Production of Polysaccharides and Single-Cell Protein by Some Local Isolates of Trichoderma spp.

<b>Background and Objective:</b> Polysaccharides and Single-cell protein are one of the best essential natural products of microorganisms, they are excreted by different microorganisms such as yeast, fungi, bacteria and algae. This study was carried out to detect the ability of four local fungal isolates of <i>Trichoderma </i>spp. to produce polysaccharides and Single-cell protein. <b>Materials and Methods:</b> Standard Czapek Dox Broth Medium was used to detect the ability of fungal isolates to produce polysaccharides and Single-cell protein, with modified the components of medium for improved production using banana peels as a source of carbon and different nitrogen sources at different concentrations and the factorial experiment was carried out using a completely randomized design <b>Results:</b> The highest dry weight and polysaccharides production and protein content have been achieved for the fungus <i>T. reesei</i> with rates of (2.15, 0.276 and 0.94) g/100 mL, respectively, in comparison with the other treatments, the use of ammonium phosphate at concentration 0.6 g L¹ has given the highest dry weight and production of polysaccharides and protein content with rates of (3.75, 0.364 and 2.77) g/100 mL, respectively, also the use of banana peels extract at concentration 40 mL L¹ has given the highest dry weight and production of polysaccharides and protein content with rates of (5.21, 0.539 and 3.63) g/100 mL, respectively. <b>Conclusion:</b> The possibility of using the local isolate of <i>T. reesei</i> in the production of polysaccharides and Single-cell protein using some cheap agricultural waste such as banana peels as a carbon source instead of throwing them as waste and pollutants for the environment.

Trichoderma-Based Biopreparation with Prebiotics Supplementation for the Naturalization of Raspberry Plant Rhizosphere.

The number of raspberry plants dying from a sudden outbreak of gray mold, verticillium wilt, anthracnosis, and phytophthora infection has increased in recent times, leading to crop failure. The plants suffer tissue collapse and black roots, symptoms similar to a Botrytis-Verticillium-Colletotrichum-Phytophthora disease complex. A sizeable number of fungal isolates were acquired from the root and rhizosphere samples of wild raspberries from different locations. Subsequent in vitro tests revealed that a core consortium of 11 isolates of selected Trichoderma spp. was the most essential element for reducing in phytopathogen expansion. For this purpose, isolates were characterized by the efficiency of their antagonistic properties against Botrytis, Verticillium, Colletotrichum and Phytophthora isolates and with hydrolytic properties accelerating the decomposition of organic matter in the soil and thus making nutrients available to plants. Prebiotic additive supplementation with a mixture of adonitol, arabitol, erythritol, mannitol, sorbitol, and adenosine was proven in a laboratory experiment to be efficient in stimulating the growth of Trichoderma isolates. Through an in vivo pathosystem experiment, different raspberry naturalization-protection strategies (root inoculations and watering with native Trichoderma isolates, applied separately or simultaneously) were tested under controlled phytotron conditions. The experimental application of phytopathogens attenuated raspberry plant and soil properties, while Trichoderma consortium incorporation exhibited a certain trend of improving these features in terms of a short-term response, depending on the pathosystem and naturalization strategy. What is more, a laboratory-scale development of a biopreparation for the naturalization of the raspberry rhizosphere based on the Trichoderma consortium was proposed in the context of two application scenarios. The first was a ready-to-use formulation to be introduced while planting (pellets, gel). The second was a variant to be applied with naturalizing watering (soluble powder).

Trichovariability in rhizosphere soil samples and their biocontrol potential against downy mildew pathogen in pearl millet.

