Mycelial Content Research Articles

Biosynthesis of Se-methyl-seleno-l-cysteine in Basidiomycetes fungus Lentinula edodes (Berk.) Pegler.

BackgroundThe aim of the current study was to investigate whether the Basidiomycetes fungus Lentinula edodes can biosynthesize Se-methyl-seleno-l-cysteine, a seleno-amino acid with strong anticancer activity, and to optimize the culture conditions for its biosynthesis. We hypothesize that preparations obtained from Se-methyl-seleno-l-cysteine-enriched mycelia from this medicinal mushroom would possess stronger cancer-preventive properties than current preparations.ResultsBy optimizing the concentration of selenium in the culture medium, we increased the mycelial concentration of Se-methyl-seleno-l-cysteine from essentially non-detectable levels to 120 µg/g dry weight. Significantly elevated levels of this amino acid also correlated with significant (twofold) inhibition of mycelial growth. Increases in the concentration of mycelial Se-methyl-seleno-l-cysteine appeared to be highly correlated with the enhanced biosynthesis of selenomethionine and total selenium content in mycelium.ConclusionsWe have demonstrated that in L. edodes, enhanced biosynthesis of this non-protein amino acid eliminates excess selenium.

Commensal relation between Bursaphelenchus xylophilus (Nematoda: Aphelenchoididae) and Monochamus alternatus (Coleoptera: Cerambycidae) within pine trees

Bursaphelenchus xylophilus (Steiner et Buhrer) Nickle causes pine wilt disease and is transmitted by Monochamus alternatus Hope adults in Japan. To determine the effects of the beetle larvae on the nematode population and the effects of the nematode population on beetle larval growth, we inoculated fresh pine bolts with various combinations of B. xylophilus, M. alternatus, and the blue-stain fungus Ophiostoma minus (Hedgc.) Syd. & P. Syd., the food of the nematodes. We also compared the content of ergosterol among the phloem, xylem, and larval frass. The nematode density was 22 or 25 times higher in frass than in phloem and the lowest in xylem, indicating positive effects of beetle larvae on the nematode population growth. Frass had twice higher ergosterol content than the phloem, indicating the fungal mycelial content was greatest in the frass. The difference in the content of fungal mycelia could explain in part the difference in B. xylophilus density between the frass and phloem. By contrast, B. xylophilus did not affect the growth and developmental rate of M. alternatus. This study showed that the relation between the beetle and nematode populations changes from mutualism to commensalism corresponding to the dispersal to reproduction stages of the nematode population.

Streptomyces subrutilus P5가 생산하는 철 함유 superoxide dismutase의 분비

We tried to analyze the growth time for secretion of the iron containing superoxide dismutase by comparing the intra-and extracellular enzyme activity from Streptomyces subrutilus P5 and analyze possible genetic information for this enzyme secretion. The mycelial dry weights and glucose concentrations in culture filtrates were determined during growth. Glucose was consumed rapidly during logarithmic growth phase and almost exhausted at 24 h of cultivation. While the intracellular activity of iron containing superoxide dismutase was first appeared at three hours, the extracellular activity of this enzyme appeared from 7.5 h of cultivation, early logarithmic growth phase. This early presence of the superoxide dismutase might not be the result of cell lysis but active secretion pathway. There was no information for signal peptide responsible for the enzyme secretion in sodF. However, we found a type three secretion box in the promoter region of sodF that has been known for the genes of type III secreted proteins in other bacteria. This is the first report on the possible existence of type III secretion in Streptomyces.

Effects of manganese, 2,5-xylidine, veratryl alcohol and tween 80 on the production of ligninolytic enzymes by Ceriporiopsis subvermispora

