Optimization of submerged culture process for the production of mycelial biomass and exo-polysaccharides by Cordyceps militaris C738

Optimization of cultural and nutritional conditions to enhance mycelial biomass of Cordyceps militaris using statistical approach

Cordyceps militaris is a fungus with numerous therapeutic properties that has gained worldwide popularity due to its potential health benefits. The fruiting body of this mushroom is highly expensive and takes a longer time to produce, making mycelial a sustainable and cost-effective alternative. The study investigates and optimizes cultural and nutritional conditions to maximize mycelial biomass. The initial optimization was done by the conventional single-factor approach, followed by Plackett-Burman design to screen the most significant variables, with yeast extract, temperature, and glucose being the most significant, contributing 11.58%, 49.74%, and 27.98%, respectively, in mycelial biomass production. These variables were then optimized using response surface methodology (RSM) based on central composite design (CCD). The study observed that temperature and glucose had the highest impact on mycelial biomass, with p-values of 0.0128 and 0.0191, respectively. Under the optimized conditions, temperature 20 °C, glucose 2.5% (w/v), and yeast extract 0.8% (w/v), the maximal yield of mycelial biomass reached 547 ± 2.09 mg/100 mL, which was 1.95-fold higher than the yield in the basal medium. These findings suggest that optimizing the cultural and nutritional conditions can enhance mycelial biomass production of Cordyceps militaris, offering a sustainable and cost-effective source of this valuable fungus.

A review on polysaccharide biosynthesis in Cordyceps militaris

Cordyceps militaris (C. militaris) is an edible parasitic fungus with medicinal properties. Its bioactive polysaccharides are structurally diverse and exhibit various metabolic and biological activities, including antitumor, hypoglycemic, antioxidant, hypolipidemic, anti-inflammatory, immunostimulatory, and anti-atherosclerotic effects. These properties make C. militaris-derived polysaccharides a promising candidate for future development. Recent advancements in microbial fermentation technology have enabled successful laboratory cultivation and extraction of these polysaccharides. These polysaccharides are structurally diverse and exhibit various biological activities, such as immunostimulatory, antioxidant, antitumor, hypolipidemic, and anti-atherosclerotic effects. This review aims to summarize the structure and production mechanisms of polysaccharides from C. militaris, covering extraction methods, key genes and pathways involved in biosynthesis, and fermentation factors that influence yield and activity. Furthermore, the future potential and challenges of utilizing polysaccharides in the development of health foods and pharmaceuticals are addressed. This review serves as a valuable reference in the fields of food and medicine, and provides a theoretical foundation for the study of polysaccharides.

The molecular recognition of cordycepin arabinoside and analysis of changes on cordycepin and its arabinoside in fruiting body and pupa of Cordyceps militaris

Cordyceps militaris is an edible fungus that is widely used as a functional food in many countries. In order to objectively evaluate its nutritional value, free and glycosidic cordycepins need to be analyzed. The cordycepin arabinoside molecule was recognized by the MS² fragmentation rule, and both cordycepin and its arabinoside were quantitatively analyzed in the fruiting body and pupa of Cordyceps militaris by high-performance liquid chromatography with tandem mass spectrometric (HPLC-MS/MS). The method had good linear regression (R² = 0.9999), with a detection limit of 0.021 ng/mL. The recovery range was 94.32-103.09% in the fruiting body and pupa. The content of cordycepin and its arabinoside showed an upward trend with growth, and the total contents reached the highest level at the mature stage (60-70th day) without mildew. This study provides a useful reference for the evaluation and application of Cordyceps militaris as a functional food resource.

Improved recombinant protein production in Aspergillus oryzae lacking both α-1,3-glucan and galactosaminogalactan in batch culture with a lab-scale bioreactor