The present work is aimed to examine the genetic variability and the distribution pattern of beneficial Trichoderma spp. isolated from rhizosphere samples and their mode of action in improving the plant health. A total of 131 suspected fungi were isolated from the rhizospheric soil and 91 isolates were confirmed as Trichoderma spp. T. asperellum and T. harzianum were found high in the frequency of occurrence. Genetic diversity analysis using RAPD and ISSR revealed the diverse distribution pattern of Trichoderma spp. indicating their capability to adapt to broad agroclimatic conditions. Analysis of genetic diversity using molecular markers revealed intra-species diversity of isolated Trichoderma spp. The frequency of pearl millet (PM) root colonization by Trichoderma spp. was found to be 100%. However, they showed varied results for indole acetic acid, siderophore, phosphate solubilization, ß-1,3-glucanase, chitinase, cellulase, lipase, and protease activity. Downy mildew disease protection studies revealed a strong involvement of Trichoderma spp. in direct suppression of the pathogen (mean 37.41) in the rhizosphere followed by inducing systemic resistance. Our findings highlights the probable distribution and diversity profile of Trichoderma spp. as well as narrate the possible utilization of Trichoderma spp. as microbial fungicides in PM cultivation across different agroclimatic zones of India.

New species and records of Trichoderma isolated as mycoparasites and endophytes from cultivated and wild coffee in Africa.

A survey for species of the genus Trichoderma occurring as endophytes of Coffea, and as mycoparasites of coffee rusts (Hemileia), was undertaken in Africa; concentrating on Cameroon and Ethiopia. Ninety-four isolates of Trichoderma were obtained during this study: 76 as endophytes of healthy leaves, stems and berries and, 18 directly from colonized rust pustules. A phylogenetic analysis of all isolates used a combination of three genes: translation elongation factor-1α (tef1), rpb2 and cal for selected isolates. GCPSR criteria were used for the recognition of species; supported by morphological and cultural characters. The results reveal a previously unrecorded diversity of Trichoderma species endophytic in both wild and cultivated Coffea, and mycoparasitic on Hemileia rusts. Sixteen species were delimited, including four novel taxa which are described herein: T. botryosum, T. caeruloviride, T. lentissimum and T. pseudopyramidale. Two of these new species, T. botryosum and T. pseudopyramidale, constituted over 60% of the total isolations, predominantly from wild C. arabica in Ethiopian cloud forest. In sharp contrast, not a single isolate of Trichoderma was obtained using the same isolation protocol during a survey of coffee in four Brazilian states, suggesting the existence of a 'Trichoderma void' in the endophyte mycobiota of coffee outside of Africa. The potential use of these African Trichoderma isolates in classical biological control, either as endophytic bodyguards-to protect coffee plants from Hemileia vastatrix, the fungus causing coffee leaf rust (CLR)-or to reduce its impact through mycoparasitism, is discussed, with reference to the on-going CLR crisis in Central America.

Biofumigation activities of volatile compounds from two Trichoderma afroharzianum strains against Fusarium infections in fresh chilies.

BACKGROUND: Two Fusarium fungi, F. oxysporum and F. proliferatum, have been recognized as major pathogenic fungi that cause postharvest decay of chili fruits. Ozone and some toxic chemicals are used to control pathogenic infections, leading to longer storage lives of agricultural commodities. However, these chemicals may pose some risks to the applicators and the environment. Therefore, alternative, easy-to-use fumigants for effective control of Fusarium infections in harvested fresh chilies are needed. RESULTS: Two endophytic fungi, Trichoderma afroharzianum strain MFLUCC19-0090 and T. afroharzianum strain MFLUCC19-0091, were isolated from Schefflera leucantha leaves. Their volatile compounds were investigated for antifungal activities against F. oxysporum and F. proliferatum. In vitro results showed that the volatile compounds produced by each strain inhibited pathogen growth. Additionally, the Trichoderma-derived volatile compounds significantly reduced Fusarium-related disease severity and incidence percentages in the inoculated fresh chilies. Antifungal properties of the volatile compounds were found to be specific to the species of the tested pathogens (MFLUCC19-0090 greatly suppressed F. oxysporum and MFLUCC19-0091 greatly suppressed F. proliferatum). Seventy-three volatile compounds were detected from both strains. Among the major volatile compounds detected, phenyl ethyl alcohol was found to possess the strongest antifungal activity against both pathogens. CONCLUSION: These Trichoderma-derived volatile compounds may be used as alternative fumigants for controlling Fusarium rot in harvested fresh chilies. The successful use of volatile compounds as biofumigants can prevent significant market losses and, more importantly, may reduce the health hazards caused by Fusarium-associated mycotoxin exposures among consumers. © 2021 Society of Chemical Industry.

