Penicillium Camemberti Research Articles

Proteolysis in Irish farmhouse Camembert cheese during ripening.

Proteolysis in an Irish farmhouse Camembert cheese was studied during 10weeks of ripening. Urea-polyacrylamide gel electrophoresis of pH 4.6-insoluble fractions of cheese showed the degradation of caseins, initially due to the action of chymosin and plasmin and later due to Penicillium camemberti proteinases. Proteolytic specificities of Penicillium camemberti proteinases on the caseins in milk hydrolysates were determined and 64, 6, 28, and 2 cleavage sites were identified in αs1 -, αs2 -, β-, and κ-casein, respectively. Proteolysis in cheese was studied and peptides produced were determined and compared to the cleavage specificities of Penicillium camemberti proteinases. Regions most susceptible to proteolysis were 1-40, 79-114, and 168-199 in αs1 -casein; 42-79 and 97-116 in αs2 -casein; 40-57, 101-125, 143-189, and 165-209 in β-casein; and 31-81 and 124-137 in κ-casein. The present study describes in detail the proteolytic action of proteinases from Penicillium camemberti in Camembert cheese during ripening. PRACTICAL APPLICATIONS: Camembert cheese is a major international cheese variety, made in many countries around the world. The ripening of the cheese involves many biochemical changes and this study provides new information on peptides produced during ripening. Penicillium camemberti is an important mold used in the production of this type of cheese and detailed information is provided on the action of its enzymes on the caseins. Data reported in this study furthers the understanding of the ripening of Camembert cheese.

Penicillium camemberti galacturonate reductase: C-1 oxidation/reduction of uronic acids and substrate inhibition mitigation by aldonic acids

The enzyme galacturonate oxidoreductase PcGOR from Penicillium camemberti reduces the C-1 carbon of D-glucuronate and C-4 epimer D-galacturonate to their corresponding aldonic acids, important reactions in both pectin catabolism and ascorbate biosynthesis. PcGOR was active on both glucuronic acid and galacturonic acid, with similar substrate specificities (kcat/Km) using the preferred co-substrate NADPH. Substrate acceptance extended to lactone congeners, and D-glucurono-3,6-lactone was converted to L-gulono-1,4-lactone, an immediate precursor of ascorbate. Reaction with glucuronate showed only minor substrate inhibition, and the product L-gulonate and L-gulono-1,4-lactone were both found to be competitive inhibitors with Ki in the low mM range. In contrast, reaction with C-4 epimer galacturonate displayed marked substrate inhibition. Moreover, the product L-galactonate and L-galactono-1,4-lactone were observed to mitigate substrate inhibition by galacturonate, with the lactone having a greater effect than the acid.

Diversity and succession of microbial communities and chemical analysis in dried Lutianus erythropterus during storage

The population, diversity and succession of microbial communities and chemical characteristics of dried crimson snapper (Lutianus erythropterus) during storage for 50 days were investigated. The population of bacteria, yeasts and filamentous fungi in the samples were enumerated by culture methods using appropriate agar media. The amplicons of the 16S rRNA of bacteria and the ITS region of fungi were sequenced and compared with gene libraries to obtain the identity and abundance of microorganisms in the community. Free amino acids and several other chemical characteristics were determined by HPLC and corresponding chemical reaction methods. Before storage, the average counts of bacteria, yeasts and filamentous fungi in the dried fish were 3.2, 2.5 and 2.2 log CFU/g, which increased to 4.6, 3.6 and 3.9 log CFU/g, respectively after storage. Major succession in the bacterial > fungal communities occurred during storage as evidenced by a significant decline in the number and diversity of microbial communities. Predominant bacterial genera were Phytobacteria, Vibrio, Acinetobacter and Macrococcus in the freshly dried fish, which were replaced by Bacillaceae, Halomonas, Lentibacillus, Alkalibacillus after storage. The fungal community of the freshly dried fish consisted of Penicillum > Yamadazyma, Malassezia, Candida and Eurotiales with Penicillum being the most dominant. Penicillium camemberti was the most abundant fungal species in the dried fish before storage with most dominant after storage and accounted for >96% of the abundance. The succession in the microbial community was accompanied by major changes in chemical characteristics with a significant decrease in fat, and an increase in total free amino acids and total volatile basic nitrogen (TVB-N).

