Changes in the populations of microorganisms associated with the application of soil amendments to control Sclerotium rolfsii Sacc.

Populations of microorganisms from soil treated with guanidine thiocyanate, guanylurea sulfate, thiourea, or furfural were compared with those of untreated soil. The materials effected quantitative and/or qualitative changes in composition of the soil microflora depending on the compound used. Guanidine thiocyanate (Gt) significantly (p0.05) increased total fungal populations relative to populations of other treatments. Populations of Penicillium purpurogenum were markedly higher in Gt-treated soil. Gt also increased total bacterial populations, and was the only compound that increased actinomycete populations. The relative percentage of Trichoderma harzianum was significantly higher in soil treated with thiourea than in the other treatments. Furfural increased the percentage of P. purpurogenum with respect to total fungi, and was as effective as guanylurea sulfate in increasing chitinolytic bacteria and those in the Pseudomonas cepacia-group. Thiourea most effectively promoted proliferation of coryneform bacteria. Chitinolytic fungi increased synergistically when Gt and guanylurea sulfate were applied in combination.     

A quantitative assessment of the antimicrobial activity of garlic (Allium sativum)

An aqueous extract of freeze-dried garlic (Allium sativum), when incorporated into growth media, inhibited many representative bacteria, yeasts, fungi and a virus. All microorganisms tested were susceptible to garlic. Quantitative assessment of the minimum inhibitory concentrations for bacteria and yeasts showed values ranging from 0.8 to 40.0 mg garlic ml^-1. Fungal radial colony growth was inhibited by at least 25% at concentrations as low as 2.0 mg garlic ml^-1. The 50% endpoint neutralization titre for rotavirus was 2.4 to 2.8 g ml^-1. Lactic acid bacteria were the least sensitive microorganisms to the inhibitory effects of garlic. In mixed culture studies of Lactobacillus acidophilus and Escherichia coli, garlic prevented the establishment of E. coli, although the final outcome of competition was not affected.L.P. Rees, S.F. Minney and N.T. Plummer are with Interprise Ltd, Baglan Bay Industrial Park, Port Talbot SA 12 7DJ, UK. J.H. Slater and D.A. Skyrme are with the School of Pure and Applied Biology, University of Wales, Cardiff, P.O. Box 915, Cardiff CF1 3TL, UK.     

Microbially induced diseases of Agaricus bisporus: biochemical mechanisms and impact on commercial mushroom production

The button mushroom, Agaricus bisporus (Lange) Imbach, the most common cultivated mushroom, is susceptible to a wide range of virus, bacterial, and fungal diseases. However, only some diseases were studied for the mechanisms involved in the host–microorganism interaction. This review deals with biochemical mechanisms related to cavity disease (Burkholderia gladioli) and to the interaction between A. bisporus and the causal agents responsible for the most severe diseases, namely the bacteria Pseudomonas tolaasii and Pseudomonas reactans and the fungi Trichoderma aggressivum and Lecanicillium fungicola.     

微生物菌剂对秸秆降解及秸秆中微生物变化规律的影响

为明确不同微生物菌剂对秸秆降解率及秸秆降解过程中秸秆周围微生物变化规律的影响，在温室大棚内进行不同微生物菌剂降解秸秆试验。以玉米秸秆为基质，设玉米秸秆（对照组）、玉米秸秆+哈茨木霉（Trichoderma harzianum）（处理1）、玉米秸秆+哈茨木霉+地衣芽胞杆菌(Bacillus licheniformis)（处理2）三个处理。研究结果显示，单独用哈茨木霉处理可显著提高秸秆降解率，前期作用尤其明显；在秸秆降解的前30 d，秸秆降解率与秸秆中可培养真菌、细菌、放线菌呈显著正相关。不同微生物菌剂对秸秆中可培养微生物数量变化有显著影响，单独接种哈茨木霉后，秸秆中可培养真菌、细菌、放线菌数在前30 d显著高于对照组和混合菌剂处理，不同处理可培养活菌数均在90～120 d达到峰值，然后开始下降。研究结果表明，不同微生物菌剂对秸秆降解有显著影响，单独用哈茨木霉处理可显著提高秸秆降解率；不同处理对秸秆中可培养真菌、细菌、放线菌的影响有显著差异。可为秸秆降解与微生物相关性研究提供参考。     

The properties of l-fucose binding agglutinin associated with the cell wall of Rhizoctonia solani

The adherence of Escherichia coli B cells to cell wall associated-agglutinin of the soil borne plant pathogen Rhizoctonia solani, was inhibited by l-fucose, l-galactose, trypsin, SDS, cycloheximide and Na₂-EDTA. The coiling of the biocontrol agent Trichoderma harzianum around Rhizoctonia hyphae was prevented by SDS, cycloheximide, Na₂-EDTA and methyl--l-fucoside — an inhibitor of Rhizoctonia agglutinin not metabolized by both fungi. The possible role of the agglutinin in Trichoderma-Rhizoctonia interaction is discussed.     