Microbiology of secondary infections in Buruli ulcer lesions; implications for therapeutic interventions.

BACKGROUND: Buruli ulcer (BU) is a skin disease caused by Mycobacterium ulcerans and is the second most common mycobacterial disease after tuberculosis in Ghana and Côte d'Ivoire. M. ulcerans produces mycolactone, an immunosuppressant macrolide toxin, responsible for the characteristic painless nature of the infection. Secondary infection of ulcers before, during and after treatment has been associated with delayed wound healing and resistance to streptomycin and rifampicin. However, not much is known of the bacteria causing these infections as well as antimicrobial drugs for treating the secondary microorganism. This study sought to identify secondary microbial infections in BU lesions and to determine their levels of antibiotic resistance due to the prolonged antibiotic therapy required for Buruli ulcer. RESULTS: Swabs from fifty-one suspected BU cases were sampled in the Amansie Central District from St. Peters Hospital (Jacobu) and through an active case surveillance. Forty of the samples were M. ulcerans (BU) positive. Secondary bacteria were identified in all sampled lesions (N = 51). The predominant bacteria identified in both BU and Non-BU groups were Staphylococci spp and Bacilli spp. The most diverse secondary bacteria were detected among BU patients who were not yet on antibiotic treatment. Fungal species identified were Candida spp, Penicillium spp and Trichodema spp. Selected secondary bacteria isolates were all susceptible to clarithromycin and amikacin among both BU and Non-BU patients. Majority, however, had high resistance to streptomycin. CONCLUSIONS: Microorganisms other than M. ulcerans colonize and proliferate on BU lesions. Secondary microorganisms of BU wounds were mainly Staphylococcus spp, Bacillus spp and Pseudomonas spp. These secondary microorganisms were less predominant in BU patients under treatment compared to those without treatment. The delay in healing that are experienced by some BU patients could be as a result of these bacteria and fungi colonizing and proliferating in BU lesions. Clarithromycin and amikacin are likely suitable drugs for clearance of secondary infection of Buruli ulcer.

Biocontrol and growth-promoting effect of Trichoderma asperellum TaspHu1 isolate from Juglans mandshurica rhizosphere soil.

To better apply the biocontrol agent Trichoderma spp. in Northeast China, collecting and screening more suitable native Trichoderma strains is necessary. In the present study, 10 isolates were obtained from Juglans mandshurica rhizosphere soils in Heilongjiang Province, and were identified as T. asperellum (four isolates), T. harzianum (four), T. hamatum (one), T. atroviride (one). The fastest-growing isolate per species on potato dextrose agar medium were further evaluated in stress tolerance tests (salt, alkali, nutritional stress, and low temperature) and confrontation assays (eight pathogens), which showed that T. asperellum TaspHu1 possessed the best adaptation and biological control ability. Then, Solanum lycopersicum (tomato) seeds were sown and treated with a series of concentrations of TaspHu1 spore suspension, as was unsown soil. Tomato seedlings treated by TaspHu1 had a significantly greater height, stem diameter, soluble protein content and soluble sugar content. Furthermore, their nitrate reductase activity and catalase activity were significantly increased, and these promoting effects depended on the concentration of the spore suspension. Meanwhile, a decrease in chlorophyll content was observed in the tomato seedlings treated with TaspHu1. In addition, strain TaspHu1 enhanced the tomato seedlings' absorption of available nitrogen, but did not influence the soil available nitrogen content. Furthermore, the resistance of tomato seedlings against Alternaria alternata was enhanced by TaspHu1 (smaller, fewer leaf spots), the seedlings' hormone signal transduction genes JAR1, MYC2, NPR1, PR1, and GH3.2 were highly expressed. Thus, TaspHu1 is a promising biocontrol candidate for use in agriculture and forestry.

