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Jean-marc Belin - One of the best experts on this subject based on the ideXlab platform.
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Metabolism of phenylalanine and biosynthesis of styrene in Penicillium camemberti.
J Dairy Res Journal of Dairy Research, 2007Co-Authors: Yves Pagot, Florence Husson, Jean-marc Belin, Henryeric SpinnlerAbstract:The occurrence of styrene in food may be an important aroma defect (celluloid odour), even at very low concentrations (Miltz et al. 1980) causing consumer rejection and is therefore a problem for the food industry. We examined the biosynthetic pathway leading to styrene formation by Penicillium camemberti using labelled compounds. As styrene is strongly hydrophobic and volatile, we first had to develop a continuous extraction process. Using resins XAD2 it was reasonable to suspect phenylalanine (Phe) as the precursor. The addition of Phe marked with 13C on the ring provokes the accumulation of labelled styrene. The enzyme activities involved were also tentatively measured. Styrene appears to be synthesized from phenylalanine by phenylalanine ammonia-lyase activity followed by a decarboxylation catalysed by a cinnamic acid decarboxylase.
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Influence of medium composition and structure on the biosynthesis of the natural flavour 1-octen-3-ol by Penicillium camemberti
Process Biochemistry, 2005Co-Authors: Florence Husson, Selim Kermasha, Krum Nikolov Krumov, Eliane Cases, Philippe Cayot, Barbara Bisakowski, Jean-marc BelinAbstract:Biomass production of Penicillium camemberti was investigated in selected media, including synthetic media supplemented with either linoleic acid or soybean oil and a dairy medium containing soybean oil and found to be 6.5, 8.3 and 61 g/l, respectively. The presence of soybean oil in the synthetic medium enhanced the production of 1-octen-3-ol, in vitro, by a factor of 8 compared to that obtained with the same synthetic medium containing linoleic acid. The use of the dairy medium in its liquid form or in its acid-gellified milk state as culture media enhanced the production, in vitro, of 1-octen-3-ol by 1.2- and three-fold, respectively, by the enzymic extracts obtained from the biomasses of P. camemberti compared to that found using the synthetic medium containing linoleic acid. However, the enzymatic production of 1-octen-3-ol by the P. camemberti extracts obtained using the dairy media was lower than that found using the synthetic medium supplemented with soybean oil.
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effect of linoleic acid induction on the production of 1 octen 3 ol by the lipoxygenase and hydroperoxide lyase activities of Penicillium camemberti
Journal of Molecular Catalysis B-enzymatic, 2002Co-Authors: Florence Husson, Selim Kermasha, Marie Thomas, Jean-marc BelinAbstract:The effect of induction by linoleic acid on the biomass production, glucose consumption, change in pH values and 1-octen-3-ol profile were investigated during the growth of Penicillium camemberti. The results showed that the presence of 1 g of linoleic acid per liter of culture medium increased the biomass from 3.0 to 7.0 g/l. In addition, incubation of crude enzymatic extracts, obtained from induced and non-induced P. camemberti cultures, indicated that the amount of 1-octen-3-ol produced by the induced enzymatic extract was approximately twice compared to that obtained by the non-induced one. The presence of 0.5 g linoleic acid in the culture medium resulted in the generation of 1.8 μg 1-octen-3-ol per mg protein as opposed to 0.8 μg 1-octen-3-ol per mg protein obtained using 1.0 mg linoleic acid. Moreover, the bioconversion of the 10-hydroperoxide of linoleic acid into 1-octen-3-ol by the enzymatic extract obtained from the induced microbial biomass was twice as high as that obtained with the non-induced one, corresponding to 9.0 and 4.6 μg 1-octen-3-ol per mg protein, respectively.
