Screening of Brazilian basidiomycetes for antimicrobial activity

Natural Compounds of Fungal Origin with Antimicrobial Activity-Potential Cosmetics Applications

The phenomenon of drug resistance in micro-organisms necessitates the search for new compounds capable of combating them. Fungi emerge as a promising source of such compounds as they produce a wide range of secondary metabolites with bacteriostatic or fungistatic activity. These compounds can serve as alternatives for commonly used antibiotics. Furthermore, fungi also accumulate compounds with antiviral activity. This review focuses on filamentous fungi and macrofungi as sources of antimicrobial compounds. The article describes both individual isolated compounds and extracts that exhibit antibacterial, antifungal, and antiviral activity. These compounds are produced by the fruiting bodies and mycelium, as well as the biomass of mycelial cultures. Additionally, this review characterizes the chemical compounds extracted from mushrooms used in the realm of cosmetology; specifically, their antimicrobial activity.

Screening of Antibacterial Activity of Some Resupinate Fungi, Reveal Gloeocystidiellum lojanense sp. nov. (Russulales) against E. coli from Ecuador

Bacterial resistance to antibiotics is a serious public health problem that needs new antibacterial compounds for control. Fungi, including resupinated fungi, are a potential source to discover new bioactive compounds efficient again to bacteria resistant to antibiotics. The inhibitory capacity against the bacterial species was statistically evaluated. All the species (basidiomata and strains) were molecularly characterized with the ITS1-5.8S-ITS2 barcoding marker. The strains Ceraceomyces sp., Fuscoporia sp., Gloeocystidiellum sp., Oliveonia sp., Phanerochaete sp., and Xenasmatella sp. correspond to resupinate Basidiomycetes, and only the strain Hypocrea sp. is an Ascomycete, suggesting contamination to the basidiome of Tulasnella sp. According to the antagonistic test, only the Gloeocystidiellum sp. strain had antibacterial activity against the bacterial species Escherichia coli of clinical interest. Statistically, Gloeocystidiellum sp. was significantly (<0.001) active against two E. coli pathotypes (O157:H7 and ATCC 25922). Contrarily, the antibacterial activity of fungi against other pathotypes of E. coli and other strains such as Serratia sp. was not significant. The antibacterial activity between 48 and 72 h increased according to the measurement of the inhibition halos. Because of this antibacterial activity, Gloeocystidiellum sp. was taxonomically studied in deep combined morphological and molecular characterization (ITS1-5.8S-ITS2; partial LSU D1/D2 of nrDNA). A new species Gloeocystidiellum lojanense, a resupinate and corticioid fungus from a tropical montane rainforest of southern Ecuador, with antibacterial potential against E. coli, is proposed to the science.

Are chemical compounds in medical mushrooms potent against colorectal cancer carcinogenesis and antimicrobial growth?

After cardiovascular diseases, cancer is the second main cause of death globally. Mushrooms have been demonstrated to contain amalgamation with properties capable of inhibiting carcinogenesis and microbial growth, principally secondary metabolites such as quinolones, steroids, terpenes, anthraquinones, and benzoic acid derivatives among others. This study aimed to substantiate their potency concerning colon cancer carcinogenesis and antimicrobial growth. A systematic search of important literature was performed considering all the articles published until April 2022. Screening was performed by searching the BMC Springer, Elsevier, Embase, Web of Science, Ovid, and MEDLINE databases. In addition, Google Scholar was used to supplement information. Titles and abstracts that matched the established criteria were selected for full-text article scrutiny and subsequently used in the updated present review. Bioactive compounds present in medicinal mushrooms such as ascorbic acid, organic acids, flavonoids, polysaccharides, glycosides, phenols, linoleic acid, grifolin, and tocopherols among other compounds play a key role in suppressing the proliferation of cancerous cells and selectively act as antibacterial and antifungal agents. These metabolites actively scavenge oxygen free radicals, hydroxyl radicals, and nitrite radicals that would otherwise increase the risks of the growth and development of cancerous cells. Mushrooms' bioactive compounds and metabolites actively inhibit nuclear factor-kappa activation, protein kinase B processes, and ultimately the expression of Cyclooxygenases 2 in cancerous cells. Medicinal mushrooms should be considered as alternative natural chemo-preventive agents in the global fight against colon cancer and the evolution of drug-resistant pathogenic microorganisms, as they exhibit robust potency. They have not been reported to exhibit adverse harmful effects compared to synthetic chemotherapies, yet they have been reported to demonstrate significant beneficial effects.

Isolation and characterization of wood-decomposing basidiomycetes from the Andean Forest in Boyacá, Colombia

This study explores the biotechnological potential of lignocellulolytic fungi collected in an oak forest. Fungal collections were obtained from natural reserves located in Boyacá-Colombia, ranging from 2700 to 3000 m.a.s.l. Twenty-three strains were isolated on malt agar, molecular characterization was performed, and ligninolytic and cellulolytic enzymatic activities were screened. Several white-rot fungi of biotechnological importance were identified as follows: Trametes sp., Trametes versicolor, Trametes villosa, Pycnoporus sanguineus, Bjerkandera adjusta, Lentinula boryana, Panus conchatus, Antrodia neotropica, Brunneoporus malicola, Laetiporus gilbertsonii, Stereum sp., Ganoderma sp., and Dichomitus sp. The strains T. versicolor 0554 and 0583, T. villosa 0562, and B. adusta 0556 showed the highest response in the qualitative enzymatic assays. These strains were used to determine their ability to decolorate the dyes aniline blue and Congo red, and it was found that T. villosa 0562 reached a level of decolorization close to 90% after 48 h of submerged culture. The fungal strains obtained here could offer alternatives to develop a process to accomplish sustainable development objectives.