Inhibition of plant pathogenic fungi by endophytic Trichoderma spp. through mycoparasitism and volatile organic compounds.

Antagonism of plant pathogenic fungi by endophytic fungi is a well-known phenomenon. In plate assays, the antagonism could be due to mycoparasitism, competition for space or antibiosis, involving a chemical diffusate, or a volatile organic compound (VOC). In this study, we demonstrate that besides mycoparasitism, VOCs play a major role in antagonism of pathogenic fungi by four endophytic fungi belonging to the genus Trichoderma. Using a double-plate assay, we show that all the four endophytic Trichoderma species significantly inhibited mycelial growth of three of the four pathogens, (Sclerotinia sclerotiorum-TSS, Sclerotium rolfsii-CSR and Fusarium oxysporum-CFO), while that of Macrophomina phaseolina-CMP was not affected. GC-MS analysis of the pure cultures of one of the endophytic fungi studied, namely, Trichoderma longibrachiatum strain 2 (Acc. No. MK751758) and the pathogens, F. oxysporum-CFO and M. phaseolina-CMP revealed the presence of several VOCs including hydrocarbons, alcohols, ketones, aldehydes, esters, acids, ethers and different classes of terpenes. In mixed double plates, where the endophyte was grown along with either of the two plant pathogens, F. oxysporum-CFO or M. phaseolina-CMP, there was an induction of a number of new VOCs that were not detected in the pure cultures of either the endophyte or the pathogens. Several of these new VOCs are reported to possess antifungal and cytotoxic activity. We discuss these results and highlight the importance of such interactions in endophyte-pathogen interactions.

Identification of native endophytic Trichoderma spp. for investigation of in vitro antagonism towards Armillaria mellea using synthetic- and plant-based substrates.

AIMS: To isolate endophytic Trichoderma species and investigate the potential for biological control of the root rot pathogen Armillaria mellea. METHODS AND RESULTS: In all, 40 Trichoderma isolates were obtained from a range of host plants and identities were confirmed by ITS, rpb2 and tef1 sequence. When tested in dual culture assays for antagonism against A. mellea, Trichoderma isolates overgrew the A. mellea colonies within four days and by eight days 38 Trichoderma isolates significantly reduced A. mellea colony size. Armillaria mellea was unable to be recovered from five of eight co-cultivations tested, suggesting Trichoderma had killed the A. mellea in these cases. Pre-colonized hazel disks were used to determine what happens in a more heterogeneous situation with A. mellea and a refined set of eight Trichoderma isolates. Similar to plate-based assays, Trichoderma quickly covered A. mellea stopping any further growth and two Trichoderma isolates were able to eradicate A. mellea. CONCLUSIONS: Of the Trichoderma spp. tested, endophytic isolates of Trichoderma virens and T. hamatum offered the greatest antagonism towards A. mellea. Using pre-colonized hazel disks was of great importance for this work to demonstrate the fungal interactions in plant material. SIGNIFICANCE AND IMPACT OF THE STUDY: Controlling Armillaria root rot is difficult with chemical treatments, thus an environmentally benign and cost-effective alternative is required. This study highlights the prospect of biological control as an effective, environmentally friendly alternative to chemicals.

MIST: a Multilocus Identification System for Trichoderma.