Biochemical characteristics of reduced-fat cheese made from high-heat treated goat’s milk supplemented with Penicillium candidum

Novel reduced-fat goat-cheese (R) was produced from high-pasteurized milk using Penicillium candidum as an adjunct. A full-fat goat-cheese (F) from pasteurized milk without mold addition was produced for comparison reasons. Physicochemical analyses of the two cheeses were performed through the 14-d period of ripening. The effect of P.candidum on proteolysis of goat-cheese caseins and the production of hydrophilic and hydrophobic peptides during cheese ripening were investigated. To our knowledge, similar results for reduced-fat, mold-ripened, goat-milk cheeses have not been previously reported before. R-cheese exhibited a higher organoleptic score and developed properties similar to Kopanisti, which is a Protected Designation of Origin Greek soft cheese with specific intense flavour manufactured from raw milk without the use of starters. Moreover, R-cheese had significantly higher moisture, protein in dry matter and water soluble nitrogen contents than F-cheese and was less adhesive. The high-pasteurization improved the texture and cheese yield, while the use of P. candidum as an adjunct improved the flavour, increased and accelerated proteolysis in R-cheese. According to the results, the technology for R-cheese employed in the present study can be easily adopted and could be used to produce a reduced-fat goat-cheese.

Rapid Phenotypic and Metabolomic Domestication of Wild Penicillium Molds on Cheese.

Fermented foods provide novel ecological opportunities for natural populations of microbes to evolve through successive recolonization of resource-rich substrates. Comparative genomic data have reconstructed the evolutionary histories of microbes adapted to food environments, but experimental studies directly demonstrating the process of domestication are lacking for most fermented food microbes. Here, we show that during adaptation to cheese, phenotypic and metabolomic traits of wild Penicillium molds rapidly change to produce domesticated phenotypes with properties similar to those of the industrial cultures used to make Camembert and other bloomy rind cheeses. Over a period of just a few weeks, populations of wild Penicillium strains serially passaged on cheese had reduced pigment, spore, and mycotoxin production. Domesticated strains also had a striking change in volatile metabolite production, shifting from production of earthy or musty volatile compounds (e.g., geosmin) to fatty and cheesy volatiles (e.g., 2-nonanone, 2-undecanone). RNA sequencing demonstrated a significant decrease in expression of 356 genes in domesticated strains, with an enrichment of many secondary metabolite production pathways in these downregulated genes. By manipulating the presence of neighboring microbial species and overall resource availability, we demonstrate that the limited competition and high nutrient availability of the cheese environment promote rapid trait evolution of Penicillium molds.IMPORTANCE Industrial cultures of filamentous fungi are used to add unique aesthetics and flavors to cheeses and other microbial foods. How these microbes adapted to live in food environments is generally unknown as most microbial domestication is unintentional. Our work demonstrates that wild molds closely related to the starter culture Penicillium camemberti can readily lose traits and quickly shift toward producing desirable aroma compounds. In addition to experimentally demonstrating a putative domestication pathway for P. camemberti, our work suggests that wild Penicillium isolates could be rapidly domesticated to produce new flavors and aesthetics in fermented foods.

Metabolomics analyses of the combined effects of lactic acid bacteria and Penicillium camemberti on the generation of volatile compounds in model mold-surface-ripened cheeses

The flavor of white mold cheese is attributed to the formation of aroma compounds associated with complex effects of bacteria and fungi, resulting in difficulties in flavor design for new cheeses. This study aimed to identify the microbial basis of flavor by identifying the combined effects of LD type lactic acid bacteria (LAB) starters and Penicillium camemberti on the generation of metabolites during the ripening process. Metabolomics analyses were performed on three model cheeses: normal cheese, no-mold cheese with only LAB, and no-LAB cheese with only white mold. Aroma compounds and their potential precursors were analyzed using headspace solid-phase microextraction-gas chromatography/mass spectrometry (GC/MS) and solvent extraction-GC/MS, respectively. Measurements during ripening and multivariate analyses on the data revealed the relationship between the microorganisms and metabolic activities, which were classified into four groups: metabolites generated by LAB and degraded by P.camemberti; metabolites generated by P.camemberti and degraded or inhibited by LAB; metabolites generated by P.camemberti and enhanced by LAB; and metabolites exhibiting no interaction between P.camemberti and LAB. The characteristic compounds in LAB and white mold cheeses were mainly products of sugar and protein metabolism, respectively. The involvement of fatty acids, methyl ketones, and secondary alcohol metabolic pathways in the late-ripening stage was confirmed, and the profiles of volatile metabolites contributing to the characteristic aroma of the white mold cheese in the fermentation process were also confirmed.