Antimicrobial Activity of Fomitopsis Officinalis (Vill.) Bondartsev & Singer in Pure Culture

Background. According to the World Health Organization antibiotic resistance is among the top ten threats to human health, food safety and development. Today antibiotic resistance has reached alarmingly high levels all over the world. Meanwhile, the increase in the synthetic drugs' production has led to the pathogenic mycobiota's rapid adaptation to the created chemicals, which have a narrow focus of application. That is why in modern biotechnology and pharmacology much attention is paid to natural producers of biologically active compounds, in particular – to xylotrophic fungi. It has been experimentally proven that the xylotrophic macromycete Fomitopsis officinalis or tinder fungus can be considered to be a promising producer of pharmacological substances with a broad spectrum of action. Studies of active metabolites, contained in the mycelial mass, culture fluid of the medicinal xylotrophic macromycete F. officinalis, and determination of their biological action remain relevant. Objective. The objective was to determine the antimicrobial activity of culture fluid and mycelial mass of F. officinalis different strains from the mushrooms collection (IBK Mushroom Culture Collection of the M.G. Kholodny Institute of Botany, NAS of Ukraine) against gram-negative and gram-positive bacteria species. Methods. An in vitro study of the antimicrobial activity of ethyl acetate extracts of culture fluid and aqueous-ethyl extracts of mycelial mass for F. officinalis strains IBK-5004, IBK-2497, IBK-2498 against gram-positive Staphylococcus aureus (B-918), Bacillus subtilis (В-901) and gram-negative Escherichia coli (B-906), Bacillus subtilis (B-900), Klebsiella pneumoniae (M-123) bacteria by disc-diffusion method was conducted. Results. High antimicrobial activity of tinder fungus culture fluid and mycelial mass extracts against Staphylococcus aureus was established after the 21st day of cultivation, while on the 28th day the zone of growth retardation was maximal (15–25 mm). The highest indices were recorded in F. officinalis IBK-5004 (20–25 mm) and IBK-2498 (20–24 mm) strains. Antimicrobial activity against Klebsiella pneumoniae in culture fluid extracts was manifested on the 21st and 28th days of cultivation. The highest antimicrobial activity against Klebsiella pneumoniae was observed in the culture fluid of the strain F. officinalis IBK-5004, the diameter of the growth retardation zone was 18 mm on the 28th day of cultivation. Mycelial mass's extracts showed moderate activity on the 14th day of cultivation (7-8 mm); maximal activity was recorded on the 28th day (12–22 mm). The most active strain was Fomitopsis officinalis IBK-2498. No antimicrobial activity against test organisms was detected in the following studied strains: Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilis. Conclusions. It has been established that the mycelial mass and culture fluid extracts of F. officinalis IBK-5004, IBK-2497, IBK-2498 strains have high antimicrobial activity against Staphylococcus aureus and moderate antimicrobial activity against Klebsiella pneumoniae on the 21st and 28th day of cultivation.

Spent Pleurotus ostreatus Substrate Has Potential for Managing Fusarium Wilt of Banana

A range of basidiomycetes including the edible mushroom Pleurotus ostreatus (Po) can suppress plant pathogens such as Fusarium spp. With the current increase in production and consumption of Po in Uganda, the spent Po substrate (SPoS) could be an alternative to manage Fusarium wilt of banana (FWB), caused by the soil borne pathogen Fusarium oxysporum f. sp. cubense, race 1 (Foc). This study determined the potential of SPoS to inhibit Foc in vitro and in potted plants. In vitro studies confirmed suppression of Foc in pure co-culture (Po vs. Foc) assays and media amended with different concentrations (0% to 50% w/v) of un-sterilized SPoS filtrates. Foc growth in the sterile SPoS filtrate was comparable to the water control, suggesting possible roles of biotic or thermolabile components of the SPoS. To further verify the suppressive effects of SPoS, pot experiments were carried out with a resistant (‘Mbwazirume’, AAA) and susceptible (‘Sukali Ndizi’, AAB) banana cultivar using both artificially and naturally infested soils. Independent of the inoculation method, SPoS significantly reduced the severity of FWB in pot experiments. Susceptible cultivar ‘Sukali Ndizi’ growing in substrates amended with SPoS showed lower (1.25) corm damage (Scale 0–5) than the un-amended control (3.75). No corm damage was observed in uninoculated controls. The resistant cultivar ‘Mbwazirume’, showed slight (0.25) corm damage only in the Foc-inoculated plants without SPoS. These findings suggest that SPoS could be used as part of the management practices to reduce the impact of FWB.

Characterization of extracellular secondary metabolites in Oudemansiella canarii BRM-044600 displaying antifungal activity against the phytopathogen Sclerotinia sclerotiorum

White mold disease, caused by the phytopathogen Sclerotinia sclerotiorum, provokes severe productivity losses in several economically important crops. Biocontrol agents, especially antagonist filamentous fungi, are environmentally friendly alternatives to the chemical fungicides used in white mold management. The objective of this study was to screen for basidiomycete fungi capable of inhibiting S. sclerotiorum and investigate their bioactive metabolites responsible for antifungal activities. Two out of 17 tested basidiomycete isolates inhibited the mycelial growth of S. sclerotiorum in pair culture experiments on agar plates, namely Oudemansiella canarii BRM-044600 and Laetisaria arvalis ATCC52088. O. canarii BRM-044600 liquid culture filtrate exhibited the greatest antifungal activity and was selected for further investigation. UHPLC-MS analysis suggests that six putative strobilurins, including strobilurin A and/or stereoisomers of this compound (m/z 259.1299, [M + H]⁺) and three putative strobilurins with m/z 257.1184 ([M + H]⁺) are likely responsible for the antifungal activity observed in the culture filtrate. For the first time, this work demonstrated the potential of O. canarii for white mold biocontrol and strobilurin production.

