Uptake of phenylacetic acid by two strains ofPenicillium chrysogenum

Abstract

Uptake of phenylacetic acid, the side‐chain precursor of benzylpenicillin, was studied in Penicillium chrysogenum Wisconsin 54‐1255 and in a strain yielding high levels of penicillin. In penicillin fermentations with the high‐yielding strain, 100% recovery of phenylacetic acid in benzylpenicillin was found, whereas in the Wisconsin strain only 17% of the supplied phenylacetic acid was incorporated into benzylpenicillin while the rest was metabolized. Accumulation of total phenylacetic acid‐derived carbon in the cells was nonsaturable in both strains at high external concentrations of phenylacetic acid (250–3500 μM), and in the high‐yielding strain at low phenylacetic acid concentrations (2.8–100 μM), indicating that phenylacetic acid enters the cells by simple diffusion, as concluded earlier for P. chrysogenum by other authors. However, at low external concentrations of phenylacetic acid saturable accumulation appeared in the Wisconsin strain. HPLC‐analyses of cell extracts from the Wisconsin strain showed that phenylacetic acid was metabolized immediately after entry into the cells and different [14C]‐labeled metabolites were detected in the cells. Up to approximately 50% of the accumulated phenylacetic acid was metabolized during the transport‐assay period, the conversion having an impact on the uptake experiments. Nevertheless, accumulation of free unchanged phenylacetic acid in the cells showed saturation kinetics, suggesting the possible involvement of a high‐affinity carrier in uptake of phenylacetic acid in P. chrysogenum Wisconsin 54‐1255. At high concentrations of phenylacetic acid, contribution to uptake by this carrier is minor in comparison to simple diffusion and therefore, of no importance in the industrial production of penicillin. © 1998 John Wiley & Sons, Inc. Biotechnol Bioeng 60: 310–316, 1998.

Penicillin productivity and glutathione-dependent detoxification of phenylacetic and phenoxyacetic acids inPenicillium chrysogenum

“…1). PA can also be hydroxylated to 2-hydroxy-PA and metabolised further by P. chrysogenum (ERIKSEN et al 1998), and the conversion of PA into ho- Highest tested concentration due to the limited solubility of protocatechuic acid in water -P < 5%; ** -P < 1%; *** -P < 0.1%. P values were calculated using the STUDENT's t-test mogentisic acid by a mutant of this fungus has been demonstrated (ISONO 1954).…”

“…This experimental arrangement offered an opportunity to seek for possible correlation between acidity, toxicity, GSH-dependent detoxification and penicillin productivity of PA, POA and their derivatives. It is worth noting that the formation of quite high quantities of hydroxylated penicillin side chain precursors has been demonstrated in idiophasic P. chrysogenum cultures by several authors (NYIRI et al 1966, CHRISTENSEN et al 1994, ERIKSEN et al 1994, ERIKSEN et al 1998). Here we also present some experimental data on their effects on the E-lactam biosynthetic machinery, the physiological status of the cells and the intracellular GSH levels.…”

“…et al 1973, SUGUMARAN and VAIDYANATHAN 1978, MINGOT et al 1999. Thick solid arrows indicate the most likely PA degradation pathway in P. chrysogenum (ISONO 1954, ERIKSEN et al 1998 …”

Effect of phenoxyacetic acid on the glutathione metabolism ofPenicillium chrysogenum

“…In high --lactam producer industrial strains 4-OH-POA is not metabolised further (ERIKSEN et al 1994). On the other hand, under penicillin G producing conditions phenylacetic acid (PA) is hydroxylated preferably at position 2 on the benzene ring (ISONO 1954aand 1954b, NYIRI et al 1966, ADLARD et al 1991, ERIKSEN et al 1998) and, especially in P. chrysogenum strains yielding lower levels of penicillin, is metabolised further probably to fumaric acid and acetoacetic acid via the homogentisic acid pathway (ISONO 1954aand 1954b, SUGUMARAN and VAIDYANATHAN, 1978, MINGOT et al 1999. It is worth noting that in this reaction scheme GSH is an indispensable cofactor for maleylacetoacetate isomerase, which catalyses the formation of fumarylacetoacetic acid from maleylacetoacetic acid (SUGUMARAN andVAIDYANATHAN 1978, FERNÁNDEZ-CAÑON andPEÑALVA 1998).…”

Thermochemistry of phenylacetic and monochlorophenylacetic acids

“…Phenylacetic acid, also known as benzeneacetic acid, is used in some perfumes, possessing a honey-like odour and is also used in penicillin production [8,9]. Natural occurrence is derived via enzymatic activity from phenylethylamine [10], an endogenous neuroamine that improves concentration, elevates mood and alleviates depression.…”