In silico prediction of polyketide biosynthetic gene clusters in the genomes of Hypericum-borne endophytic fungi.

BACKGROUND: The search for new bioactive natural compounds with anticancer activity is still of great importance. Even though their potential for diagnostics and treatment of cancer has already been proved, the availability is still limited. Hypericin, a naphthodianthrone isolated essentially from plant source Hypericum perforatum L. along with other related anthraquinones and bisanthraquinones belongs to this group of compounds. Although it has been proven that hypericin is synthesized by the polyketide pathway in plants, none of the candidate genes coding for key enzymes has been experimentally validated yet. Despite the rare occurrence of anthraquinones in plants, their presence in microorganisms, including endophytic fungi, is quite common. Unlike plants, several biosynthetic genes grouped into clusters (BGCs) in fungal endophytes have already been characterized. RESULTS: The aim of this work was to predict, identify and characterize the anthraquinone BGCs in de novo assembled and functionally annotated genomes of selected endophytic fungal isolates (Fusarium oxysporum, Plectosphaerella cucumerina, Scedosporium apiospermum, Diaporthe eres, Canariomyces subthermophilus) obtained from different tissues of Hypericum spp. The number of predicted type I polyketide synthase (PKS) BGCs in the studied genomes varied. The non-reducing type I PKS lacking thioesterase domain and adjacent discrete gene encoding protein with product release function were identified only in the genomes of C. subthermophilus and D. eres. A candidate bisanthraquinone BGC was predicted in C. subthermophilus genome and comprised genes coding the enzymes that catalyze formation of the basic anthraquinone skeleton (PKS, metallo-beta-lactamase, decarboxylase, anthrone oxygenase), putative dimerization enzyme (cytochrome P450 monooxygenase), other tailoring enzymes (oxidoreductase, dehydrogenase/reductase), and non-catalytic proteins (fungal transcription factor, transporter protein). CONCLUSIONS: The results provide an insight into genetic background of anthraquinone biosynthesis in Hypericum-borne endophytes. The predicted bisanthraquinone gene cluster represents a basis for functional validation of the candidate biosynthetic genes in a simple eukaryotic system as a prospective biotechnological alternative for production of hypericin and related bioactive anthraquinones.

New cytotoxic secondary metabolites against human pancreatic cancer cells from the Hypericum perforatum endophytic fungus Aspergillus terreus.

Four new compounds, including two lovastatin analogues, terrstatins A and B (1 and 2), and a pair of butenolide derivatives, (±)-asperteretone F (3a/3b), along with eleven known compounds (4-14), were isolated from the Hypericum perforatum endophytic fungus Aspergillus terreus. Their structures and absolute configurations were determined based on extensive spectroscopic analysis, experimental and calculated electronic circular dichroism (ECD) analysis. All isolates were evaluated for cytotoxic activities against five human cancer cell lines, and compounds 3a/3b and 6 showed potential cytotoxic activities against human pancreatic cancer cells, including AsPC-1, SW1990 and PANC-1 cells, with IC50 values ranging from 1.2 to 15.6 µM.

Hypericibacter terrae gen. nov., sp. nov. and Hypericibacter adhaerens sp. nov., two new members of the family Rhodospirillaceae isolated from the rhizosphere of Hypericum perforatum.

Two strains of the family Rhodospirillaceae were isolated from the rhizosphere of the medicinal plant Hypericum perforatum. Cells of both strains were Gram-stain-negative, motile by means of a single polar flagellum, non-spore-forming, non-capsulated, short rods that divided by binary fission. Colonies were small and white. Strains R5913T and R5959T were oxidase-positive, mesophilic, neutrophilic and grew optimally without NaCl. Both grew under aerobic and microaerophilic conditions and on a limited range of substrates with best results on yeast extract. Major fatty acids were C19 : 0 cyclo ω8c and C16 : 0; in addition, C18 : 1ω7c was also found as a predominant fatty acid in strain R5913T. The major respiratory quinone was ubiquinone 10 (Q-10). The DNA G+C contents of strains R5913T and R5959T were 66.0 and 67.4 mol%, respectively. 16S rRNA gene sequence comparison revealed that the closest relatives (<92 % similarity) of the strains are Oceanibaculum pacificum MCCC 1A02656T, Dongia mobilis CGMCC 1.7660T, Dongia soli D78T and Dongia rigui 04SU4-PT. The two novel strains shared 98.6 % sequence similarity and represent different species on the basis of low average nucleotide identity of their genomes (83.8 %). Based on the combined phenotypic, genomic and phylogenetic investigations, the two strains represent two novel species of a new genus in the family Rhodospirillaceae, for which the name Hypericibacter gen. nov. is proposed, comprising the type species Hypericibacter terrae sp. nov. (type strain R5913T=DSM 109816T=CECT 9472T) and Hypericibacter adhaerens sp. nov. (type strain R5959T=DSM 109817T=CECT 9620T).