Evaluation of alginate and zein films as a carrier of natamycin to increase the shelf life of kashar cheese

The aim of this study was to develop alginate and zein films containing natamycin, a natural antifungal agent, in order to limit/prevent the mould growth on the surface of kashar cheeses. The films were prepared by casting, and characterized in terms of antimicrobial and mechanical properties (tensile strength, elongation‐at‐break, and elastic modulus), and their morphology was examined by scanning electron microscopy (SEM). Mechanical properties of the zein films were found to be weaker than the alginate films. SEM analysis indicated that alginate films have a more regular structure than zein films, and a more homogenous distribution was observed at lower concentrations of natamycin. The antifungal activities of both films increased as the natamycin concentration (100, 200, 500, 1000, 2000, and 4000 ppm) increased; however, alginate films exhibited relatively high antifungal activity. The effects of films on the shelf life of kashar cheeses inoculated with Aspergillus niger and Penicillium camemberti were investigated during their storage under refrigerator conditions for 45 days. At high‐natamycin concentrations, zein films showed higher antifungal activity against both fungi at the end of the storage period.

Biocatalytic Synthesis of Natural Dihydrocoumarin by Microbial Reduction of Coumarin

Dihydrocoumarin is a natural product of great relevance for the flavour industry. In this work, we describe a study on the biotransformation of the toxic compound coumarin into natural dihydrocoumarin, recognized as safe for food aromatization. To this end, we screened a variety of yeasts and filamentous fungi, isolated from different sources, in order to evaluate their ability to reduce selectively the conjugated double bond of coumarin. Moreover, since coumarin induces cytotoxicity and therefore inhibits cell growth as well as the cell metabolic activity, we tested out different substrate concentrations. All strains were able to convert the substrate, although showing very different conversion rates and different sensitivity to the coumarin concentration. In particular, the yeasts Torulaspora delbrueckii, Kluyveromyces marxianus and the fungus Penicillium camemberti displayed the higher activity and selectivity in the substrate transformation. Among the latter strains, Kluyveromyces marxianus presented the best resistance to substrate toxicity, allowing the biotransformation process even with coumarin concentration up to 1.8 g/L.

Kinetic study of isopropyl palmitate synthesis catalyzed by lipases immobilized on a magnetic copolymer support

Synthesis experiments of isopropyl palmitate, an emollient ester, were conducted using various reactant molar ratios and enzyme concentrations. Reactions were catalyzed by Candida rugosa or Penicillium camemberti lipases immobilized on magnetic poly(styrene-co-divinylbenzene). A kinetic model for the esterification reaction was developed based on a ping-pong bi-bi mechanism and validated with the experimental data obtained herein. Systems with different catalysts were compared, and correlations were found between parameters. Satisfactory predictions were obtained through curve fitting (R2 of 0.89 for C. rugosa and R2 of 0.92 for P. camemberti).

Cyclopiazonic acid gene expression as strategy to minimizing mycotoxin contamination in cheese

Expression of genes associated with cyclopiazonic acid (CPA) biosynthesis by Penicillium strains in a cheese-based medium has not been previously studied. To control CPA biosynthesis, it would be useful to understand the changes in gene expression during cheese production and relate them to toxin production. The objective was to evaluate the influence of pH, aw, and temperature on expression of dmaT, which encodes the enzyme dimethylallyl tryptophan synthase involved in the biosynthesis of CPA. We assayed three Penicillium strains, Penicillium commune CBS311 and CBS341 and Penicillium camemberti CBS273, using reverse transcription real-time PCR. Our results showed that the expression patterns of the gene were influenced by strain and environmental conditions. The highest expression for the P. commune strains was observed at pH 6.0, 0.95 aw, at 25 or 30 °C, depending on the strain. In contrast, P. camemberti CBS273 showed a lower dmaT expression with a maximum at 25 °C, pH 5.0 and 0.95 aw. Correlation analysis indicated that the three toxigenic strains showed a strong correlation between the relative expression of the dmaT gene and concentration of CPA under conditions simulating cheese ripening. This method could be used to control CPA production in cheese by detection of dmaT expression.