Taxonomy, Diversity and Cultivation of the Oudemansielloid/Xeruloid Taxa Hymenopellis, Mucidula, Oudemansiella, and Xerula with Respect to Their Bioactivities: A Review

The oudemansielloid/xeruloid taxa Hymenopellis, Mucidula, Oudemansiella, and Xerula are genera of Basidiomycota that constitute an important resource of bioactive compounds. Numerous studies have shown antimicrobial, anti-oxidative, anti-cancer, anti-inflammatory and other bioactivities of their extracts. The bioactive principles can be divided into two major groups: (a) hydrophilic polysaccharides with relatively high molecular weights and (b) low molecular medium polar secondary metabolites, such as the antifungal strobilurins. In this review, we summarize the state of the art on biodiversity, cultivation of the fungi and bioactivities of their secondary metabolites and discuss future applications. Although the strobilurins are well-documented, with commercial applications as agrochemical fungicides, there are also other known compounds from this group that have not yet been well-studied. Polysaccharides, dihydro-citrinone phenol A acid, scalusamides, and acetylenic lactones such as xerulin, also have potential applications in the nutraceutical, pharmaceutical and medicinal market and should be further explored. Further studies are recommended to isolate high quality bioactive compounds and fully understand their modes of action. Given that only few species of oudemansielloid/xeruloid mushrooms have been explored for their production of secondary metabolites, these taxa represent unexplored sources of potentially useful and novel bioactive metabolites.

A Review on Antistaphylococcal Secondary Metabolites from Basidiomycetes

Fungi are a rich source of secondary metabolites with several pharmacological activities such as antifungal, antioxidant, antibacterial and anticancer to name a few. Due to the large number of diverse structured chemical compounds they produce, fungi from the phyla Ascomycota, Basidiomycota and Muccoromycota have been intensively studied for isolation of bioactive compounds. Basidiomycetes-derived secondary metabolites are known as a promising source of antibacterial compounds with activity against Gram-positive bacteria. The continued emergence of antimicrobial resistance (AMR) poses a major challenge to patient health as it leads to higher morbidity and mortality, higher hospital-stay duration and substantial economic burden in global healthcare sector. One of the key culprits for AMR crisis is Staphylococcus aureus causing community-acquired infections as the pathogen develops resistance towards multiple antibiotics. The recent emergence of community strains of S. aureus harbouring methicillin-resistant (MRSA), vancomycin-intermediate (VISA) and vancomycin-resistant (VRSA) genes associated with increased virulence is challenging. Despite the few significant developments in antibiotic research, successful MRSA therapeutic options are still needed to reduce the use of scanty and expensive second-line treatments. This paper provides an overview of findings from various studies on antibacterial secondary metabolites from basidiomycetes, with a special focus on antistaphylococcal activity.

Evaluation of the Antibacterial Activity of Pleurotus spp. Cultivated on Different Agricultural Wastes in Chiro, Ethiopia

In the present study, mushrooms, Pleurotus ostreatus and Pleurotus florida, were cultivated on different agricultural wastes namely coffee straw (CS), pea straw (PS), Sorghum Grain Residue (SGR), and Wheat Grain (WG) for the evaluation of antibacterial activity. Antimicrobial activity evaluation was carried out against human pathogenic microorganisms, namely, Escherichia coli, Bacillus subtilis, Streptococcus faecalis, Pseudomonas aeruginosa, and Salmonella typhi by using the disc diffusion method. Methanolic extracts of P. ostreatus cultivated on a Sorghum grain residue substrate were recorded for the highest antibacterial activity against E. coli (19.8 mm) and P. aeruginosa (16.4 mm), and methanolic extracts of P. florida cultivated on a wheat grain substrate were recorded for the highest antibacterial activity against E. coli (18.6 mm) and S. faecalis (14.8 mm). Therefore, results suggested that P. ostreatus and P. florida cultivated on the coffee straw and Sorghum grain substrate were found with the highest antimicrobial activity in comparison to other substrates. The results supported that the methanolic extracts of P. ostreatus and P. florida might indeed be potential sources of antibacterial agents.

Immunological Activities of Crude Polysaccharides Extracts of Climacodon pulcherrimus (Phanerochaetaceae) in Lipopolysaccharide-Induced Rat Macrophages and Neutrophils' Responses

Mushroom contains a wide variety of components with high immune-modulating properties. Mushroom polysaccharides are known as immunocorrectors with wide areas of usage, which balance the immune system without resulting in the entire immune suppression or overreaction. To explore the potentially immunomodulatory role of Climacodon pulcherrimus, the present study was intended to evaluate the in vitro immunomodulatory activity of C. pulcherrimus polysaccharides (CPP) on rat neutrophils and macrophages. CPP was studied on lipopolysaccharide-induced neutrophils and macrophages' responses. The effect on phagocytosis, release of reactive oxygen intermediates (ROI), nitric oxide (NO), lysosomal enzyme release and neutrophil myeloperoxidase, and neutrophil adherence was assessed. The cytotoxicity of CPP against macrophages using 3-(4,5-dimethylthiazole-2-yl)-2, 5-diphenyltetrazolium bromide assay and neutral red inclusion assay was also assessed. ENPC (endopolysaccharides) markedly enhanced phagocytosis of macrophages and neutrophils, whereas the EXPC (exopolysaccharides) increased only that of neutrophils at 0.34 and 0.68 mg/mL. The production of NO evidently increased in ENPC- and EXPC-treated neutrophil and macrophage cultures. The production of ROI in a concentration-dependent manner increased in ENPC-treated (0.08-5.55 mg/mL) and EXPC-treated (0.17 and 0.34 mg/mL) macrophage cultures and ENPC-treated neutrophils, whereas it decreased in EXPC-treated neutrophils. The secretion of acid phosphatase increased in ENPC- and EXPC-treated macrophage and neutrophil cultures. Neutrophil myeloperoxidase release increased in EXPC-treated (5.55 mg/mL) cultures, whereas it decreased in ENPC-treated cultures. ENPC and EXPC increased the adhesion of neutrophils to microplate. These findings demonstrated that CPP displayed a dual mode of action, inhibiting or enhancing numerous phagocytic activities of macrophages and neutrophils.