Transgenic expression of Hyp-1 gene from Hypericum perforatum L. alters expression of defense-related genes and modulates recalcitrance to Agrobacterium tumefaciens.

MAIN CONCLUSION: Phenolic oxidative coupling protein (Hyp-1) isolated from Hypericum perforatum L. was characterized as a defense gene involved in H. perforatum recalcitrance to Agrobacterium tumefaciens-mediated transformation Hypericum perforatum L. is a reservoir of high-value secondary metabolites of increasing interest to researchers and to the pharmaceutical industry. However, improving their production via genetic manipulation is a challenging task, as H. perforatum is recalcitrant to Agrobacterium tumefaciens-mediated transformation. Here, phenolic oxidative coupling protein (Hyp-1), a pathogenesis-related (PR) class 10 family gene, was selected from a subtractive cDNA library from A. tumefaciens-treated H. perforatum suspension cells. The role of Hyp-1 in defense against A. tumefaciens was analyzed in transgenic Nicotiana tabacum and Lactuca sativa overexpressing Hyp-1, and in Catharanthus roseus silenced for its homologous Hyp-1 gene, CrIPR. Results showed that Agrobacterium-mediated expression efficiency greatly decreased in Hyp-1 transgenic plants. However, silencing of CrIPR induced CrPR-5 expression and decreased expression efficiency of Agrobacterium. The expression of core genes involved in several defense pathways was also analyzed in Hyp-1 transgenic tobacco plants. Overexpression of Hyp-1 led to an ample down-regulation of key genes involved in auxin signaling, microRNA-based gene silencing, detoxification of reactive oxygen species, phenylpropanoid pathway and PRs. Moreover, Hyp-1 was detected in the nucleus, plasma membrane and the cytoplasm of epidermal cells by confocal microscopy. Overall, our findings suggest Hyp-1 modulates recalcitrance to A. tumefaciens-mediated transformation in H. perforatum.

Host metabolite producing endophytic fungi isolated from Hypericum perforatum.

In the present study, endophytic fungi have been isolated from various parts of the medicinal herb Hypericum perforatum (St. John's Wort), which is known as a source of medically important metabolites. The isolated strains were cultured in liquid media and their ability to synthesize hypericin, the secondary metabolite of the host and its suspected precursor, emodin was tested analyzing the extracts of the fermentation broth and the mycelia. The HPLC-UV analysis of the chloroform/methanol extracts of the mycelia revealed that three isolates were able to produce emodin (SZMC 23771, 19.9 ng/mg; SZMC 23772, 20.8 ng/mg; SZMC 23769, 427.9 ng/mg) and one of them also could synthesize hypericin (SZMC 23769, 320.4 ng/mg). These results were also confirmed via UHPLC-HRMS technique both in full scan and MS/MS mode. The strains producing only emodin belong to the section Alternata of the genus Alternaria, while the isolate producing both metabolites was identified as Epicoccum nigrum. The mycelial extracts of E. nigrum and the Alternaria sp. SZMC 23772 showed higher inhibitory activities in the antimicrobial tests against the six selected bacteria compared to the hypericin and emodin standards in the applied concentration (100 µg/mL), while in case of the Alternaria sp. SZMC 23771 lower inhibition activities were observed on Staphylococcus aureus and Streptomyces albus than the pure compounds.

Arbuscular mycorrhizal fungi altered the hypericin, pseudohypericin, and hyperforin content in flowers of Hypericum perforatum grown under contrasting P availability in a highly organic substrate.

