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doi: 10.1007/BF01576172pmid: N/A
Microbodies are ubiquitous organelles in fungal cells, occurring in both vegetative hyphae and spores. They are bounded by a single membrane and may contain a crystalloid inclusion with subunits spaced at regular intervals. Typically, they contain catalase which reacts with the cytochemical stain 3,3′-diaminobenzidine to yield an electron-opaque product, urate oxidase, l -α-hydroxy acid oxidase and d -amino acid oxidase. Their fragility and the necessity to disrupt the tough fungal cell wall before isolating them make them difficult to isolate. Analysis of enzymes in purified or partially purified microbodies from fungi indicates that they participate in fatty acid degradation, the glyoxylate cycle, purine metabolism, methanol oxidation, assimilation of nitrogenous compounds, amine metabolism and oxalate synthesis. In organisms where microbodies are known to contain enzymes of the glyoxylate cycle, they are known as glyoxysomes; where they are known to contain peroxidatic activity, they are known as peroxisomes. In some cases microbodies contain enzymes for only a portion of a pathway or cycle. Thus, they must be involved in metabolic cooperation with other organelles, particularly mitochondria. The number, size and shape of microbodies in cells, their buoyant density and their enzyme contents may vary with the composition of the medium; their proliferation in cells is regulated by the growth environment. The isolation from the same organism of microbodies with different buoyant densities and different enzymes suggests strongly that more than one type of microbody can be formed by fungi.
Wiwat, Chanpen; Panbangred, Watanalai; Bhumiratana, Amaret
doi: 10.1007/BF01576173pmid: N/A
The plasmids pBC16 and pC194 from Bacilus thuringiensis subsp. israelensis strains A084-16-194 were transferred to 25 subspecies of B. thuringiensis by a conjugation-like process using broth mating technique. The frequencies of transfer varied considerably between different mating pairs, ranging from 1.1×10 −9 to 9.8×10 −5 . Additionally, chromosomal transfer could also be demonstrated in ten B. thuringiensis subspecies with very low frequencies (4.3×10 −9 to 3.7×10 −7 ). The intersubspecies matings within a group of eight subspecies strains gave higher frequencies of transfer than the matings between the subspecies. Furthermore, the results indicated that the capability to transfer plasmids among these various subspecies did not depend on the presence of large plasmid.
Taylor, K.; Beck, M.; Huang, D.; Sakai, T.
doi: 10.1007/BF01576174pmid: N/A
The fermentation of d -xylose by Pachysolen tannophilus, Candida shehatae , and Pichia stipitis has been investigated by 13 C-nuclear magnetic resonance spectroscopy of both whole cells and extracts. The spectra of whole cells metabolizing d -xylose with natural isotopic abundance had significant resonance signals corresponding only to xylitol, ethanol and xylose. The spectra of whole cells in the presence of (1- 13 C)xylose or (2- 13 C)xylose had resonance signals corresponding to the C-1 or C-2, respectively, of xylose, the C-1 or C-2, respectively, of xylitol, and the C-2 or C-1, respectively, of ethanol. Xylitol was metabolized only in the presence of an electron acceptor (acetone) and the only identifiable product was ethanol. The fact that the amount of ethanol was insufficient to account for the xylitol metabolized indicates that an additional fate of xylitol carbon must exist, probably carbon dioxide. The rapid metabolism of xylulose to ethanol, xylitol and arabinitol indicates that xylulose is a true intermediate and that xylitol dehydrogenase catalyzes the reduction (or oxidation) with different stereochemical specificity from that which interconverts xylitol and d -xylulose. The amino acid l -alanine was identified by the resonance position of the C-3 carbon and by enzymatic analysis of incubation mixtures containing yeast and (1- 13 C)xylose or (1- 13 C)glucose. The position of the label from both substrates and the identification of isotope also in C-1 of alamine indicates flux through the transketolase/transaldolase pathway in the metabolism. The identification of a resonance signal corresponding to the C-1 of ethanol in spectra of yeast in the presence of (1- 13 C)xylose and fluoroacetate (but not arsenite) indicates the existence of equilibration of some precursor of ethanol (e.g. pyruvate) with a symmetric intermediate (e.g. fumarate or succinate) under these conditions.
