Bark degradation by Aspergillus fumigatus. Growth studies

1974 ◽  
Vol 20 (3) ◽  
pp. 283-298 ◽  
Author(s):  
U. Marie Nordström
Keyword(s):  
Energy Source ◽  
Aspergillus Fumigatus ◽  
Submerged Culture ◽  
Nitrogen Concentration ◽  
Fungal Growth ◽  
Solid Material ◽  
Growth Cycle ◽  
Carbon And Nitrogen ◽  
Nitrogen Concentrations

A fungus, Aspergillus fumigatus Fres., which used bark as its sole carbon and energy source, was isolated. Difficulties arose in measuring fungal growth, since the hyphae and the bark could not be separated. Measurement of the weight loss of the solid material did not quantitatively estimate fungal growth. Therefore, two methods were developed to estimate fungal mass when the carbon and energy source is particulate and contributes to the parameter used as a measure of growth. They were based on determination of nitrogen either in the solid material or in the medium. The nitrogen concentration in A. fumigatus was found to be nearly constant throughout the growth cycle and to be independent of the carbon and nitrogen concentrations in the medium but to vary with the carbon source used.Aspergillus fumigatus was grown at 37C as a submerged culture in salts medium with finely ground bark from Picea abies as sole carbon and energy source. The bark medium was heat-sterilized before inoculation with spores. The fungus utilized cellulose and hemicellulose but not lignin. Substances solubilized from the bark contributed to the growth. The yield was the same on unextracted as on water-extracted bark, although growth was delayed on the former. Growth was rapid and comparable to growth on other polymeric polysaccharides, i.e. starch. Aspergillus fumigatus degraded 32–40% of the polymeric part of the bark within 4 days and with an economic coefficient of about 50%.

scholarly journals Mycelial biomass cultivation of Lentinus crinitus

2020 ◽  
Vol 36 (6) ◽  
Author(s):  
Itaruã Machri Colla ◽  
Olavo Bilac Quaresma de Oliveira Filho ◽  
Janyeli Dorini Silva de Freitas ◽  
Míria Benetati Delgado Bertéli ◽  
Giani Andrea Linde ◽  
...  
Keyword(s):  
Soybean Meal ◽  
Nitrogen Concentration ◽  
Fungal Growth ◽  
Malt Extract ◽  
Biomass Growth ◽  
Mycelial Biomass ◽  
Protein Nitrogen ◽  
Temperature Growth ◽  
Nitrogen Concentrations ◽  
High Concentrations

Lentinus crinitus is a medicinal basidiomycete, little studied regarding the basic cultivation conditions, which is used in bioremediation and consumed by native Indians from the Brazilian Amazon. Also, it produces a fungal secondary metabolite panepoxydone that has been described as an essential regulator of the inflammatory and immune response. This study aimed to evaluate basic conditions of temperature, pH, and nitrogen concentration and source in the cultivation of L. crinitus mycelial biomass. In order to evaluate fungal growth temperature, 2% malt extract agar (MEA) medium, pH 5.5, was utilized from 19 to 40 °C. For pH, MEA had pH adjusted from 2 to 11 and cultivated at 28 °C. Urea or soybean meal was added to MEA to obtain final concentration from 0.5 and 16 g/L of nitrogen, pH of 5.5, cultivated at 28 °C. The best temperature growth varies from 31 to 34 ºC and the optimal one is 32.7º C, and the best pH ranges from 4.5 to 6.5 and the optimal one is 6.1. Protein or non-protein nitrogen concentration is inversely proportional to the mycelial biomass growth. Nitrogen concentrations of 2.0 g/L soybean meal and urea inhibit mycelial biomass growth in 11% and 12%, respectively, but high concentrations of 16.0 g/L nitrogen inhibit the growth in 46% and 95%, respectively. The fungus is robust and grows under extreme conditions of temperature and pH, but smaller adaptation with increasing nitrogen concentrations in the cultivation medium, mainly non-protein nitrogen.