St. John's Wort (Hypericum perforatum) is a perennial herb able to produce water-soluble active ingredients (a.i.), mostly in flowers, with a wide range of medicinal and biotechnological uses. However, information about the ability of arbuscular mycorrhizal fungi (AMF) to affect its biomass accumulation, flower production, and concentration of a.i. under contrasting nutrient availability is still scarce. In the present experiment, we evaluated the role of AMF on growth, flower production, and concentration of bioactive secondary metabolites (hypericin, pseudohypericin, and hyperforin) of H. perforatum under contrasting P availability. AMF stimulated the production of aboveground biomass under low P conditions and increased the production of root biomass. AMF almost halved the number of flowers per plant by means of a reduction of the number of flower-bearing stems per plant under high P availability and through a lower number of flowers per stem in the low-P treatment. Flower hyperforin concentration was 17.5% lower in mycorrhizal than in non-mycorrhizal plants. On the contrary, pseudohypericin and hypericin concentrations increased by 166.8 and 279.2%, respectively, with AMF under low P availability, whereas no effect of AMF was found under high P availability. These results have implications for modulating the secondary metabolite production of H. perforatum. However, further studies are needed to evaluate the competition for photosynthates between AMF and flowers at different nutrient availabilities for both plant and AM fungus.

Anti-microbial screening of endophytic fungi from Hypericum perforatum Linn.

Anti-microbial properties of 21 endophytic fungal strains from Hypericum perforatum Linn. were evaluated against three human pathogens, Staphyloccocus aureus, Escherichia coli and Rhodotorula glutinis, and two phytopathogens, Rhizoctonia cerealis and Pyricularia grisea. The results indicated that the ethyl acetate extracts of endophytic fermentation broth had stronger anti-microbial activities than their fermentation broth. And the inhibitory effect of the endophytic extracts on human pathogens was better than those on phytopathogens. Among these endophytic fungi, strains GYLQ-10, GYLQ-24 and GYLQ-22 respectively showed the strongest activities against S. aureu, E. coli, R. glutinis. GYLQ-14 and GYLQ-22 exhibited the most pronounced effect on P. Grisea while both GYLQ-06 and GYLQ-08 had the strongest anti-microbial activities against R. cerealis. Till now, this study is the first report on the isolation of endophytic fungi from H. perforatum Linn. and their anti-microbial evaluation.

Beer fermentation: monitoring of process parameters by FT-NIR and multivariate data analysis.

This work investigates the capability of Fourier-Transform near infrared (FT-NIR) spectroscopy to monitor and assess process parameters in beer fermentation at different operative conditions. For this purpose, the fermentation of wort with two different yeast strains and at different temperatures was monitored for nine days by FT-NIR. To correlate the collected spectra with °Brix, pH and biomass, different multivariate data methodologies were applied. Principal component analysis (PCA), partial least squares (PLS) and locally weighted regression (LWR) were used to assess the relationship between FT-NIR spectra and the abovementioned process parameters that define the beer fermentation. The accuracy and robustness of the obtained results clearly show the suitability of FT-NIR spectroscopy, combined with multivariate data analysis, to be used as a quality control tool in the beer fermentation process. FT-NIR spectroscopy, when combined with LWR, demonstrates to be a perfectly suitable quantitative method to be implemented in the production of beer.

Elicitation of secondary metabolism in Hypericum perforatum by rhizosphere bacteria and derived elicitors in seedlings and shoot cultures.

CONTEXT: Hypericum perforatum L. (Guttiferae) appears as an alternative treatment to mild and moderate depression and been traditionally used as a health enhancer based on the phytochemicals hyperforin and hypericin. However, field grown medicinal plants show variable levels of phytopharmaceuticals depending on environmental conditions. Elicitation is a good strategy to trigger secondary metabolism. OBJECTIVE: This study explored the ability of 6 rhizobacterial strains to trigger secondary metabolism in H. perforatum seedlings and molecular elicitors from the most effective strain N5.18 were tested in shoot cultures. MATERIALS AND METHODS: Hypericin and pseudohypericin were determined on seedlings and shoot cultures by HPLC. Three putative elicitors from bacterial culture media were assayed in three different concentrations. RESULTS: Strain N5.18 significantly increased hypericin up to 1.2 ppm and pseudohypericin up to 3.4 ppm, over controls (0.3 and 2.5 ppm, respectively) when delivered to seedlings. In shoot cultures, only pseudohypericin was detected (168.9 ppm) and significant increases were observed under the different elicitors, reaching values of 3164.8 ppm with small elicitors in the middle concentration. DISCUSSION AND CONCLUSION: Secondary metabolism in plants is highly inducible due to its role in plant communication and defense. Our findings demonstrate that some beneficial bacterial strains are able to trigger secondary metabolism in H. perforatum plants when delivered through the roots and bacterial determinants released to culture media are able to reproduce the effect in shoot cultures. Therefore, these elicitors have great potential to enhance phytopharmaceutical production.

A three-step culture system to increase the xanthone production and antifungal activity of Hypericum perforatum subsp. angustifolium in vitro roots.