The effects of adding manganese, 2,5-xylidine, veratryl alcohol and Tween 80 in a culture medium used for the production of ligninolytic enzymes by polyurethane foam-immobilized Ceriporiopsis subvermispora were studied. While 11 ppm Mn2+ promoted the highest maximum activity of manganese peroxidase (108.0 ± 43.3 U/L, in the 6th day of cultivation), the medium without manganese led to the highest maximum activity of laccase (15.5 ± 2.1 U/L, in the 12th day of cultivation). By supplementing the medium containing 11 ppm Mn2+ with 1.0 mM 2,5-xylidine, it was possible to improve the maximum activity of laccase to 21.5 ± 4.9 U/L. The supplementation of the medium containing 11 ppm Mn2+ with 1.0 mM veratryl alcohol, in turn, led to an apparent second peak of MnP activity (110.0 ± 1.4 U/L, in the 24th day of cultivation; compared to 147.5 ± 60.1 U/L, in the 9th day of cultivation). When the medium containing 11 ppm Mn2+ and 1.0 mM 2,5-xylidine was supplemented with 0.05% (v/v) Tween 80, the maximum activities of Lac and MnP reached 53.3 ± 17.7 U/L (21st day of cultivation) and 174.8 ± 1.4 U/L (9th day of cultivation), respectively. During the cultivations, the exhaustion of glucose in the medium promoted nutritional stress, which, in turn, led to cell autolysis; reflected by an apparent reduction in the concentration of mycelium, and by an increase in the concentration of ammonium. The concentrations of extracellular proteins increased throughout the cultivations; such concentrations, however, did not generally exhibit good correlations with the measured enzyme activities. Key words: Ceriporiopsis subvermispora, manganese, 2,5-xylidine, veratryl alcohol, Tween 80; manganese peroxidase, laccase.

Mycelial fermentation characteristics and antiproliferative activity of Phellinus vaninii Ljup.

Background:The mycelial fermentation of higher fungi were investigated to posses various bioactivities.Materials and Methods:The mycelial growth and pellet morphology in a 5-L bioreactor were investigated. The mycelial broth containing biomass and extracellular products harvested from the fermentor was tested for antiproliferative activity of colon cancer LoVo cells using 3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetrazolium Bromide assay.Results:The maximum mycelial concentration in a 5-L bioreactor was 12.5 g/L after 8 days cultivation. Further investigation in the mycelial pellets during the fermentation period revealed that the mean diameter of the pellet morphology was positively correlated with mycelial biomass (R2 = 0.82, P < 0.05) and broth viscosity (R2 = 0.90, P < 0.01), significantly. The ethyl acetate extract showed the most significant effects, increasing the inhibition rate up to 87.5% after 48 h at concentration of 1000 μg/mL.Conclusion:The results demonstrated the feasibility of P. vaninii Ljup mycelial fermentation for large-scale production of bioactive and medicinal compounds.

Dynamics of Penicillium camemberti growth quantified by real-time PCR on Camembert-type cheeses under different conditions of temperature and relative humidity

Penicillium camemberti plays a major role in the flavor and appearance of Camembert-type cheeses. However, little is known about its mycelium growth kinetics during ripening. We monitored the growth of P. camemberti mycelium in Camembert-type cheeses using real-time PCR in 4 ripening runs, performed at 2 temperatures (8 and 16°C) and 2 relative humidities (88 and 98%). These findings were compared with P. camemberti quantification by spore concentration. During the first phase, the mycelium grew but no spores were produced, regardless of the ripening conditions. During the second phase, which began when lactose was depleted, the concentration of spores increased, especially in the cheeses ripened at 16°C. Sporulation was associated with a large decrease in the mycelial concentration in the cheeses ripened at 16°C and 98% relative humidity. It was hypothesized that lactose is the main energy source for the growth of P. camemberti mycelium at the beginning of ripening and that its depletion would trigger stress, resulting in sporulation.

Acceleration of &amp;lt;i&amp;gt;Hericium erinaceum&amp;lt;/i&amp;gt; mycelial growth in submerged culture using yogurt whey as an alternative nitrogen source

The effects of various carbon sources and their initial concentrations on mycelia production by Hericium erinaceum were investigated by determining the dry cell weight (DCW) and β-glucan content of mycelia in submerged culture. Glucose and xylose were superior carbon sources for promoting mycelial growth resulting in mycelial concentrations of 3.99 g/L and 4.01 g/L, respectively; glucose was the best carbon source in terms of productivity (0.44 g/L/day). Experiments were also performed using yogurt whey as an alternative nitrogen source for submerged cultivation of H. erinaceum mycelia, and DCW and β-glucan content were compared with those with chemical nutrient medium. When whey was used as a nitrogen source, DCW and total amount of β-glucan were 2.3- and 2.8-fold higher, respectively, than that with chemical nutrient medium. Thus, whey appears to be an alternative nitrogen source for promoting H. erinaceum mycelial growth.