Response of Pseudomonas tolaasii,the causal agent of mushroom brown blotch disease to the volatile compounds produced by endofungal bacteria

Volatile organic compounds (VOCs) produced by bacteria have significant potential to control phytopathogens. In this study, the VOCs produced by endofungal bacteria Pseudomonas sp. Bi1, Bacillus sp. De3, Pantoea sp. Ma3 and Pseudomonas sp. De1 isolated from wild growing mushrooms were evaluated in vitro for their antagonistic activity against Pseudomonas tolaasii Pt18, the causal agent of mushroom brown blotch disease. The gas chromatography–mass spectrometry (GC–MS) analysis revealed that strains Pseudomonas sp. Bi1, Pseudomonas sp. De1, Bacillus sp. De3 and Pantoea sp. Ma3 produced eight, sixteen, nine, and twelve VOCs, respectively. All antagonistic endofungal bacteria produced VOCs which significantly reduced brown blotch symptoms on mushroom caps and inhibited the growth of P. tolaasii Pt18 at the varying levels. Scanning electron microscopy revealed severe morphological changes in cells of P. tolaasii Pt18 following exposure to the VOCs of Pseudomonas sp. Bi1 and De1. Furthermore, The VOCs produced by endofungal bacteria significantly reduced swarming, swimming, twitching, chemotaxis motility and biofilm formation by P. tolaasii Pt18 cells, which are essential contributors to pathogenicity. This is to first report about the inhibition effects of VOCs produced by antagonistic bacteria on virulence traits of P. tolaasii. Our findings provide new insights regarding the potential of antibacterial VOCs as a safe fumigant to control mushroom brown blotch disease.

     

Molecular genetic characterization of bacterial isolates causing brown blotch on cultivated mushrooms in Japan

The polymerase chain-reaction (PCR) was used to amplify 16S ribosomal DNA (16S rDNA) from bacteria, identified asPseudomonas tolaasii orP. fluorescens, causing brown blotch on cultivated mushrooms in Japan. PCR-amplified 16S rDNA was analyzed on the basis of nucleotide sequence and restriction fragment length polymorphisms (RFLP) to determine the specific identity of isolates. Banding patterns obtained through PCR using primers corresponding to repetitive extragenic palindromic sequences of enteric bacteria (REP-PCR) were used to determine the relatedness of conspecific isolates. AllP. tolaasii isolates and a mushroom pathogen identified asP. fluorescens had identical RFLP patterns and partial 16S sequences, and are considered conspecific. An isolate ofP. fluorescens from creamery wastes (IFO 3507) differed slightly from isolates ofP. tolaasii in both 16S sequence (0.8%) and RFLP patterns (d=0.08), and had almost entirely different REP-PCR bands (d=0.88–1.0). Phylogenetic analyses based on 16S sequences indicated thatP. tolaasii andP. fluorescens are close members ofPseudomonas sensu stricto. REP-PCR shows promise in characterizing isolates pathogenic on different mushroom crops. Two isolates ofP. tolaasii pathogenic onPleurotus ostreatus had identical banding patterns, but three isolates fromLentinula edodes showed the greatest diversity. Contribution No. 312 of the Tottori Mycological Institute, Totori, Japan.     

<Emphasis Type="Italic">Pezicula cinnamomea</Emphasis> from cherry tree: pathogenicity tests and photomorphogenesis in culture

Pezicula cinnamomea (DC.: Fr.) Sacc. was frequently isolated from dead twigs of flowering cherry (Prunus × yedoensis Matsum.) in Aomori Prefecture, Japan. Inoculations of flowering cherry tree twigs with the fungus resulted in longitudinal browning of heartwood tissues 3–4cm long after 7 months, showing no apparent symptoms on the bark. The fungus were reisolated at high rates from the affected tissues. Apothecia were formed on cut affected twigs when they were placed in a moist Petri dish and kept under near-UV (Black Light Blue; BL-B) light irradiation. On potato sucrose agar (PSA) plates, the fungus failed to form apothecia in the dark, while many apothecia were formed under BL-B and, to a lesser extent, under white light. In nature, the light, especially near-UV, might be an important factor in apothecium formation. Under near-UV from BL-B conidiomata with conidia formed after 5–6 days and mature apothecia after about 14 days. The developmental processes of the apothecium were histologically studied under light and electron microscopes. Pezicula cinnamomea, which is homothallic and fruits easily in culture, may be very useful for life cycle studies and the elucidation of ecological role of this group of fungi.     