‘Lipase and protease production of dairy Penicillium sp. on milk‐protein‐based solid substrates’

The lipolytic and proteolytic activity of Penicillium camemberti PC TT033 and Penicillium roqueforti PR G3, cultured on the whey solids or simulated cheese media, were compared under several pH reaction conditions. Lipolytic activity was higher when both strains had been cultured on the whey medium than on the simulated cheese medium, whereas proteolytic activity was less influenced by the culture medium. The relationship between the reaction pH and these enzyme activities was dependent on the culture medium, which suggested that the expression level and balance of isozyme rely on the culture substrate.

Lactobacillus rhamnosus GG improves the sensorial profile of Camembert-type cheese: An approach through flash-profile and CATA

Camembert is a white-mould ripened cheese in which intense proteolysis, caused mainly by the fungus Penicillium candidum, among other factors, leads to a substantial production of aromatic and flavor compounds. The aim of this study was to evaluate the sensory profile of the Camembert-type cheese made from raw milk and from pasteurized milk with or without the addition of Lactobacillus rhamnosus GG. The cheeses were analyzed after 50 days of ripening through a combination of Flash-Profile (n = 15) and Check-All-That-Apply (CATA) (n = 80) sensory methods with global acceptance. The 51 sensory attributes obtained allowed the separation of the samples in three clusters. Through the CATA, a significant difference (p < 0.05) was observed for 21 of the 51 descriptors evaluated. Camembert-type cheese obtained from pasteurized milk with the addition of Lactobacillus rhamnosus GG showed greater global acceptance when compared to the other cheeses, which did not significantly differ between them. The addition of the adjunct culture was a good technological strategy to improve the sensory characteristics of industrial Camembert-type cheese obtained from pasteurized milk, bringing its sensory attributes closer to the ideal product and the sensorial characteristics of a cheese produced with raw milk, but in a standardized and microbiologically safe way.

Expanded cardboard waste sorting and occupational exposure to microbial species

Member states of the European Union have to maximize recycling. The current, Danish cardboard recycling system can be improved by increasing the kinds of cardboard products that can be recycled to include e.g. used beverage cartons and pizza boxes (i.e. an expanded cardboard fraction (ECF)). This study aims to obtain knowledge about exposure to airborne endotoxin and microorganisms at species level at different collection frequencies of ECF, and whether an increase in waste sorted fractions means that each waste fraction is collected less frequently. Bacterial and endotoxin concentrations were associated significantly with temperature inside the waste containers and endotoxin and fungal exposures with collection frequency. The concentration of fungi was highest at the truck back and for reduced collection frequencies. The geometric mean diameters of particles with bacteria were between 3.0 and 5.2 μm and with fungi between 3.8 μm and 6.0 μm. In total, 81 and 25 different bacterial and fungal species were found at the waste receiving plant, respectively. Work with ECF caused exposures to food-related microorganisms (e.g. Arthrobacter arilaitensis and Penicillium camemberti), potential pathogens (e.g. Bacillus cereus, Salmonella sp. and P. expansum), and commensal bacteria. Bacillus cereus and Salmonella were found in the particle size fraction often being swallowed. Workers collecting EFC will be at risk of being exposed to microbial species that normally are related to residual waste. It seems to be advisable with an EFC collection frequency shorter than eight weeks. However, introduction of new waste fractions has generally been associated with reduced collection frequencies.

Unprecedented Enzymatic Synthesis of Perfectly Structured Alternating Copolymers via "Green" Reaction Cocatalyzed by Laccase and Lipase Compartmentalized within Supramolecular Complexes.

