grow on polygalacturonate to the same extent as the wild-type strain. The expression of MOD1 was detected in pectin-grown cells, but the MOD2-gene expression detected by pectin was much lower than that of MOD1. Moreover, pectin could induce peroxisome proliferation in P. methanolica, like methanol and oleic acid. These findings showed that P. methanolica was able to utilize the methylester moiety of pectin by means of methanol-metabolic enzymes in peroxisomes, and that the functional AOD subunit for pectin utilization was Mod1p in P. methanolica.
Nakagawa
Tomoyuki
T
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
Yamada
Kaichiro
K
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
Fujimura
Shuki
S
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
Ito
Takashi
T
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
Miyaji
Tatsuro
T
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
Tomizuka
Noboru
N
Department of Food Science and Technology, Faculty of Bioindustry, Tokyo University of Agriculture, 196 Yasaka, Abashiri, Hokkaido 099-2493, Japan.
D000429:Alcohol Oxidoreductases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism; D004591:Electrophoresis, Polyacrylamide Gel; D017353:Gene Deletion; D015870:Gene Expression; D000432:Methanol / Q000378:metabolism; D010368:Pectins / Q000378:metabolism*; D020675:Peroxisomes / Q000648:ultrastructure; D010843:Pichia / Q000235:genetics / Q000254:growth & development / Q000378:metabolism* / Q000648:ultrastructure; D012331:RNA, Fungal / Q000032:analysis; D012333:RNA, Messenger / Q000032:analysis; D014158:Transcription, Genetic
D012331:RNA, Fungal; D012333:RNA, Messenger; D010368:Pectins; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D002265:Carboxylic Ester Hydrolases; C022323:pectinesterase; C003181:polygalacturonic acid; D000432:Methanol