Penicillium Camemberti Research Articles

Penicillium rubrum and Penicillium biforme, new sources of rugulovasines A and B.

An isolate of Penicillium biforme Thom produced rugulovasines A and B. An isolate of Penicillium rubrum Stoll produced rugulovasines A and B and also chlororugulovasines A and B. Both fungi represent new sources of the rugulovasines.

Cyclopiazonic acid production by Penicillium camemberti Thom and natural occurrence of this mycotoxin in cheese.

Every Penicillium camemberti strain freshly isolated from 20 commercial cheese brands produced cyclopiazonic acid in two culture media at 25, 13, and 4 degrees C; the toxin yield was greatly dependent on the strain and environmental parameters (medium, temperature, and incubation time). The toxigenic ability appeared as a log-normal distribution. This mycotoxin was found in the crust (0.05 to 0.1 microgram/g in three samples, 0.1 to 0.2 microgram/g in five samples, and 0.4, 1, and 1.5 microgram/g in three other samples) but not in the inner part. When its acute toxicity is considered, doses eventually ingested by consumers are very low (lower than 4 microgram). Means for prevention are discussed. A highly toxigenic strength and rate appear to be necessary features leading to natural contamination in cheeses. The distribution of toxigenic ability makes possible without delay a choice of weakly toxic strains.

Gentian Violet as a Possible Fungal Inhibitor in Poultry Feed: Plate Assays on its Antifungal Activity

The effect of gentian violet as a fungal inhibitor was studied on five selected fungal species—Aspergillus flavus, Aspergillus fumigatus, Candida albicans, Fusarium moniliforme and Penicillium camemberti. Seventeen other chemicals were also studied and compared. These included: acetic acid, benzoic acid, calcium propionate, cupric sulfate, propionic acid, propylene glycol, sodium propionate, sorbic acid and others. Standard pour plate technique with medium containing various levels of the tested chemical was used. Gentian violet inhibited fungal growth at lower concentrations than did most of the other tested chemicals.Three commercial fungistatic feed additives with different active ingredients were compared for their antifungal activity and the product containing gentian violet was shown to be superior.

Pyruvate carboxylase from Penicillium camemberti 5. Regulation of the enzyme activity by the ratio of ATP and ADP

1. 1. Pyruvate carboxylase from Penicillium camemberti was studied on a partially purified preparation using kinetic methods. 2. 2. The equilibrium concentrations of all ions in the dissociation equilibrium between magnesium, ATP, and ADP were calculated. The enzyme activity was determined as a function of the actual concentrations of substiates and inhibitors. 3. 3. The apparent Michaelis constant for MgATP 2− was 0·24 m M at pH 8·0 and under a defined concentration of all other ions. Magnesium did not influence the K m value of MgATPsu2− but diminished the V max. MgADP − is a competitive inhibitor against MgATP 2− ( K i = 0.17 m M). 4. 4. The dependence of the pyruvate carboxylase activity on the energy charge of the adenylate pool, as calculated from the values of K i for MgADP − and K m for MgATP 2−, coincides with the experimentally derived results.

Attraction of the Grain Mite, Acarus siro (Acarina: Acaridae), to Solvent Extracts of Fungi Associated with Stored-Food Commodities1

Eight species of 2-week-old fungi associated with cheese and grain were extracted with absolute ethyl alcohol, benzene, chloroform, and Skelly B hexane. The extracts were tested for their capacity to attract Acarus siro L. and were evaluated for their attractive potential, solvent effectiveness, and concentration effects. Solvent extractions of the fungi elicited varying degrees of mite response, but the results indicated that chemical extraction of attractive volatiles was possible for all fungi tested. Data for Aspergillus repens indicated that this fungus was the most effective of the 8 fungi tested where a maximum mite response of 65% to the benzene extract at 4× was observed. Eleven concentrations of benzene extracts of A. repens, A. ruber , and Penicillium camemberti were tested to determine cut-off points for maximal and minimal mite response. Data for A. repens and A. ruber resembled those of linear regression.

Response of the Grain Mite, Acarus siro (Acarina: Acaridae), to Fungi Associated with Stored-Food Commodities1

Observations were recorded on the response of Acarus siro L. to fungi associated with such stored foods as cheese and grain. An arena-testing technique for the evaluation of mite attraction and feeding response is described. Disc segments of agar cultures of 17 species of fungi were exposed in the arena test chamber. Mites responded to all species of fungi with a maximum response occurring within 3 hours of exposure for most species tested. The degree of response indicated little variation between cultures ranging in age from 3 days to 4 weeks. Choice tests between 2 species of fungi indicated that A. siro often had definite preferences between similarly attractive fungi. The greatest attraction and feeding response was demonstrated for Penicillium camemberti Thorn, Aspergillus flavus Link, and A. repens (Corda) Debary, and the least response observed for Trichoderma lignorum (Tode) Harz and Fusarium monilifonnc Sheldon.

Regulation of pyruvate carboxylase of penicillium camemberti by the adenylate system

The chapter focuses on the physiology and metabolic controls of fungal growth. The chapter considers those areas of fungal physiology and biochemistry that have been researched in depth, and attempts to indicate areas that are unexplored. In addition, it explains the modulation of fungal metabolism in response to growth conditions. Palpable absences from this chapter are references to “secondary” or “shunt” metabolism, at which fungi are most adept, and to the metabolic control of differentiation: in both of these areas, notable advances have been made in recent years. The chapter also considers some aspects of macromolecule synthesis, particularly the synthesis of RNA and protein, in terms of overall rate-limiting processes in fungal growth. Strain instability also has plagued the efforts of the fungal physiologist, and this has been an acute problem in relation to the Fungi Imperfecti many of which are of major interest in the context of commercial fermentations.

The role of fungi in cheese ripening

Fungi are important in the manufacture of two types of cheese—blue-veined cheeses, and Camembert and Brie. Among the former are Roquefort, Gorgonzola and Stilton, dependent on the mold Penicillium roqueforti and the bacterium Streptococcus lactis. Camembert and Brie require Penicillium camemberti and lactic acid- producing streptococci; the mold Oospora lactis and the organism Bacterium linens may also play roles in their manufacture.

The Intracellular Enzymes of Lower Fungi, Especially those of Penicillium Camemberti

The Intracellular Enzymes of Lower Fungi, Especially those of Penicillium Camemberti