Filamentous fungi are used as production hosts for various commercially valuable enzymes and chemicals including organic acids and secondary metabolites. We previously revealed that α-1,3-glucan and galactosaminogalactan (GAG) contribute to hyphal aggregation in the industrial fungus Aspergillus oryzae, and that production of recombinant protein in shake-flask culture is higher in a mutant lacking both α-1,3-glucan and GAG (AGΔ-GAGΔ) than in the parental strain. Here, we compared the productivity of the wild type, AGΔ-GAGΔ, and mutants lacking α-1,3-glucan (AGΔ) or GAG (GAGΔ) in batch culture with intermittent addition of glucose in a 5-L lab-scale bioreactor. The hyphae of the wild type and all mutants were dispersed by agitation, although the wild type and AGΔ formed small amounts of aggregates. Although mycelial weight was similar among the strains, the concentration of a secreted recombinant protein (CutL1) was the highest in AGΔ-GAGΔ. Evaluation of fluid properties revealed that the apparent viscosities of mycelial cultures of the wild type and AGΔ-GAGΔ decreased as the agitation speed was increased. The apparent viscosity of the AGΔ-GAGΔ culture tended to be lower than that of the wild-type strain at each agitation speed, and was significantly lower at 600 rpm. Overall, the lack of α-1,3-glucan and GAG in the hyphae improved culture rheology, resulting in an increase in recombinant protein production in AGΔ-GAGΔ. This is the first report of flow behavior improvement by a cell-surface component defect in a filamentous fungus.

Bioremediation Potential of Streptomyces sp. MOE6 for Toxic Metals and Oil

Toxic metal contamination has serious effects on human health. Crude oil that may contain toxic metals and oil spills can further contaminate the environment and lead to increased exposure. This being the case, we chose to study the bio-production of inexpensive, environmentally safe materials for remediation. Streptomyces sp. MOE6 is a Gram-positive, filamentous bacterium from soil that produces an extracellular polysaccharide (MOE6-EPS). A one-factor-at-a-time experiments showed that the maximum production of MOE6-EPS was achieved at 35 °C, pH 6, after nine days of incubation with soluble starch and yeast extract as carbon sources and the latter as the nitrogen source. We demonstrated that MOE6-EPS has the capacity to remove toxic metals such as Co(II), Cr(VI), Cu(II) and U(VI) and from solution either by chelation and/or reduction. Additionally, the bacterium was found to produce siderophores, which contribute to the removal of metals, specifically Fe(III). Additionally, purified MOE6-EPS showed emulsifying activities against various hydrophobic substances, including olive oil, corn oil, benzene, toluene and engine oil. These results indicate that EPS from Streptomyces sp. MOE6 may be useful to sequester toxic metals and oil in contaminated environments.

Structure and hypoglycemic activity of a novel exopolysaccharide of Cordyceps militaris

A novel neutral exopolysaccharide (EPS-III) was isolated from culture broth of Cordyceps militaris (C. militaris). The EPS-III was a homogeneous polysaccharide with M_w of 1.56 × 10³ kDa. The yield of EPS-III from culture broth was 123.2 ± 3.1 mg/L and the sugar content was 93.32 ± 0.87%. The backbone of EPS-III was mainly consisted of →4)-α-D-Galp-(1→, while →3, 6)-α-D-Manp-(1→, →4)-α-D-Manp-(1→, →3)-β-D-Galp-(1→ and →3)-α-D-Glcp-(1→ were distributed in the backbone or in the branch chains. The EPS-III had helix structure when dissolved in weak alkaline solution. It also had branched and intertwined form on the surface. The inhibition of α-glucosidase significantly increased as the increase of purity of exopolysaccharides. The EPS-III had effective inhibition on the α-glucosidase with dose-effect relationship. Besides, the results of hypoglycemic activity analysis in vivo indicated that EPS-III can alleviate weight loss, reduce plasma glucose concentration, improve glucose tolerance, protect immune organs and repair dyslipidemia to relieve diabetes in STZ-induced diabetic mice. The manuscript first studied the hypoglycemic activity of exopolysaccharide of by C. militaris, proving and promoting the application value of culture broth. The structure characterization of EPS-III laid experimental foundations on the exploration of structure-activity relationship.

Extracellular polysaccharide biosynthesis in Cordyceps

Cordyceps is a parasitic edible fungus with a variety of metabolically active ingredients. The main active ingredient, extracellular polysaccharide (EPS), shows favourable application prospects in prevention and treatment of certain diseases. EPS extracted from different parts of various Cordyceps species can be used in health foods or medicinal preparations because of the structural diversity and multiple bioactivities. In terms of the complexity of composition and structure, researchers have speculated on the anabolic pathways of EPSs and the genes involved in the synthesis process. Studies to increase the yield of polysaccharides are limited because the synthesis pathways and anabolic regulation mechanisms of Cordyceps exopolysaccharide remain unknown. This review summarises the current researches in the yield of Cordyceps polysaccharides. A mechanism for the biosynthesis of Cordyceps polysaccharides was proposed by referring to the polysaccharide synthesis in other species. Furthermore, we also discuss the future perspective and ongoing challenges of EPS in uses of health foods and pharmaceutics.