Comparison of Riboflavin and Toluidine Blue O as Photosensitizers for Photoactivated Disinfection on Endodontic and Periodontal Pathogens In Vitro

Photoactivated disinfection has a strong local antimicrobial effect. In the field of dentistry it is an emerging adjunct to mechanical debridement during endodontic and periodontal treatment. In the present study, we investigate the effect of photoactivated disinfection using riboflavin as a photosensitizer and blue LED light for activation, and compare it to photoactivated disinfection with the widely used combination of toluidine blue O and red light. Riboflavin is highly biocompatible and can be activated with LED lamps at hand in the dental office. To date, no reports are available on the antimicrobial effect of photoactivated disinfection using riboflavin/blue light on oral microorganisms. Planktonic cultures of eight organisms frequently isolated from periodontal and/or endodontic lesions (Aggregatibacter actinomycetemcomitans, Candida albicans, Enterococcus faecalis, Escherischia coli, Lactobacillus paracasei, Porphyromonas gingivalis, Prevotella intermedia and Propionibacterium acnes) were subjected to photoactivated disinfection with riboflavin/blue light and toluidine blue O/red light, and survival rates were determined by CFU counts. Within the limited irradiation time of one minute, photoactivated disinfection with riboflavin/blue light only resulted in minor reductions in CFU counts, whereas full kills were achieved for all organisms when using toluidine blue O/red light. The black pigmented anaerobes P. gingivalis and P. intermedia were eradicated completely by riboflavin/blue light, but also by blue light treatment alone, suggesting that endogenous chromophores acted as photosensitizers in these bacteria. On the basis of our results, riboflavin cannot be recommended as a photosensitizer used for photoactivated disinfection of periodontal or endodontic infections.     

Several pseudomonads, associated with the cultivated mushrooms Agaricus bisporus or Pleurotus sp., are hemolytic

Pseudomonas tolaasii, causing brown blotch disease on cultivated mushrooms, and yielding a white line precipitate towards P. “reactans”, has been shown to induce lysis of erythrocytes. Some Finnish strains isolated from diseased mushroom fruit bodies, although harboring the typical features of P. tolaasii, proved to be distinct, and have been allocated to a nov. sp. P. costantinii. We examined in these study whether all brown blotch causing agents were hemolytic. The induction of erythrocytes lysis seemed to be a rather common feature of mushroom associated-pseudomonads, especially for strains involved in the production of a white-line-in agar.     

Exposure to Bioaerosols during the Growth Season of Tomatoes in an Organic Greenhouse Using Supresivit (Trichoderma harzianum) and Mycostop (Streptomyces griseoviridis)