Hypericum perforatum is a well-known medicinal plant. Among all secondary metabolites produced by this species, xanthones are very interesting for their antifungal activity. In the present study, with the aim to improve xanthone production and antifungal activity of H. perforatum subsp. angustifolium (sin. Fröhlich) Borkh in vitro roots, a new methodology consisting of a three-step culture system, has been developed. Regenerated roots of H. perforatum were cultured in a three-step culture system: in the first step, to increase biomass, the roots were cultured in half-strength liquid Murashige and Skoog (MS) medium supplemented with 1 mg L(-1) indole butyric acid (IBA) and 1.5% sucrose. In the second and third steps, to stimulate secondary metabolism, the roots were cultured with 1.1 mg L(-1) 2,4-dichlorophenoxyacetic acid (2,4-D), 0.215 mg L(-1) kinetin (KIN), and 0.186 mg L(-1) 1-naphthalenacetic acid (NAA). In the third step, some of the roots were treated with chitosan. Xanthone production increased 2.7 times following the three-step method. The mean minimal inhibitory concentration (MIC) values were of 36.9, 26.7, and 65 µg mL(-1), against Candida species, Cryptococcus neoformans and dermatophytes, respectively. A positive correlation between xanthone accumulation and antifungal activity has been shown.

Hypericin and pseudohypericin concentrations of a valuable medicinal plant Hypericum perforatum L. are enhanced by arbuscular mycorrhizal fungi.

Hypericum perforatum L. (St. John's-wort, Hypericaceae) is a valuable medicinal plant species cultivated for pharmaceutical purposes. Although the chemical composition and pharmacological activities of H. perforatum have been well studied, no data are available concerning the influence of arbuscular mycorrhizal fungi (AMF) on this important herb. A laboratory experiment was therefore conducted in order to test three AMF inocula on H. perforatum with a view to show whether AMF could influence plant vitality (biomass and photosynthetic activity) and the production of the most valuable secondary metabolites, namely anthraquinone derivatives (hypericin and pseudohypericin) as well as the prenylated phloroglucinol-hyperforin. The following treatments were prepared: (1) control-sterile soil without AMF inoculation, (2) Rhizophagus intraradices (syn. Glomus intraradices), (3) Funneliformis mosseae (syn. Glomus mosseae), and (4) an AMF Mix which contained: Funneliformis constrictum (syn. Glomus constrictum), Funneliformis geosporum (syn. Glomus geosporum), F. mosseae, and R. intraradices. The application of R. intraradices inoculum resulted in the highest mycorrhizal colonization, whereas the lowest values of mycorrhizal parameters were detected in the AMF Mix. There were no statistically significant differences in H. perforatum shoot mass in any of the treatments. However, we found AMF species specificity in the stimulation of H. perforatum photosynthetic activity and the production of secondary metabolites. Inoculation with the AMF Mix resulted in higher photosynthetic performance index (PI(total)) values in comparison to all the other treatments. The plants inoculated with R. intraradices and the AMF Mix were characterized by a higher concentration of hypericin and pseudohypericin in the shoots. However, no differences in the content of these metabolites were detected after the application of F. mosseae. In the case of hyperforin, no significant differences were found between the control plants and those inoculated with any of the AMF applied. The enhanced content of anthraquinone derivatives and, at the same time, better plant vitality suggest that the improved production of these metabolites was a result of the positive effect of the applied AMF strains on H. perforatum. This could be due to improved mineral nutrition or to AMF-induced changes in the phytohormonal balance. Our results are promising from the biotechnological point of view, i.e. the future inoculation of H. perforatum with AMF in order to improve the quality of medicinal plant raw material obtained from cultivation.

Bioactive xanthones from the roots of Hypericum perforatum (common St John's wort).