Factors affecting vegetative growth and the production of perithecia in culture by Ophiobolus graminis. I. Variations in media and age of mycelium

1970 ◽  
Vol 18 (1) ◽  
pp. 1 ◽  
Author(s):  
G Weste
Keyword(s):  
Carbon Concentration ◽  
Vegetative Growth ◽  
Solid Medium ◽  
Nitrogen Concentration ◽  
Restricted Range ◽  
Factors Affecting ◽  
Carbon And Nitrogen ◽  
Nitrogen Concentrations ◽  
High Concentrations ◽  
Carbon Concentrations

Perithecia were readily produced in culture on a suitable solid medium under certain conditions of light and temperature, once vegetative growth was established. Investigations into the carbon and nitrogen requirements for both vegetative growth and fruiting showed that, whereas vegetative growth increased with increasing carbon supplies up to10%, reproduction occurred only within a restricted range of carbon and nitrogen concentrations. No perithecia were produced on a starvation medium. Factors involved in fruiting included concentration of nutrients and the balance between them; both were important. A suitable fruiting medium required a minimum carbon concentration of 3000 p.p.m., supplied as 0.75 % glucose or fructose, and an optimum carbon concentration of 6000 p.p.m. supplied as 1.5 % glucose or fructose. The maximum number of perithecia was produced on a medium containing 1% glucose and 0.2 % asparagine (400 p.p.m. nitrogen), which had a carbonlnitrogen ratio of 11.8. A higher than optimum nitrogen concentration was partially offset by increasing the carbon concentration, that is by keeping the carbonlnitrogen ratio approximately constant. The actual concentrations inhibiting and promoting fruiting of the fungus were influenced by the balance between carbon and nitrogen supplies. High concentrations of carbon and nitrogen increased vegetative growth but decreased the number of perithecia. There was no sudden inhibition of perithecia with increased carbon concentrations, but at 10% glucose (40,000 p.p.m. carbon) vegetative growth and pigmentation were maximal but few or no perithecia developed. No evidence was obtained that perithecial production was influenced by ageing of the mycelium, the presence of staling factors, or exhaustion of food supplies.

scholarly journals Nitrogen Concentrations Affect Pepper Yield and Leachate Nitrate-nitrogen from Rockwool Culture

HortScience ◽  
1994 ◽  
Vol 29 (10) ◽  
pp. 1139-1142 ◽  
Author(s):  
M.K. Schon ◽  
M. Peggy Compton ◽  
E. Bell ◽  
I. Burns
Keyword(s):  
Nitrate Nitrogen ◽  
Nitrogen Concentration ◽  
Growth Cycle ◽  
Fruit Weight ◽  
N Concentration ◽  
Nitrogen Concentrations ◽  
Blossom End Rot ◽  
Rockwool Culture ◽  
Marketable Fruit ◽  
Nutrient Solutions

Experiments were conducted to determine the effect of varying solution N concentrations on fruit yield and NO3-N concentration in leachate from rockwool-grown `Midal' peppers (Capsicum annuum L.) in Florida. Treatment 1 plants received a series of nutrient solutions containing N at 60, 90, and 120 mg·liter–1 (60–90–120 mg·liter–1) during their growth cycle. Plants in treatments 2 and 3 were grown with N at 120 or 175 mg·liter–1, respectively, throughout their entire growth cycle. Two trials were conducted; trial 1 from 17 Nov. 1991 to 1 July 1992, and trial 2 from 31 July 1992 to 23 Feb. 1993. In both trials, total marketable fruit weight was significantly (P ≤ 0.05) higher (16% to 67%) for plants grown with N at 175 than with 60–90–120 mg·liter–1. In trial 2, plants receiving N at 175 mg·liter–1 produced significantly more fruit (8%) and 14% higher total fruit weight than plants receiving N at 120 mg·liter–1. The trend toward higher yield with N at 175 rather than 120 mg·liter–1 also occurred during trial 1, but differences were not significant. Nitrogen concentration did not significantly affect the percentage of total fruit having blossom-end rot in either trial (41% in trial 1; 13% in trial 2). Nitrogen at 175 mg·liter–1 resulted in 10% to 40% increases in total nutrient solution use and 2.5- to 3.5-fold increases in leachate NO3-N concentration compared to N at 120 mg·liter–1.

scholarly journals Azole and Amphotericin B MIC Values against Aspergillus fumigatus: High Agreement between Spectrophotometric and Visual Readings Using the EUCAST EDef 9.3.2 Procedure

