Mycelial Production Research Articles

Influence of Chitosan on the Viability of Encapsulated and Dehydrated Formulations of Vegetative Cells of Actinomycetes.

This study focuses on developing an encapsulated and dehydrated formulation of vegetative actinobacteria cells for an efficient application in sustainable agriculture, both as a fungicidal agent in crop protection and as a growth-stimulating agent in plants. Three strains of actinobacteria were used: one from a collection (Streptomyces sp.) and two natives to agricultural soil, which were identified as S3 and S6. Vegetative cells propagated in a specific liquid medium for mycelium production were encapsulated in various alginate-chitosan composites produced by extrusion. Optimal conditions for cell encapsulation were determined, and cell damage from air-drying at room temperature was evaluated. The fresh and dehydrated composites were characterized by porosity, functional groups, size and shape, and their ability to protect the immobilized vegetative cells' viability. Actinomycetes were immobilized in capsules of 2.1-2.7 mm diameter with a sphericity index ranging from 0.058 to 0.112. Encapsulation efficiency ranged from 50% to 88%, and cell viability after drying varied between 44% and 96%, depending on the composite type, strain, and airflow. Among the three immobilized and dried strains, S3 and S6 showed greater resistance to encapsulation and drying with a 4 L·min-1 airflow when immobilized in coated and core-shell composites. Encapsulation in alginate-chitosan matrices effectively protects vegetative actinobacteria cells during dehydration, maintaining their viability and functionality for agricultural applications.

Using pre-fermented sugar beet pulp as a growth medium to produce Pleurotus ostreatus mycelium for meat alternatives

This study aimed to determine the compatibility of pre-fermented sugar beet pulp to support the growth of Pleurotus ostreatus mycelium in submerged fermentation. The goal was to create a meat alternative based on mycelial-fermented pulp. It was further explored whether pre-fermentation with lactic acid bacteria (LAB) on the pulp increased meat-like properties, such as aroma, springiness, and hardness, in the final product. Three strains were selected from a high throughput screening of 105 plant-derived LAB based on their acidification and metabolite production in the pulp. Two homofermentative strains (Lactococcus lactis) and one heterofermentative strain (Levilactobacillus brevis) were selected based on their low ethanol production, high lactic acid production, and overall acidification of the pulp. Mycelium of P. ostreatus was grown in submerged fermentations on the pre-fermented pulp, and the biomass was removed by centrifugation. The fungal strain consumed all available sugars and acids and released arabinose to the media. Volatiles were detected using GC–MS, and a large increase in concentrations of hexanal, 1-octen-3-ol, and 2-octenal was measured. Concentration of 1-octen-3-ol was lower in the pre-fermented samples vs. the non-pre-fermented. LC-MS amino acid analysis showed the presence of all essential amino acids on day 0 and 7 of fermentation. The highest concentration of amino acids was for glutamic acid/glutamine and aspartic acid/asparagine. A decrease in all amino acids after 7 days of fungal fermentation was measured for all fermentations. The decrease was more significant for pre-fermented samples. This was also confirmed through a total protein determination, except for samples pre-fermented with Lactococcus lactis strain NFICC142 which increased in total protein content after fungal fermentation. The protein digestibility increased after fungal fermentation, and the highest increase was seen for non-pre-fermented samples. The springiness of the fermented product indicated similarities to meat alternatives, while the hardness was much lower than other meat alternatives. The results indicate that dried sugar beet pulp can be used for submerged cultivation of P. ostreatus, but that pre-fermentation does not improve the physical or nutritional properties of the end product significantly, except for an increased protein content for NFICC142 pre-fermented media. This is the first known attempt to use LAB and P. ostreatus in mixed fermentation to produce fungal mycelium, as well as the first attempt at using SBP in a liquid fermentation for mycelial production of P. ostreatus.