BACKGROUND: Extracts of Hypericum perforatum L. (common St John's wort; Hypericaceae) are sold as phytopharmaceuticals and herbal supplements to treat mild to moderate depression and as food additives. Extensively cultivated in Europe, plants can be infected by anthracnose (Colletotrichum gloeosporioides), a virulent fungal pathogen that causes tissue necrosis and dramatically decreases crop value. Such infections triggered the production of new secondary metabolites, specifically xanthones, in cell culture experiments. RESULTS: Bioassay-guided fractionation of H. perforatum root extracts, testing for growth inhibition of plant pathogenic fungi from the genera Colletotrichum, Botrytis, Fusarium and Phomopsis, was performed. In vitro anti-inflammatory activity through inhibition of COX-1, COX-2 and 5-LOX-catalyzed LTB(4) formation was also evaluated. Extracts were analyzed by various chromatographic means and structure elucidation was performed using data from nuclear magnetic resonance and mass spectrometry. CONCLUSION: Researchers have previously described constituents from the aerial parts of this species, but few reports describe secondary metabolites found in underground parts, of particular interest because the lower stem and upper root are often sites of fungal infection. This work resulted in the isolation of three xanthones: 1,6-dihydroxy-5-methoxy-4',5'-dihydro-4',4',5'-trimethylfurano-(2',3':3,4)-xanthone; 4,6-dihydroxy-2,3-dimethoxyxanthone; and cis-kielcorin, one of which possessed novel bioactivity against species of Phomopsis and inhibited 5-LOX-mediated LTB(4) formation.

Light-independent metabolomics of endophytic Thielavia subthermophila provides insight into microbial hypericin biosynthesis.

The possible microbial mechanism of hypericin (1) and emodin (2) biosynthesis was studied in axenic submerged culture conditions in the endophytic fungus Thielavia subthermophila, isolated from Hypericum perforatum. The growth and secondary metabolite production of the endophyte remained independent of the illumination conditions. This production remained unaltered on spiking the medium with 3 or 5 mM 2, although the biomass accumulation was reduced. Neither emodin anthrone (3) nor protohypericin (4) could be detected at any stage of fermentation, irrespective of either spiking or illumination conditions. The endophytic metabolites exhibited photodynamic cytotoxicity against the human acute monocytic leukemia cell line (THP-1), at 92.7 vs 4.9%, and 91.1 vs 1.0% viability by resazurin and ATPlite assays, in light and in the dark, respectively. In trying to ascertain the presence/expression of the candidate hyp-1 gene in the endophyte, it was revealed that the hyp-1 gene was absent in T. subthermophila, indicating that the biosynthetic pathway in the endophytic fungus might be different and/or governed by a different molecular mechanism than the host plant or host cell suspension cultures. We have discussed the biosynthetic principles and evolutionary implications relating to endophytic T. subthermophila based on the results obtained.

Evidence for the evolution of reduced mycorrhizal dependence during plant invasion.

Introduced species inevitably experience novel selection pressures in their new environments as a result of changes in mutualist and antagonist relationships. While most previous work has examined how escape from specialist enemies has influenced herbivore or pathogen resistance of exotic species, post-introduction shifts in exotic dependence on mutualists have not been considered. In a common environment, we compared dependence on AM fungi of North American and European populations of Hypericum perforatum (St. John's Wort), a forb native to Europe. Introduced North American populations responded less to inoculation with AM fungi than did European populations. Root architecture was strongly correlated with mycorrhizal response, and introduced populations had finer root architecture than native populations. Finally, introduced populations exhibited decreased root and increased reproductive allocation relative to European populations, consistent with a transition to a weedier life history; however, biomass allocation patterns were uncorrelated with mycorrhizal response. These findings are the first demonstration of a genetically based reduction of mycorrhizal dependence and shift in root architecture in an introduced species.

Agrobacterium rhizogenes-mediated transformation of Hypericum tomentosum L and Hypericum tetrapterum Fries.

This is the first evidence on successful Agrobacterium rhizogenes-mediated genetic transformation of two species from the genus Hypericum, H. tomentosum L. and H. tetrapterum Fries. Hairy root cultures were induced from root segments of both Hypericum species by two agropine wild-type strains of A. rhizogenes, ATCC 15834 and A4. The transgenic character of the hairy root cultures was proved by PCR amplification of the rolABCD genes. In some H. tetrapterum transgenic lines aux genes were detected as well.

Hypericum perforatum plant cells reduce Agrobacterium viability during co-cultivation.

Plant recalcitrance is the major barrier in developing Agrobacterium-mediated transformation protocols for several important plant species. Despite the substantial knowledge of T-DNA transfer process, very little is known about the factors leading to the plant recalcitrance. Here, we analyzed the basis of Hypericum perforatum L. (HP) recalcitrance to Agrobacterium-mediated transformation using cell suspension culture. When challenged with Agrobacterium, HP cells swiftly produced an intense oxidative burst, a typical reaction of plant defense. Agrobacterium viability started to decline and reached 99% mortality within 12 h, while the plant cells did not suffer apoptotic process. This is the first evidence showing that the reduction of Agrobacterium viability during co-cultivation with recalcitrant plant cells can affect transformation.

