Penicillium Waksmanii Research Articles

Evaluation of Antifungal Activity of Oil Extracted from Two Varieties of Tomato Seeds against Fungal organisms Causing Rot in Tomato Fruits

Evaluation of the antifungal activity of oil extracted from two varieties of tomato seeds against fungal organisms causing rot in tomato fruits was carried out in Makurdi. The presence of decay caused by Fungi on tomatoes results in postharvest losses. Riogrande and Roma VF tomato seeds were washed, dried at 50˚C for 3 days in an oven, and milled. With the aid of a soxhlet extractor, using n-Hexane at 40-60°C for 6 hours, oil was extracted from the milled samples. Analysis of the oil revealed that oil is stable, translucent, and highly penetrating. A portion of tomatoes showing signs and symptoms of rot were detached, sterilized, and placed in a medium of Potato Dextrose Agar for one week for fungal growth. Fungi growths were identified macroscopically and microscopically and matched with standards. Fungi such as Curvularia affinis, Aspergillus flavus, Aspergillus niger, and Penicillium waksmanii were isolated. The pour plate method was used for fungi growth in the presence of the oil extracted. At days 3-7, the Riogrande seed oil media inhibit the growth of the isolated fungi with Aspergillus niger having the highest inhibition ranging from 1.333 to 1.733 mm and the Roma seed oil media inhibit the growth of Curvularia affinis with the highest inhibition ranging from 1.266 to 1.950 mm and while the control ranged from 3.533 to 8.100 mm. The results showed that numerous fungi are involved in rot of tomatoes and the extracted oil contains phytochemicals that are responsible for inhibiting fungal growth in the plates.

Selection and Characterization of Phosphate-Solubilizing Fungi and Their Effects on Coffee Plantations.

The use of phosphate-solubilizing fungi in coffee cultivation is an alternative to the use of traditional fertilizers. The objective of this study was to analyze the mechanisms involved in the phosphorus solubilization of fungal strains and to evaluate the effect of a phosphate-solubilizing strain on coffee plants. For this, phosphorus-solubilizing fungal strains were selected for evaluation of their solubilization potential and phosphatase activity. Coffee plants were inoculated in the field with a phosphate-solubilizing strain, and the soil and foliar soluble phosphorus contents, as well as coffee bean yield, were quantified. Of the 151 strains analyzed, Sagenomella diversispora, Penicillium waksmanii, and Penicillium brevicompactum showed the highest solubilization. Aspergillus niger and P. waksmanii presented the highest soluble phosphorus values; however, P. brevicompactum showed the highest phosphatase activity. The P. brevicompactum strain inoculated on the coffee plants did not favor the foliar phosphorus content but increased the soil soluble phosphorus content in two of the coffee plantations. The plants inoculated with the phosphate-solubilizing strain showed an increase in coffee bean weight on all plantations, although this increase was only significant in two of the three selected coffee plantations.

The Fungal Microbiota of the Digestive Tract of the Chagas Disease Vectors Triatoma infestans Klug, 1834 and Panstrongylus megistus Burmeister, 1835

Chagas is a neglected disease, one of Brazil’s main medical and social problems and a serious public health problem in the Americas, with more recent occurrences in non-endemic countries outside of the Americas. Research into the microbiota of triatomines is relevant because of its potential role in vector competence and as a proposed biological control strategy. Stressing a possible insect-fungal interaction in the development of Trypanosoma cruzi, and considering the lack of studies on the subject, we analyzed the fungal microbiota of the digestive tract of two species considered important vectors of Trypanosoma cruzi: Triatoma infestans and Panstrongylus megistus. Specimens were dissected, digestive tracts macerated and contents serially diluted. Each aliquot was seeded in three culture media. The plates were incubated in type B.O.D. climate chambers for 21 days, after which isolated colonies were morphological characterized and identified. There have been few published studies on the fungal microbiota of the triatomine digestive tract. Comparing the results found here with existing data reveals that the genera Aspergillus and Penicillium are commonly found in the digestive tract of the studied triatomines. Among the several genera identified, the species found in the highest percentages were Aspergillus flavus, Paecilomyces variotii, Penicillium waksmanii, Penicillium raistrickii and Penicillium fellutanum. Quantitative differences in the number of isolated fungal strains were observed according to sex and nymphal stage of the vector. The present findings corroborate those found in the literature, showing that there is a natural fungal microbiota in triatomines. Data revealing quantitative differences in isolated fungal strains found in male, female and nymphs reinforce the idea that their presence is related to physiology and fasting resistance. The secondary metabolite-producing fungi isolated in this work have in their biology great potential to be tested with regard to the establishment of T. cruzi in the digestive tract of its vector.