In working environments, especially in confined spaces like greenhouses, elevated concentrations of airborne microorganisms may become a problem for workers'' health. Additionally, the use of microbial pest control agents (MPCAs) may increase exposure to microorganisms. The aim of this study was to investigate tomato growers'' exposure to naturally occurring bioaerosol components [dust, bacteria, fungi, actinomycetes, (1→3)-β-d-glucans, and endotoxin] and MPCAs applied by drip irrigation. Airborne dust was collected with filter samplers and analyzed for microorganisms by plate counts and total counts using a microscope. Analysis of (1→3)-β-d-glucan and endotoxin content was performed by kinetic, chromatic Limulus amoebocyte lysate tests. The fungal strain (Trichoderma harzianum) from the biocontrol product Supresivit was identified by PCR analysis. Measurements were performed on the day of drip irrigation and 1 week, 1 month, and 3 months after the irrigation. T. harzianum from Supresivit could be detected only on the day of treatment. Streptomyces griseoviridis, an applied MPCA, was not detected in the air during this investigation. We found that bioaerosol exposure increases during the growth season and that exposure to fungi, bacteria, and endotoxin can reach levels during the harvest period that may cause respiratory symptoms in growers. The collected data indicate that MPCAs applied by drip irrigation do not become airborne later in the season.In greenhouses, the growth conditions for plants are optimized to increase crop yield. However, the confined environment can increase growers'' exposure to bioaerosols (fungal spores, bacteria, pollen, etc.) and agents for plant protection (25). It is well documented that workers in agriculture are exposed to high concentrations of airborne microorganisms due to the handling of organic materials (31, 52), but less is known about greenhouse workers'' exposure.Inhalation of microorganisms can cause respiratory symptoms and lung function impairment (2, 4, 10, 11, 29, 56). The components (1→3)-β-d-glucan (β-glucan) and endotoxin are found to be associated with respiratory symptoms as well (8, 40, 41). Endotoxin is found predominantly on the outer surface of Gram-negative bacteria, and β-glucans are a part of the cell wall in fungi, as well as in some plants. There are strong indications that inhalation of propagules from the actinomycete Streptomyces may evoke an immunological response leading to respiratory diseases (16). Occupational asthma and rhinitis have been reported for greenhouse workers sensitized to workplace flowers or molds (42, 43, 45, 46). Another health concern is that some fungal species, e.g., the thermophilic Aspergillus fumigatus, can infect immunosuppressed people (30).Microbial pest control agents (MPCAs) are species of microorganisms that can suppress plant pests and pathogens (5). Application of biocontrol products that contain MPCAs may increase growers'' exposure to the microbial agent (9, 19, 26, 27). The biocontrol product Supresivit contains the ascomycete Trichoderma harzianum (Rifai 1969) which belongs to the family Hypocreaceae. The genus Trichoderma is beneficial in vegetable production due to its ability to outcompete plant-pathogenic microorganisms. It is also a parasite on other fungi and can induce systemic and localized resistance to pathogens in plants (21). T. harzianum is applied to foliage, seeds, or soil but can also be applied to plant wounds as a paste. Another fungal species used in biocontrol products is, e.g., Beauveria bassiana, which is applied by soil treatment or spraying. The biocontrol product Mycostop contains the actinomycete Streptomyces griseoviridis strain K61. Actinomycetes are Gram-positive bacteria that reproduce through spore release. S. griseoviridis can suppress a range of seed- and soilborne fungal pathogens through the release of antibiotics (28).The aim of this study was to investigate growers'' exposure to MPCAs and other bioaerosol components during the growth season of greenhouse tomatoes. We monitored the exposure to dust, microorganisms, endotoxin, and β-glucans from the time of application of MPCAs by drip irrigation in late winter to tomato harvest in late spring.     

Production of bacteriolytic enzymes by mycoparasitic Trichoderma strains

Eighteen mycoparasitic Trichoderma strains were tested for their ability to degrade heat-inactivated Bacillus cereus var. mycoides, B. megaterium, B. subtilis, Escherichia coli, Micrococcus luteus, Pseudomonas aeruginosa and Serratia marcescens cells. The non-inductive and inductive ferment broths of five strains with good degrading abilities towards B. subtilis were investigated for specific degrading enzyme activities. In addition to trypsin- and chymotrypsin-like protease activities, -1,4-N-acetyl-glucosaminidase (NAGase) was also secreted. Strain Trichoderma harzianum T19 had the most outstanding degrading abilities. The extracellular degrading enzymes of this strain were separated on a Sephadex G-150 column, and their preliminary characterization was performed. The results demonstrated that muramidase-like activities are present in the ferment broth of this T. harzianum strain.     

Nanocrystal Cu2O-loaded TiO2 nanotube array films as high-performance visible-light bactericidal photocatalyst

In this work, we report the use of a non-toxic nanocrystal Cu₂O-loaded TiO₂ nanotube array (Cu₂O/TNTs) film as high-performance visible-light bactericidal photocatalyst. The samples were characterized by field-emission scanning electron microscopy, X-ray photoelectron spectroscopy, and ultraviolet–visible diffusion reflection spectroscopy. This Cu₂O/TNTs film photocatalyst is capable of complete inactivation of Escherichia coli in 5?×?10⁷ colony-forming units/mL within a record short disinfection time of 20?min under visible-light irradiation. The average bactericidal percentage of the Cu₂O/TNTs for E. coli under visible-light irradiation are 20 times and 6.6 times higher than those of TNTs under the same conditions and Cu₂O/TNTs without light, respectively. This superior bactericidal performance is mainly attributed to the high ability to produce OH radicals by both photogenerated electron and hole of the prepared photocatalyst under visible light. The Cu₂O/TNTs film photocatalyst makes it applicable to broad fields including drinking water disinfection.     