Fast quantification of free amino acids in food by microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry

A method based on microfluidic voltage-assisted liquid desorption electrospray ionization-tandem mass spectrometry (VAL-DESI-MS/MS) has been developed for fast quantification of free amino acids in food. Food extracts were transferred to the microfluidic platform and analyzed by liquid desorption ESI-MS/MS. Deuterated aspartic acid (i.e., 2,2,3-d3-Asp) was used as internal standard for analysis. The method had linear calibration curves with r2 values > 0.998. Limits of detection were at the level of sub μM for the amino acids tested, i.e., glutamic acid (Glu), arginine (Arg), tyrosine (Tyr), tryptophan (Trp), and phenylalanine (Phe). To validate the proposed method in food analysis, extracts of Cordyceps fungi were analyzed. Amino acid contents were found in the range from 0.63 mg/g (Tyr in Cordyceps sinensis) to 4.44 mg/g (Glu in Cordyceps militaris). Assay repeatability (RSD) was ≤ 5.2% for all the five amino acids measured in all the samples analyzed. Recovery was found in the range from 95.8 to 105.1% at two spiking concentrations of 0.250 mg/g and 1.00 mg/g. These results prove that the proposed microfluidic VAL-DESI-MS/MS method offers a quick and convenient means of quantifying free amino acids with accuracy and repeatability. Therefore, it may have potential in food analysis for nutritional and quality assessment purposes. Graphical abstract.

The effect of fermentation conditions on the structure and anti-tumor activity of polysaccharides from Cordyceps gunnii

This study investigates the effect of fermentation conditions on the structure and anti-tumor activity of intracellular polysaccharides (IPS) of Cordyceps gunnii (C. gunnii) in submerged fermentation. The environmental and nutritional conditions are determined in a shaker flask by a single factor test. The inhibition of IPS on S180 cells was as an optimization index. The results show that the optimal fermentation conditions of C. gunnii are an initial pH value of 6, a temperature of 25 °C, a rotation speed of 150 rpm, 4% glucose, and 1.0% peptone. Under these conditions, the macro molecular weight (M w) polysaccharide content and anti-tumor activity of IPS are significantly higher than that in the basal culture medium. GC, HPGPC, periodate oxidation-Smith degradation, NMR, and FT-IR determine the structural characteristics of CPS-JC and CPS-YH (pure IPS cultured in basal culture medium and optimal culture medium, respectively). The results indicate that CPS-JC is mainly composed of α-d-glucans, whereas CPS-YH primarily contain α-d-glucans with a trace amount of β-d-glucans.

Optimization of liquid fermentation conditions for biotransformation zein by Cordyceps militaris 202 and characterization of physicochemical and functional properties of fermentative hydrolysates

Cordyceps militaris 202 is a potential fungus for biotransformation zein, due to its various proteases, high tolerance and viability in nature. In this article, single factor experiment and response surface methodology were applied to optimize the liquid fermentation conditions and improve the ability of biotransformation zein. The optimized fermentation conditions were as follows: inoculum concentration of 19%, volume of liquor of 130 mL/500 mL and pH of 4.7. Under this condition, the degree of hydrolysis (DH) was 27.31%. The zein hydrolysates from fungi fermentation maintained a high thermal stability. Compared to the original zein, the zein hydrolysates were found to have high solubility, which most likely results in improved foaming and emulsifying properties. Overall, this research demonstrates that hydrolysis of zein by C. militaris 202 is a potential method for improving the functional properties of zein, and the zein hydrolysates can be used as functional ingredients with an increased antioxidant effect in both food and non-food applications.