Due to the rapid expansion in microbial taxonomy, precise identification of common industrially and agriculturally relevant fungi such as Trichoderma species is challenging. In this study, we introduce the online multilocus identification system (MIST) for automated detection of 349 Trichoderma species based on a set of three DNA barcodes. MIST is based on the reference databases of validated sequences of three commonly used phylogenetic markers collected from public databases. The databases consist of 414 complete sequences of the nuclear rRNA internal transcribed spacers (ITS) 1 and 2, 583 sequence fragments of the gene encoding translation elongation factor 1-alpha (tef1), and 534 sequence fragments of the gene encoding RNA polymerase subunit 2 (rpb2). Through MIST, information from different DNA barcodes can be combined and the identification of Trichoderma species can be achieved based on the integrated parametric sequence similarity search (blastn) performed in the manner of a decision tree classifier. In the verification process, MIST provided correct identification for 44 Trichoderma species based on DNA barcodes consisting of tef1 and rpb2 markers. Thus, MIST can be used to obtain an automated species identification as well as to retrieve sequences required for manual identification by means of phylogenetic analysis.IMPORTANCE The genus Trichoderma is important to humankind, with a wide range of applications in industry, agriculture, and bioremediation. Thus, quick and accurate identification of Trichoderma species is paramount, since it is usually the first step in Trichoderma-based research. However, it frequently becomes a limitation, especially for researchers who lack taxonomic knowledge of fungi. Moreover, as the number of Trichoderma-based studies has increased, a growing number of unidentified sequences have been stored in public databases, which has made the species identification more ambiguous. In this study, we provide an easy-to-use tool, MIST, for automated species identification, a list of Trichoderma species, and corresponding sequences of reference DNA barcodes. Therefore, this study will facilitate the research on the biodiversity and applications of the genus Trichoderma.

Humidity governs the wall-inhabiting fungal community composition in a 1600-year tomb of Emperor Yang.

Biodeterioration caused by filamentous fungi is often a threat to the architectural heritage (i.e. tombs and historic sites). To specifically understand the deterioration phenomena caused by microorganisms in tombs and how these are shaped due to various environmental factors, the fungal communities in the coffin chamber of the Chinese emperor Yang (BC 569-618) were investigated at different heights using denaturant gradient gel electrophoresis (DGGE) fingerprinting. The associated environmental conditions, such as humidity, temperature, height and illumination, were also assessed. The results showed that a great diversity of fungal species (Cordyceps, Fusarium, Harpochytrium, Emericellopsis, Volutella, Cladosporium, Stachybotrys, Trichoderma, Cochlonema and two unknown fungal species) was present in emperor Yang's coffin chamber. The predominant species were Stachybotrys, Fusarium, Trichoderma and Cochlonema. Redundancy analysis (RDA) indicated that humidity, temperature, height and illumination were the most significantly related factors shaping the fungal communities. Humidity showed the highest degree of variance description (19.2%) than all other environmental factors, followed by illumination (18.3%) and height (12.8%). Furthermore, fungal richness and diversity indices showed a positive correlation with humidity (p < 0.05). These results help in understanding the fungal community in tombs, promoting the mitigation of deterioration phenomena of such building heritage for the present and future.

Quantification of Trichoderma afroharzianum, Trichoderma harzianum and Trichoderma gamsii inoculants in soil, the wheat rhizosphere and in planta suppression of the crown rot pathogen Fusarium pseudograminearum.

AIMS: Develop quantitative assays (qPCR) to determine the detection threshold limits, colonization and persistence of Trichoderma gamsii, Trichoderma afroharzianum and T. harzianum inoculants in cropping soils, the wheat rhizosphere and their in planta suppressive efficacy against the crown rot pathogen Fusarium pseudograminearum. METHODS AND RESULTS: Trichoderma qPCR primers were designed from the internal transcribed spacer region of 5.8S rDNA and from sequences of DNA fragments diagnostic for each inoculant genotype. The minimum detection thresholds of qPCR assays varied between 1 × 103 (log 3) and 8 × 104 (log 4·9) conidia (genome) equivalents per gram of soil for multi- and single-copy target sequences, respectively and were independent of soil type. There was a strong correlation (r > 0·974) between culture-dependent and culture-independent (qPCR) quantification methods. In wheat bioassays, Trichoderma inoculants colonized rhizosphere soils and wheat roots at 56-112 days postemergence to a depth of 20 cm but were more abundant (P < 0·001) at 0-10 cm root depth, means ranging from 2 × 102 (log 2·3) to 4 × 105 (log 5·6) conidia equivalents per gram of rhizosphere soil or root tissue. Inoculants reduced (P < 0·001) F. pseudograminearum biomass in wheat crown and root tissue by up to 5754-fold and increased (P = 0·008) plant biomass, relative to the pathogen control. CONCLUSIONS: The qPCR assays provided sensitive and accurate assessment of wheat root and rhizosphere soil colonization of Trichoderma inoculants. Strains persisted through to grain maturity at levels shown to significantly suppress F. pseudograminearum in planta. SIGNIFICANCE AND IMPACT OF THE STUDY: The qPCR assays developed here were used to determine the wheat rhizosphere dynamics of T. harzianum, T. afroharzianum and T. gamsii inoculants and their suppressive efficacy against F. pseudograminearum in planta. These assays can be applied to monitor inoculant dynamics in suppressing crown rot and other wheat root diseases in the field.