An endophytic fungus from Hypericum perforatum that produces hypericin.

For the first time, an endophytic fungus has been isolated from the stems of the medicinal herb Hypericum perforatum (St. John's Wort). The fungus produced the napthodianthrone derivative hypericin ( 1) in rich mycological medium (potato dextrose broth) under shake flask and bench scale fermentation conditions. Emodin ( 2) was also produced simultaneously by the fungus under the same culture conditions. We propose 2 as the main precursor in the microbial metabolic pathway to 1. The fungus was identified by morphology and authenticated by 28S (LSU) rDNA sequencing. Compounds 1 and 2 were identified by LC-HRMS, LC-MS/MS, and LC-HRMS/MS and confirmed by comparison with authentic standards. In bioassays with a panel of laboratory standard pathogenic control strains, including fungi and bacteria, both fungal 1 and 2 possessed antimicrobial activity comparable to authentic standards. This endophytic fungus has significant scientific and industrial potential to meet the pharmaceutical demands for 1 in a cost-effective, easily accessible, and reproducible way.

A comparison of selected media and incubation temperatures for isolation of microscopic fungi from dried medicinal plants.

The study compared selected media and incubation temperatures for isolation of fungi from dried medicinal plants (chamomile, peppermint, lemon balm, St. John's wort and two herbal mixtures). The DG18 medium was found to be the most suitable for characterization of the mycoflora at 25 degrees C. The medium selection for 37 degrees C was dependent on the species to be isolated. MEA + 40% sacharose and YpSs were found to be the best media for isolation of thermophilic and thermotolerant fungi from dried medicinal plants.

Herbal drug quality and phytochemical composition of Hypericum perforatum L. affected by ash yellows phytoplasma infection.

Qualitative/quantitative phytochemical variations were observed in dried flowering tops of cultivated Hypericum perforatum L. cv. Zorzi infected by phytoplasmas of the "ash yellows" class, identified by direct and nested polymerase chain reaction (PCR); this is the first report of ribosomial group 16SrVII phytoplasmas in St. John's Wort. Methanolic extracts of healthy and infected plants were separated by reversed phase high-performance liquid chromatography to quantify naphthodianthrones and flavonoids, while essential oils were analyzed by means of gas chromatography (GC)-GC/MS. The affected plants exhibited decreased amounts of rutin (1.96 +/- 0.23 vs 4.96 +/- 0.02 mg/g), hyperoside (2.38 +/- 0.21 vs 3.04 +/- 0.05 mg/g), isoquercitrin (1.47 +/- 0.04 vs 3.50 +/- 0.08 mg/g), amentoflavone (0.12 +/- 0.01 vs 0.39 +/- 0.02 mg/g), and pseudohypericin (1.41 +/- 0.23 vs 2.29 +/- 0.07 mg/g), whereas the chlorogenic acid content was doubled (1.56 +/- 0.11 vs 0.77 +/- 0.02 mg/g). Hypericin, quercitrin, and quercetin contents were not severely affected. The essential oil yield was drastically reduced in infected material (0.11 vs 0.75% in healthy material) and revealed an increased abundance of sesquiterpenes (beta-caryophyllene, delta-elemene, and germacrene D, in particular) and a matching decrease in monoterpene hydrocarbons and aliphatics. The consequences that the phytopathological condition of cultivated H. perforatum plants has on the commercial quality, market value, and therapeutic efficacy are outlined.

[Study on the quantitative and qualitative composition of fungi in dried medicinal plants]. / Badania skladu ilosciowego i jakosciowego grzybów w suszach roslin leczniczych.

The quantitative and qualitative composition of fungi was determined in selected dried medicinal plants purchased in one of the herbal shops in Szczecin, Poland. The samples examined were as follows: chamomile (Flos Chamomillae), peppermint (Folium Menthae piperitae), lemon balm (Folium Melissae), St. John's wort (Herba Hyperici), and two herbal mixtures. The fungal composition depended on the specified sample. Xerophilic fungi, i.e. Eurotium amstelodami, E. herbariorum, E. rubrum and Wallemia sebi were isolated from dried medicinal plants. E. amstelodami was the predominating species. The prevailing thermophilic and thermotolerant species were Rhizopus microsporus var. rhizopodiformis and Aspergillus fumigatus. Pink and white yeasts were also numerous in some samples. Except for Aspergillus niger, mesophilic and toxigenous species were found to occur infrequently in the samples. However, Aspergillus versicolor was found to occur abundantly in lemon balm.