Antidepressant-like effects of Marasmius androsaceus metabolic exopolysaccharides on chronic unpredictable mild stress-induced rat model

Marasmius androsaceus (M. androsaceus), a medicinal fungus, has various pharmacological activities including antidepression. The present study investigated the effects of exopolysaccharides obtained during M. androsaceus submerged fermentation in a chronic unpredictable mild stress (CUMS)‑induced depression rat model. Similar to fluoxetine (positive drug), 4‑week administration of M. androsaceus exopolysaccharides (MEPS) at doses of 6, 30 and 150 mg/kg strongly enhanced bodyweight gain and sucrose consumption, and reduced the immobility time in forced swimming test and tail suspension test in CUMS rats. MEPS resulted in significant enhancement on the levels of noradrenalin, dopamine, 5‑hydroxytryptamine (5‑HT), and 5‑hydroxyindoleacetic acid in the serum and hypothalamus of CUMS rats, as detected by ELISA. Western blotting results revealed that MEPS upregulated the protein expression levels of tyrosine hydroxylase in the hypothalamus of CUMS rats. In conclusion, these results confirmed the antidepressant‑like effects of MEPS, and suggested that the monoamine neurotransmitter system is involved in its antidepressive effects in a CUMS rat model. The present study provided evidence for the clinical application of MEPS as an effective agent against depression.

Production and Preliminary Characterization of Antioxidant Polysaccharide by Submerged Culture of Culinary and Medicinal Fungi Cordyceps militaris CICC14013

Polysaccharides from Cordyceps militaris show multiple biological activities, such as antioxidation, antitumor, antivirus and immunomodulating properties, etc. The nutritional requirements for antioxidant polysaccharide bio-synthesis by submerged culture of C. militaris were evaluated on the basis of assay for DPPH radical scavenging ability and reducing power in this work. The results showed the best antioxidant activity of polysaccharide could be achieved when the media consisted of mannose, peptone, MgSO4, Na2HPO4, and KH2PO4. Furthermore, the main fraction of antioxidant polysaccharide, CMP-2, was preliminary isolated from the fermentation broth of C. militaris by ethanol precipitation, filtration, and DEAE cellulose-52 chromatography. CMP-2 was composed of mannose, rhamnose, glucose and galactose in a ratio of 2527:164:172:100, and had an average molecular weight (Mw) of approximately 8175 Da. The results suggested antioxidant polysaccharide could be produced by submerged culture of C. militaris and the medium composition significantly affected its DPPH radical scavenging ability and reducing power.

Production of mycelial biomass by the Amazonian edible mushroom Pleurotus albidus

Edible mushroom species are considered as an adequate source of food in a healthy diet due to high content of protein, fiber, vitamins, and a variety of minerals. The representatives of Pleurotus genus are characterized by distinct gastronomic, nutritional, and medicinal properties among the edible mushrooms commercialized worldwide. In the present study, the growth of mycelial biomass of Pleurotus albidus cultivated in submerged fermentation was evaluated. Saccharose, fructose, and maltose were the three main carbon sources for mycelial biomass formation with corresponding yields of 7.28 g L⁻¹, 7.07 g L⁻¹, and 6.99 g L⁻¹. Inorganic nitrogen sources did not stimulate growth and the optimal yield was significantly higher with yeast extract (7.98 g L⁻¹). The factorial design used to evaluate the influence of saccharose and yeast extract concentration, agitation speed, and initial pH indicated that all variables significantly influenced the production of biomass, especially the concentration of saccharose. The greater amount of saccharose resulted in the production of significantly more biomass. The highest mycelial biomass production (9.81 g L⁻¹) was reached in the medium formulated with 30.0 g L⁻¹ saccharose, 2.5 g L⁻¹ yeast extract, pH 7.0, and a speed of agitation at 180 rpm. Furthermore, P. albidus manifested different aspects of morphology and physiology under the growth conditions employed. Media composition affected mycelial biomass production indicating that the diversification of carbon sources promoted its improvement and can be used as food or supplement.

