Intermediary Metabolism

Laere, André Van

doi:10.1007/978-0-585-27576-5_10

Cited by 7 publications

(7 citation statements)

References 205 publications

(142 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Our results agree with the reported stimulation of the biosynthesis of secondary metabolites by high level of glycolytic intermediate (Smith and Berry, 1974). Glycerol leads to glycolytic intermediate accumulation (dihydroxy acetone phosphate, glycerol 3-phosphate) and influences reducing equivalent fluxes (Van Laere, 1994). Better effects of reciprocal agitation are probably due to higher oxygen availability since it becomes rate limiting during the late-stage aerobic oxidation of statins (Moore et al, 1985;Wagschal et al, 1996).…”

Section: Resultsmentioning

confidence: 99%

Production of lovastatin examined by an integrated approach based on chemometrics and DOSY‐NMR

Bradamante

Barenghi

Beretta

et al. 2002

Biotech & Bioengineering

View full text Add to dashboard Cite

Microbial secondary metabolites are one of the sources of therapeutic molecules in the pharmaceutical industry. Product quality and high yields of secondary metabolites are the main goals for the commercial success of a fermentation process. Our novel approach was based on the decision-tree algorithm to determine the key variables correlated with the process outcome and on DOSY-NMR to identify both co-metabolites and impurities, and it improves fermentation systems and speeds up bioprocess development. The approach has been validated in the case of lovastatin production from Aspergillus terreus.

show abstract

Section: Resultsmentioning

confidence: 99%

Production of lovastatin examined by an integrated approach based on chemometrics and DOSY‐NMR

Bradamante

Barenghi

Beretta

et al. 2002

Biotech & Bioengineering

View full text Add to dashboard Cite

show abstract

“…1; Table 2). Mannitol and arabitol are synthesized from glucose and arabinose, respectively (57). Glucose might result from plant starch degradation, but not significantly from cellulose, as suggested by the small amount of cellulase observed compared with high amylase activity (Fig.…”

Section: Discussionmentioning

confidence: 94%

“…3). Xylitol can be generated from xylose in fungi (57), but this polyol was not detected in fungus gardens, indicating that the xylose generated in the fungus garden is preferentially used as a carbon source for microbial growth and maintenance. However, the rapid production of arabitol and temporal coincidence of arabitol and arabinose concentration peaks (Fig.…”

Section: Discussionmentioning

confidence: 99%

“…Therefore, major processes generating polyols in the fungus garden involve plant starch conversion to mannitol and plant hemicellulose conversion to arabitol through L. gongylophorus. Polyols that accumulate in minor amounts, i.e., sorbitol and inositol, can also be synthesized from glucose (57). Inositol was detected in staphyla secretions, but not sorbitol, which might be produced by microbial sources other than L. gongylophorus (Fig.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