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Comparison of Volatile Flavor Compounds Produced by Ten Strains of Penicillium camemberti Thom
Journal of Dairy Science, 1993Co-Authors: Nathalie Jollivet, Jean-marc Belin, Yves VayssierAbstract:Abstract Volatile compounds produced by Penicillium camemberti Thom in a milk culture medium were identified using gas chromatography coupled with mass spectrometry. Volatile compounds were mainly methyl ketones and their corresponding secondary alcohols, fatty acids, and the alcohols 3-methylbutanol, 2-methylpropanol, 3-octanol, and 1-octen-3-ol. Comparison of 10 strains of P. camemberti Thom resulted in their being grouped into 6 aromatic strain groups, This grouping seems to be useful for the selection of strains for cheese making.
Florence Husson - One of the best experts on this subject based on the ideXlab platform.
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biocatalysis with hydroperoxide lyase in extracts from Penicillium camemberti in neat organic solvent media
Biocatalysis and Biotransformation, 2013Co-Authors: Watchareeya Kuldamrong, Florence Husson, Selim KermashaAbstract:AbstractBiocatalysis with hydroperoxide lyase (HPL) in extracts from Penicillium camemberti, in neat organic solvent media has been investigated. The effects of reaction conditions including organic solvent mixtures, initial water activity (aw) and reaction temperature as well as the effect of the lyoprotectants, KCl and dextran 1 kDa, on HPL activity were studied. The addition of KCl to the enzymatic extract (70:1 protein, w/w) prior to lyophilization, enhanced HPL activity 6.53-fold. In contrast, the presence of dextran at a ratio of 8:1 decreased the enzymatic activity. Using hexane as the reaction medium, with an initial aw of 0.1 and 0.5, the HPL specific activity was determined to be as 6.3 and 65.9 nmol converted 10-HPOD/mg protein/min, for the enzymatic extract without and with KCl present, respectively. Although HPL enzymatic extract with KCl showed a relatively low optimum reaction temperature (45°C) compared to 55°C without KCl, it exhibited a 2.51- and 2.78-fold higher thermal stability at 60 ...
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Immobilization of an enzymatic extract from Penicillium camemberti containing lipoxygenase and hydroperoxide lyase activities
Journal of Molecular Catalysis B: Enzymatic, 2008Co-Authors: Colin Eric Hall, Florence Husson, Salwa Karboune, Selim KermashaAbstract:An enzymatic extract from Penicillium camemberti, containing lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities, was immobilized on oxirane acrylic beads, Eupergit C and Eupergit C250L-iminodiacetic acid (IDA). The optimum pH for LOX activity was determined to be 4.0 and 6.0 for the free enzyme extract and 6.0 for the immobilized one, whereas that for the HPL activity was 4.0 and 6.0 for the immobilized and free extracts. The optimal reaction temperature for LOX activity was 30 and 55 °C for the free and immobilized enzyme extracts, respectively, whereas the HPL activity showed its optima at 45 and 30 °C, for the free and immobilized extracts, respectively. The immobilization of the enzymatic extract dramatically enhanced the thermostability of LOX and HPL activities. In term of enzymatic stability, the lyophilized immobilized extract showed that its HPL activity at 4 °C was more stable than that of LOX. The results indicated a decrease and an increase in enzyme efficiency for LOX and HPL activity, respectively, upon immobilization.
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Stabilization of an enzymatic extract from Penicillium camemberti containing lipoxygenase and hydroperoxide lyase activities
Process Biochemistry, 2008Co-Authors: Colin Eric Hall, Salwa Karboune, Florence HussonAbstract:The stabilization of an enzymatic extract, obtained from Penicillium camemberti containing lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities, was investigated using selected additives. Although the addition of KCl (86%, w/w) to the enzymatic extract decreased slightly (7%) the LOX activity, it increased HPL activity by 2.25 fold; however, the addition of dextran resulted in the inactivation of both enzymatic activities. The stability of the solid lyophilized enzymatic extract was greater in the presence of KCl than that without it, with ∼100% residual activity after 8 and 4 weeks of storage at −80 °C, for LOX and HPL, respectively. The rate constants of inactivation (Kinactivation) and the C(1/2) values showed that glycine was the most appropriate additive for LOX and HPL. All other investigated additives, including glycerol, polyethylene glycol, mannitol and sucrose, demonstrated a higher inactivation effect on both enzymatic activities. Although most of the investigated additives provided certain enhancement of the thermostability of LOX activity but not for HPL, a high thermostability (80 °C, 1 h) was obtained with 5% mannitol for LOX and 10% glycine for HPL.