Statistical optimization of culture medium for production of exopolysaccharide from endophytic fungus Bionectria ochroleuca and its antitumor effect in vitro

Endophytic fungi have been recognized as possible useful sources of bioactive metabolites. However, exopolysaccharide (EPS) production from endophytic fungi and its antitumor activity have been less explored. In the present study, endophtic fungus Bionectria ochroleuca M21 was exploited for the production of EPS in submerged culture. Among tested medium components, glucose, yeast extract, MgSO₄ and Tween80 were found to be effective and significant on EPS production. Response surface methodology (RSM) was employed to optimize medium composition. The results showed that the significant factors were glucose, yeast extract and Tween80. The optimal medium was observed at the composition of glucose 55.7 g/L, yeast extract 6.04 g/L, MgSO₄ 0.25g/L and Tween80 0.1 % (v/v). Using the optimized medium, EPS production was achieve at 2.65 ± 0.16 g/L after 4 days fermentation in a 5L bioreactor. Examination of cytotoxicity showed that the EPS from B. ochroleuca M21 did not have cytotoxic activity on human liver HL-7702 cells at concentration 0.025-1.6 mg/mL. In contrast, the EPS exhibited antiproliferative activities against cell lines of liver cancer (HepG2), gastric cancer (SGC-7901) and colon cancer (HT29) in a dose- and time-dependent manner in the concentration ranges of 0.1-0.45 mg/mL.

Investigation of the antidepressant effects of exopolysaccharides obtained from Marasmius androsaceus fermentation in a mouse model

Marasmius androsaceus, a well‑known medical fungus, possesses antihypertensive, analgesic and antioxidant effects. Exopolysaccharide (EPS), produced by microorganism secretion, exerts various types of biological activities. The present study aimed to investigate the antidepressant‑like effect of the EPS produced during Marasmius androsaceus submerge fermentation (MEPS). Based on the assessment of acute toxicity and behavior, a forced swimming test (FST), tail suspension test (TST), 5‑hydroxytryptophan‑induced head‑twitch assessment and reserpine‑induced hypothermia assessment were performed. The administration of MEPS for 7 days enhanced mouse locomotor and balance ability in the mice. Similar to the results following treatment with fluoxetine, which was used as positive control drug, MEPS significantly decreased the duration of immobility in the FST and TST, increased head twitches in the 5‑HTP‑induced head‑twitch test and enhanced rectal temperature in resperpine‑induced hypothermia. MEPS altered the abnormal concentrations of 5‑hydroxytryptamine, 5‑hydroxyindoleacetic acid, dopamine and norepinephrine in the hypothalamus in the resperine‑induced mouse model. Additionally, an increase in the expression of tyrosine hydroxylase and a reduction in the level of dopamine transporter in the hypothalamus were noted following 7 days of MEPS administration. Taken together, the EPS produced during MEPS exhibited antidepressant‑like effects, which may be associated with its regulation on the dopaminergic system. The results of the present study provide experimental evidence supporting the clinical use of MEPS as an effective agent against depression.

Optimization of fermentation process of Cordyceps militaris and antitumor activities of polysaccharides in vitro

The influence of medium composition and cultural conditions on simultaneous yield of mycelia, intracellular polysaccharide, adenosine, and mannitol by Cordyceps militaris CGMCC 2909 was investigated with desirability functions in this study. An optimization strategy based on the desirability function approach, together with response surface methodology (RSM) has been used to optimize medium composition, and the optimal medium was obtained via the desirability as follows: yeast extract 10.33 g/L, sucrose 27.24 g/L, KH₂PO₄ 5.60 g/L and the optimal culture conditions are initial pH 6, 25°C, rotation speed 150 r/minute, inoculum size 4%(v/v), and medium capacity 40 mL/250 mL. Under these conditions, the yield of mycelia, intracellular polysaccharide, adenosine and mannitol reached 12.19 g/L, 0.6 g/L, 61.84 mg/L, and 1.38 g/L, respectively, and the D value was 0.77. Furthermore, the polysaccharides showed significant antitumor activities against HeLa and HepG2 in vitro in a dose-dependent manner in 72 hours. At a concentration of 1000 mg/mL, the inhibition rate of polysaccharides was 92.38% and 98.79%. The IC50 for HeLa and HepG2 were 70.91 μg/mL and 97.63 μg/mL, respectively.

Nutritional optimization of a native Beauveria bassiana isolate (HQ917687) pathogenic to housefly, Musca domestica L

A new Beauveria bassiana isolate, showing high activity against Musca domestica L. (Diptera: Muscidae) adults (mortality-100.0 %), larvae (mortality-72.3 %) and pupae (Infection in emerged flies-96.7 %) was used. The isolate was subjected to a combinational approach towards selection of process parameters for its growth optimization. Initial screening of several carbon and nitrogen sources revealed glucose and NaNO3 as the most suitable source for optimal biomass and spore production. Further, optimization through Placket-Burman and a 2(5) full factorial central composite design revealed highly significant effect of glucose and pH. The optimum composition for maximum biomass yield was (g/l): glucose 28; NaNO3 2.43; KH2PO4 1.32; MgSO4 0.60; and pH 7.00. Glucose concentration showed almost linear relationship with biomass yield, indicating its significant contribution in medium composition for fungal growth. Highly significant interactions were observed between glucose and pH, followed by glucose and NaNO3 concentration.