Assessment of Agaricus Bisporus S-II Extract as a Bio-Controlling Agent against Human Pathogenic Bacterial Species

Agaricus bisporus mushrooms are well known for their nutritional and medicinal values. A. bisporus is a source of protein (about 40% on a dry basis), ergosterol, several minerals, carbohydrate, and fat. The present study was conducted to investigate the effect of A. bisporus S-II extracts on human pathogenic bacteria in-vitro condition. Totally, three human pathogenic bacterial strains (MTCC culture type) were procured from the Institute of Microbial Technology, India. Out of these three bacterial strains, one was Gram-negative (namely P. aeruginosa MTCC741), and the other two were Gram-positive (B. cereus MTCC9786 and S. aureus MTCC740). Microdilution assay was applied for the evaluation of the minimum inhibitory concentration (MIC). The highest antimicrobial activity was observed in methanol extract (26.5%) against S. aureus MTCC740, compared to ethanol extract (17%). Similar results were obtained for P. aeruginosa MTCC741 (21.8%) and B. cereus MTCC9786 (15%) in methanol extract. Least microbial growth inhibition observed for B. cereus MTCC9786 (13.82%) followed by P. aeruginosa MTCC741 (14%), compared to control in ethanol extract. The highest antimicrobial activity up to 17% with ethanolic extracts recorded against S. aureus MTCC740. The MIC results in microtitre plates showed the growth inhibition of P. aeruginosa MTCC741 and S. aureus MTCC740 at extract concentrations of 15 mg/ml and 20 mg/ml, respectively. However, no MIC detected for B. cereus MTCC9786 below 20 mg/ml extract concentration. Regarding minimum bactericidal concentration, the bactericidal value for P. aeruginosa MTCC741 and S. aureus MTCC740 was obtained at 10 mg/ml concentration. The present study indicated that the extracts of the A. bisporus S-II mushrooms had promising antimicrobial activities against the tested organisms.

Biochemical Properties and Effects on Mitochondrial Respiration of Aqueous Extracts of Basidiomycete Mushrooms

There are different varieties of mushrooms not yet studied spread all over the planet. The objective of this study was to evaluate biochemical properties and effects on mitochondrial respiration of eight Basidiomycete mushrooms: Flaviporus venustus EF30, Hydnopolyporus fimbriatus EF41 and EF44, Inonotus splitgerberi EF46, Oudemansiella canarii EF72, Perenniporia sp. EF79, Phellinus linteus EF81, and Pleurotus albidus EF84. Total phenols, ABTS, TEAC, FRAP, and ORAC were measured in order to determine the antioxidant capacity. Antimicrobial potential was studied by disc-diffusion and microdilution method. Cytotoxicity was determined in murine peritoneal macrophages. The bioenergetic aspects were evaluated by the uncoupling of the oxidative phosphorylation in mitochondrias. The H. fimbriatus mushroom was the one that presented the most significant results for the antioxidant assays. Three mushrooms presented antimicrobial activity, indicating a potential for formulation of drugs. The results suggest that I. spligerberi has an uncoupling activity, even at the lowest concentration tested, dissipating the mitochondrial electrochemical gradient. On the other hand, P. albidus has effect only on succinate-oxidase activity without influencing mitochondrial respiratory efficiency. Therefore, both interfere negatively in mitochondrial respiration. In relation with the cytotoxicity in peritoneal macrophages, O. canarii and F. venustus were cytotoxic in this type of cells.

The impact of Andean Patagonian mycoflora in the search for new lead molecules

Secondary metabolites from fungi have become a major source of chemical innovation in programs searching for lead molecules with bioactivities, especially over the last 50 years. In this review, we discuss the fundamental considerations in the discovery of molecules for agricultural and medicinal uses. This group of organisms possesses a strong potential for scientific and industrial communities. Recently, the incorporation of new technologies for the artificial cultivation of fungi and the use of better equipment to isolate and identify active metabolites has allowed the discovery of leading molecules for the design of new and safer drugs and pesticides. The geographical region including the Patagonian Andes mountains harbors a wide diversity of fungi, many of them still unknown and so far associated with Chilean-Argentinian Andean endemic forests. There have been very few chemical studies of the fungi located in this region. However, those few studies have allowed the discovery of new molecules. We argue that the richness of fungal biodiversity in this region offers an interesting source for the discovery of bioactive molecules for the basic and applied sciences.

Antimicrobials from Mushrooms for Assuring Food Safety

The interest in discovering and developing natural antimicrobials has significantly increased due to consumer preferences for foods that are free of chemical preservatives while still microbiologically safe. One of the best sources of natural antimicrobials is certain mushrooms (fungi) as many of them not only have nutraceutical functions but also possess antimicrobial properties. This article reviews the available information on mushroom antimicrobials for food safety control. It includes available resources, extraction procedures, antimicrobial activities, and the status of their applications to food safety. The review indicates that there are great potential benefits to be gained from mushroom antimicrobials in food production, processing, and preservation as a biosolution to meet the increasing demands for food quality and safety.