Inoculación de hongos solubilizadores de fósforo y micorrizas arbusculares en plantas de jitomate

La necesidad de reducir el uso de fertilizantes químicos demanda la creación de estrategias alternativas que mantengan una producción vegetal competitiva sin deterioro del ambiente. En este estudio, se evaluó la efectividad de la inoculación de hongos micorrícicos y solubilizadores de fósforo (solos y en consorcios) sobre la micorrización, el contenido de fósforo en la parte aérea, la altura, y longitud de la raíz de las plantas de jitomate. Los tratamientos incluyeron tres cepas de hongos solubilizadores (Aspergillus niger, Penicillium brevicompactum y Penicillium waksmanii), un consorcio de micorrizas y todas sus posibles combinaciones incluyendo un testigo (sin hongos). Después de cuatro meses, se cuantificó la colonización micorrícica, el contenido de fósforo de la parte aérea por el método del azul de molibdato y las variables altura y longitud de raíz. Los resultados obtenidos demostraron un rango de colonización del 48-66%; los valores más altos se detectaron con los tratamientos de HMA y HMA + An. Los tratamientos consorcios de HSF y HSF + HMA exhibieron 191% de incremento del fósforo foliar respecto a los testigos. La altura de las plantas de jitomate fue significativamente mayor en todos los tratamientos con respecto al testigo. Para la longitud de raíz el tratamiento HMA y el testigo presentaron los valores más altos. Los consorcios de hongos solubilizadores de fósforo en combinación con el consorcio de hongos micorrícicos tienen un alto potencial para ser utilizados como biofertilizantes de jitomate en invernadero.

In vitro Potential of Aqueous Extracts of Plant Leaves to inhibit Pathogenic Fungi

The in vitro potential of aqueous extracts of plant leaves to inhibit pathogenic fungi was carried out. The effect of leaf extract and concentration on growth inhibition of organism I (Aspergillus flavus) in vitro revealed that a concentration of 100g/mL, Moringa oleifera leaf extract (MLE) gave the highest growth inhibition of (59.14) followed by Neem (Azadirachta indica) leaf extract (NLE) (49.70) and Bitter leaf (Vernonia amygdalina) extract (BLE) (45.84) respectively while the least growth inhibition on organism 1 (Aspergillus flavus) was by MLE at concentration of 40 g/mL (30.11) followed by NLE at 60 g/mL (32.11) and BLE at 40 g/mL (40.13). On organism 2 (Penicillium waksmanii), MLE at a concentration of 100 g/mL gave the highest growth inhibition of (50.49) followed by NLE (49.01) and BLE (36.72) respectively while the least inhibition on growth of organism 2 in vitro was by BLE at concentration of 60 g/mL (16.05) followed by MLE (40.70) and NLE (40.70) at concentration of 80 g/mL respectively. On organism 3 (Botryodiplodia theobromae), MLE at concentration of 100 g/mL gave the highest inhibition of growth (57.00) followed by NLE (52.71) and BLE (50.15) respectively while the least inhibition on growth of organism 3 in vitro was by BLE at 40 g/mL (21.50) followed by MLE at 60 g/mL (31.06) and NLE at 40 g/mL (41.89). On organism 4 (Fusarium oxysporum), the highest growth inhibition was by MLE at 100g/mL (54.02) followed by NLE at 100 g/mL (49.62) and BLE at 100 g/mL (44.41) while MLE showed the least growth inhibition at 60 g/mL (24.04) followed by BLE at 40 g/mL (26.60) and NLE at 40 g/mL (30.12). NLE showed the highest grand inhibitory effect of extract concentration on growth inhibition of organism 5 (Colletotrichum asianum) in vitro at 100 g/mL (53.68) followed by MLE at 100 g/mL (51.51) and BLE at 100 g/mL (40.94). The least inhibitory effect on the growth of organism 5 in vitro was by BLE at 80 g/mL (21.26) followed by NLE at 40 g/mL (22.25) and MLE at 40 g/mL (32.69). The controls ranged from 2.23 to 4.31 across all extract concentrations and fungal isolates. There were significant differences in growth inhibition between extract concentrations and their controls on all fungal isolates. The use of plant extracts provides alternative means for controlling plant pathogenic fungi.