The genus Cordyceps: a chemical and pharmacological review

Objectives

Natural remedies are becoming increasingly popular and important in the public and scientific communities. Historically, natural remedies have been shown to present interesting biological and pharmacological activity and are used as chemotherapeutic agents. For centuries Cordyceps, which is a genus of more than 400 species in the family Clavicipitaceae, has been used in traditional Chinese medicine. This study highlights the chemistry and pharmacology of Cordyceps, especially Cordyceps sinensis (Berk.) Sacc. and C. militaris (Fr.) L. Information was obtained from Google Scholar and the journal databases PubMed and Scopus.

Key findings

Many bioactive components of Cordyceps have been extracted, such as cordycepin, cordycepic acid, ergosterol, polysaccharides, nucleosides and peptides. Studies show that Cordyceps and its active principles possess a wide range of pharmacological actions, such as anti-inflammatory, antioxidant, antitumour, antihyperglycaemic, antiapoptosis, immunomodulatory, nephroprotective, and hepatoprotective.

Summary

More research is required to discover the full extent of the activity of Cordyceps.

Fermentation optimization, characterization and bioactivity of exopolysaccharides from Funalia trogii

Optimization of culture conditions for exopolysaccharide (EPS) by Funalia trogii in submerged culture was investigated using one-factor-at-a-time method and uniform design (UD). Under the optimized conditions, the maximum concentration of EPS was 8.68 g/l. After EPS was deproteinized by Sevag method, two groups of EPSs (designated as Fr-I and Fr-II) were obtained from the culture filtrates by gel filtration chromatography on Sepharose CL-6B. Furthermore, EPSs were characterized by size exclusion chromatography (SEC) coupled with a multiangle laser-light scattering (MALLS) and refractive index (RI) detector system. The weight-average molar masses of the Fr-I and Fr-II were determined to be 1.007 × 10(5) and 2.393 × 10(4)g/mol, respectively. The root mean square (RMS) radii for both peaks ranged from 9.7 to 10.8 nm with no clear trends. Pharmacology experiments indicated F. trogii EPS were useful to the therapy of free radical injury and cancer diseases.

Utilization of chicken feather hydrolysate as a novel fermentation substrate for production of exopolysaccharide and mycelial biomass from edible mushroom Morchella esculenta

This study was performed to investigate the usability of chicken feather hydrolysate (Chicken feather peptone (CFP)) as substrate for mycelial biomass and extracellular polysaccharides (EPS) production from edible mushroom Morchella esculenta. The ability of CFP to support biomass and EPS production in edible mushroom M. esculenta was compared to those of two commercial peptones (Tryptone peptone (TP) and Fish peptone (FP)). The maximum biomass (16.3 g/l) and EPS (4.8 g/l) concentrations were achieved with TP. Second, high biomass (15.9 g/l) and EPS (4.6 g/l) concentrations were obtained with CFP. Also, biomass and EPS concentrations in CFP medium were statistically near to those in the TP medium. CFP and TP resulted in not only uniform pellets with smaller size (5 mm) but also faster mycelial growth compared to FP. This study showed for the first time that CFP could be effectively used as a novel EPS production substrate.

On the reliability of fungal materials used in studies on Ophiocordyceps sinensis