Enhancement of downy mildew disease resistance in pearl millet by the G_app7 bioactive compound produced by Ganoderma applanatum

Pearl millet (Pennisetum glaucum) stands sixth among the most important cereal crops grown in the semi-arid and arid regions of the world. The downy mildew disease caused by Sclerospora graminicola, an oomycete pathogen, has been recognized as a major biotic constraint in pearl millet production. On the other hand, basidiomycetes are known to produce a large number of antimicrobial metabolites, providing a good source of anti-oomycete agrochemicals. Here, we report the discovery and efficacy of a compound, named G_app7, purified from Ganoderma applanatum on inhibition of growth and development of S. graminicola, as well as the effects of seed treatment with G_app7 on protection of pearl millet from downy mildew. G_app7 consistently demonstrated remarkable effects against S. graminicola by recording significant inhibition of sporangium formation (41.4%), zoospore release (77.5%) and zoospore motility (91%). Analyses of G_app7 compound using two-dimensional nuclear magnetic resonance spectroscopy and liquid chromatography-mass spectrometry revealed its close resemblance to metominostrobin, a derivative of strobilurin group of fungicides. Furthermore, the G_app7 was shown to stably maintain the inhibitory effects at different temperatures between 25 and 80 °C. In addition, the anti-oomycete activity of G_app7 was fairly stable for a period of at least 12 months at 4 °C and was only completely lost after being autoclaved. Seed treatment with G_app7 resulted in a significant increase in disease protection (63%) under greenhouse conditions compared with water control. The identification and isolation of this novel and functional anti-oomycete compound from G. applanatum provide a considerable agrochemical importance for plant protection against downy mildew in an environmentally safe and economical manner.

An agile, simplified and sonication mediated one-pot aqueous extraction and antibacterial assessment of predominant Korean mushrooms

Rapid sonication based aqueous extraction of antimicrobials from mushrooms.

Evaluation of edible mushroom Oudemansiella canarii cultivation on different lignocellulosic substrates

In this study, the mycelial growth rate, mycelial colonization time, yield, and biological efficiency of the edible mushroom Oudemansiella canarii were determined, and the effects of different substrate combinations on productivity, chemical contents and amino acids were evaluated. Lignocellulosic wastes, such as cottonseed hull, sawdust, corncob, and their combinations supplemented with 18% wheat bran and 2% lime, were used for the cultivation of O. canarii. The biological efficiency (BE) and essential amino acid content of treatment T1, which consisted of 80% cottonseed hull, were the highest among all the tested treatments. Mixtures that included sawdust, such as treatments T2 (80% sawdust), T4 (40% sawdust + 40% cottonseed hull), and T6 (40% sawdust + 40% corncob), exhibited lower yield and BE. Corncob was good for O. canarii production in terms of yield and BE, whereas the mycelial growth rate and colonization time were lower compared to those on other substrates. Comparing the BE, essential amino acids, and other traits of the six treatments, treatment T1 (80% cottonseed hull) was the best formula for O. canarii cultivation and should be extended in the future.

Bioactive composition, antimicrobial activities and the influence of Agrocybe aegerita (Brig.) Sing on certain quorum-sensing-regulated functions and biofilm formation by Pseudomonas aeruginosa

Agrocybe aegerita (Brig.) Sing is a basidiomycete, white rot fungus. Antimicrobial activities and the antiqourum effect on Pseudomonas aeruginosa of an A. aegerita methanolic extract were investigated. The extract showed very good antimicrobial activity against all the tested microorganisms in a dose dependent manner. Effects of the Sub-MIC, MIC and 2MIC of the A. aegerita methanolic extract regulated the virulence factors in the quorum sensing (QS) test, as well as biofilm formation on P. aeruginosa. Sub-inhibitory and inhibitory concentrations of the extract demonstrated the reduction of virulence factors such as pyocyanin production, twitching and swimming motility. The biofilm forming capability of P. aeruginosa PAO1 was also reduced in a concentration-dependent manner. Furthermore, the chemical composition of the methanolic extract was determined considering its phenolic composition. The methanolic extract of A. aegerita can be a very good source of bioactive substances. This research is of great importance due to the prevalence of drug-resistant microorganisms.

Screening of antimicrobial, antioxidant properties and bioactive compounds of some edible mushrooms cultivated in Bangladesh

BACKGROUND

For a long time mushrooms have been playing an important role in several aspects of the human activity. Recently edible mushrooms are used extensively in cooking and make part of new food in Bangladesh for their beneficial properties. The aim of this study is to screen some values of mushrooms used in Bangladesh.

METHODS

Methanolic extracts of 3 edible mushrooms (Pleurotus ostreatus, Lentinula edodes, Hypsizigus tessulatus) isolated from Chittagong, Bangladesh were used in this study. Phenolic compounds in the mushroom methanolic extracts were estimated by a colorimetric assay. The antioxidant activity was determined by radical 1, 1-diphenyl;-2-picrylhydrazyl (DPPH) radical scavenging assay. Eight microbial isolates were used for antimicrobial activity of methanolic extract of mushrooms by the agar well diffusion method with slight modification.