2020 ◽  
Vol 65 (1) ◽  
pp. e01693-20 ◽  
Author(s):  
Julia Serrano-Lobo ◽  
Ana Gómez ◽  
Waldo Sánchez-Yebra ◽  
Miguel Fajardo ◽  
Belén Lorenzo ◽  
...  
Keyword(s):  
Aspergillus Fumigatus ◽  
Amphotericin B ◽  
Fungal Growth ◽  
Sensu Stricto ◽  
Resistance Rate ◽  
Wild Type ◽  
Growth Reduction ◽  
High Agreement ◽  
Content Type

ABSTRACTThe EUCAST EDef 9.3.2 procedure recommends visual readings of azole and amphotericin B MICs against Aspergillus spp. Visual determination of MICs may be challenging. In this work, we aim to obtain and compare visual and spectrophotometric MIC readings of azoles and amphotericin B against Aspergillus fumigatussensu lato isolates. A total of 847 A. fumigatussensu lato isolates (A. fumigatus sensu stricto [n = 828] and cryptic species [n = 19]) were tested against amphotericin B, itraconazole, voriconazole, posaconazole, and isavuconazole using the EUCAST EDef 9.3.2 procedure. Isolates were classified as susceptible or resistant/non-wild type according to the 2020 updated breakpoints. The area of technical uncertainty for the azoles was defined in the updated breakpoints. Visual and spectrophotometric (fungal growth reduction of >95% compared to the control, read at 540 nm) MICs were compared. Essential (±1 2-fold dilution) and categorical agreements were calculated. Overall, high essential (97.1%) and categorical (99.6%) agreements were found. We obtained 100% categorical agreements for amphotericin B, itraconazole, and posaconazole, and consequently, no errors were found. Categorical agreements were 98.7 and 99.3% for voriconazole and isavuconazole, respectively. Most of the misclassifications for voriconazole and isavuconazole were found to be associated with MIC results falling either in the area of technical uncertainty or within one 2-fold dilution above the breakpoint. The resistance rate was slightly lower when the MICs were obtained by spectrophotometric readings. However, all relevant cyp51A mutants were correctly classified as resistant. Spectrophotometric determination of azole and amphotericin B MICs against A. fumigatussensu lato isolates may be a convenient alternative to visual endpoint readings.

scholarly journals Optimization of Mycological Media Using Agro Waste for the Production of Antimicrobial Substance

2020 ◽  
pp. 67-73
Author(s):  
Evangeline Ogonna Okpalauwaekwe ◽  
Chinelo Ursula Umedum ◽  
Ikechukwu Harmony Iheukwumere ◽  
Leona Chisara Akakuru
Keyword(s):  
Aspergillus Fumigatus ◽  
Nitrogen Source ◽  
Sweet Potato ◽  
Fungal Growth ◽  
Antimicrobial Substance ◽  
Zone Of Inhibition ◽  
Experimental Conditions ◽  
Anambra State ◽  
Carbon And Nitrogen ◽  
Nutritional Conditions

Aim: This present study was conducted to optimize mycological media using agro waste for the production of antimicrobial substance. Place and Duration of Study: Agro waste (sugarcane and sweet potato, sugarcane and jack fruit) collected within Anambra state between February- August 2019. Methodology: Sugarcane and sweet potato (AMSSP), sugarcane and jack fruit (AMSJ) were peeled and the peels were air-dried and then ground into powdered form. 10 g each of the agro waste samples was weighed into 400 ml of distilled water in 1000 ml Erlenmeyer flask and allowed for 7 days, after which the mixture was filtered. Then 200 ml of the filtrate was used. The experimental conditions were optimized by using agro wastes (20/80 and 50/50 concentrations) as a culture medium, altering the temperature (30ºC and 37ºC), pH (5, 6, 7, 8, and 9), as well as the carbon and nitrogen source (glucose and NaNO3). The fungi used were Aspergillus niger, Aspergillus fischeri, Aspergillus aculeatus and Aspergillus fumigatus. Results:  Various agro wastes medium AMSSP and AMSJ were formulated as mycological media and the growth and nutritional conditions were optimized to ascertain antimicrobial substance production using some fungal isolates. Based on different concentrations Aspergillus fumigatus showed a promising zone of inhibition on AMSSP at a concentration of 20/80 while in AMSJ the concentration the 50/50 showed a maximum zone of inhibition on Aspergillus fumigatus ascertaining the presence of antimicrobial substance. AMSSP was able to produce maximum antimicrobial substance when supplemented with 1.0% glucose, 1.0% NaNO3 at pH 7 and at temperature of 30 ± 2ºC. Conclusion: Agro wastes from AMSSP as well as from AMSJ contain nutrients that may support fungal growth. Maximum antimicrobial substance production is enhanced when supplemented with 1.0% of the carbon and nitrogen source at a pH of 7 and at a temperature of 30 ± 2ºC.