Selection of inactivation medium for fungal spores in clinical wastes by supercritical carbon dioxide.

The present study aimed to select the best medium for inactivation of Aspergillus fumigatus, Aspergillus spp. in section Nigri, A. niger, A. terreus var. terreus, A. tubingensis, Penicillium waksmanii, P. simplicissimum, and Aspergillus sp. strain no. 145 spores in clinical wastes by using supercritical carbon dioxide (SC-CO2). There were three types of solutions used including normal saline, seawater, distilled water, and physiological saline with 1% of methanol; each solution was tested at 5, 10, and 20mL of the water contents. The experiments were conducted at the optimum operating parameters of supercritical carbon dioxide (30MPa, 75°C, 90min). The results showed that the inactivation rate was more effective in distilled water with the presence of 1% methanol (6 log reductions). Meanwhile, the seawater decreases inactivation rate more than normal saline (4.5 vs. 5.1 log reduction). On the other hand, the experiments performed with different volumes of distilled water (5, 10, and 20mL) indicated that A. niger spores were completely inactivated with 10mL of distilled water. The inactivation rate of fungal spores decreased from 6 to 4.5 log as the amount of distilled water increased from 10 to 20mL. The analysis for the spore morphology of A. fumigatus and Aspergillus spp. in section Nigri using scanning electron microscopy (SEM) has revealed the role of temperature and pressure in the SC-CO2 in the destruction of the cell walls of the spores. It can be concluded that the distilled water represent the best medium for inactivation of fungal spores in the clinical solid wastes by SC-CO2.

Assessment of relevant fungal species in clinical solid wastes.

The study aimed to determine the fungal diversity in clinical waste samples from a healthcare facility in Penang Malaysia. Different fungi species were detected in 83.75% of the 92 clinical waste samples that were screened from different sections of the healthcare facility. One hundred fifty fungal isolates comprising of 8 genera and 36 species were obtained. They were purified by using single spore isolation technique. Subsequently, the isolates were identified by phenotypic method based on morphological and culture characteristics on different culture media. Among all fungal isolates, Aspergillus spp. in section Nigri 10.2%, Aspergillus niger 9.5%, Aspergillus fumigatus 8.8%, Penicillium. simplicissium 8%, Aspergillus tubingensis 7.3%, Aspergillus terreus var. terreus 6.6%, Penicillium waksmanii 5.9% and Curvularia lunata 6.5% were the most frequent. Among five sections of the Wellness Centre, the clinical wastes collected from the diagnostic labs of haematology section had the highest numbers of fungal species (29 species). Glove wastes had the highest numbers of fungal species (19 species) among 17 types of clinical wastes screened. Among all fungal species, Aspergillus spp. exhibited higher growth at 37°C than at 28°C, indicating the potential of these opportunistic fungi to cause diseases in human. These results indicated the potential of hospital wastes as reservoirs for fungal species.

Mycological contamination in dental unit waterlines in Istanbul, Turkey.

Studies on dental units (DUs) are conducted either for the prevention or the reduction of the density of bacterial contamination in dental unit waterlines (DUWLs). However, the existence of fungi in the these systems requires more attention. During dental treatment, direct contact with water contaminated with fungi such as Candida, Aspergillus, or inhalation of aerosols from high-speed drill may cause various respiratory infections, such as asthma, allergies, and wounds on mucose membranes, especially on immunocompromised patients and dentists. The aims of this study are to investigate the number and colonization of fungi in DUWLs in the city of Istanbul, Turkey. Water samples were collected from air-water syringes, high-speed drills, and inlet waters from 41 DUs. The aerobic mesophilic fungi count in high- speed drills was higher than inlet waters and air-water syringes. Non-sporulating fungi were found in 7 DUs. The isolated fungi were identified as Penicillium waksmanii, Cladosporium spp., Penicillium spp., Candida famata, Cryptococcus laurentii, Candida guilliermondii, Penicillium verrucosum, Aspergillus pseudoglaucus, Penicillium decumbens, and Acremonium sp. Some of these fungal genera are known as opportunistic pathogens that led to respiratory diseases such as allergic rhinits. This study shows the importance of regular control of mycological contamination on water at DUs.