Ophiocordyceps sinensis (≡Cordyceps sinensis) is one of the best known traditional Chinese medicines, with great benefits to human health and huge economic value. The reliability of fungal materials used in studies of the species is particularly important because contradictory results have been found in various studies in the past decades. Examination of fungal materials specified in reports on O. sinensis showed great variation in both sources and culture conditions of living strains. To test the reliability of the materials used, experiments were carried out to study the effect of culture conditions on the growth of living strains of O. sinensis by using six reliable strains representing the major production regions of the fungus on the Tibetan Plateau. The results showed that O. sinensis is a slow-growing fungus at comparatively low temperature, and that temperature and growth period are crucial factors which can be verified by experiment. Analyses of fungal materials used in 152 papers on O. sinensis from PubMed since 1998 showed that 41 papers lacked detailed information on the fungal materials; 26 used natural products, 11 used artificially cultivated fruit bodies, and 80 used fermentation products from living strains. Of the latter category (using fermentation products), 64 of the papers were found to use unreliable (45) or uncertain (19) strains for fermentation products based on the temperature and growth period for O. sinensis strains verified in this study. Apart from the natural products of O. sinensis, which require scientific identification, a total of at least 116 papers (over three-quarters) used unreliable, uncertain or unspecified materials, including so-called cultivated fruit bodies which were apparently from other species. The reliability of materials or living strains used in studies on O. sinensis is discussed in this paper, and suggestions are made for use of reliable fungal materials in further studies of this fungus.

Medicinal uses of the mushroom Cordyceps militaris: current state and prospects

Cordyceps militaris is a potential harbour of bio-metabolites for herbal drugs and evidences are available about its applications for revitalization of various systems of the body from ancient times. Amongst all the species, C. militaris is considered as the oldest source of some useful chemical constituents. Besides their popular applications for tonic medicine by the all stairs of the community, the constituents of C. militaris are now used extensively in modern systems of medicine. The current survey records the mysterious potentials of C. militaris are boosting up the present herbal treatments, as well as gearing up the green pharmacy revolution, in order to create a friendly environment with reasonable safety. Evidence showed that the active principles of C. militaris are beneficial to act as pro-sexual, anti-inflammatory, anti-oxidant/anti-aging, anti-tumour/anti-cancer/anti-leukemic, anti-proliferative, anti-metastatic, immunomodulatory, anti-microbial, anti-bacterial, anti-viral, anti-fungal, anti-protozoal, insecticidal, larvicidal, anti-fibrotic, steroidogenic, hypoglacaemic, hypolipidaemic, anti-angiogenetic, anti-diabetic, anti-HIV, anti-malarial, anti-fatigue, neuroprotective, liver-protective, reno-protective as well as pneumo-protective, let alone their other synergistic activities, which let it be marketable in the western countries as over-the-counter medicine. A number of culture techniques for this mushroom have been noticed, for example, storage/stock culture, pre-culture, popular/indigenous culture (spawn culture, husked rice culture and saw dust culture) and, special/laboratory culture (shaking culture, submerged culture, surface liquid culture and continuous/repeated batch culture). The prospects for herbal biotechnology regarding drug discovery using C. militaris delivering what it has promised are high, as the technology is now extremely more powerful than before. This study chiefly highlights the medicinal uses of the mushroom C. militaris including its culture techniques, also aiming to draw sufficient attention of the researchers to the frontier research needs in this context.

Exobiopolymer production of Ophiocordyceps dipterigena BCC 2073: optimization, production in bioreactor and characterization

Background

Biopolymers have various applications in medicine, food and petroleum industries. The ascomycetous fungus Ophiocordyceps dipterigena BCC 2073 produces an exobiopolymer, a (1→3)-β-D-glucan, in low quantity under screening conditions. Optimization of O. dipterigena BCC 2073 exobiopolymer production using experimental designs, a scale-up in 5 liter bioreactor, analysis of molecular weight at different cultivation times, and levels of induction of interleukin-8 synthesis are described in this study.

Results

In order to improve and certify the productivity of this strain, a sequential approach of 4 steps was followed. The first step was the qualitative selection of the most appropriate carbon and nitrogen sources (general factorial design) and the second step was quantitative optimization of 5 physiological factors (fractional factorial design). The best carbon and nitrogen source was glucose and malt extract respectively. From an initial production of 2.53 g·L^-1, over 13 g·L^-1 could be obtained in flasks under the improved conditions (5-fold increase). The third step was cultivation in a 5 L bioreactor, which produced a specific growth rate, biomass yield, exobiopolymer yield and exobiopolymer production rate of 0.014 h^-1, 0.32 g·g^-1 glucose, 2.95 g·g biomass^-1 (1.31 g·g^-1 sugar), and 0.65 g.(L·d)^-1, respectively. A maximum yield of 41.2 g·L^-1 was obtained after 377 h, a dramatic improvement in comparison to the initial production. In the last step, the basic characteristics of the biopolymer were determined. The molecular weight of the polymer was in the range of 6.3 × 10⁵ - 7.7 × 10⁵ Da. The exobiopolymer, at 50 and 100. μg·mL^-1, induced synthesis in normal dermal human fibroblasts of 2227 and 3363 pg·mL^-1 interleukin-8 respectively.