Quantification of extraradical soil mycelium and ectomycorrhizas of Boletus edulis in a Scots pine forest with variable sporocarp productivity

The availability of most edible ectomycorrhizal mushrooms depends on their natural fructification. Sporocarp formation of these fungi is linked to habitat characteristics and climate conditions, but these data alone do not explain all the trends of fungal fruiting and dynamics. It could be hypothesized that the amount of soil mycelia could also be related to the production of carpophores. Soil samples (five cylinders of 250 cm(3) per plot) were taken monthly, from September to November, in five fenced permanent plots (5 × 5 m) in Pinar Grande (Soria, Spain), a Pinus sylvestris stand situated in the north of the Sistema Ibérico mountain range. Plots were chosen to establish a gradient of Boletus edulis productivity from 0 to 38.5 kg/ha year, according to the mean fresh weight of sporocarps collected during the last 10 years. B. edulis ectomycorrhizal root tips were identified in each soil sample according to its morphology and counted. DNA extractions were performed with the PowerSoil(TM) DNA Isolation Kit and quantification of extraradical soil mycelium by real-time polymerase chain reaction using specific primers and a TaqMan® probe. The concentration of soil mycelium of B. edulis (mg mycelium/g soil) did not differ significantly between plots (p = 0.1397), and sampling time (p = 0.7643) within the fructification period. The number of mycorrhizal short roots per soil volume showed significant differences between the plots (p = 0.0050) and the three sampling times (p < 0.0001). No significant correlation between the number of mycorrhizas and the productivity of the plot (kg of B. edulis/ha year) was detected (p = 0.615). A statistically significant positive correlation (p = 0.0481) was detected between the concentration of mycelia of B. edulis in the soil samples and the presence of short roots mycorrhizal with B. edulis in these samples. The productivity of the plots, in terms of sporocarps produced during the last 10 years, was not correlated either with the concentration of soil mycelium or with the presence or abundance of ectomycorrhizas.

Stereoselective hydroxylation of ethylbenzene to (R)-1-phenylethanol using mycelia of Aspergillus niger as catalyst

Abstract The mycelia of Aspergillus niger MTCC-404 have been shown to act as a biocatalyst for the transformation of ethylbenzene to (R)-1-phenylethanol in 99% enantiomeric excess. 72% of the products are (R)-1-phenylethanol. The conversion yield is dependent on pH, temperature and mycelia concentration in suspension. A. niger MTCC-404 facilitates methylbenzene transformation to benzylalcohol, and propylbenzene to 1-phenylpropanol. Therefore, A. niger serves as a biocatalyst for hydroxylation of alkylbenzene's benzylic position.

Fusarium ananatum sp. nov. in the Gibberella fujikuroi species complex from pineapples with fruit rot in South Africa

Pineapple ( Ananas comosus) is native to South America and widely planted as a fruit crop in the tropics and sub-tropics. This plant is susceptible to a number of fungal diseases of which the most severe is fusariosis. The disease is caused by Fusarium guttiforme and occurs only in South and Central America. The occurrence of a similar disease on pineapples in South Africa has prompted a re-evaluation of the Fusarium sp. associated with pineapple fruit rot. Phylogenetic relationships of isolates from pineapples collected in Brazil and South Africa were assessed based on sequence data for the translation elongation factor-1-α, histone H3 and β-tubulin gene regions. Analyses showed that the South African isolates represent a species distinct from Brazilian isolates. The South African isolates are characterised by a concentration of aerial mycelium at the centres of the colonies, different to the Brazilian isolates that have an even distribution of aerial mycelium. Both phylogenetic and morphological data show that the disease on pineapple in South Africa is caused by a new Fusarium species described here as F. ananatum sp. nov.