RESULTS

Determination of antimicrobial activity indicated considerable activity against all bacteria and fungi reveling zone of inhibition ranged from 7 ± 0.2 to 20 ± 0.1 mm. Minimum inhibitory concentration values of the extracts showed that they are also active even in least concentrations ranged from 1 mg/ml to 9 mg/ml. Lentinula edodes showed the best antimicrobial activity than others. Pseudomonas aeruginosa was quite resistant and Saccharomyces cerevisiae was more sensitive than others microbial isolates. Antioxidant efficiency by inhibitory concentration on 1,1-Diphenly-2-picrylhydrazyl (DPPH) was found significant when compared to standard antioxidant like ascorbic Acid . The concentration (IC50) ranged from 100 ± 1.20 to 110 ± 1.24 μg/ml. Total phenols are the major bioactive component found in extracts of isolates expressed as mg of GAE per gram of fruit body, which ranged from 3.20 ± 0.05 to 10.66 ± 0.52 mg/ml. Average concentration of flavonoid ranged from 2.50 ± 0.008 mg/ml to 4.76 ± 0.11 mg/ml; followed by very small concentration of ascorbic acid (range, 0.06 ± 0.00 mg/ml to 0.21 ± 0.01 mg/ml) in all the isolates. All the isolates showed high phenol and flavonoid content (except Pleurotus ostreatus), but ascorbic acid content was found in traces.

CONCLUSION

This study has revealed that selected edible mushrooms have not only nutritional values but also some therapeutic values. Proper and more investigations can lead us to use these as strong medicine in future.

Wild-growing lignicolous mushroom species as sources of novel agents with antioxidative and antibacterial potentials

Crude extracts of two edible and two medicinal lignicolous mushroom species: Meripilus giganteus, Agrocybe aegerita, Fomes fomentarius and Xylaria polymorpha, growing wild in Serbia, were analyzed for their antioxidative and antibacterial potentials. Free radical scavenging capacity (RSC) on DPPH(•) and (•)OH was evaluated both by spectrophotometer and by Electron Spin Resonance (ESR) spectroscopy against DPPH(•). The highest antioxidant and antibacterial bioactivity was obtained with F. fomentarius extracts (IC50 ≈ 10.7 µg/ml in DPPH(•) assay; 136.6 mg ascorbic acid equivalents (AAE)/g dry weight (d.w.) for ferric reducing antioxidant power FRAP). It also showed the highest total phenol (TP) (82.54 mg gallic acid equivalents (GAE)/g dry weight (d.w.)) and total flavonoid (TF) content (76.8 µg rutin equivalents (RE)/g dry weight (d.w.)). A. aegerita showed the best antioxidant activity (IC50 = 0.87 mg/ml) against DPPH(•) in ESR analysis. Total redox potential of extracts was in direct positive correlation with TP content (r(2 )= 0.98) and TF content (r(2 )= 0.58). GC/MS analysis detected major constituents of extracts, confirming the presence of the following organic and phenolic acids: fumaric, succinic, mallic, 4-hydroxy benzoic, gentisic, protocatechuic, vanillic, gallic and p-coumaric acid.

Antioxidant activity via DPPH, gram-positive and gram-negative antimicrobial potential in edible mushrooms

Edible mushrooms (EMs) are nutritionally rich source of proteins and essential amino acids. In the present study, the antioxidant activity via 1,1-diphenyl-2-picrylhydrazyl (DPPH) and antimicrobial potential in EMs ( Pleurotus ostreatus, Morchella esculenta, P. ostreatus (Black), P. ostreatus (Yellow) and Pleurotus sajor-caju) were investigated. The DPPH radical scavenging activity revealed that the significantly higher activity (66.47%) was observed in Morchella esculenta at a maximum concentration. Similarly, the dose-dependent concentrations (200, 400, 600, 800 and 1000 µg) were also used for other four EMs. Pleurotus ostreatus exhibited 36.13% activity, P. ostreatus (Black (B)) exhibited 30.64%, P. ostreatus (Yellow (Y)) exhibited 40.75% and Pleurotus sajor-caju exhibited 47.39% activity at higher concentrations. Furthermore, the antimicrobial potential were investigated for its toxicity against gram-negative bacterial strains ( Escherichia coli, Pseudomonas aeroginosa, Salmonella typhi, Klebsiella pneumonia, Erwinia carotovora and Agrobacterium tumifaciens), gram-positive bacterial strains ( Bacillus subtilis, Bacillus atrophaeus and Staphylococcus aureus) and a fungal strain ( Candida albicans) in comparison with standard antibiotics. Antimicrobial screening revealed that the ethanol extract of P. ostreatus was active against all microorganism tested except E. coli. Maximum zone of inhibition (13 mm) was observed against fungus and A. tumifaciens. P. sajor-caju showed best activities (12.5 mm) against B. subtilis, B. atrophaeus and K. pneumonia. P. ostreatus (Y) showed best activities against P. aeroginosa (21.83 mm), B. atrophaeus (20 mm) and C. albicans (21 mm). P. ostreatus (B) exhibited best activities against C. albicans (16 mm) and slightly lower activities against all other microbes except S. typhi. M. esculenta possess maximum activities in terms of inhibition zone against all microorganisms tested except S. typhi.

Agaricus blazei Murill as an efficient hepatoprotective and antioxidant agent against CCl4-induced liver injury in rats

Agaricus blazei Murill is one of the very popular edible medicinal mushrooms. The present study investigated the protective effect of this biologically active mushroom on the tissue peroxidative damage and abnormal antioxidant levels in carbon tetrachloride induced hepatotoxicity in male albino rats. Male albino rats of Sprague-Dawley strain weighting (120-150 g) were categorized into five groups. The first group served as the normal control, the second and the third groups were treated with Agaricus blazei Mushroom extract and carbon tetrachloride dose, respectively. Fourth group (protective group) was first treated with Agaricus blazei Mushroom extract followed by carbon tetrachloride treatment and fifth (therapeutic group) with carbon tetrachloride first followed by Agaricus blazei Mushroom treatment. The wet fruiting bodies of mushroom Agaricus blazei Murill, crushed and suspended in distilled water was administered orally to the treated groups of male albino rats. The activities of various enzymes (aspartate and alanine transaminase, lactate dehydrogenase, glutathione reductase), levels of non-enzymatic antioxidants (glutathione, vitamin C, vitamin E) and level of lipid peroxidation (malondialdehyde) were determined in the serum of all the experimental animals. Decrease in all the enzymes and non-enzymatic antioxidant, along with an increase in the lipid peroxidative index (malondialdehyde) was found in all the carbon tetrachloride treated rats as compared with normal controls. Also increase level of non-enzymatic antioxidant along with the decrease level in malondialdehyde was found in all experimental animals which were treated with Agaricus blazei Mushroom extract as compared with normal controls. The findings indicate that the extract of Agaricus blazei Murill can protect the liver against carbon tetrachloride induced oxidative damage in rats and is an efficient hepatoprotective and antioxidant agent against carbon tetrachloride induced liver injury.

