Gluconic acid synthesis by the ectomycorrhizal fungus Tricholoma robustum

1992 ◽  
Vol 70 (1) ◽  
pp. 84-88 ◽  
Author(s):  
Koji Iwase

During mycelial culture of Tricholoma robustum, the medium gradually became acidified to approximately pH 3.9. High performance liquid chromatography showed that gluconic acid was secreted into the culture medium, and the amount of gluconic acid produced was measured by enzymatic analysis. Gluconic acid synthesis by all other related species, Tricholoma matsutake, Tricholoma caligatum, Tricholoma ponderosum, Tricholoma fulvocastaneum, and Tricholoma zelleri was poor, except for Tricholoma bakamatsutake, which showed relatively high productivity. Activity of glucose oxidase, which is responsible for gluconic acid production, was highest in T. robustum and second highest in T. bakamatsutake. The activity in these two species was much higher than those of other species. These results indicate that gluconic acid was synthesized from glucose by glucose oxidase in T. robustum as well as in T. bakamatsutake. Key words: ectomycorrhizal fungi, gluconic acid, glucose oxidase, Tricholoma robustum.


1992 ◽  
Vol 70 (6) ◽  
pp. 1234-1238 ◽  
Author(s):  
Koji Iwase

Basidiospore germination in the ectomycorrhizal fungus Tricholoma robustum and related species Tricholoma matsutake, Tricholoma caligatum, and Tricholoma ponderosum was examined. Basidiospore germination in T. robustum was induced by the presence of conspecific mycelium but not by the mycelium of related species. Germination also occurred on conditioned medium prepared by preculturing with conspecific mycelium. Gluconic acid, which is produced by T. robustum, also induced basidiospore germination in that species. After storage at 5 °C, germination of basidiospores in T. robustum was stimulated by incubation with conspecific mycelium but not with gluconic acid. These findings suggest that gluconic acid is but one of perhaps many germination-inducing substances produced by the mycelium of T. robustum. Key words: basidiospore germination, ectomycorrhizal fungi, gluconic acid, mycelial culture, Tricholoma robustum.



2016 ◽  
Vol 181 (2) ◽  
pp. 526-535 ◽  
Author(s):  
Caixia Cui ◽  
Haibin Chen ◽  
Biqiang Chen ◽  
Tianwei Tan


1989 ◽  
Vol 67 (10) ◽  
pp. 2888-2893 ◽  
Author(s):  
Bernard Donèche

The pathways of glucose catabolism were examined in a B. cinerea strain isolated from grape. Respirometric and enzymatic studies indicated that this plant parasite catabolized glucose through the Embden–Meyerhof and hexose monophosphate shunt pathways. Data also suggested functioning of an active tricarboxylic acid cycle and presence of the glyoxylate cycle. Direct oxidation of glucose by means of glucose oxidase led to gluconic acid accumulation in the medium during the stationary phase of growth. Part of the glucose oxidase was extracellular and could have technological consequences in wine making.





2021 ◽  
Vol 8 (02) ◽  
pp. e62-e68
Author(s):  
Jeeta Sarkar ◽  
Nirmalya Banerjee

AbstractSteroid alkaloid solasodine is a nitrogen analogue of diosgenin and has great importance in the production of steroidal medicines. Solanum erianthum D. Don (Solanaceae) is a good source of solasodine. The aim of this study was to evaluate the effect of different cytokinins on the production of secondary metabolites, especially solasodine in the in vitro culture of S. erianthum. For solasodine estimation, field-grown plant parts and in vitro tissues were extracted thrice and subjected to high-performance liquid Chromatography. Quantitative analysis of different secondary metabolites showed that the amount was higher in the in vitro regenerated plantlets compared to callus and field-grown plants. The present study critically evaluates the effect of the type of cytokinin used in the culture medium on solasodine accumulation in regenerated plants. The highest solasodine content (46.78±3.23 mg g-1) was recorded in leaf extracts of the in vitro grown plantlets in the presence of 6-γ,γ-dimethylallylamino purine in the culture medium and the content was 3.8-fold higher compared to the mother plant.