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Metabolism of phenylalanine and biosynthesis of styrene in Penicillium camemberti.
J Dairy Res Journal of Dairy Research, 2007Co-Authors: Yves Pagot, Florence Husson, Jean-marc Belin, Henryeric SpinnlerAbstract:The occurrence of styrene in food may be an important aroma defect (celluloid odour), even at very low concentrations (Miltz et al. 1980) causing consumer rejection and is therefore a problem for the food industry. We examined the biosynthetic pathway leading to styrene formation by Penicillium camemberti using labelled compounds. As styrene is strongly hydrophobic and volatile, we first had to develop a continuous extraction process. Using resins XAD2 it was reasonable to suspect phenylalanine (Phe) as the precursor. The addition of Phe marked with 13C on the ring provokes the accumulation of labelled styrene. The enzyme activities involved were also tentatively measured. Styrene appears to be synthesized from phenylalanine by phenylalanine ammonia-lyase activity followed by a decarboxylation catalysed by a cinnamic acid decarboxylase.
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Influence of medium composition and structure on the biosynthesis of the natural flavour 1-octen-3-ol by Penicillium camemberti
Process Biochemistry, 2005Co-Authors: Florence Husson, Selim Kermasha, Krum Nikolov Krumov, Eliane Cases, Philippe Cayot, Barbara Bisakowski, Jean-marc BelinAbstract:Biomass production of Penicillium camemberti was investigated in selected media, including synthetic media supplemented with either linoleic acid or soybean oil and a dairy medium containing soybean oil and found to be 6.5, 8.3 and 61 g/l, respectively. The presence of soybean oil in the synthetic medium enhanced the production of 1-octen-3-ol, in vitro, by a factor of 8 compared to that obtained with the same synthetic medium containing linoleic acid. The use of the dairy medium in its liquid form or in its acid-gellified milk state as culture media enhanced the production, in vitro, of 1-octen-3-ol by 1.2- and three-fold, respectively, by the enzymic extracts obtained from the biomasses of P. camemberti compared to that found using the synthetic medium containing linoleic acid. However, the enzymatic production of 1-octen-3-ol by the P. camemberti extracts obtained using the dairy media was lower than that found using the synthetic medium supplemented with soybean oil.
Y. Prigent - One of the best experts on this subject based on the ideXlab platform.
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carbon and nitrogen substrates consumption ammonia release and proton transfer in relation with growth of geotrichum candidum and Penicillium camemberti on a solid medium
Journal of Biotechnology, 2002Co-Authors: M Aldarf, A. Amrane, Y. PrigentAbstract:Abstract It is difficult to determine fungal biomass growing on a solid medium directly. Therefore, indirect ways of measuring this growth have to be used instead. For this purpose, the kinetics of growth, of substrate consumption and of release of metabolites must be correlated. This has been carried out for Geotrichum candidum and Penicillium camemberti growing on a gelified lactic acid+peptone medium. Peptone was shown to be preferred by G. candidum as a carbon and energy source, in contrast to the behaviour observed for P. camemberti . At the end of growth, G. candidum released about three times more ammonia than P. camemberti . In both cases, the total number of protons consumed during growth was close to the sum of the number of moles of metabolized lactic acid and formed ammonia. During the main part of growth, constant biomass on substrate yields (peptone, lactic acid) was observed for both microorganisms. Therefore, in pure solid cultures, the biomass concentration of both species could be deduced either from ΔpH or from the reduction of substrates. From the above, an estimate of G. candidum biomass in mixed culture could be derived from the determination of ammonia release.
