Nutritional regulation of synthetic lignin (DHP) degradation by Phlebia (Merulius) tremellosa: effects of nitrogen

1991 ◽  
Vol 69 (1) ◽  
pp. 156-160 ◽  
Author(s):  
Ian D. Reid
Keyword(s):  
Energy Source ◽  
Key Words ◽  
Ammonium Chloride ◽  
Yeast Extract ◽  
Lignin Degradation ◽  
Synthetic Medium ◽  
Lignin Biodegradation ◽  
Nutritional Regulation

Supplementary nitrogen added to cultures of Phlebia tremellosa in a nitrogen-limited synthetic medium delayed the appearance of lignin-degrading activity. It also accelerated the consumption of the carbon (energy) source by the cultures, decreasing the amount of cosubstrate available to support lignin biodegradation. Ammonium chloride, glutamate, albumin, and yeast extract all had similar effects, with small differences in the timing and extent of the lignin degradation that they allowed. Key words: lignin biodegradation, cosubstrate, nitrogen, selectivity.

Nutritional regulation of synthetic lignin (DHP) degradation by the selective white-rot fungus Phlebia (Merulius) tremellosa: effects of glucose and other cosubstrates

1991 ◽  
Vol 69 (1) ◽  
pp. 147-155 ◽  
Author(s):  
Ian D. Reid ◽  
Alain M. Deschamps
Keyword(s):  
Energy Source ◽  
Lignin Degradation ◽  
Tricarboxylic Acid Cycle ◽  
Wood Decay ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Nutritional Regulation ◽  
Carbohydrate Degradation ◽  
Lignin Metabolism

Phlebia tremellosa is a white-rot fungus which selectively degrades lignin, i.e., its ratio of lignin degradation to carbohydrate degradation during wood decay is higher than that of "simultaneous" white rots. Its need for a cosubstrate to support lignin degradation, and the effect of glucose supply on rate and extent of lignin metabolism, were examined in a synthetic, nitrogen-limited medium. Lignin metabolism by P. tremellosa, like simultaneous white rots, requires a cosubstrate. Glucose partially represses lignin degradation, but it is metabolized to extracellular intermediates, including ethanol. Subsequent utilization of ethanol as energy source supports rapid lignin degradation. Phlebia tremellosa grows well with cellulose, glucose, xylose, ethanol, or lactate as sole carbon (energy) source, and more slowly with glycerol or methanol. It appears unable to use kraft lignin, ferulate, vanillin, or acetate as sole carbon source. Cellulose, glycerol, and ethanol efficiently supported degradation of ring-labelled lignin to CO2, whereas glucose, xylose, and lactate were less efficient cosubstrates; methanol did not support lignin degradation. A relationship between tricarboxylic acid cycle operation and metabolism of lignin ring carbons to CO2, is suggested. Key words: lignin biodegradation, cosubstrate, glucose, ethanol, selectivity.

A SYNTHETIC MEDIUM FOR EXTREMELY HALOPHILIC BACTERIA

1965 ◽  
Vol 11 (2) ◽  
pp. 365-373 ◽  
Author(s):  
H. Onishi ◽  
Margaret E. McCance ◽  
N. E. Gibbons
Keyword(s):  
Amino Acids ◽  
Ammonium Chloride ◽  
Yeast Extract ◽  
Synthetic Medium ◽  
Halophilic Bacteria ◽  
Casein Hydrolysate ◽  
Complex Medium ◽  
Halobacterium Halobium ◽  
Halobacterium Salinarium ◽  
Cell Densities

A synthetic medium, made up of 15 amino acids, adenylic and uridylic acid, glycerol, asparagine or ammonium chloride, and various salts, has been developed for halophilic bacteria. Halobacterium cutirubrum and Sarcina litoralis grew as well in this medium as in a complex medium containing casein hydrolysate and yeast extract. Growth of Halobacterium halobium, Halobacterium salinarium, and Sarcina morrhuae was slower in the synthetic medium and the final cell densities were not as great as in the complex medium.