This study describes the first use of laccase-lipase enzymatic reaction for the synthesis of novel perfectly structured alternating copolymers. Initially, six types of complexing agents, linear(A)-linear(B), linear(A)-linear(B)-linear(A), linear-dendritic, dendritic-linear-dendritic, linear-hyperbranched, and hyperbranched-linear-hyperbranched amphiphilic block copolymers, are proven to significantly enhance enzyme activity of three different types of lipases - Penicillium camemberti, Candida rugosa, and Burkholderia cepacia (up to 1400%, 1700%, and 870% increase with respect to the native enzymes). The copolymerization is performed in several consecutive steps: (a) lipase and laccase are dissolved in aqueous medium at neutral pH; (b) a complexing agent is added leading to cocompartmentalization of the two enzymes within a micelle or physical network; (c) the two comonomers are introduced simultaneously to the tandem enzyme complex. The reaction proceeds in the following pathway: laccase catalyzes the oxidation of catechol to o-quinone followed by lipase comediated Michael addition of a diamine. While laccase could catalyze the entire process, addition of lipase is able to increase copolymer yield up to 30.7%. Addition of a complexing agent improves the yield further up to 67.9% (23.2% yield obtained for native laccase). Complexing agents significantly increase polymer molecular mass ( Mw = 130 900 vs 35 500 Da for the native enzymes reaction system). The resulting copolymers are highly fluorescent (quantum yield up to 0.733) and demonstrate pH sensitive behavior, properties that hint toward their potential as imaging agents.

Fungal mycobiota and mycotoxin risk for traditional artisan Italian cave cheese

Cave cheese is a surface mold-ripened variety of cheese produced also in South of Italy, exploiting fungal population naturally occurring on cave walls, as part of secondary microbiota for ripening. In this study, 148 fungal strains were isolated from 22 independent cave cheese samples, collected in 13 Italian geographical locations, mostly in Apulian area.DNA-based identification showed the presence of twenty-four fungal species in the outer part of the cheese ripened in caves. Aspergillus westerdijkiae and Penicillium biforme resulted the most frequently isolated species, followed by Penicillium roqueforti and Penicillium solitum. The 86% of cheese sample presented at least one toxigenic species and the 45% revealed the presence of ochratoxigenic species, A. westerdijkiae and A. steynii, suggesting possible mycotoxin risk during ripening stage in caves, confirmed by the presence of ochratoxin A (OTA) in the rind of 36% of samples.In conclusion, cave cheese is a susceptible product for toxigenic mold growth and in particular OTA contamination, therefore adeguate scientific tools for matching organolectic consumer expectations and complete safety of food should be developed, as well as spontaneously molded and not monitored cheeses should not be consumed to avoid mycotoxin risk.

Ergot Alkaloid Synthesis Capacity of Penicillium camemberti.

Ergot alkaloids are specialized fungal metabolites with potent biological activities. They are encoded by well-characterized gene clusters in the genomes of producing fungi. Penicillium camemberti plays a major role in the ripening of Brie and Camembert cheeses. The P. camemberti genome contains a cluster of five genes shown in other fungi to be required for synthesis of the important ergot alkaloid intermediate chanoclavine-I aldehyde and two additional genes (easH and easQ) that may control modification of chanoclavine-I aldehyde into other ergot alkaloids. We analyzed samples of Brie and Camembert cheeses, as well as cultures of P. camemberti, and did not detect chanoclavine-I aldehyde or its derivatives. To create a functioning facsimile of the P. camembertieas cluster, we expressed P. camemberti easH and easQ in a chanoclavine-I aldehyde-accumulating easA knockout mutant of Neosartorya fumigata The easH-easQ-engineered N. fumigata strain accumulated a pair of compounds of m/z 269.1288 in positive-mode liquid chromatography-mass spectrometry (LC-MS). The analytes fragmented in a manner typical of the stereoisomeric ergot alkaloids rugulovasine A and B, and the related rugulovasine producer Penicillium biforme accumulated the same isomeric pair of analytes. The P. camemberti eas genes were transcribed in culture, but comparison of the P. camemberti eas cluster with the functional cluster from P. biforme indicated 11 polymorphisms. Whereas other P. camembertieas genes functioned when expressed in N. fumigata, P. camembertieasC did not restore ergot alkaloids when expressed in an easC mutant. The data indicate that P. camemberti formerly had the capacity to produce the ergot alkaloids rugulovasine A and B.IMPORTANCE The presence of ergot alkaloid synthesis genes in the genome of Penicillium camemberti is significant, because the fungus is widely consumed in Brie and Camembert cheeses. Our results show that, although the fungus has several functional genes from the ergot alkaloid pathway, it produces only an early pathway intermediate in culture and does not produce ergot alkaloids in cheese. Penicillium biforme, a close relative of P. camemberti, contains a similar but fully functional set of ergot alkaloid synthesis genes and produces ergot alkaloids chanoclavine-I, chanoclavine-I aldehyde, and rugulovasine A and B. Our reconstruction of the P. camemberti pathway in the model fungus Neosartorya fumigata indicated that P. camemberti formerly had the capacity to produce these same ergot alkaloids. Neither P. camemberti nor P. biforme produced ergot alkaloids in cheese, indicating that nutritionally driven gene regulation prevents these fungi from producing ergot alkaloids in a dairy environment.