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carbon and nitrogen substrates consumption ammonia release and proton transfer in relation with growth of geotrichum candidum and Penicillium camemberti on a solid medium
Journal of Biotechnology, 2002Co-Authors: M Aldarf, A. Amrane, Y. PrigentAbstract:It is difficult to determine fungal biomass growing on a solid medium directly. Therefore, indirect ways of measuring this growth have to be used instead. For this purpose, the kinetics of growth, of substrate consumption and of release of metabolites must be correlated. This has been carried out for Geotrichum candidum and Penicillium camemberti growing on a gelified lactic acid+peptone medium. Peptone was shown to be preferred by G. candidum as a carbon and energy source, in contrast to the behaviour observed for P. camemberti. At the end of growth, G. candidum released about three times more ammonia than P. camemberti. In both cases, the total number of protons consumed during growth was close to the sum of the number of moles of metabolized lactic acid and formed ammonia. During the main part of growth, constant biomass on substrate yields (peptone, lactic acid) was observed for both microorganisms. Therefore, in pure solid cultures, the biomass concentration of both species could be deduced either from DeltapH or from the reduction of substrates. From the above, an estimate of G. candidum biomass in mixed culture could be derived from the determination of ammonia release.
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Growth of Geotrichum candidum and Penicillium camemberti Cultivated on Liquid Media Correlated with Ammonia and Methanethiol Emission
Acta Biotechnologica, 2001Co-Authors: A. Amrane, Y. PrigentAbstract:The growth of Geotrichum candidum and Penicillium camemberti plays an important role in the ripening of Camembert-type cheeses, but the monitoring of the corresponding kinetics for fungal cocultures on solid media appears difficult. Continuous and non-intrusive methods to characterize the growth of both species (like the monitoring of the emissions of ammonia and volatile sulphur compounds) may be highly relevant, under the condition that such emissions could be correlated with growth. This would be easier to investigate in submerged culture, since total biomass concentration is known to vary in proportion to broth turbidity. For this reason, growth kinetics, ammonia and flavour gas emission of both Geotrichum candidum and Penicillium camemberti grown separately in submerged cultures under the conditions of low aeration rate and uncontrolled pH were continuously recorded. In the basal medium (peptone + lactate supplemented with both glutamic acid and methionine [1 g/l] each), no significant gas emission was observed during the growth of both fungi. Ammonia and sulphur gas emissions by G. candidum were a little stimulated by supplementing the basal medium with trace elements, and, at a larger extent, by the addition of inorganic phosphate: Such a gaseous emission took place at the end of the growth phase of G.candidum. Irrespective of the basal medium supplementation, no significant emission of ammonia and sulphur gas was observed during the growth of P.camemberti. For the media and strains used, ammonia and volatile sulphur compounds emissions unequivocally showed the growth of Geotrichum candidum.
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kinetics of growth and medium de acidification for geotrichum candidum and Penicillium camemberti cultivated on complex liquid media
World Journal of Microbiology & Biotechnology, 1999Co-Authors: A. Amrane, F Plihon, Y. PrigentAbstract:Growth kinetics of Geotrichum candidum and Penicillium camemberti in submerged cultures under conditions of low aeration rate and uncontrolled pH were continuously recorded turbidimetrically. In these conditions the exponential growth phase was short, and ceased at a total biomass concentration of about 0.5 gl−1 for G. candidum and 0.8 gl−1 for P. candidum. The succeeding linear growth phase was also short, and its end corresponded to a biomass of 1.5 and 2.5 gl−1 for G. candidum and P. camemberti respectively. A fair growth was recorded for P. camemberti on peptone-lactate medium, but G. candidum required addition of trace elements. For neither of these species growth was stimulated by growth factors of yeast extract. In peptone-lactate medium, the final pH did not depend on supplementation: 8–8.4 was recorded for G. candidum and 8.7–8.8 for P. camemberti.