Antifungal compounds with anticancer potential from Trichoderma sp. P8BDA1F1, an endophytic fungus from Begonia venosa.

Fungi in the genus Trichoderma are notorious producers of secondary metabolites with diverse applications, such as antibacterial, antifungal, and plant growth-promoting properties. Peptaibols are linear peptides produced by such fungi, with more than 440 compounds described to date, including tricholongins, longibrachins, trichobrachins, and trichovirins. Peptaibols are synthesized by non-ribosomal peptide synthetases and they have several biological activities. Our research group isolated four peptaibols (6DP2, 6DP3, 6DP4, and 6DP5) with antifungal activity against the plant pathogen Colletotrichum gloeosporioides and the proteasome (a cancer chemotherapy target) from Trichoderma sp. P8BDA1F1, an endophytic fungus from Begonia venosa. The ethyl acetate extract of this endophyte showed activity of 6.01% and 75% against C. gloeosporioides and the proteasome, respectively. The isolated compounds were identified by MS/MS and compared to literature data, suggesting the presence of trilongins BI, BII, BIII, and BIV, which are peptaibols containing 20 amino acid residues. The minimum inhibitory concentration against C. gloeosporioides was 40 µM for trilongin BI, 320 µM for trilongin BII, 160 µM for trilongin BIII, and 310 µM for trilongin BIV. BI-BIV trilongins inhibited proteasome ChTL activity, with IC50 values of 6.5 ± 2.7; 4.7 ± 1.8; 6.3 ± 2.2; and 2.7 ± 0.5 µM, respectively. The compounds were tested ex vivo against the intracellular amastigotes of Leishmania (L.) infantum but showed no selectivity. It is the first report of trilongins BI-BIV with antifungal activity against C. gloeosporioides and the proteasome target.

Trichoderma panacis sp. nov., an endophyte isolated from Panax notoginseng.

An endophytic member of the genus Trichoderma was isolated from the root of a healthy 3-year-old Panax notoginseng in Yunnan province, PR China. The results of phylogenetic analyses based on a combined of ITS, tef1 and rpb2 indicated that this isolate was distinct from other species of the genus Trichoderma and closely related to Trichoderma songyi. It can be distinguished from T. songyi by its slower growth rates on PDA and colony morphology. The novel isolate formed conidia in thick white pustules scattered mostly at the margin. Its conidiophores tended to be regularly verticillium-like, little branched, sometimes substituted by phialides singly or in whorls. Conidia are smooth, mostly broadly subglobose to ellipsoidal. In combination with the genotypic and phenotypic characteristics, all data demonstrated that the fungus studied represented a unique and distinguishable novel species of the genus Trichoderma, for which the name Trichoderma panacis sp. nov. is proposed.

Isolation of Trichoderma in the rhizosphere soil of Syringa oblata from Harbin and their biocontrol and growth promotion function.