Diversity and antimicrobial activities of the fungal endophyte community associated with the traditional Brazilian medicinal plant Solanum cernuum Vell. (Solanaceae)

The diversity and antimicrobial activity of endophytic fungi associated with the Brazilian medicinal plant Solanum cernuum Vell. were studied during summer and winter seasons. A total of 246 fungal isolates were obtained, including 225 filamentous fungi and 21 yeasts. They were identified by morphological, physiological, and molecular methods. Fifty-five different taxa represented by the phyla Ascomycota (33 taxa), Basidiomycota (21 taxa), and Zygomycota (one taxon) were identified. The most abundant taxa were closely related to Arthrobotrys foliicola , Colletotrichum gloeosporioides , Coprinellus radians , Glomerella acutata , Diatrypella frostii , Phoma glomerata , Mucor sp., Phlebia subserialis , Phoma moricola , Phanerochaete sordida , and Colletotrichum sp. A total of 265 fungal extracts were screened and 64 (26.01%) displayed antimicrobial activities. Among these extracts, 18 (28.12%) presented antibacterial and antifungal activities, 42 (65.62%) displayed selective antibacterial activity, and four (6.25%) exhibited only antifungal activity. The best values of minimum inhibitory concentration were obtained from extracts of Cryptococcus rajasthanensis , Glomerella acutata, Leptosphaeria sp., and Phoma glomerata ranging from 7.8 to 15.62 µg/mL. This study is the first survey of the endophytic fungi community associated with S. cernuum, and our results show that they can represent a promising source of bioactive compounds.

Emergence of Candida spp. and exploration of natural bioactive molecules for anticandidal therapy--status quo

The opportunistic yeast pathogen Candida albicans and the emerging non-albicans Candida spp. cause life-threatening infections in immuno-compromised patients, leading to an increase in mortality rate. At present, the emergence of non-albicans Candida spp. causes serious infections that are difficult to treat the human populations worldwide. The available, synthetic antifungal drugs show high toxicity to host tissues causing adverse effects. Many metabolites of terrestrial and marine plants, microbes, algae, etc., contain a rich source of unexplored novel leads of different types, which are under use to treat various diseases. Such natural drugs are less expensive and have lower toxicity to host tissues. The patent search on identified and potential anticandidal-lead molecules, from various patent databases, has been described in this review. Furthermore, this article consolidates the trends in the development of anticandidal drug discovery worldwide. Most of the investigations on natural, bioactive molecules against candidiasis are in various phases of clinical trials, of which, two drugs Caspofungin acetate and Micafungin sodium were approved by the U.S. FDA. In conclusion, the exploration of drugs from natural resources serves as a better alternative source in anticandidal therapeutics, having great scope for drug discovery in the future.

Antimicrobial activity of endophytic fungi associated with Orchidaceae in Brazil

The purpose of this study was to examine antimicrobial activity of endophytic fungi isolated from the leaves, stems, and roots of 54 species of Orchidaceae collected in a Brazilian tropical ecosystem. In total, 382 filamentous fungi and 13 yeast isolates were obtained and cultured to examine the production of crude extracts. Thirty-three percent of the isolates displayed antimicrobial activity against at least one target microorganism. The multivariate statistical analyses conducted indicate that the extracts of endophytic fungi isolated from leaves of terrestrial orchids in semideciduous forest were more active against Escherichia coli, whereas extracts of endophytic fungi from roots of rupicolous orchids collected in rock fields were more active against Candida krusei and Candida albicans. Among the fungi that were screened in the study, 22 isolates held their antimicrobial activities after replication and were therefore selected for assessment of the minimum inhibitory concentration (MIC), which ranged from 62.5 to 250 microg/mL and 7.8 to 250 microg/mL against bacteria and fungi, respectively. One isolate of Alternaria sp. and one isolate of Fusarium oxysporum presented the strongest antibacterial activity. Three Fusarium isolates, Epicoccum nigrum, and Sclerostagonospora opuntiae showed the greatest MIC values against the pathogenic yeasts. This study is the first survey investigating the bioactive potential of endophytic fungi associated with tropical Orchidaceae species present in Brazilian ecosystems.

Agaricales Fungi from atlantic rain forest fragments in Minas Gerais, Brazil

Two Atlantic Rain Forest fragments in Minas Gerais state were studied to access their Agaricales fungal richness. A total of 187 specimens were collected and 109 species, 39 genera, and eight families were identified. Thirty-three species were cited for the first time in Brazil.