Hybrid modeling of penicillin fermentation process based on least square support vector machine

According to the problem of the pre-estimation with least square support vector machine (LSSVM) modeling is not ideal in the initial stages of penicillin fermentation process, two hybrid models are designed by utilizing the advantage of LSSVM and kinetics model. Through selecting the appropriate state variables and adopting these methods for penicillin fermentation, the mycelial concentration can be pre-estimated. Experiment results show that these hybrid modeling methods not only improve the above problem, but also have higher predicting accuracy and more powerful generalization ability than the single LSSVM method.

Are stag beetles fungivorous?

Stag beetle larvae generally feed on decaying wood; however, it was unknown whether they can use wood-rotting fungi alone as food. Here, to clarify this, newly hatched larvae of Dorcus rectus (Motschulsky) (Coleoptera: Lucanidae) were reared for 14 days on artificial diets containing a fixed amount of freeze-dried mycelia of the following fungi: Bjerkandera adusta, Trametes versicolor, Pleurotus ostreatus, and Fomitopsis pinicola. The mean incremental gain in larval body mass was greatest on diets containing B. adusta, followed by T. versicolor, P. ostreatus, and F. pinicola. The growth rate of body mass correlated positively with mycelial nitrogen content of the different fungi. It also correlated positively with the mycelial content of B. adusta in the diet. Addition of antibiotics to diets with mycelia nearly halved larval growth, indicating that larvae were able to use fungal mycelia as food without the assistance of associated microbes although the microbes positively affected larval growth. Four newly hatched larvae reared on artificial diets containing B. adusta mycelia developed to the second instar in 21–34 days; and one developed to the third (=final) instar. This study provides evidence that fungi may constitute the bulk of the diet of D. rectus larvae.

A novel method to enhance the mycelia production of Ganoderma lucidum in submerged cultures by polymer additives and agitation strategies

The purpose of this research was to study the feasibility of the enhancement of mycelium production in the cultures of Ganoderma lucidum BCRC36123 by the control of morphological forms. Polymer additives and a novel agitation scheme were employed to vary mycelia morphology, which in turn led to higher mycelium production rates. The effect of various polymer additives on the mycelia growth was investigated in 250 mL flasks. The appearance of G. lucidum mycelia varied considerably ranging from large globes to tiny pellets. Agar, even at a lower concentration, was more effective than sodium alginate and polyacrylamide in shortening the size of pellets. When the agitation rate of the fermentor was maintained at 100 rpm, the mycelium concentration of 1.31 g/L was obtained in 5 days. Alternatively, an intermittent agitation scheme was employed and proved to be effective for enhancing mycelium production rate, causing the increase of mycelia concentration to 3.00 g/L. Moreover, when a polytron was connected with the fermentor, the level even rose to around 6.30 g/L. This study demonstrates that the control of mycelia morphology was very effective to enhance mycelium production of medicinal mushrooms in submerged cultures.

Biodegradation of Methyl red by Galactomyces geotrichum MTCC 1360

Galactomyces geotrichum MTCC 1360 can decolorize triphenylmethane, azo and reactive high exhaust textile dyes. At shaking condition this strain showed 100% decolorization of a toxic azo dye Methyl red (100 m gl −1) within 1 h in deionized water at 30 °C. The degradation of Methyl red was possible through a broad pH (3–12) and temperature (5–50 °C) range. Glucose and mycelium concentration had increased the decolorization rate, but the addition of 1 gl −1 molasses in deionized water made decolorization possible in only 10 min. Induction in the NADH–dichloro phenol indophenol (NADH–DCIP) reductase, Malachite green reductase, laccase and lignin peroxidase (Lip) activities were observed in the cells obtained after complete decolorization, showing that there is direct involvement in the degradation of Methyl red. The absence of N- N′-dimethyl-p-phenylenediamine (DMPD) in 5 °C, 2-aminobenzoic acid (ABA) in 50 °C and both the compounds in 30 °C sample have shown the differences in the metabolic fate of Methyl red at different temperatures. The untreated dye at 300 mg l −1 concentration showed 88% germination inhibition in Sorghum bicolor, whereas it was 72% in Triticum aestivum. There was no germination inhibition for both the plants by Methyl red metabolites at 300 mg l −1 concentration. The scientific relevance of the paper The azo dye Methyl red (100 mg l −1) was decolorized by G. geotrichum MTCC 1360 within 1 h at shaking condition in deionized water. This organism could decolorize Methyl red at wide pH and temperature ranges. Decolorization time was reduced to 10 min by the addition of molasses to deionized water. There was induction in laccase and Lip, NADH–DCIP reductase and Malachite green reductase activities. The metabolic fate of Methyl red changes with temperature which can be evidenced by the formation of 2-ABA at 5 °C, N- N′-DMPD at 50 °C and both the compounds were absent at 30 °C. Phytotoxicity showed that metabolites of dye had induced shoot and root length of both the tested plants.