Degradation of natural and Kraft lignins by the microflora of soil and water

1977 ◽  
Vol 23 (4) ◽  
pp. 434-440 ◽  
Author(s):  
Don L. Crawford ◽  
Suellen Floyd ◽  
Anthony L. Pometto III ◽  
Ronald L. Crawford
Keyword(s):  
Molecular Weight ◽  
Microbial Degradation ◽  
Lignin Degradation ◽  
Kraft Lignin ◽  
Lignin Biodegradation ◽  
Incubation Periods ◽  
Molecular Weight Fractions ◽  
Soil And Water ◽  
Different Molecular Weight ◽  
Microbial Attack

The comparative rates of microbial degradation 14C-lignin-labeled lignocelluloses and 14C-Kraft lignins were investigated using selected soil and water samples as sources of microorganisms. Natural lignocelluloses containing 14C primarily in their lignin components were prepared by feeding plants uniformly labeled L-[14C]phenylalanine through their cut stems. 14C-Kraft lignins were prepared by pulping lignin-labeled lignocelluloses. Rates of lignin biodegradation were determined by monitoring 14CO2 evolution from incubation mixtures over incubation periods of up to 1000 h. Observed rates of lignin degradation were slow in all cases. Kraft lignins appeared more resistant to microbial attack than natural lignins, even though they were decomposed more rapidly during the first 100–200 h of incubation. Similar degradation patterns were observed in both soil and water. Individual samples, however, varied greatly in their overall rates of degradation of either lignin type. A Kraft-lignin preparation was separated into a variety of molecular weight fractions by column chromatography on LH-20 Sephadex and the biodegradability of the different molecular weight fractions determined. The lower molecular weight fractions of the Kraft lignin were decomposed at a significantly faster rate by the microflora of soil than were the fractions of higher molecular weight.

DISTRIBUTION OF ENERGY SOURCE EXPENDITURE IN WARM- AND COLD-EXPOSED SHEEP

1984 ◽  
Vol 64 (5) ◽  
pp. 265-266 ◽  
Author(s):  
TSUNEYUKI TSUDA ◽  
YOSHIO SHOJI ◽  
KAICHI AMBO ◽  
MASANORI FUJITA ◽  
KATSUNORI SUNAGAWA
Keyword(s):  
Energy Source ◽  
Fatty Acids ◽  
Acetic Acid ◽  
Free Fatty Acids ◽  
Key Words ◽  
Heat Production ◽  
Total Heat

The heat production of sheep exposed to 0 °C increased 2.14 times compared with that at 20 °C. At 0 °C, the percentage of heat derived from oxidation of acetic acid decreased but that of free fatty acids increased remarkably. The substances which comprise 50% of total heat production remained unknown. Key words: Sheep, cold, heat production, energy source

scholarly journals Detection and Quantitation of Aflatoxin for the Diagnosis of Aspergillus flavus

2015 ◽  
Vol 3 (1) ◽  
pp. 6-9 ◽  
Author(s):  
Geeta Rajbhandari Shrestha ◽  
Amin Udhin Mridha
Keyword(s):  
Aspergillus Flavus ◽  
Yeast Extract ◽  
Aflatoxin B1 ◽  
Sucrose Concentration ◽  
Synthetic Medium ◽  
Enzyme Linked Immunosorbent Assay ◽  
P Value ◽  
Detection And Diagnosis ◽  
Immunological Assays ◽  
Yeast Extract Sucrose

Aflatoxins are the potent mycotoxins produced by Aspergillus flavus, which is hepatotoxic causing hepatocellular carcinoma. A. flavus produces sufficient amount of Aflatoxin B1 under favourable environments. Inhalation of spores and use of Aflatoxin B1, contaminated food by Aspergillus spp., could transfuse the toxins in the blood streams. The presence of these toxins in body fluid can be detected by immunological assays and which provides an effective technique for the diagnosis of the disease caused by A. flavus. Aflatoxins producing strain of A. flavus were screened in Aflatoxin Producing Medium. Production of Aflatoxin B1 by A. flavus was studied in different parameters such as incubation periods, temperatures, pH variations, sucrose concentration in Yeast Extract Sucrose medium and different natural media such as par-boiled rice, corn and groundnuts. The detection of toxins was done by TLC using silica gel (Merk) coated plates and confirmative test was done by Association of Official Analytical Chemists (AOAC) method. Presence and quantization was done by Enzyme Linked Immunosorbent Assay (ELISA) technique. Highest amount of Aflatoxin B1 was reported 68.56 ng/ml by ELISA in synthetic medium (Yeast Extract Sucrose) with 2% sucrose, pH 5.5, on 14th days of incubation, at 28±1°C (p-value 0.05). Similarly, highest amount was recorded in groundnuts (121.20ng/g) by ELISA and (500ng/kg) by TLC methods. ELISA is one of the most efficient methods used for detection and diagnosis of human diseases cause due to exposure of Aflatoxin B1 and A. flavus.Nepal Journal of Biotechnology. Dec. 2015 Vol. 3, No. 1: 6-9