Extramatrical mycelial biomass is mediated by fine root mass and ectomycorrhizal fungal community composition across tree species

In many ecosystems, a large fraction of gross primary production is invested in mycorrhiza. Ectomycorrhizal (ECM) mycelium is involved in regulating soil carbon and nutrient cycling. However, little is known about how mycelial biomass, production and turnover differ depending on ECM fungal community composition and associated tree species. We quantified fine root biomass and length using soil cores, and mycelial traits (biomass, production, and turnover) using mesh-bags and ergosterol analysis, and identified ECM exploration types by Illumina MiSeq sequencing of four ECM-dominated tree species (Picea asperata, Larix gmelinii, Quercus aquifolioides and Betula albosinensis) in subalpine forest. The ECM fungal community composition separated between needle-leaved and broadleaved species, and between evergreen and deciduous species. The ratio of mycelial to fine root biomass was similar across the species regardless of genus-scale community composition and the relative abundance of exploration types. Compared to the other species, Q. aquifolioides displayed higher fine root biomass and mycelial biomass and production, dominated by contact-short exploration type. Mycelial turnover rate tended to be lowest in P. asperata, dominated by medium-long exploration type. Much higher production of mycelium and only slightly higher turnover rate in Q. aquifolioides suggests that its steady-state mycelial biomass would be higher than of the other species. Moreover, compared to the two deciduous species, with similar production but somewhat lower turnover rate, the standing crop of mycelium in P. asperata may stabilize at a higher value. Our findings, that exploration type may affect production and turnover, highlight the importance of characterizing ECM fungal communities by exploration types when estimating the contribution of mycelium biomass to forest carbon sink and storage.

Study on Optimization of Liquid Fermentation Medium and Antitumor Activity of the Mycelium on Phyllopora lonicerae.

Phylloporia lonicerae is an annual fungus that specifically parasitizes living Lonicera plants, offering significant potential for developing new resource food and medicine. However, wild resources and mycelium production of this fungus is limited, and its anti-tumor active ingredients and mechanisms remain unclear, hampering the development of this fungus. Thus, we optimized the fermentation medium of P. lonicerae and studied the anti-tumor activity of its mycelium. The results indicated that the optimum fermentation medium consisted of 2% sucrose, 0.2% peptone, 0.1% KH2PO4, 0.05% MgSO4·7H2O, 0.16% Lonicera japonica petals, 0.18% P fungal elicitor, and 0.21% L. japonica stem. The biomass reached 7.82 ± 0.41 g/l after 15 days of cultivation in the optimized medium, a 142% increase compared with the potato dextrose broth medium, with a 64% reduction in cultivation time. The intracellular alcohol extract had a higher inhibitory effect on A549 and Eca-109 cells than the intracellular water extract, with half-maximal inhibitory concentration values of 2.42 and 2.92 mg/ml, respectively. Graded extraction of the alcohol extract yielded petroleum ether phase, chloroform phase, ethyl acetate phase, and n-butanol phase. Among them, the petroleum ether phase exhibited a better effect than the positive control, with a half-maximal inhibitory concentration of 113.3 μg/ml. Flow cytometry analysis indicated that petroleum ether components could induce apoptosis of Eca-109 cells, suggesting that this extracted component can be utilized as an anticancer agent in functional foods. This study offers valuable technical support and a theoretical foundation for promoting the comprehensive development and efficient utilization of P. lonicerae.

Solid-State Fermentation of Quinoa Flour: An In-Depth Analysis of Ingredient Characteristics

Plant protein ingredients are gaining attention for human nutrition, yet they differ significantly from animal proteins in functionality and nutrition. Fungal solid-state fermentation (SSF) can modulate the composition and functionality, increasing their applicability in foods. Quinoa flour (QF) served as a substrate for Aspergillus oryzae and Rhizopus oligosporus, resulting in two fermented ingredients (QFA and QFR) with different nutritional, functional, and aroma characteristics. A higher increase in protein (+35%) and nitrogen (+24%) was observed in the QFA, while fat was predominantly increased in the QFR (+78%). Fermentable oligo-, di-, monosaccharides and polyols (FODMAPs) decreased in the QFR but increased in the QFA due to polyol production. Metabolomic analysis revealed higher lactic acid concentrations in the QFA, and higher citric, malic, and fumaric acid contents in the QFR. The SSF reduced most antinutrients, while R. oligosporus produced saponins. Olfactometry showed the development of fruity ester compounds and a decrease in metallic and cardboard aromas. Both ingredients showed an enhanced water-holding capacity, with the QFA also demonstrating an increased oil-holding capacity. Complex formation increased the particle size, reduced the solubility, and decreased the foaming properties. Mycelium production darkened the ingredients, with the QFR having a higher differential colour index. This study highlights the potential of SSF to produce ingredients with improved nutritional, sensory, and functional properties.