In vitro protoscolicidal effects of fungal chitosan isolated from Penicillium waksmanii and Penicillium citrinum

Hydatidosis is caused by a tapeworm which infects humans by the larval stage. In humans, the disease is so serious that it requires surgery for treatment. Documents show that there have been many efforts in finding new scolicidal agents for reducing the rate of the infection. The objective of this study was determination of the scolicidal effect of two fungal chitosan types, produced from Penicillium spp. and commercially chitosan (CC) on Echinococcus granulosus protoscolex. Protoscolices were aseptically aspirated from sheep livers hydatid cysts. Four concentrations (50, 100, 200, 400μg/ml) of each type of prepared chitosan were used for 10, 30, 60 and 180min. Viability of protoscolices was detected by 0.1% eosin staining. Fungal chitosan which was the most bioactive type with higher degree of deacetylation showed stronger scolicidal activity in vitro (P<0.05). Fungal chitosan could be recommended, as good as CC for hydatid cysts control and is a noble alternative for synthetic and chemical scolicidal.

Fungus-Mediated Synthesis of Gold Nanoparticles: A Novel Biological Approach to Nanoparticle Synthesis

The biological effects of nanoparticles and their uses as molecular probes are research areas of growing interest. The present study demonstrates an eco-friendly biosynthesis of gold nanoparticles. The pure colonies of penicillium aurantiogriseum, penicillium citrinum, and penicillium waksmanii were cultured in fluid czapek dox broth. Then, their supernatants were examined for the ability to produce gold nanoparticles. In this step, 1 mM solution of AuCl added to the reaction matrixes separately. The reactions were performed in a dark environment at 28 degrees C. After 24 hours, it was observed that the color of the solutions turned to dark purple from light yellow. Synthesized gold nanoparticles were characterized by using UV-Visible Spectroscopy, Nano Zeta Sizer, Scanning Electron Microscopy and Fourier transformed infrared spectroscopy. The results showed that the gold nanoparticles were formed fairly uniform with spherical shape with the Z-average diameter of 153.3 nm, 172 nm and 160.1 nm for penicillium aurantiogriseum, penicillium citrinum, and penicillium waksmanii, respectively. The Fourier transformed infrared spectra revealed the presence of different functional groups to gold nanoparticles which were present in the fungal extract. The current approach suggests that the rapid synthesis of nanoparticles would be proper for developing a biological process for mass scale production.

Purification, Characterization, and Specificity Determination of a New Serine Protease Secreted by Penicillium waksmanii

The purpose of this work was to purify a protease from Penicillium waksmanii and to determine its biochemical characteristics and specificity. The extracellular protease isolated that was produced by P. waksmanii is a serine protease that is essential for the reproduction and growth of the fungus. The protease isolated showed 32 kDa, and has optimal activity at pH 8.0 and 35 °C towards the substrate Abz-KLRSSKQ-EDDnp. The protease is active in the presence of CaCl(2), KCl, and BaCl, and partially inhibited by CuCl(2), CoCl(2) and totally inhibited by AlCl(3) and LiCl. In the presence of 1 M urea, the protease remains 50 % active. The activity of the protease increases 60 % when it is exposed to 0.4 % nonionic surfactant-Triton X-100 and loses 10 % activity in the presence of 0.4 % Tween-80. Using fluorescence resonance energy transfer analysis, the protease showed the most specificity for the peptide Abz-KIRSSKQ-EDDnp with k (cat)/K (m) of 10,666 mM(-1) s(-1), followed by the peptide Abz-GLRSSKQ-EDDnp with a k (cat)/K (m) of 7,500 mM(-1) s(-1). Basic and acidic side chain-containing amino acids performed best at subsite S(1). Subsites S(2), S(3), S(') (2), and S(') (1), S(') (3) showed a preference for binding for amino acids with hydrophobic and basic amino acid side chain, respectively. High values of k (cat)/K (m) were observed for the subsites S(2), S(3), and S(') (2.) The sequence of the N-terminus (ANVVQSNVPSWGLARLSSKKTGTTDYTYD) showed high similarity to the fungi Penicillium citrinum and Penicillium chrysogenum, with 89 % of identity at the amino acid level.