Production of Extracellular l-Asparaginases by Microorganisms

A variety of microorganisms were tested for their extracellular l-asparaginase productivity and it was found that many bacteria, fungi and yeasts are positive for it. Especially some strains in the genera Pseudomonas, Candida and Rhodotorula were able to produce a large amounts of the enzyme. Escherichia coli, however, that contained intracellular enzyme was unable to produce extracellular one. In enzymological properties some differences were noted among these extracellular enzymes. Pseudomonas asparaginase showed glutaminase activity too, but the asparaginases of Candida and Rhodotorula were unable to hydrolyze glutamine. Candida l-asparaginase was most stable to heat-treatment.     

A polymerase chain reaction-based test for the identification of Trichoderma harzianum biotypes 2 and 4, responsible for the worldwide green mold epidemic in cultivated Agaricus bisporus

We describe a polymerase chain reaction (PCR)-based test that is specific for the pathogenic European biotype 2 (Th2) and North American biotype 4 (Th4) of Trichoderma harzianum, responsible for the green mold epidemic in the cultivated mushroom, Agaricus bisporus. A PCR primer pair was designed that targets a 444-bp arbitrary sequence in the genome of Th4. The primers also amplified the same product with Th2, but showed no reactivity with other biotypes of T. harzianum, several biocontrol Trichoderma, or with 31 other genera and species of fungi. The PCR-based test should have application in disease management programs, and in the evaluation of biocontrol Trichoderma for potential pathogenicity on mushrooms. Received: 23 November 1998 / Received revision: 19 February 1999 / Accepted: 5 March 1999     

A Comparative Study of the Bactericidal Activity and Daily Disinfection Housekeeping Surfaces by a New Portable Pulsed UV Radiation Device

Daily cleaning and disinfecting of non-critical surfaces in the patient-care areas are known to reduce the occurrence of health care-associated infections. However, the conventional means for decontamination of housekeeping surfaces of sites of frequent hand contact such as manual disinfection using ethanol wipes are laborious and time-consuming in daily practice. This study evaluated a newly developed portable pulsed ultraviolet (UV) radiation device for its bactericidal activity in comparison with continuous UV-C, and investigated its effect on the labor burden when implemented in a hospital ward. Pseudomonas aeruginosa, Multidrug-resistant P. aeruginosa, Escherichia coli, Acinetobacter baumannii, Amikacin and Ciprofloxacin-resistant A. baumannii, Staphylococcus aureus, Methicillin-resistant S. aureus and Bacillus cereus were irradiated with pulsed UV or continuous UV-C. Pulsed UV and continuous UV-C required 5 and 30 s of irradiation, respectively, to attain bactericidal activity with more than 2Log growth inhibition of all the species. The use of pulsed UV in daily disinfection of housekeeping surfaces reduced the working hours by half in comparison to manual disinfection using ethanol wipes. The new portable pulsed UV radiation device was proven to have a bactericidal activity against critical nosocomial bacteria, including antimicrobial-resistant bacteria after short irradiation, and was thus found to be practical as a method for disinfecting housekeeping surfaces and decreasing the labor burden.     

In vitro antagonism of bioluminescent fungi by Trichoderma harzianum

Two species of bioluminescent fungi, Panellus stypticus and Omphalotus olearius were placed in contact with three different strains of interfungal pathogenic Trichoderma harzianum. Subsequent light emission by the luminous fungi and advance of the interfungal pathogens were compared. Relative differences among the pathogens were reflected in their rate of mycelial advance, the total area over which they produced spores upon the host fungi, and decreases in host bioluminescence. After ten days differences in the total surface areas of spore production varied from 1 to 53 per cent. Differences in the reduction of bioluminescence of the same material ranged over 2 orders of magnitude. Final reduction in luminescence ranged over 6 orders of magnitude. A marked reduction in bioluminescence was observed to precede the advance of spore production. The greatest reduction in luminescence was correlated with the presence of T. harzianum hyphae. Two strains of T. harzianum, NRRL 1698 and ATCC 58674, were effective against both bioluminescent fungi within the study period while a third strain, NRRL 13019, was only effective against Omphalotus olearius.     