Chitin Deacetylase Homologous Gene cda Contributes to Development and Aflatoxin Synthesis in Aspergillus flavus.

The fungal cell wall serves as the primary interface between fungi and their external environment, providing protection and facilitating interactions with the surroundings. Chitin is a vital structural element in fungal cell wall. Chitin deacetylase (CDA) can transform chitin into chitosan through deacetylation, providing various biological functions across fungal species. Although this modification is widespread in fungi, the biological functions of CDA enzymes in Aspergillus flavus remain largely unexplored. In this study, we aimed to investigate the biofunctions of the CDA family in A. flavus. The A. flavus genome contains six annotated putative chitin deacetylases. We constructed knockout strains targeting each member of the CDA family, including Δcda1, Δcda2, Δcda3, Δcda4, Δcda5, and Δcda6. Functional analyses revealed that the deletion of CDA family members neither significantly affects the chitin content nor exhibits the expected chitin deacetylation function in A. flavus. However, the Δcda6 strain displayed distinct phenotypic characteristics compared to the wild-type (WT), including an increased conidia count, decreased mycelium production, heightened aflatoxin production, and impaired seed colonization. Subcellular localization experiments indicated the cellular localization of CDA6 protein within the cell wall of A. flavus filaments. Moreover, our findings highlight the significance of the CBD1 and CBD2 structural domains in mediating the functional role of the CDA6 protein. Overall, we analyzed the gene functions of CDA family in A. flavus, which contribute to a deeper understanding of the mechanisms underlying aflatoxin contamination and lay the groundwork for potential biocontrol strategies targeting A. flavus.

Optimization of inoculum production of Stemphylium botryosum for large-scale resistance screening of lentils

BackgroundStemphylium blight incited by Stemphylium botryosum poses a significant threat to lentil crops worldwide, inducing severe defoliation and causing substantial yield losses in susceptible varieties under favorable conditions. While some moderate levels of resistance have been identified within lentil germplasm, a low number of resistant cultivars are available to farmers. Adding to the common constraints of resistance breeding, a notable challenge is generating a sufficient number of spores for large-scale screenings, which are essential for pinpointing additional sources of resistance for integration into breeding programs. Therefore, there is a pressing need to improve existing screening methods and tailor them for large-scale material selection. In pursuit of this objective, a protocol for the efficient production of fungal material has been adapted.ResultsOptimization of fungal material production was successfully achieved by comparing the use of fungal mycelia and spores. Spore production was found to be optimal when produced on solid V8-PDA(hi) medium, while liquid Richard’s medium was identified as superior for mycelium yield. Furthermore, a refined screening method was developed by evaluating the resistance of six lentil accessions to stemphylium blight. This assessment included the use of either fungal mycelia (at densities ranging from 1 to 5 g L− 1) or spores (with densities ranging from 5 × 104 to 2 × 105 conidia mL− 1) under three different relative humidity levels (from 50 to 100%). Both humidity levels and inoculum dose significantly influenced the final disease rating (DR) and the relative Area Under the Disease Progress Curve (rAUDPC). Differences among genotypes in final symptom severity (DR) became more pronounced after inoculation with inoculum densities of 5 g L− 1 of mycelium or of 105 and 2 × 105 conidia mL− 1 of spore under 100% relative humidity. Given the challenges associated with the large-scale production of S. botryosum spores, inoculations with 5 g L− 1 of mycelium is highly recommended as a practical alternative for conducting mass-scale screenings.ConclusionsThe findings from this study underscore the critical importance of maintaining high level of humidity during inoculation and disease progression development for accurately assessing resistance to stemphylium blight. The optimization of mycelial production for suspension inoculation emerges as a more reliable and efficient approach for conducting large-scale screening to assess germplasm resistance against stemphylium blight in lentil crops.

AflaILVB/G/I and AflaILVD are involved in mycelial production, aflatoxin biosynthesis, and fungal virulence in Aspergillus flavus.