Investigation Of Blister Formed On Coated Mild Steel Using Scanning Kelvin Probe

2012 ◽  
Author(s):  
Zalilah Sharer Sahir ◽  
John Malcolm Sykes
Keyword(s):  
Mild Steel ◽  
Key Words ◽  
Ammonium Chloride ◽  
Chloride Solution ◽  
Organic Coating ◽  
Kelvin Probe ◽  
Scanning Kelvin Probe ◽  
Coated Metal ◽  
Potential Map ◽  
Electrochemical Potentials

Degradasi pada besi bersalut cat dari segi gelembung yang terbentuk telah dikaji selepas direndam di dalam larutan 3% natrium klorida dan 3% ammonium klorida. Imbasan probe Kelvin (SKP) telah digunakan untuk menghasilkan peta keupayaan kimia–elektro bagi mengenal pasti kawasan anod dan katod dibawah gelembung dan kawasan persekitarannya. Bagi gelembung yang terhasil pada panel yang direndam dalam larutan 3% sodium klorida, peta upaya SKP menunjukkan gelembung yang terbentuk adalah di kawasan katod yang disebabkan oleh alkali, dimana kawasan anod juga dilihat terbentuk berdekatan. Walhal bagi peta upaya SKP untuk gelembung yang terhasil pada panel yang direndam di dalam larutan 3% ammonium klorida menunjukkan kehadiran kawasan katod dikelilingi oleh kawasan anod. Kata kunci: Cat organik; imbasan probe Kelvin; gelembung The degradation of a coated metal in term of the area underneath a blister has been studied after being immersed in 3% sodium chlorida and 3% ammonium chloride solution. Scanning Kelvin probe (SKP) was used to map electrochemical potentials, identifying anodic and cathodic regions underneath a blister and the surrounding coating. For blisters formed on coated panel immersed in sodium chlorida solution, SKP potential map reveals that the blister has formed at a cathode due to alkali but anodes form nearby (not remote). Meanwhile SKP potential map for blister formed on coated panel in 3% ammonium chloride reveals the presence of cathodic regions within the anodic areas. Key words: Organic coating; scanning Kelvin Probe; blister

Regulation by amino acids of α-amylase and endo-β(1→4)-glucanase induction in mycelial culture of the mushroom Termitomyces clypeatus

1990 ◽  
Vol 36 (9) ◽  
pp. 617-624 ◽  
Author(s):  
Saswati Sengupta ◽  
S. Sengupta
Keyword(s):  
Amino Acids ◽  
Yeast Extract ◽  
Enzyme Production ◽  
Late Phase ◽  
Synthetic Medium ◽  
Extracellular Enzyme ◽  
Mycelial Culture ◽  
Termitomyces Clypeatus ◽  
Yeast Extract Medium