Reaction of microorganisms to the digestive fluid of earthworms

The reaction of soil bacteria and fungi to the digestive fluid of the earthworm Aporrectodea caliginosa was studied. The fluid was obtained by centrifugation of the native enzymes of the digestive tract. The inhibition of growth of certain bacteria, spores, and fungal hyphae under the effect of extracts from the anterior and middle sections of the digestive tract of A. caliginosa was discovered for the first time. In bacteria, microcolony formation was inhibited as early as 20–30 s after the application of the gut extracts, which may indicate the nonenzymatic nature of the effect. The digestive fluid exhibited the same microbicidal activity whether the earthworms were feeding on soil or sterile sand. This indicates that the microbicidal agents are formed within the earthworm’s body, rather than by soil microorganisms. The effect of the digestive fluid from the anterior and middle divisions is selective in relation to different microorganisms. Of 42 strains of soil bacteria, seven were susceptible to the microbicidal action of the fluid (Alcaligenes faecalis 345-1, Microbacterium sp. 423-1, Arthrobacter sp. 430-1, Bacillus megaterium 401-1, B. megaterium 413-1, Kluyvera ascorbata 301-1, Pseudomonas reactans 387-2). The remaining bacteria did not die in the digestive fluid. Of 13 micromycetes, the digestive fluid inhibited spore germination in Aspergillus terreus and Paecilomyces lilacinus and the growth of hyphae in Trichoderma harzianum and Penicillium decumbens. The digestive fluid stimulated spore germination in Alternaria alternata and the growth of hyphae in Penicillium chrysogenum. The reaction of the remaining micromycetes was neutral. The gut fluid from the posterior division of the abdominal tract did not possess microbicidal activity. No relation was found between the reaction of microorganisms to the effects of the digestive fluid and the taxonomic position of the microorganisms. The effects revealed are similar to those shown earlier for millipedes and wood lice in the following parameters: quick action of the digestive fluid on microorganisms, and the selectivity of the action on microorganisms revealed at the strain level. The selective effect of the digestive gut fluid of the earthworms on soil microorganisms is important for animal feeding, maintaining the homeostasis of the gut microbial community, and the formation of microbial communities in soils.     

Effects of Glycine and d-Amino Acids on Growth of Various Microorganisms

Growth of various microorganisms in media containing high concentrations of glycine or d-amino acids was examined. Susceptibilities to glycine or d-amino acids differed among microorganisms, and the differences in susceptibility have no direct relation with Gram staining, morphological forms, and aerobic or anaerobic nature of the organisms. Certain glycine-resistant bacteria tested, which included Bacillus cereus, Staphylococcus aureus and Serratia marcescens, exhibited relatively high oxidative activities towards glycine. The inhibition of the growth of Escherichia coli by either glycine or d-amino acids, which included d-threonine, d-alanine and d-lysine, was reversed by l-alanine, partialy by l-serine, and not by l-lysine or l-threonine. These results suggest that the growth inhibition of microorganisms by d-amino acids was similar to that by glycine. The incorporation of l-alanine into E. coli cells which were preincubated with glycine was less than those of preincubated without glycine. Particularly, the incorporation into the cell wall fraction was most susceptible to glycine. An additive effect of penicillin and glycine was observed in the inhibition of cell wall biosynthesis as determined by the intracellular accumulation of N-acetylamino sugar compounds.     

Bioprospecting of <Emphasis Type="Italic">Diaporthe terebinthifolii</Emphasis> LGMF907 for antimicrobial compounds

Antibiotic-resistant bacteria have been observed with increasing frequency over the past decades, driving the search for new drugs and stimulating the interest in natural products sources. Endophytic fungi from medicinal plants represent a great source of novel bioactive compounds useful to pharmaceutical and agronomical purposes. Diaporthe terebinthifolii is an endophytic species isolated from Schinus terebinthifolius, a plant used in popular medicine for several health problems. The strain D. terebinthifolii LGMF907 was previously reported by our group to produce secondary metabolites with biological activity against phytopathogens. Based on these data, strain LGMF907 was chosen for bioprospecting against microorganisms of clinical importance and for characterization of major secondary metabolites. In this study, different culture conditions were evaluated and the biological activity of this strain was expanded. The crude extracts demonstrated high antibacterial activity against Escherichia coli, Micrococcus luteus, Saccharomyces cerevisiae, methicillin-sensitive Staphylococcus aureus, and methicillin-resistant S. aureus. The compounds diaporthin and orthosporin were characterized and also showed activity against the clinical microorganisms evaluated. This study discloses the first isolation of diaporthin and orthosporin from D. terebinthifolii, and revealed the potential of this endophytic fungus to produce secondary metabolites with antimicrobial activity.