Aflatoxins (AFs) are produced by fungi such as Aspergillus flavus and A. parasiticus and are one of the most toxic mycotoxins found in agricultural products and food. Aflatoxin contamination, which requires the control of A. flavus, remains problematic because of the lack of effective strategies and the exploration of new compounds that can inhibit A. flavus growth and mycotoxin production is urgently required to alleviate potential deleterious effects. Acetohydroxy acid synthase (AHAS) and dihydroxy acid dehydratase are important enzymes in the biosynthetic pathways of branched-chain amino acids (BCAAs), including isoleucine, leucine, and valine. Enzymes involved in BCAA biosynthesis are present in bacteria, plants, and fungi, but not in mammals, and are therefore, attractive targets for antimicrobial and herbicide development. In this study, we characterized AflaILVB/G/I and AflaILVD, which encode the catalytic and regulatory subunits of AHAS and dihydroxy acid dehydratase, from the pathogenic fungus Aspergillus flavus. The AflaILVB/G/I and AflaILVD deletion mutant grew slower and produced smaller colonies than the wild-type strain when grown on glucose minimal medium, potato dextrose agar, and yeast extract medium for three days at 28°C, and disruption of AflaILVB/G/I caused a significant reduction in conidia production when grown on all kinds of media. Cellular stress assays determined that all strains were sensitive to H2O2. Importantly, the pathogenicity and aflatoxin production were affected when AflaILVB/G/I and AflaILVD were knocked out, particularly AflaILVB/G/I. A series of genes that encoded enzymes involved in aflatoxin synthesis were downregulated, meaning that the knockout of AflaILVB/G/I influenced aflatoxin synthesis in A. flavus strain WT. Collectively, our results demonstrate the potential value of antifungals targeting AflaILVB/G/I in A. flavus.

Isolasi, Identifikasi, dan Produksi Miselia Rhizopus sp. Berkadar Asam Nukleat Rendah untuk Pengembangan Mikoprotein

Fungi, including Rhizopus sp., are food sources that commonly contain high nucleic acid levels. Therefore, the nucleic acid content must be reduced to achieve health standard requirements. This study aimed to isolate, identify, and produce Rhizopus sp. mycelium containing low nucleic acid. The Rhizopus spp. were isolated from tempeh collected from 12 different areas in Indonesia. Fungal identification was conducted based on morphological characteristics. The fungal isolates were selected based on mycelial growth and spore production on PDA. Biomass production of mycelium was carried out in potato extract and soybean extract media obtained from 200 g/L and 333.3 g/L, respectively. In each medium, 6 sugar levels were added, namely 0, 2, 3, 4, 5, and 6 g/L. Mycelium nucleic acid content reduction was achieved by heat treatment at 50°C and 60°C for 15 minutes and measured by a spectrophotometer at 260 nm. Fifty-eight isolates that were identified into 3 species were obtained in this experiment: R. oryzae, R. stolonifera, and R. microsporus. R. Microsporus had higher mycelium biomass and lower spore number than the other species. R. Microsporus produced a higher mycelium biomass in the soybean extract medium with 5 g/L additional sugar. The nucleic acid content of the 50°C heat-treated mycelium was 1.82% and 1.73% at 65°C. These values fulfilled the standard of mycelial nucleic acid content permitted in food by the USDA.
 
 Keywords: morphology, Rhizopus microspores, spore, soybean extract, tempeh

Mycelium-based-composites – Vision for substitution of fossil-based materials

For decades, fossil-based materials have formed the basis of an almost endless range of technical products. Through variable chemical composition and several additives, especially plastics can have a wide range of properties, which form the basis for the diversity of plastic-based products. While this variability enables many sustainability strategies, such as lightweighting, it is also impeding a fully circular economy. Therefore, in recent years, a number of new raw materials have been developed, but they can only cover a very limited part of the wide range of properties of fossil-based plastics. Another promising class of materials are composites based on fungal mycelium.However, these are mainly limited to the consumer sector, e.g. vegan leather, where there is smaller demand for durability, functionality etc. The step from consumer to engineering materials require the production (or growth) process to be reproducible within the necessary quality requirements. Cyber-physical production systems have the potential to realise necessary technical qualities despite e.g. quality fluctuations of the raw material and production processes that are susceptible to interference. For this reason, this paper analyses the state of the art in production of mycelium based composites, shows the existing gaps and draws a vision to close these gaps.