Cytotoxic, immunosuppressive, trypanocidal and antileishmanial activities of Basidiomycota fungi present in Atlantic Rainforest in Brazil

One hundred three Basidiomycota fungi representing 84 species and 17 families were collected from different Atlantic Rainforest in Brazil. Their basidiomes and fermentation broth extracts were screened in a bioassay panel that included three human cancer cells lines, human peripheral blood mononuclear cells (PBMCs), the enzyme trypanothione reductase (TryR) from Trypanosoma cruzi, and amastigote forms of Leishmania amazonensis. Forty-two extracts representing 21 genera and 35 species presented activities higher than 60% in one or more assays employed in this study. Eighteen extracts were toxic to one or more human cancer cell lines. Extracts from Lentinus strigosus CCB 178 and Lentinus sp. UFMGCB 38 showed selectivity towards cancer cells as they showed only a minor impact on PBMCs. Six extracts suppressed PBMCs proliferation and showed low toxic effect to cancer cells. Thirty-four extracts inhibited the activity of the TryR. Of these, five showed low toxicity towards PBMCs. Extracts from Gymnopilus areolatus, Irpex lacteus, L. strigosus, Nothopanus hygrophanus, Pleurotus flabellatus, and unidentified Basidiomycetes were toxic to L. amazonensis. The results of this screening reinforce the potential of Basidiomycota fungi as sources of bioactive natural products that may be developed into new therapeutic agents for cancer and neglected diseases such as trypanosomiasis and leishmaniasis.

Hypoglycemic effect of Lentinus strigosus (Schwein.) Fr. crude exopolysaccharide in streptozotocin-induced diabetic rats

ABSTRACT This study reports the hypoglycemic effects of the crude exopolysaccharide (EPS) produced from submerged mycelial culture of Lentinus strigosus (Schwein.) Fr. (Family Polyporaceae) in streptozotocin (STZ)-induced diabetic rats. In a dose-dependent study, diabetic rats were treated with EPS at doses of 50-150 mg/kg of body weight for 7 days. Serum glucose and plasma insulin levels were measured in normal, STZ-induced diabetic, and EPS-treated diabetic rats. Following oral administration of EPS dosages for 7 days, the serum glucose levels in the STZ-induced diabetic rats were reduced up to 21.1% at the dose of 150 mg/kg of body weight. The results revealed that orally administered L. strigosus EPS, at the dose of 150 mg/kg, exhibited a considerable hypoglycemic effect in STZ-induced diabetic rats. Plasma insulin levels of STZ-induced diabetic rats decreased as compared to control group rats (P < .05). Although insulin levels slightly increased in the EPS-treated groups the increase was not statistically significant. The hypoglycemic potential of the EPS was further supported by histological observations of pancreatic islets of Langerhans.

Antimicrobial activity of two wild mushrooms Clitocybe alexandri (Gill.) Konr. and Rhizopogon roseolus (Corda) T.M. Fries collected from Turkey

Two edible wild mushrooms, namely Clitocybe alexandri (Gill.) Konr. (Tricholomataceae) and Rhizopogon roseolus (Corda) T.M. Fries (Rhizopogonaceae), collected from the southwest of Turkey, were tested for their antimicrobial activity by using the disc diffusion method. The ethanol, methanol, diethyl ether, water, ethylacetate and n-hexane extracts from the fruit bodies of mushrooms were assayed against 13 microorganisms. In comparison with the test antibiotics penicillin, novobiocin, nalidixic acid and ampicillin, the methanol extract obtained from the two mushrooms presented significant activity against E. coli, Bacillus subtilis and Enterobacter aerogenes. On the other hand, the ethylacetate extract from C. alexandri was found to be active against Candida albicans and Saccharomyces cerevisiae, whereas the ethanol extract of Rhizopogon roseolus was active against Saccharomyces cerevisiae. This research has shown that various extracts obtained from two macrofungi could be used in vitro to inhibit the growth of some important bacteria and fungi.

Altenusin, a biphenyl isolated from the endophytic fungus Alternaria sp., inhibits trypanothione reductase from Trypanosoma cruzi

Parasitic protozoan species belonging to the genera Trypanosoma and Leishmania are the etiological agents of several diseases in tropical areas of the world, for which there is an urgent need for effective and affordable treatment. In this regard, we are screening the Brazilian biodiversity, especially its flora and mycota, for natural products that could serve as leads for drug development against these diseases. Trypanothione reductase (TR) is an enzyme involved in the protection of Trypanosoma and Leishmania species against oxidative stress, and is considered to be a validated drug target. The endophytic fungus Alternaria sp. (UFMGCB55) was isolated from the plant Trixis vauthieri DC (Asteraceae), known to contain trypanocidal compounds. The organic extract of the culture of Alternaria sp. was able to inhibit TR by 99%, when tested at 20 microg mL(-1). Fractionation of the extract identified altenusin, a biphenyl derivative with an IC50 value of 4.3+/-0.3 microM in the TR assay. This compound is the first in its class to have shown TR inhibitory activity, opening new perspectives for the design of more effective derivatives that could serve as drug leads for new chemotherapeutic agents to treat trypanosomiasis and leishmaniasis.

An extract of the mushroom Agaricus blazei Murill administered orally protects against systemic Streptococcus pneumoniae infection in mice

The aim was to investigate the antibacterial effect of the biologically active and edible mushroom Agaricus blazei Murill (AbM). A water extract of AbM or PBS control was administered orally before or with challenge to NIH/OlaHsd mice, experimentally infected intraperitoneally with the moderately virulent Streptococcus pneumoniae serotype 6B. End points were bacteraemia and survival rate. The AbM extract, protected against systemic S. pneumoniae 6B infection in the mice. It was most effective when given 24 h before inoculation but did also have protective effects when given together with challenge compared with control. The lack of antibiotic effect on pneumococci in vitro and increased levels of cytokines MIP-2 and TNF-alpha in the serum of mice receiving AbM extract, indicated that the protective effect of AbM was due to the involvement of the native immune system. This is the first report of anti-infection effects of AbM in vivo. Our results suggest that AbM extract may be useful as additional prophylactic and possibly therapeutic treatment against bacterial and possibly other infections in humans.