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proton transfer in relation to growth of geotrichum candidum and Penicillium camemberti in synthetic liquid media
Enzyme and Microbial Technology, 1999Co-Authors: A. Amrane, F Plihon, Y. PrigentAbstract:Since continuous monitoring of mycelial growth in liquid media is still difficult, indirect ways of calculating on-line the total biomass concentration are of great interest. Growth of fungi like G. candidum and P. camemberti (widely used in cheese ripening) in liquid media may induce large pH changes. When nitrogen is supplied by glutamic acid (also able to supply carbon), an alkalinization of the medium is recorded, irrespective of the presence of an extra carbon source; when nitrogen is provided by lysine (unable to supply carbon) supplemented by glucose, an acidification is observed, Depending on the amino acid used, the pH variation is linearly correlated with growth (glutamic acid) or not (lysine). A simple model predicts that the concentration of proton transferred vary in proportion to that of the total biomass: the former variable may be easily derived from the pH history and the buffer capacity of the medium. For all combinations of nitrogen and carbon sources tested, the model has been experimentally validated for both microorganisms during the main growth period: following a preliminary calibration, fungal growth may be monitored on-line by pH measurements. 1999 Elsevier Science Inc. All rights reserved.
Selim Kermasha - One of the best experts on this subject based on the ideXlab platform.
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biocatalysis with hydroperoxide lyase in extracts from Penicillium camemberti in neat organic solvent media
Biocatalysis and Biotransformation, 2013Co-Authors: Watchareeya Kuldamrong, Florence Husson, Selim KermashaAbstract:AbstractBiocatalysis with hydroperoxide lyase (HPL) in extracts from Penicillium camemberti, in neat organic solvent media has been investigated. The effects of reaction conditions including organic solvent mixtures, initial water activity (aw) and reaction temperature as well as the effect of the lyoprotectants, KCl and dextran 1 kDa, on HPL activity were studied. The addition of KCl to the enzymatic extract (70:1 protein, w/w) prior to lyophilization, enhanced HPL activity 6.53-fold. In contrast, the presence of dextran at a ratio of 8:1 decreased the enzymatic activity. Using hexane as the reaction medium, with an initial aw of 0.1 and 0.5, the HPL specific activity was determined to be as 6.3 and 65.9 nmol converted 10-HPOD/mg protein/min, for the enzymatic extract without and with KCl present, respectively. Although HPL enzymatic extract with KCl showed a relatively low optimum reaction temperature (45°C) compared to 55°C without KCl, it exhibited a 2.51- and 2.78-fold higher thermal stability at 60 ...
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Immobilization of an enzymatic extract from Penicillium camemberti containing lipoxygenase and hydroperoxide lyase activities
Journal of Molecular Catalysis B: Enzymatic, 2008Co-Authors: Colin Eric Hall, Florence Husson, Salwa Karboune, Selim KermashaAbstract:An enzymatic extract from Penicillium camemberti, containing lipoxygenase (LOX) and hydroperoxide lyase (HPL) activities, was immobilized on oxirane acrylic beads, Eupergit C and Eupergit C250L-iminodiacetic acid (IDA). The optimum pH for LOX activity was determined to be 4.0 and 6.0 for the free enzyme extract and 6.0 for the immobilized one, whereas that for the HPL activity was 4.0 and 6.0 for the immobilized and free extracts. The optimal reaction temperature for LOX activity was 30 and 55 °C for the free and immobilized enzyme extracts, respectively, whereas the HPL activity showed its optima at 45 and 30 °C, for the free and immobilized extracts, respectively. The immobilization of the enzymatic extract dramatically enhanced the thermostability of LOX and HPL activities. In term of enzymatic stability, the lyophilized immobilized extract showed that its HPL activity at 4 °C was more stable than that of LOX. The results indicated a decrease and an increase in enzyme efficiency for LOX and HPL activity, respectively, upon immobilization.