Somera

Lima

Santos-Neto

et al. 2015

Appl Environ Microbiol

View full text Add to dashboard Cite

b Leaf-cutter ants use plant matter to culture the obligate mutualistic basidiomycete Leucoagaricus gongylophorus. This fungus mediates ant nutrition on plant resources. Furthermore, other microbes living in the fungus garden might also contribute to plant digestion. The fungus garden comprises a young sector with recently incorporated leaf fragments and an old sector with partially digested plant matter. Here, we show that the young and old sectors of the grass-cutter Atta bisphaerica fungus garden operate as a biphasic solid-state mixed fermenting system. An initial plant digestion phase occurred in the young sector in the fungus garden periphery, with prevailing hemicellulose and starch degradation into arabinose, mannose, xylose, and glucose. These products support fast microbial growth but were mostly converted into four polyols. Three polyols, mannitol, arabitol, and inositol, were secreted by L. gongylophorus, and a fourth polyol, sorbitol, was likely secreted by another, unidentified, microbe. A second plant digestion phase occurred in the old sector, located in the fungus garden core, comprising stocks of microbial biomass growing slowly on monosaccharides and polyols. This biphasic operation was efficient in mediating symbiotic nutrition on plant matter: the microbes, accounting for 4% of the fungus garden biomass, converted plant matter biomass into monosaccharides and polyols, which were completely consumed by the resident ants and microbes. However, when consumption was inhibited through laboratory manipulation, most of the plant polysaccharides were degraded, products rapidly accumulated, and yields could be preferentially switched between polyols and monosaccharides. This feature might be useful in biotechnology. In the nests of leaf-cutter ants of the genera Atta and Acromyrmex, gardens of the obligate mutualistic basidiomycete fungus Leucoagaricus gongylophorus (1, 2) are cultivated on fresh vegetal materials (3-5). Although few leaf-cutter species prefer monocots, most leaf-cutter ants collect plant materials from both monocots and dicots (6). The ants collect and transport these plants to their nests and then fractionate and extensively clean the leaf fragments (7,8). Subsequently, the ants deposit a drop of fecal fluid onto the leaf fragment surface and inoculate the leaf fragment with L. gongylophorus hyphae. The plant-digesting enzymes in the fecal fluid facilitate fungal development (9). This fungus produces swollen hyphal tips, called gongylidia, that cluster together to form macroscopic structures known as staphylae, which are food sources for the ants (3-5). L. gongylophorus also secretes enzymes that act synergistically with ant enzymes to degrade plant matter, generating soluble compounds that are subsequently ingested by the ants (10-13). These enzymes attack plant polysaccharides, including starch, hemicellulose, pectin, and, to a lesser extent, cellulose (10,(14)(15)(16)(17)(18)(19)(20)(21)(22)(23). In addition, other microbes living in the fungus garden might mediate ant nutrition...

show abstract

“…Thus, the possible routes of C from glycine into the plant are indirect. Glycine could be converted through serine to pyruvate and metabolized through the tricarboxylic acid cycle (Stryer, 1988), or glycine could be deaminated to form acetate and then contribute C skeletons via the glyoxylate cycle (Van Laere, 1994). In either case, the labelled C would be diluted by a large pool of unlabelled metabolic intermediates and its appearance in the plant in detectable levels would be unlikely.…”

Section: mentioning

confidence: 99%

Ectomycorrhizal transfer of amino acid‐nitrogen to the alpine sedge Kobresia myosuroides

Lipson¹,

Schadt²,

Schmidt³

et al. 1999

New Phytologist

View full text Add to dashboard Cite

Previous work in the Colorado alpine ecosystem has shown that amino acids are a potentially important N source for the sedge, Kobresia myosuroides. This plant is the only known sedge to harbour associations with ectomycorrhizal fungi. The aim of the present work was to test the hypothesis that these ectomycorrhizas transfer N from amino acids in the soil solution to the host plant, and thereby have an important role in the N nutrition of this species. We used a two-chamber system (rhizoboxes) in which K. myosuroides plants were separated from a soil chamber by nylon mesh that allowed fungal hyphae, but not plant roots, to cross it. Injections of ["&N, 2-"$C]glycine were made into the soil chamber. The hyphal crossings on half of the rhizoboxes were regularly disrupted to control for leakage of label across the barrier. Plants in the intact rhizoboxes showed significantly higher "&N enrichment than those in controls, and mycorrhizal root tips were significantly more enriched than bulk roots. The mycorrhizas transferred an average of 1n3% of the added "&N label to plants, a figure comparable to those obtained in previous studies in which plant roots were directly exposed to label. We conclude that fungal associations have an important role in the N nutrition of K. myosuroides by transferring N from amino acids to their hosts.

show abstract

Intermediary Metabolism

Cited by 7 publications

References 205 publications

Production of lovastatin examined by an integrated approach based on chemometrics and DOSY‐NMR

Production of lovastatin examined by an integrated approach based on chemometrics and DOSY‐NMR

Leaf-Cutter Ant Fungus Gardens Are Biphasic Mixed Microbial Bioreactors That Convert Plant Biomass to Polyols with Biotechnological Applications

Ectomycorrhizal transfer of amino acid‐nitrogen to the alpine sedge Kobresia myosuroides

Contact Info

Product

Resources

About