Termitomyces clypeatus constitutively liberated amyloglucosidase; the liberation was not repressed by glucose. Growth of the mushroom in synthetic medium was slow with starch, and only amyloglucosidase was liberated. Yeast extract stimulated growth and enzyme production in starch medium, and α-amylase along with amyloglucosidase was detected extracellularly. The mushroom could not utilise cellulose or liberate endo-β(1 → 4)-glucanase even when inducer cellobiose or glucose was added to cellulose at different concentrations. Cellobiose alone also failed to induce any extracellular endo-β(1 → 4)-glucanase production. Yeast extract in both cellulose and cellobiose media supported liberation of endo-β(1 → 4)-glucanase. Lactose was found to be a poor inducer even in yeast extract medium. However, both α-amylase and endo-β(1 → 4)-glucanase were detected intracellularly at a basal level even when the enzymes were absent extracellularly under inducing and noninducing conditions. The intracellular enzymes were only freely liberated into the medium in the presence of yeast extract. It appeared that induction of α-amylase and endo-β(1 → 4)-glucanase was largely inhibited by the restricted liberation of the enzymes in absence of yeast extract. Of the yeast extract components, amino acids were the active ingredient mimicking the role of yeast extract in induction. Yeast extract was found to relieve catabolic inhibition observed at the late phase of enzyme production. It is proposed that catabolic inhibition might have a role in the enzyme liberation and that amino acids supported extracellular enzyme production by relieving this inhibition. Key words: mushroom, Termitomyces clypeatus, catabolic inhibition, polysaccharidase induction, amino acid.

Enhancement of lignin degradation and laccase activity in Pleurotus ostreatus by cotton stalk extract

1998 ◽  
Vol 44 (7) ◽  
pp. 676-680 ◽  
Author(s):  
Orly Ardon ◽  
Zohar Kerem ◽  
Yitzhak Hadar
Keyword(s):  
Oxygen Consumption ◽  
Pleurotus Ostreatus ◽  
Lignin Degradation ◽  
Laccase Activity ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Cotton Stalk ◽  
Fermentation System ◽  
Uv Visible

The white rot fungus Pleurotus ostreatus was grown in a chemically defined solid state fermentation system amended with cotton stalk extract (CSE).Treated cultures exhibited increased laccase activity as well as enhanced lignin mineralization. Mineralization of [14C]lignin initialized 4 days earlier in CSE-supplemented cultures than in control cultures. Total mineralization in the first 16 days was 15% in the CSE-treated cultures, compared with only 7% in the controls. Cotton stalk extract also contained compounds that serve as substrates for laccase purified from P. ostreatus as shown by oxygen consumption, as well as changes in the UV–visible spectrum.Key words: cotton, Pleurotusostreatus, white rot, laccase, lignin biodegradation.

scholarly journals Transcriptomics analysis reveals the high biodegradation efficiency of white-rot fungus Phanerochaete sordida YK-624 on native lignin

2020 ◽  
Author(s):  
Jianqiao Wang ◽  
Tomohiro Suzuki ◽  
Hideo Dohra ◽  
Toshio Mori ◽  
Hirokazu Kawagishi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Lignin Degradation ◽  
Ligninolytic Enzymes ◽  
Organic Matrix ◽  
Tca Cycle ◽  
Underlying Mechanism ◽  
White Rot ◽  
White Rot Fungus ◽  
Lignin Biodegradation ◽  
Phanerochaete Sordida

Abstract Background Lignocellulosic biomass is an organic matrix composed of cellulose, hemicellulose, and lignin. In nature, lignin degradation by basidiomycetes is the key step in lignocellulose decay. The white-rot fungus Phanerochaete sordida YK-624 (YK-624) has been extensively studied due to its high lignin degradation ability. In our previous study, it was demonstrated that YK-624 can secrete lignin peroxidase and manganese peroxidase for lignin degradation. However, the underlying mechanism for lignin degradation by YK-624 remains unknown.Results Here, we analyzed YK-624 gene expression following growth under ligninolytic and nonligninolytic conditions and compared the differentially expressed genes in YK-624 to those in the model white-rot fungus P. chrysosporium by next-generation sequencing. More ligninolytic enzymes and lignin-degrading auxiliary enzymes were upregulated in YK-624. This might explain the high degradation efficiency of YK-624. In addition, the genes involved in energy metabolism pathways, such as the TCA cycle, oxidative phosphorylation, lipid metabolism, carbon metabolism and glycolysis, were upregulated under ligninolytic conditions in YK-624.Conclusions In the present study, the first differential gene expression analysis of YK-624 under ligninolytic and nonligninolytic conditions was reported. The results obtained in this study indicated that YK-624 produces more energy- and lignin-degrading enzymes for more efficient lignin biodegradation.

Sign in / Sign up

Export Citation Format

Share Document