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Influence of medium composition and structure on the biosynthesis of the natural flavour 1-octen-3-ol by Penicillium camemberti
Process Biochemistry, 2005Co-Authors: Florence Husson, Selim Kermasha, Krum Nikolov Krumov, Eliane Cases, Philippe Cayot, Barbara Bisakowski, Jean-marc BelinAbstract:Biomass production of Penicillium camemberti was investigated in selected media, including synthetic media supplemented with either linoleic acid or soybean oil and a dairy medium containing soybean oil and found to be 6.5, 8.3 and 61 g/l, respectively. The presence of soybean oil in the synthetic medium enhanced the production of 1-octen-3-ol, in vitro, by a factor of 8 compared to that obtained with the same synthetic medium containing linoleic acid. The use of the dairy medium in its liquid form or in its acid-gellified milk state as culture media enhanced the production, in vitro, of 1-octen-3-ol by 1.2- and three-fold, respectively, by the enzymic extracts obtained from the biomasses of P. camemberti compared to that found using the synthetic medium containing linoleic acid. However, the enzymatic production of 1-octen-3-ol by the P. camemberti extracts obtained using the dairy media was lower than that found using the synthetic medium supplemented with soybean oil.
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effect of linoleic acid induction on the production of 1 octen 3 ol by the lipoxygenase and hydroperoxide lyase activities of Penicillium camemberti
Journal of Molecular Catalysis B-enzymatic, 2002Co-Authors: Florence Husson, Selim Kermasha, Marie Thomas, Jean-marc BelinAbstract:The effect of induction by linoleic acid on the biomass production, glucose consumption, change in pH values and 1-octen-3-ol profile were investigated during the growth of Penicillium camemberti. The results showed that the presence of 1 g of linoleic acid per liter of culture medium increased the biomass from 3.0 to 7.0 g/l. In addition, incubation of crude enzymatic extracts, obtained from induced and non-induced P. camemberti cultures, indicated that the amount of 1-octen-3-ol produced by the induced enzymatic extract was approximately twice compared to that obtained by the non-induced one. The presence of 0.5 g linoleic acid in the culture medium resulted in the generation of 1.8 μg 1-octen-3-ol per mg protein as opposed to 0.8 μg 1-octen-3-ol per mg protein obtained using 1.0 mg linoleic acid. Moreover, the bioconversion of the 10-hydroperoxide of linoleic acid into 1-octen-3-ol by the enzymatic extract obtained from the induced microbial biomass was twice as high as that obtained with the non-induced one, corresponding to 9.0 and 4.6 μg 1-octen-3-ol per mg protein, respectively.
Christophe Monnet - One of the best experts on this subject based on the ideXlab platform.
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dynamics of Penicillium camemberti growth quantified by real time pcr on camembert type cheeses under different conditions of temperature and relative humidity
Journal of Dairy Science, 2013Co-Authors: Daniel Picque, Marie Noelle Leclercqperlat, Sandra Teresita Martin Del Campo Barba, Christophe MonnetAbstract:Penicillium camemberti plays a major role in the flavor and appearance of Camembert-type cheeses. However, little is known about its mycelium growth kinetics during ripening. We monitored the growth of P. camemberti mycelium in Camembert-type cheeses using real-time PCR in 4 ripening runs, performed at 2 temperatures (8 and 16°C) and 2 relative humidities (88 and 98%). These findings were compared with P. camemberti quantification by spore concentration. During the first phase, the mycelium grew but no spores were produced, regardless of the ripening conditions. During the second phase, which began when lactose was depleted, the concentration of spores increased, especially in the cheeses ripened at 16°C. Sporulation was associated with a large decrease in the mycelial concentration in the cheeses ripened at 16°C and 98% relative humidity. It was hypothesized that lactose is the main energy source for the growth of P. camemberti mycelium at the beginning of ripening and that its depletion would trigger stress, resulting in sporulation.