Sustainable Pultruded Sandwich Profiles with Mycelium Core.

This research focuses on exploring the potential of mycelium as a sustainable alternative to wood or solid foam in pultruded glass fiber-reinforced plastic (GFRP) sandwich profiles. The study evaluates the performance and the environmental sustainability potential of this composite by mechanical tests and life cycle assessment (LCA). Analysis and comparison of pultruded sandwich profiles with mycelium, polyurethane (PUR) foam and chipboard demonstrate that mycelium is competitive in terms of its performance and environmental impact. The LCA indicates that 88% of greenhouse gas emissions are attributed to mycelium production, with the heat pressing (laboratory scale) being the main culprit. When pultruded profiles with mycelium cores of densities 350 and 550 kg/m³ are produced using an oil-heated lab press, a global warming potential (GWP) of 5.74 and 9.10 kg CO2-eq. per functional unit was calculated, respectively. When using an electrically heated press, the GWP decreases to 1.50 and 1.78 kg CO2-eq. Compared to PUR foam, a reduction of 23% in GWP is possible. In order to leverage this potential, the material performance and the reproducibility of the properties must be further increased. Additionally, an adjustment of the manufacturing process with in situ mycelium deactivation during pultrusion could further reduce the energy consumption.

Identification and Characterization of an Antifungal Gene Mt1 from Bacillus subtilis by Affecting Amino Acid Metabolism in Fusarium graminearum.

Fusarium head blight is a devastating disease that causes significant economic losses worldwide. Fusarium graminearum is a crucial pathogen that requires close attention when controlling wheat diseases. Here, we aimed to identify genes and proteins that could confer resistance to F. graminearum. By extensively screening recombinants, we identified an antifungal gene, Mt1 (240 bp), from Bacillus subtilis 330-2. We recombinantly expressed Mt1 in F. graminearum and observed a substantial reduction in the production of aerial mycelium, mycelial growth rate, biomass, and pathogenicity. However, recombinant mycelium and spore morphology remained unchanged. Transcriptome analysis of the recombinants revealed significant down-regulation of genes related to amino acid metabolism and degradation pathways. This finding indicated that Mt1 inhibited amino acid metabolism, leading to limited mycelial growth and, thus, reduced pathogenicity. Based on the results of recombinant phenotypes and transcriptome analysis, we hypothesize that the effect of Mt1 on F. graminearum could be related to the metabolism of branched-chain amino acids (BCAAs), the most affected metabolic pathway with significant down-regulation of several genes. Our findings provide new insights into antifungal gene research and offer promising targets for developing novel strategies to control Fusarium head blight in wheat.

Mycelium as sustainable textile material – review on recent research and future prospective

PurposeMycelium is an upcoming bio-based alternative material that has various applications in different industries. Mycelium materials used as composites, leather, construction materials and some are even available for commercial purposes. However, there was not much research found when it came to the application of mycelium as a textile alternative. The purpose of this paper is to examine the potential of mycelium in the textile industry and its possible applications.Design/methodology/approachThis review consolidates literature that refers the two major methods used in fungal mycelium production namely; as a composite and as a pure self-grown mycelium sheet. The study compared the current research status in this respective field and reported the scope in the pure mycelium development.FindingsThe results of the review reported that several research works are performed in composite production with different feedstock. The production methods and product development steps were well established for several applications from home utilities to construction materials. Whereas, in the case of self-grown mycelium sheet production only limited research works were found. Though the possibilities of engineered composite sheets are developed with various properties, research on self-grown pure mycelium sheets are at infant stage. Sensitive production methods, lower tensile, tearing, poor handle properties with brittle structure and non-uniformity in thickness are noted as limitations. Sustainable nature, self-grown three-dimensional nano-fibril network with porous structure are found to be advantageous.Originality/valueThe solid culture method was identified as a potential method to develop a sheet-like self-grown mycelium with different dimensions. The review results clearly show the lack of research in the direct application of self-grown pure mycelium area concerning feedstock material, fungal species selection and characterization of the developed product. Addressing the existing limitations will yield a sustainable textile material for fashion and textile industry with great potential.