MALDI-TOF mass spectrometry can be used for detection of pathogenic microorganisms in soil

MALDI-TOF mass spectrometry is a useful technique for the identification of microorganisms. Here we investigate whether it can be used for the identification of organisms in soil. The results show that MALDI-TOF mass spectrometry can be used for analysis of DNA from soil. Reproducible results were obtained with DNA extracted from soil containing a range of mycelial concentrations.

A study of steroid hydroxylation activity of Curvularia lunata mycelium

It has been demonstrated that the mycelium of Curvularia lunata at the end of the logarithmic growth phase displays a maximal 11-hydroxylase activity towards cortexolone (4-6 g/l) used for transformation as a microcrystalline suspension in phosphate buffer. The mycelium at a later stage of fungal growth displays an elevated 14-hydroxylase activity, necessary for generation of 14-hydroxyandrostenedione. The effects of different forms of substrate added to the reaction mixture, age and concentration of mycelium, and fungal clones tolerant to salts of heavy metals (0.35-0.5%) were studied to remove the side 14-hydroxylation, accompanying the main cortexolone transformation. Mycelia of the fungal clones tolerant to Co2+ and Cu2+ displayed a weak hydroxylase activity or its complete absence and an elevated content of melanin, the biosynthesis of which is intensified under adverse conditions. The results obtained suggest that the transformation of steroids by the studied C. lunata strain is a detoxication of foreign compounds.

Differential effect of &lt;I&gt;Agaricus&lt;/I&gt; host species on the population development of &lt;I&gt;Megaselia halterata&lt;/I&gt; (Diptera: Phoridae)

Twelve isolates from the genus Agaricus (Fungi, Basidiomycota) were investigated for their ability to support development of the phorid fly, Megaselia halterata (Wood), which is an important pest of the commercial white button mushroom Agaricus bisporus. Combined effects of oviposition of adult female M. halterata and larval development in mushroom compost inoculated with Agaricus mycelium were determined using bioassays. The numbers of M. halterata offspring that developed were affected by the Agaricus isolate used, and there was a significant separation between resistant and susceptible isolates. In a bioassay where the female phorids had a choice of all 12 isolates for oviposition, three isolates produced >200 adults per 100 g compost pot while the remaining nine isolates had <20 adults per pot. Where there was no choice of Agaricus isolate for oviposition, five isolates resulted in >100 adults per 100 g compost pot while the remainder resulted in <4 adults per pot. With the susceptible isolates, there was a positive correlation between increasing concentration of mycelium in the substrate and phorid development until the concentration exceeded 40% after which numbers of emerging phorids declined. Genetic identity of Agaricus isolates was determined using ITS sequencing and phylogenetic methods, which revealed two major cluster groups. Isolates supporting the development of large populations of M. halterata were located in one of these clusters (group I), and were either Agaricus bisporus or other species from the same Agaricus section Duploannulatae. Isolates that did not support the development of M. halterata populations were located in a different cluster (group II) and were more genetically distant from A. bisporus, e.g. Agaricus sections Arvenses, Minores and Xanthodermatei. Species of Agaricus with resistance to M. halterata could have significant potential for the breeding and cultivation of phorid-free mushrooms.