Alkali pretreated of wheat straw and its enzymatic hydrolysis

The efficiency of enzymatic hydrolysis of cellulose can be improved by various pretreatments of the substrate. In order to increase the efficiency of enzymatic saccharification of the wheat straw, we determined the effect of different pretreatments on the physical structure, chemical components and enzymatic saccharification of wheat straw. Our results showed that combination of grinding and sodium hydroxide (NaOH) treatment had high effect on the enzymatic hydrolysis of wheat straws. The optimal pretreatment condition was to grind the wheat straws into the sizes of 120 meshes followed by treatment with 1.0% NaOH for 1.5 h (121°C/15psi). Under this condition, the cellulose content of wheat straw was increased by 44.52%, while the content of hemicellulose and lignin was decreased by 44.15% and 42.52%, respectively. Scanning Electronic Microscopy and infrared spectrum analyses showed that significant changes occurred in the structure of wheat straws after pretreatment, which is favorable for the hydrolysis and saccharification. Cellulase produced by Penicillium waksmanii F10–2 was used to hydrolyze the pretreated wheat straw and the optimal condition was determined to be 30 h of enzymatic reaction under the temperature of 55°C, pH 5.5 and substrate concentration of 3%.

New producers of biologically active compounds—fungal strains of the genus Penicillium isolated from permafrost

Screening of producers of secondary metabolites was carried out among 25 fungal strains of Penicillium genus isolated from permafrost in Arctic and Antarctic regions and Kamchatka. Nearly 50% of the investigated strains synthesize biologically active substances of alkaloid nature: ergot alkaloids, diketopiperazines, and quinoline derivatives. A large group of the identified metabolites belongs to mycotoxins. A strain of Penicillium waksmanii was found producing epoxiagroclavine-I and quinocitrinins. The main physiological and biochemical characteristics of this producer were investigated.

Growth-Phase-Related Changes in Reactive Oxygen Species Generation as a Cold Stress Response in Antarctic Penicillium Strains

ABSTRACTThe Free Radical/Oxidative Stress Theory of Aging postulated that the accumulation of damage caused by reactive oxygen species (ROS) was the underlying mechanism by which organisms age. Our previous studies reported that the growth at low temperature caused oxidative stress events in Antarctic strains, including enhanced ROS generation. However, there is no data about age-related differences in cold stress-induced ROS accumulation in microorganisms living permanently in cold environments. The aim of the present paper was to evaluate the growth-phase-related changes in ROS level in two Antarctic strains belonging to different thermal classes, psychrotolerant (Penicillium olsonii p14) and mesophilic (Penicillium waksmanii m12) and the role of cold adaptation in this process. Intact cells and mitochondrial fractions from the middle exponential phase or stationary phase at optimal temperature were exposure to temperature of 6°C and 15°C, respectively. The results demonstrated that the temperature downshift led to a significant induction in the superoxide and H2O2 level in a dose- and growth-phase-dependent manner. Additionally, cold-stress response is not dependent on cold-adaptation of the model strains.

Optimizing cellulase production of Penicillium waksmanii F10-2 with response surface methodology

Cellulase is an enzyme complex which breaks down cellulose to s-glucose. It has been used widely in commercial food processing, textile industry and laundry detergents. In this article, medium composition and fermentation conditions for Penicillium waksmanii F10-2, an isolated cellulase production strain, are studied. Wheat straw and peptone are found to be the most promising and effective carbon and nitrogen sources for cellulase production by P. waksmanii F10-2. Response surface methodology (RSM) is employed to optimize the medium constituents (wheat straw, peptone and minerals) and fermentation conditions (pH, rev and temperature) for cellulase production. The predicted maximal cellulase activity is about 5.64 U/mL, which is achieved at the following condition: pH: 6.4, rev: 136.2 r/min, temperature: 26.5°C, fermentation condition: wheat straw 20.3 g/L, peptone 11.3 g/L, KH 2 PO 4 2.7 g/L, NaCl 3.3 g/L, MgSO 4 .7H 2 O 0.2 g/L. Under the proposed optimized conditions, the model predicted a cellulase activity of 5.64 U/mL, which is very closely matching the experimental activity of 5.9 U/mL.