1987 ◽  
Vol 7 (3) ◽  
pp. 285-288 ◽  
Author(s):  
W. Babel ◽  
R. H. Müller
Keyword(s):  


2004 ◽  
Vol 70 (12) ◽  
pp. 7413-7417 ◽  
Author(s):  
Mikael Courbot ◽  
Laurent Diez ◽  
Roberta Ruotolo ◽  
Michel Chalot ◽  
Pierre Leroy

ABSTRACT Molecular and cellular mechanisms underlying the sustained metal tolerance of ectomycorrhizal fungi are largely unknown. Some of the main mechanisms involved in metal detoxification appear to involve the chelation of metal ions in the cytosol with thiol-containing compounds, such as glutathione, phytochelatins, or metallothioneins. We used an improved high-performance liquid chromatography method for the simultaneous measurement of thiol-containing compounds from cysteine and its derivatives (γ-glutamylcysteine, glutathione) to higher-molecular-mass compounds (phytochelatins). We found that glutathione and γ-glutamylcysteine contents increased when the ectomycorrhizal fungus Paxillus involutus was exposed to cadmium. An additional compound with a 3-kDa molecular mass, most probably related to a metallothionein, increased drastically in mycelia exposed to cadmium. The relative lack of phytochelatins and the presence of a putative metallothionein suggest that ectomycorrhizal fungi may use a different means to tolerate heavy metals, such as Cd, than do their plant hosts.



Author(s):  
Ken-ji Yokoi ◽  
Sosyu Tsutsui ◽  
Gen-ya Arakawa ◽  
Masakazu Takaba ◽  
Koichi Fujii ◽  
...  

Abstract Information about the inulosucrase of non-lactic acid bacteria is scarce. We found a gene encoding inulosucrase (inuBK) in the genome of the gram-positive bacterium Alkalihalobacillus krulwichiae JCM 11691. The inuBK open reading frame encoded a protein comprising 456 amino acids. We expressed His-tagged InuBK in culture medium using a Brevibacillus system. The optimal pH and temperature of purified InuBK were 7.0–9.0 and 50 °C–55 °C, respectively. The findings of high-performance anion-exchange chromatography, nuclear magnetic resonance spectroscopy, and high-performance size-exclusion chromatography with multi-angle laser light scattering showed that the polysaccharide produced by InuBK was an inulin with a molecular weight of 3,806, a polydispersity index (PI) of 1.047, and fructosyl chain lengths with 3–27 degrees of polymerization. The size of InuBK was smaller than commercial inulins, and the PI of the inulin that it produced was lower.



2021 ◽  
Author(s):  
SOYEON PARK ◽  
KUN (KELVIN) FU

Polymer nanocomposites have advantages in mechanical, electrical, and optical properties compared to individual components. These unique properties of the nanocomposites have attracted attention in many applications, including electronics, robotics, biomedical fields, automotive industries. To achieve their high performance, it is crucial to control the orientation of nanomaterials within the polymer matrix. For example, the electric conductivity will be maximized in the ordered direction of conductive nanomaterials such as graphene and carbon nanotubes (CNTs). Conventional fabrication methods are commonly used to obtain polymer nanocomposites with the controlled alignment of nanomaterials using electric or magnetic fields, fluid flow, and shear forces. Such approaches may be complex in preparing a manufacturing system, have low fabrication rate, and even limited structure scalability and complexity required for customized functional products. Recently, additive manufacturing (AM), also called 3D printing, has been developed as a major fabrication technology for nanocomposites with aligned reinforcements. AM has the ability to control the orientation of nanoparticles and offers a great way to produce the composites with cost-efficiency, high productivity, scalability, and design flexibility. Herein, we propose a manufacturing process using AM for the architected structure of polymer nanocomposites with oriented nanomaterials using a polylactic acid polymer as the matrix and graphite and CNTs as fillers. AM can achieve the aligned orientation of the nanofillers along the printing direction. Thus, it enables the fabrication of multifunctional nanocomposites with complex shapes and higher precision, from micron to macro scale. This method will offer great opportunities in the advanced applications that require complex multiscale structures such as energy storage devices (e.g., batteries and supercapacitors) and structural electronic devices (e.g., circuits and sensors).



2007 ◽  
Vol 70 (9) ◽  
pp. 2155-2160 ◽  
Author(s):  
VINCENZO DEL PRETE ◽  
HECTOR RODRIGUEZ ◽  
ALFONSO V. CARRASCOSA ◽  
BLANCA de las RIVAS ◽  
EMILIA GARCIA-MORUNO ◽  
...  

A study was carried out to determine the in vitro interaction between ochratoxin A (OTA) and wine lactic acid bacteria (LAB). Fifteen strains belonging to five relevant oenological LAB species were grown in liquid synthetic culture medium containing OTA. The portion of OTA removed during the bacterial growth was 8 to 28%. The OTA removed from the supernatants was partially recovered (31 to 57%) from the bacterial pellet. Cell-free extracts of three representative strains were produced by disrupting cells in a French pressure cell. The ability of crude cell-free extracts to degrade OTA was studied. OTA was not degraded by cell-free extracts of wine LAB strains, and no degradation products of OTA were detected in the high-performance liquid chromatograms of the methanol extract of the bacterial pellet. On the basis of these results, we conclude that OTA removal by wine LAB is a cell-binding phenomenon. The chemistry and the molecular basis of OTA binding to wine LAB remains unknown.



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