For the effective biocontrol of Syringa powdery mildew (Mircosphaera syringejaponicae) and to promote seedling growth, we identified 44 of the 181 Trichoderma isolates (T1-T181) isolated from the rhizosphere soil. Analysis identified 10 Trichoderma species, and T. pseudoharzianum T1 (TpseT1), T. afroharzianum T52 (TafrT52), and T. asperelloides T57 (TaspT57) were selected to make Trichoderma biofertilizer because of their fast growth and high spore production. Exposing Syringa oblata to Trichoderma biofertilizer showed that TafrT52 and TaspT57 could induce abscisic acid (ABA) production, and promote the shedding of diseased leaves and the generation of new leaves. Furthermore, TafrT52 increased the catalase (CAT) activity and reduced the H2O2 content. And the disease incidence was reduced by 37.84 % by Tasp (highest) in 2017 year and by 13.84 % by TpseT1(lowest) in 2018 year. In addition, all Trichoderma strains we selected could promote the lateral root growth of S. oblata seedlings; however, because of the downregulated gene expression at the late stage of chlorophyll synthesis, the chlorophyll content decreased in the new leaves. Antagonism among different Trichoderma species led to low biocontrol and growth promotion effects, thus the Trichoderma mixture cannot be use as biofertilizer. TafrT52, with better biocontrol and growth promotion effects, could be used for biocontrol of M. syringejaponicae.

Trichoderma from Brazilian garlic and onion crop soils and description of two new species: Trichoderma azevedoi and Trichoderma peberdyi.

Fifty four Trichoderma strains were isolated from soil samples collected from garlic and onion crops in eight different sites in Brazil and were identified using phylogenetic analysis based on combined ITS region, tef1-α, cal, act and rpb2 sequences. The genetic variability of the recovered Trichoderma species was analysed by AFLP and their phenotypic variability determined using MALDI-TOF. The strain clusters from both typing techniques coincided with the taxonomic determinations made from phylogenetic analysis. The phylogenetic analysis showed the occurrence of Trichoderma asperellum, Trichoderma asperelloides, Trichoderma afroharzianum, Trichoderma hamatum, Trichoderma lentiforme, Trichoderma koningiopsis, Trichoderma longibrachiatum and Trichoderma erinaceum, in the soil samples. We also identified and describe two new Trichoderma species, both in the harzianum clade of section Pachybasium, which we have named Trichoderma azevedoi sp. nov. and Trichoderma peberdyi sp. nov. The examined strains of both T. azevedoi (three strains) and T. peberdyi (12 strains) display significant genotypic and phenotypic variability, but form monophyletic clades with strong bootstrap and posterior probability support and are morphologically distinct from their respective most closely related species.

Molecular Identification of Endophytic Fungi and Their Pathogenicity Evaluation Against Dendrobium nobile and Dendrobium officinale.

: Dendrobium are tropical orchid plants that host diverse endophytic fungi. The role of these fungi is not currently well understood in Dendrobium plants. We morphologically and molecularly identified these fungal endophytes, and created an efficient system for evaluating the pathogenicity and symptoms of endophytic fungi on Dendrobium nobile and Dendrobium officinale though in vitro co-culturing. ReThe colony morphological traits of Dendrobium myco-endophytes (DMEs) were recorded for their identification. Molecular identification revealed the presence of Colletotrichum tropicicola, Fusarium keratoplasticum, Fusarium oxysporum, Fusarium solani, and Trichoderma longibrachiatum. The pathogenicity results revealed that T. longibrachiatum produced the least pathogenic effects against D. nobile protocorms. In seedlings, T. longibrachiatum showed the least pathogenic effects against D. officinale seedlings after seven days. C. tropicicola produced highly pathogenic effects against both Dendrobium seedlings. The results of histological examination of infected tissues revealed that F. keratoplasticum and T. longibrachiatum fulfill Koch's postulates for the existence of endophytes inside the living tissues. The DMEs are cross-transmitted inside the host plant cells, playing an important role in plant host development, resistance, and alkaloids stimulation.

Application of laser capture microdissection and polymerase chain reaction in the diagnosis of Trichoderma longibrachiatum infection: a promising diagnostic tool for 'fungal contaminants' infection.