Conclusions

High exobiopolymer yield produced by O. dipterigena BCC 2073 after optimization by qualitative and quantitative methods is attractive for various applications. It induced high IL-8 production by normal dermal fibroblasts, which makes it promising for application as wound healing material. However, there are still other possible applications for this biopolymer, such as an alternative source of biopolymer substitute for hyaluronic acid, which is costly, as a thickening agent in the cosmetic industry due to its high viscosity property, as a moisturizer, and in encapsulation.

Pharmacological actions of Cordyceps, a prized folk medicine

Cordyceps species, including C. sinensis, C. militaris, C. pruinosa and C. ophioglossoides, are prized traditional medicinal materials. The aim of this article is to review the chemical constituents and pharmacological actions of Cordyceps species. The chemical constituents include cordycepin (3′-deoxyadenosine) and its derivatives, ergosterol, polysaccharides, a glycoprotein and peptides containing α-aminoisobutyric acid. They include anti-tumour, anti-metastatic, immunomodulatory, antioxidant, anti-inflammatory, insecticidal, antimicrobial, hypolipidaemic, hypoglycaemic, anti-ageing, neuroprotective and renoprotective effects. Polysaccharide accounts for the anti-inflammatory, antioxidant, anti-tumour, anti-metastatic, immunomodulatory, hypoglycaemic, steroidogenic and hypolipidaemic effects. Cordycepin contributes to the anti-tumour, insecticidal and antibacterial activity. Ergosterol exhibits anti-tumour and immunomodulatory activity. A DNase has been characterized.

Ergothioneine contents in fruiting bodies and their enhancement in mycelial cultures by the addition of methionine

The levels of ergothioneine (ERG), which have been shown to act as an excellent antioxidant, were determined in both fruiting bodies and mycelia of various mushroom species. We found that ERG accumulated at different levels in fruiting bodies of mushrooms and showed up to a 92.3-fold difference between mushrooms. We also found that ERG accumulated at higher levels in mycelia than in fruiting bodies of economically important mushroom species such as Ganoderma neo-japonicum, G. applanatum and Paecilomyces tenuipes. The addition of 2 mM methionine (Met) to mycelial culture medium increased the ERG contents in most mushroom species tested, indicating that Met is a good additive to enhance the ERG levels in a variety of mushroom species. Taking these results into consideration, we suggest that the addition of Met to the mycelial culture medium is an efficient way to enhance the antioxidant properties in economically important mushroom species.

Cordyceps: a traditional Chinese medicine and another fungal therapeutic biofactory?

Traditional Chinese medicines (TCM) are growing in popularity. However, are they effective? Cordyceps is not studied as systematically for bioactivity as another TCM, Ganoderma. Cordyceps is fascinating per se, especially because of the pathogenic lifestyle on Lepidopteron insects. The combination of the fungus and dead insect has been used as a TCM for centuries. However, the natural fungus has been harvested to the extent that it is an endangered species. The effectiveness has been attributed to the Chinese philosophical concept of Yin and Yang and can this be compatible with scientific philosophy? A vast literature exists, some of which is scientific, although others are popular myth, and even hype. Cordyceps sinensis is the most explored species followed by Cordyceps militaris. However, taxonomic concepts were confused until a recent revision, with undefined material being used that cannot be verified. Holomorphism is relevant and contamination might account for some of the activity. The role of the insect has been ignored. Some of the analytical methodologies are poor. Data on the "old" compound cordycepin are still being published: ergosterol and related compounds are reported despite being universal to fungi. There is too much work on crude extracts rather than pure compounds with water and methanol solvents being over-represented in this respect (although methanol is an effective solvent). Excessive speculation exists as to the curative properties. However, there are some excellent pharmacological data and relating to apoptosis. For example, some preparations are active against cancers or diabetes which should be fully investigated. Polysaccharides and secondary metabolites are of particular interest. The use of genuine anamorphic forms in bioreactors is encouraged.