Potential Protein Production from Lignocellulosic Materials Using Edible Mushroom Forming Fungi.

There is a need for new protein sources to feed the world in a sustainable way. Converting non-food-grade "woody" side streams into food containing proteins will contribute to this mission. Mushroom forming fungi are unique in their capability to convert lignocellulosic substances into edible biomass containing protein. Especially if substrate mycelium can be used instead of mushrooms, this technology could be a serious contribution to addressing the protein challenge. In this Perspective, we discuss challenges toward production, purification, and market introduction of mushroom mycelium based foods.

Metabolic activity on Biolog FF MicroPlate suggests organic substrate decomposition by Aspergillus terreus NTOU4989 isolated from Kueishan Island Hydrothermal Vent Field, Taiwan

Aspergillus terreus NTOU4989 was isolated from sulfur sediment collected at Kueishan Island Hydrothermal Vent Field, Taiwan, and was shown to be able to grow at 45 °C and pH 3 in seawater, characteristics of hydrothermal vent sites. Fungi are one of the major decomposers in the marine environment, and to find out whether A. terreus NTOU4989 can fulfill such a role at the site, this study investigated its metabolic activity using the Biolog FF MicroPlate™ under different growth conditions (45 °C/pH 3, 45 °C/pH 7, 25 °C/pH 3, 25 °C/pH 7) with/without addition of Al 3+ , Fe 2+ and Mn 2+ , major metal ions in the vent effluent. The greatest metabolic activity was observed at 25 °C/pH 3 with/without the metal ions based on substrate richness (R S , metabolic richness), average well colour development (AWCD, metabolic capacity) and average well turbidity development (AWTD, mycelial production). Significant low R S , AWCD and AWTD were observed at 45 °C, suggesting that A. terreus NTOU4989 is a thermotolerant fungus. The presence of the metal ions did not have a significant effect on its metabolic activity. Monomers of lignin, cellulose and hemicellulose, and common sugars and amino acids of algae were utilized in selected conditions, providing evidence of wood and algal decomposition by the fungus at the hydrothermal vent site.

Do ectomycorrhizal exploration types reflect mycelial foraging strategies?

Ectomycorrhizal exploration types are commonly assumed to denote spatial foraging patterns and resource-related niches of extraradical mycelia. However, empirical evidence of the consistency of foraging strategies within exploration types is lacking. Here, we analysed ectomycorrhizal foraging patterns by incubating root-excluding ingrowth mesh bags filled with six different substrates in mature Picea abies forests. High-throughput sequencing was used to characterise ectomycorrhizal fungal communities in the mesh bags and on adjacent fine roots after one growing season. Contrary to expectations, many ectomycorrhizal genera of exploration types that are thought to produce little extraradical mycelium colonised ingrowth bags extensively, whereas genera commonly associated with ample mycelial production occurred sparsely in ingrowth bags relative to their abundance on roots. Previous assumptions about soil foraging patterns of exploration types do not seem to hold. Instead, we propose that variation in the proliferation of extraradical mycelium is related to intergeneric differences in mycelial longevity and the mobility of targeted resources.

A New Strain of Lecanicillium uredinophilum Isolated from Tibetan Plateau and Its Insecticidal Activity.

A new strain QHLA of Lecanicillium uredinophilum was isolated from a Chinese caterpillar fungus complex and its optimum growth temperature and fermentation conditions were studied. Its insecticidal activity was tested against larvae of seven different insect pests, including Henosepilachna vigintioctopunctata, Spodoptera exigua, Plutella xylostella, Spodoptera frugiperda, Sitobion avenae, Hyalopterus perikonus, and Aphis citricola. The optimum growth temperature was 21–24 °C. The highest spore production of the strain QHLA was 4.08 × 106 spore/mL on solid medium with a nitrogen source of NH4Cl. However, the highest mycelial growth rate of the strain QHLA was on solid medium with a nitrogen source from yeast extract (4.63 ± 0.03 mm/d). When the liquid medium contained peptone, yeast extract, and glucose, the water content of the mycelia was the lowest, while the spore production was the highest until day 12. When the liquid medium contained glucose, tussah pupa powder, KH2PO4, and MgSO4, the mycelia production was highest until day 8. The bioassay for insecticidal activity indicated that the LC50 values of QHLA were 6.32 × 103 spore/mL and 6.35 × 103 spore/mL against Sitobion avenae and Aphis citricola, respectively, while the LC90 values of the strain QHLA against Aphis citricola and Sitobion avenae were 2.11 × 107 spore/mL and 2.36 × 108 spore/mL, respectively. Our results demonstrated that the strain QHLA was a high virulence pathogenic fungus against insect pests, with the potential to be developed as a microbial pesticide.