Although Trichoderma species are usually considered to be culture contaminants, an increasing number of case reports have demonstrated their pathogenicity. Current diagnostic tools, including fungal culture, radiology, histopathology, and direct microscopy examination, are often unable to differentiate the pathogenicity of 'fungal contaminants' such as Trichoderma species in patients. Accurate diagnostic tools for 'fungal contaminants' infection have become the urgent needs. To that end, we applicated laser capture microdissection (LCM) and polymerase chain reaction (PCR) to confirm T. longibrachiatum infection for the first time. A 57-year-old man presented with a cough and hemoptysis lasting for more than 40 days. Computed tomography scan revealed a mass at the left hilum. In addition to pulmonary spindle cell carcinoma, fungal hyphae were also detected in histopathological examination. The cultured fungus was identified as T. longibrachiatum using molecular procedures. The results from DNA sequencing of DNA obtained by LCM revealed the identical result. Antifungal susceptibility testing revealed resistance to itraconazole, fluconazole and flucytosine. The patient was managed with oral voriconazole for 4 months. No relapse of Trichoderma infection was observed at a year follow-up visit. Although there are potential disadvantages, LCM-based molecular biology technology is a promising diagnostic tool for 'fungal contaminants' infection.

Isolation of Trichoderma from forestry model base and the antifungal properties of isolate TpsT17 toward Fusarium oxysporum.

Eleven soil samples were collected from different plantations at the Forestry Model Base, Northeast Forestry University, China (45°43'10″N, 126°37'15″E), and 122 Trichoderma strains (T1-T122) were isolated. Nine Trichoderma species were identified based on morphological and molecular classification methods. The diversity of woody fungi was analyzed based on the type and quantity of Trichoderma spp. in the soil samples isolated from each plantation. Subdominant T. pseudoharzianum T17 (TpsT17) was screened and its biocontrol potential against Fusarium oxysporum CFCC86068 (Fox68) and growth promotion of Populus davidiana × P. alba var. pyramidalis (PdPap) seedlings were investigated. Compared with PdPap + Fox68 treatment, PdPap + TpsT17 + Fox68 treatment had an obvious antagonistic effect on Fox68 based on the status of roots and stomata of the poplar seedlings. In addition, pretreatment with TpsT17 increased catalase activity 14-fold and decreased hydrogen peroxide and malondialdehyde concentrations 2.57- and 7-fold, respectively, in the PdPap + TpsT17 + Fox68 treatment compared with the PdPap + Fox68 treatment. The transcription levels of PR1, JAZ6751, MYC2, MP, and JAR1 in PdPap + TpsT17+Fox68-treated plants were upregulated 5.75-, 5.63-, 14.88-, 8.24-, and 10.45-fold, respectively, at 3 d, while LAX2 exhibited little change in comparison with the level in PdPap + Fox-treated plants. TpsT17 was detected in the roots and stems of PdPap + TpsT17- and PdPap + TpsT17+Fox68-treated PdPap 28 d after inoculation, which demonstrated the endogenous capacity of TpsT17.

Chromium (VI) bioremediation potential of filamentous fungi isolated from Peruvian tannery industry effluents.

The tannery is an important trade in various Peruvian regions; however, tannery effluents are a serious local environmental threat due to its highly toxics components and lack of efficient treatment. The untreated effluents produced by tannery factories in Arequipa Rio Seco Industrial Park (PIRS) have formed a lake in the region nearby. In this work, we study the capability of filamentous fungi species found in this effluents lake with potential for chromium (VI) bioremediation. Fourteen species of filamentous fungi were isolated; only two species were identified Penicillium citrinum and Trichoderma viride, and third strain identified as Penicillium sp. The filamentous fungi showed that are fully tolerant to chromium (VI) concentrations up to 100 mg/L. These fungal strains showed significant growth in chromium (VI) concentrations up to 250 mg/L. Tolerant index (TI) analysis revealed that P. citrinum and T. viride began adaptation to chromium (IV) concentrations of 250 and 500 mg/L, after 6 and 12 days, respectively. When exposed to higher Cr (VI) concentrations (1000 mg/L), only T. viride was able to show growth (enhance phase). Interestingly, one of the significant responses from these fungal strains to increasing chromium (VI) concentrations was an increment in secreted laccase enzymes. Our results show tolerance and adaptation to elevated concentrations of chromium (VI) of these fungal strains suggesting their potential as effective agents for bioremediation of tannery effluents.