Decolorisation of natural organic matter by Phanerochaete chrysosporium: the effect of environmental conditions

2004 ◽  
Vol 4 (4) ◽  
pp. 175-182 ◽  
Author(s):  
K. Rojek ◽  
F.A. Roddick ◽  
A. Parkinson
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Natural Organic Matter ◽  
Phanerochaete Chrysosporium ◽  
Fungal Growth ◽  
Low Ph ◽  
Colour Removal ◽  
Humic Material ◽  
Carbon And Nitrogen ◽  
Carbon And Nitrogen Content

Phanerochaete chrysosporium was shown to rapidly decolorise a solution of natural organic matter (NOM). The effect of various parameters such as carbon and nitrogen content, pH, ionic strength, NOM concentration and addition of Mn2+ on the colour removal process was investigated. The rapid decolorisation was related to fungal growth and biosorption rather than biodegradation as neither carbon nor nitrogen limitation, nor Mn2+ addition, triggered the decolorisation process. Low pH (pH 3) and increased ionic strength (up to 50 g L‒1 added NaCl) led to greater specific removal (NOM/unit biomass), probably due to increased electrostatic bonding between the humic material and the biomass. Adsorption of NOM with viable and inactivated (autoclaved or by sodium azide) fungal pellets occurred within 24 hours and the colour removal depended on the viability, method of inactivation and pH. Colour removal by viable pellets was higher under the same conditions, and this, combined with desorption data, confirmed that fungal metabolic activity was important in the decolorisation process. Overall, removals of up to 40–50% NOM from solution were obtained. Of this, removal by adsorption was estimated as 60–70%, half of which was physicochemical, the other half metabolically-dependent biosorption and bioaccumulation. The remainder was considered to be removed by biodegradation, although some of this may be ascribed to bioaccumulation and metabolically-dependent biosorption.

Nitrogen cycling in a Venezuelan tropical seasonally flooded forest: soil nitrogen mineralization and nitrification

1994 ◽  
Vol 10 (3) ◽  
pp. 399-416 ◽  
Author(s):  
Barrios E. ◽  
Herrera R.
Keyword(s):  
Soil Nitrogen ◽  
Nitrogen Availability ◽  
Inorganic Nitrogen ◽  
Nitrogen Concentration ◽  
Ammonium Nitrogen ◽  
Wet Season ◽  
Flooded Forest ◽  
Nitrogen Concentrations ◽  
Minimum Stress ◽  
Seasonally Flooded

ABSTRACTSeasonally flooded forests represent a transition between terrestrial and aquatic ecosystems. The Mapire river, a tributary of the Orinoco river, floods its surrounding forests during the wet season (May–December). The soils are very acid and the total nitrogen concentration (0.1%) is only half that found in nearby soils flooded by Orinoco waters. Ammonium-nitrogen predominates in the soil during the flooded period while nitrate-nitrogen concentrations are higher in the dry period. Wide fluctuations in the inorganic nitrogen fractions did not considerably affect the annual course of soil nitrogen.The predominance of mineralization versus nitrification (56 and 5 μgsoil month−1respectively) and possibly the synchronization of nitrogen availability with plant demand could be considered as nitrogen conserving mechanisms.In synchrony with the hydrologic cycle, the seasonally flooded forest studied shows a nitrogencycle where inputs and accumulation are maximized when the system is under minimum stress (dry season). During flooding, the system enters a period of dormancy making minimal use of nutrient and energy to avoid or tolerate anaerobiosis.

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