Temperature downshift induces antioxidant response in fungi isolated from Antarctica

Although investigators have been studying the cold-shock response in a variety of organisms for the last two decades or more, comparatively little is known about the difference between antioxidant cell response to cold stress in Antarctic and temperate microorganisms. The change of environmental temperature, which is one of the most common stresses, could be crucial for their use in the biotechnological industry and in ecological research. We compared the effect of short-term temperature downshift on antioxidant cell response in Antarctic and temperate fungi belonging to the genus Penicillium. Our study showed that downshift from an optimal temperature to 15 degrees or 6 degrees C led to a cell response typical of oxidative stress: significant reduction of biomass production; increase in the levels of oxidative damaged proteins and accumulation of storage carbohydrates (glycogen and trehalose) in comparison to growth at optimal temperature. Cell response against cold stress includes also increase in the activities of SOD and CAT, which are key enzymes for directly scavenging reactive oxygen species. This response is more species-dependent than dependent on the degree of cold-shock. Antarctic psychrotolerant strain Penicillium olsonii p14 that is adapted to life in extremely cold conditions demonstrated enhanced tolerance to temperature downshift in comparison with both mesophilic strains (Antarctic Penicillium waksmanii m12 and temperate Penicillium sp. t35).

Isolation and screening of fungal species isolated from Brazilian cerrado soil for antibacterial activity against Escherichia coli, Staphylococcus aureus, Salmonella typhimurium, Streptococcus pyogenes and Listeria monocytogenes

Summary Objective To study the antimicrobial activity of fungi isolated from Brazilian cerrado soil. Material and methods A total of 200 fungal strains were isolated from soil samples collected from Serra do Cipo National Park in Brazil. Antibacterial activity against Escherichia coli , Staphylococcus aureus , Salmonella typhimurium , Streptococcus pyogenes and Listeria monocytogenes was screened. Results Around 67% of the extracts showed activity against at least one of the tested bacteria. Thirteen isolates, selected as the most common species found in the studied soil samples (over 50% of all isolates), were microscopically identified as Chaetomium cupreum, Curvularia senegalensis, Fusarium oxysporum, Penicillium citrinum, Penicillium janthinellum, Penicillium paxilli, Penicillium sclerotiorum, Penicillium simplicissimum, Penicillium waksmanii, Rhizopus stolonifer, Syncephalastrum racemosum, Trichoderma koningii and Trichoderma reesei . Large scale experiment proved positive antibacterial results for Penicillium sclerotiorum and Penicillium simplicissimum , since bioactive metabolites (sclerotiorin, isochromophilone VI, pencolide and penicillic acid) were recovered from their fermentation in preparative scale. Conclusion Cerrado soil fungi constitute another important source of antibiotics producing micro-organisms that can be further exploited as source of lead compounds for anti-infective agents industry.

ChemInform Abstract: PF1270A, B and C, Novel Histamine H3 Receptor Ligands Produced by Penicillium waksmanii PF1270.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

PF1270A, B and C, Novel Histamine H3 Receptor Ligands Produced by Penicillium waksmanii PF1270

Three novel histamine H3 receptor (H3R) ligands, PF1270A (1), PF1270B (2) and PF1270C (3) were isolated from the culture broth of the fungal strain PF1270. The strain was identified as Penicillium waksmanii on the basis of morphological characteristics. These compounds were obtained from the culture broth by solvent extraction and chromatographic purification. Their structures were established by spectroscopic methods and X-ray crystallographic analysis. They possess pentacyclic spiroindolinone skeletons. 1, 2 and 3 displayed high affinity for the rat H3R (Ki=0.058, 0.17 and 0.19 microM, respectively) and human H3R (Ki=0.047, 0.12 and 0.22 microM, respectively). Moreover, 1, 2 and 3 acted as potent agonists with the EC50 values of 0.12, 0.15 and 0.20 microM, respectively.

Detection of griseofulvin in a marine strain of Penicillium waksmanii by ion trap mass spectrometry

A marine strain of Penicillium waksmanii Zaleski was isolated from a sample of seawater from shellfish-farming area in the Loire estuary (France). The in vitro marine culture showed an important antifungal activity. Bioassay-guided fractionation was used to purify the crude extract. Dereplication by electrospray-ion trap/mass spectrometry (ESI-IT/MS) afforded the identification of the antifungal compound, after a semi-purification consisting of two stages. A comparison of the ionic composition between the active and the non-active fractions allowed the detection of a monocharged ion at m/ z 353 containing a chlorine atom, which could be attributed to the antifungal griseofulvin [C 17H 17ClO 6+H] +. Multi-stage fragmentation (MS n) confirmed the identity of the m/ z 353 ion of the antifungal fraction as griseofulvin. It is the first description of griseofulvin production by a strain of P. waksmanii and the first chemical study of a strain of this species isolated from marine temperate cold water.