Improving of hydrolases biosythesis by solid-state fermentation of Penicillium camemberti on rapeseed cake

The study show usefulness of rapeseed cake, rich in fats and proteins byproduct generated after oil production, which may be used as a microbial medium for lipase and protease biosynthesis. Of 26 different filamentous fungi screened by solid-state fermentation, Penicillium camemberti AM83 was found to abundantly produce lipase and protease. Various process parameters were then optimized to maximize lipase and protease secretion, including carbon and nitrogen source, C/N ratio, metal ions, temperature, moisture content, initial pH, and inoculum size. Lipase production increased approximately 11.2-fold in solid-state cultures on rapeseed cake supplemented with lactose and calcium chloride, alkalinized to pH 8, hydrated to 80%, and inoculated with 1.2 × 106 spores/mL. Similarly, protease production increased approximately 8.4-fold in optimized cultures inoculated with 3.2 × 108 spores/mL, and grown on rapeseed cake with lactose and ammonium sulfate at pH 9 and moisture content 60%. The results highlight the potential economic value of solid-state fermentation on rapeseed cake to produce industrial hydrolases.

Diversity and Characteristics of the Meat Microbiological Community on Dry Aged Beef.

Beef was dry aged for 40-60 days under controlled environmental conditions in a refrigerated room with a relative humidity of 75%-80% and air-flow. To date, there is little information on the microbial diversity and characteristics of dry aged beef. In this study, we explored the effect of change in meat microorganisms on dry aged beef. Initially, the total bacteria and LAB were significantly increased for 50 days during all dry aging periods. There was an absence of representative foodborne pathogens as well as coliforms. Interestingly, fungi including yeast and mold that possess specific features were observed during the dry aging period. The 5.8S rRNA sequencing results showed that potentially harmful yeasts/molds (Candida sp., Cladosporium sp., Rhodotorula sp.) were present at the initial point of dry aging and they disappeared with increasing dry aging time. Interestingly, Penicillium camemberti and Debaryomyces hansenii used for cheese manufacturing were observed with an increase in the dry aging period. Taken together, our results showed that the change in microorganisms exerts an influence on the quality and safety of dry aged beef, and our study identified that fungi may play an important role in the palatability and flavor development of dry aged beef.

Water-Retaining Polymers in Organic Solvent Increase Lipase Activity for Biodiesel Synthesis

Background: Biocatalyzed esterification reactions in non-aqueous media require water removal materials and optimized enzyme formulations to improve reaction rate and conversion. We have tested a lipase biocatalysis process using anionic polymeric chains of polyacrylate as super-absorbent of water in the conversion of methyl oleate from oleic acid and methanol and in toluene as reaction medium. The water removal material that we used also for the enzyme immobilization is commercially named Aquasorb 3005K2 (herein called Aquasorb). Methods and findings: The synthesis of methyl oleate was catalyzed by Candida rugosa lipase or lipase G from Penicillium camemberti in the presence or absence of Aquasorb. The simple addition of Aquasorb to the reaction media of the lipase (commercial sample) catalyzed reaction allowed an enzyme activity 20% and 40% higher than that in the absence of Aquasorb for lipase from C. rugosa and lipase G, respectively. Furthermore, for the commercial form of lipase G, when used in the presence of Aquasorb, it was obtained a higher conversion of esterification (93% instead of 60%). Aquasorb was used also as support for the adsorption of the enzyme (via hydrogel formation followed by lyophilization) producing a lipase that was 100% and 60% more active than the enzyme dissolved in buffer in the absence of Aquasorb and lyophilized. However, these lipase formulations showed only about 20 % activity compared to when dry Aquasorb was simply added to the non-aqueous reaction medium. Conclusions: The use of Aquasorb appears beneficial as additive in esterification reactions (e.g., for biodiesel production) catalyzed by lipases in non-aqueous reaction media.

Production of Milk Clotting Enzyme by Penicillium camemberti

Production of Milk Clotting Enzyme by Penicillium camemberti