Differential effect of Agaricus host species on the population development of Megaselia halterata (Diptera: Phoridae)

AbstractTwelve isolates from the genus Agaricus (Fungi, Basidiomycota) were investigated for their ability to support development of the phorid fly, Megaselia halterata (Wood), which is an important pest of the commercial white button mushroom Agaricus bisporus. Combined effects of oviposition of adult female M. halterata and larval development in mushroom compost inoculated with Agaricus mycelium were determined using bioassays. The numbers of M. halterata offspring that developed were affected by the Agaricus isolate used, and there was a significant separation between resistant and susceptible isolates. In a bioassay where the female phorids had a choice of all 12 isolates for oviposition, three isolates produced &gt;200 adults per 100 g compost pot while the remaining nine isolates had &lt;20 adults per pot. Where there was no choice of Agaricus isolate for oviposition, five isolates resulted in &gt;100 adults per 100 g compost pot while the remainder resulted in &lt;4 adults per pot. With the susceptible isolates, there was a positive correlation between increasing concentration of mycelium in the substrate and phorid development until the concentration exceeded 40% after which numbers of emerging phorids declined. Genetic identity of Agaricus isolates was determined using ITS sequencing and phylogenetic methods, which revealed two major cluster groups. Isolates supporting the development of large populations of M. halterata were located in one of these clusters (group I), and were either Agaricus bisporus or other species from the same Agaricus section Duploannulatae. Isolates that did not support the development of M. halterata populations were located in a different cluster (group II) and were more genetically distant from A. bisporus, e.g. Agaricus sections Arvenses, Minores and Xanthodermatei. Species of Agaricus with resistance to M. halterata could have significant potential for the breeding and cultivation of phorid-free mushrooms.

Identification and production of n−8 odd‐numbered polyunsaturated fatty acids by a Δ12 desaturation‐defective mutant of Mortierella alpina 1S‐4

A mutant of Mortierella alpina, JT-180, which is defective in its delta12 desaturase activity but exhibits enhanced activities of delta5 and delta6 desaturases, produced a high proportion (up to 80%) of odd-chain FA when grown on 3% n-heptadecane. Following growth of the mutant on n-heptadecane, three unusual odd-chain fatty acyl residues were identified as 6,9-heptadecadienoic acid (17:2), 8,11 -nonadecadienoic acid (19:2), and 5,8,11-nonadecatrienoic acid (19:3) by means of GC-MS, MS-MS, and NMR analyses. The mycelial contents of these FA reached 20.3, 3.6, and 5.8 mg/g dry mycelia, respectively, when it was cultivated in medium comprising 4% (vol/vol) n-heptadecane and 1% (wt/vol) yeast extract, pH 6.0, at 28 degrees C for 7 d. The biosynthetic route (n-8 route) to 19:3 was presumed to mimic the n-9 route to Mead acid (20:3n-9) in mammals: 17:0 --> 9-17:1 --> 6,9-17:2 --> 8,11-19:2 --> 5,8,11-19:3.

“Assumed inherent sensor” inversion based ANN dynamic soft-sensing method and its application in erythromycin fermentation process

An artificial neural network (ANN) soft-sensing method, based on the “assumed inherent sensor” and its inversion concepts, is proposed and used to estimate some crucial process variables which would be very difficult to be measured directly. For a real biochemical process whose mathematical model is a general nonlinear dynamic system, one may assume that, in its interior, there exists an “inherent sensor” subsystem whose inputs are exactly the process variables to be estimated while whose outputs are the directly measurable ones. To verify this assumption, this paper presents an algorithm to construct the mathematical model of the “assumed inherent sensor” and furthermore presents a global invertibility condition of the “assumed inherent sensor” which guarantees the existence of the inversion of such an “assumed inherent sensor” in theory. The “assumed inherent sensor” inversion consists of a set of nonlinear functions and a series of differentiators and could be treated as the dynamic soft-sensing model because its outputs are capable of reproducing the input variables of the “assumed inherent sensor”, or the process variables to be estimated. To overcome the difficulty in constructing the above “assumed inherent sensor” inversion in an analytic manner, a static ANN is used to approximate the nonlinear function so that the ANN-inversion dynamic soft-sensing model or the desired soft-sensor is finally completed. This makes the proposed ANN-inversion soft-sensor stricter in construction principle and more credible in practical use than most proposed soft-sensors. The soft-sensor consisting of a static ANN and a set of differentiators has been put into use of estimating such crucial biochemical variables as mycelia concentration, sugar concentration and chemical potency in erythromycin fermentation process. The field results show that the soft-sensing values approximately coincide with the offline analyzing ones sampled from the production process.