SEED PRODUCTION TRIALS OF VOLVARIELLA VOLVACEA ON VARIOUS SUBSTRATES IN DALOA (CENTRAL WEST - COTE DIVOIRE)

The objective of this study was to improve the seed production of Volvariellavolvaceain Daloa(central-west Cote dIvoire). Tissue fragments were cultured on PDA (Potato Dextrose Agar)medium for the production of mycelium. Once the mycelium was obtained, it was inoculated into jars containing pre-cooked cereals (maize, sorghum) and legumes and sterilized (at 121°C). When the jars are completely covered with mycelium, the different parameters are measured. The results obtained showed that the mycelium of Volvariellavolvaceacan propagate on PDA medium, legumes and also cereals. The seed production of Volvariellavolvaceais susceptible to contamination. Results after 10 days of incubation showed that the mycelium grows best on the following substrates: sorghum (14.1 cm), soybean (13.4) and bean (12.9 cm). Corn showed low values (6.3 cm) for mycelial growth.

In Vitro Propagation of A Cuban Arbuscular Mycorrhizal Fungal Strain

In vitro root cultivation techniques based on modified root systems are often used in studies on Arbuscular Mycorrhizal Fungi (AMF). It is a simplified but powerful tool to investigate AMF root colonization and development of the extraradical mycelium. The aim of this study was to establish and characterize the in vitro culture of a Cuban strain of Rhizophagus irregularis (INCAM 11) by using transformed chicory roots. For that, superficially disinfected propagules of R. irregularis were co-culture with the hairy transformed chicory roots on Modified Strullu and Romand (MSR) medium during five months. Spore germination was observed 3-5 days after surface disinfection. The first contact between AMF hyphae and roots occurred 1-3 days after germination and a significant production of extensive extraradical mycelium was observed. New spore formation started within 21-25 days. After 5 months, 2000 spores could be observed per plate which were able to germinate, colonize, establish and reproduce again spores when associated to young transformed roots of chicory. The most frequent associated microorganism to the in vitro culture of INCAM 11 was isolated and identified as Paenibacillus sp.

The impact of host plant (Pinus thunbergii) on the mycelial features of the ectomycorrhizal fungus Rhizopogon roseolus

ABSTRACT The impact of host plant on the mycelial features of mycorrhizal symbiont and its characteristics has been poorly investigated. This study aimed to compare and quantify (statistically tested) some of the mycelial features of an ectomycorrhiza (ECM)-forming fungus with and without the ECM host. The ECM-forming fungus, Rhizopogon roseolus, inoculated with or without Pinus thunbergii on both rich and poor nutrient media, was observed under laboratory conditions. On rich medium, fungi with the host had the highest colony diameter and consistently produced the highest hyphal length relative to fungi on other media. Thus, the host had a significant impact on the mycelium production of R. roseolus in both rich and poor media. Further, fungi without the host had a higher number of hyphal anastomoses per hyphal length on both poor and rich media than fungi with the host in the same medium. Anastomosis, which refers to the fusion of two parallel hyphae, was evident in all experiments. However, there was no significant impact of the host on the number of hyphal anastomoses. In addition, fungi without the host had more frequent hyphal branching on both rich and poor media than fungi with the host. The occurrence of a host only had a significant impact on the formation of the hyphal branch on poor medium. Further, a chlamydospore-like structure was identified, which had a higher diameter when formed with the host on both rich and poor media. The present data provide new insights into the host plant’s impact on the mycelial features of ECM-forming fungi.