Wallace, Kimberlee; Payne, Gregory; Speedie, Marilyn
doi: 10.1007/BF01576175pmid: 1366800
A defined medium containing glucose and ammonium as the sole carbon and nitrogen sources was developed to support growth and streptonigrin production. In this defined medium, increased initial levels of ammonium resulted in increased growth suggesting that nitrogen is the growth limiting nutrient. In some cases, increased initial ammonium levels resulted in decreased specific streptonigrin productivity, suggesting that nitrogen regulatory mechanisms may adversely affect streptonigrin biosynthesis. This suggestion that nitrogen regulation adversely affects antibiotic biosynthesis is further supported by results from two studies in which the ammonium supply to the cells was controlled. In the first study, streptonigrin productivity and final titer were enhanced by the addition of an ammonium trapping agent. In the second experiment, when ammonium chloride was fed slowly throughout the course of cultivation, the production phase was lengthened and the maximum antibiotic concentration was enhanced compared to the batch controls containing either the same initial or the same total ammonium chloride levels. Although our results indicate streptonigrin production may be subject to nitrogen regulatory mechanisms, the effect of nitrogen on streptonigrin production cannot be strictly correlated to the extracellular ammonium concentration. In fact, we observed that when ammonium was depleted from the medium, streptonigrin production ceased.
Olson, Gregory; Sakai, Craig; Parks, E.; Brinckman, F.
doi: 10.1007/BF01576176pmid: N/A
The bioleaching of cobalt from domestic, industrial smelter wastes was studied. Thiobacillus ferrooxidans solubilized Co from sulfidic dross furnace mattes. At pulp densities of 4% (w/v) up to 600 mg of Co per liter of leaching solution was released from nickel matte, corresponding to removal of about two-thirds of the original amount of Co in the matte. Bioleaching methods may be useful as a component of a process for solubilization and recovery of Co from sulfidic smelter mattes.
Stewart, D.; Thomas, B.; Bean, R.; Fredrickson, J.
doi: 10.1007/BF01576177pmid: N/A
A Penicillium sp. previously shown to grow on lignite coals degraded an air-oxidized bituminous coal (Illinois #6) to a material that was more than 80% soluble in 0.5 N NaOH. Scanning electron microscopy of the oxidized Illinois #6 revealed colonization of the surface by the Penicillium sp., production of conidia, and erosion of the coal surface. The average molecular weight (MW) of Illinois #6 degraded by the fungus and base-solubilized was approximately 1000 Da. The average MW for base-solubilized Illinois #6 that was not exposed to the fungus was 6000 Da, suggesting solubilizing mechanisms other than base catalysis. A spectrophotometric assay to quantify the microbial conversion of biosolubilized coal was developed. Standard curves were constructed based on the absorbance at 450 nm of different quantities of microbe-solubilized coal. An acid precipitation step was necessary to remove medium and/or microbial metabolites from solubilized coal to prevent overestimation of the extent of coal biosolubilization. Furthermore, the absorption spectra for different coal products varied, necessitating construction of standard curves for individual coals.
Pope, Joseph; Nelson, Richard; Schaffner, Carl; Rosen, Robert; Pandey, Ramesh
doi: 10.1007/BF01576178pmid: 1369285
Thin layer chromatography (TLC), high performance liquid chromatography (HPLC) and mass spectrometry (MS) methods have been developed for the analysis of the antibiotic nybomycin, its derivatives deoxynybomycin and nybomycin acetate, during the fermentation and isolation of nybomycin. Using a quantitative HPLC based assay, the time course of nybomycin production (nybomycin titers) in 1000 liter fermentations was determined. Desorption chemical ionization mass spectrometry (DCI/MS) of standard nybomycin samples, fermentation broth samples and purified fractions suggested the co-production of deoxynybomycin which was not reported previously from this organism. TLC and HPLC were used to confirm the presence of deoxynybomycin in the crude extracts of fermentation broths.
Lipkus, Alan; Chittur, Krishnan; Vesper, Stephen; Robinson, Jayne; Pierce, George
doi: 10.1007/BF01576179pmid: 1366801
A study motivated by the recent revival of interest in the use of IR spectroscopy to identify bacteria is reported. A library of FT-IR spectra of dried bacterial films was compled using 16 different strains. A test set was complied from spectra of the same strains grown several months later. The test set was quantitatively compared with the library on the basis of spectral similarity in the region 980–1190 cm −1 . Six of the strains in the test set were not matched with the correct strain in the library despite efforts to reproduce the conditions under which cells were grown and prepared. The results suggest that reproducibility of the bacterial spectra is a potential difficulty that must be addressed by any attempts to develop FT-IR spectroscopy as a bacterial identification method.
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