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Mycelial Morphology (mycelial + morphology)
Selected AbstractsDependence of Apparent Viscosity on Mycelial Morphology of Streptomyces fradiae Culture in Various Nitrogen SourcesBIOTECHNOLOGY PROGRESS, Issue 4 2000Du Bok Choi To examine what causes increased viscosity in culture broth in Streptomyces fradiae culture, various natural nitrogen sources were investigated. Extracellular protease activity increased with culture time and decomposed the natural nitrogen source into amino acids. In the case of gluten meal, after a culture time of 5 d, concentrations of glutamic acid and aspartic acid had increased to 600 and 200 mg/L, respectively, which were about 3- and 2-fold as high as levels in cultures under similar conditions using Pharmamedia. For various amino acids tested, the addition of glutamic acid or aspartic acid mixture to the culture medium raised the apparent viscosity to its highest demonstrated value, 260 mPa·s after 5 d of culture, which was 3-fold higher than without amino acids. Consumption of the decomposed glutamic acid and aspartic acid was dependent on the activities of glutamate dehydrogenase and aspartate aminotransferase, respectively. When ammonium ion was used as the nitrogen source, cell concentration reached 1.75 g/L measured as an intracellular nucleic acid concentration,which was about 2.3-fold higher than that with any other natural nitrogen source. However, apparent viscosity was only 75 mPa·s, a value one-third that of the amino acid mixture, and 70% of the pellets were bigger than 1.2 × 104 ,m2. In the case of gluten meal or the amino acid mixture, pellets bigger than 1.2 × 104 ,m2 comprised only 8%. This demonstrates that consumption of some amino acids affected the formation of filamentous morphology, which caused an increase in the apparent viscosity of the culture broth, and the apparent viscosity was not caused by the mycelial concentration but the mycelial morphology. [source] Coordinated Development of Yeast Colonies: An Experimental Analysis of the Adaptation to Different Nutrient Concentrations , Part 1ENGINEERING IN LIFE SCIENCES (ELECTRONIC), Issue 2 2005T. Walther Abstract The development of yeast colonies on solid agar substrates served as a model system to investigate the growth of higher fungi in a heterogeneous environment. Applying a new analytical technique , which was based on the estimation of the intensity of transmitted light from microscopic images taken along the colony radius , cell-density distributions inside fungal mycelia were measured at an extremely high spatial resolution. Using this method, the adaptation of yeast colonies to the limitation of different nutrients was investigated. Under conditions of carbon or nitrogen limitation, populations of the dimorphic model yeasts Yarrowia lipolytica and Candida boidinii underwent a transition in their morphology from solid colony to mycelial colony patterns. When grown under conditions that induced the mycelial morphology, colonies extended linearly at a constant rate irrespective of the initial nutrient concentration. In general, the cell density within the population declined at higher degrees of limitation. Nitrogen-limited colonies of both model yeasts, as well as carbon-limited Y.,lipolytica colonies proceeded to extend until the growth field was finally covered by the population. Under these conditions, areas of fairly constant cell densities were formed during the growth process. Only carbon-limited C.,boidinii colonies stopped extending at a final diameter which was small when compared to the size of the growth field, and formed a cell-density profile which was monotonically declining. The observed differences in the final colony diameter, and in the cell-density profile morphology indicated the presence of different regulatory mechanisms that ruled the colony development of the model yeasts. The presented monitoring technique for the biomass distribution inside fungal populations provided the basis for a quantitative and non-invasive description of mycelial development. [source] Effect of agitation intensity on the exo-biopolymer production and mycelial morphology in Cordyceps militarisLETTERS IN APPLIED MICROBIOLOGY, Issue 6 2002J.P. Park Aims:,The influence of agitation intensity on Cordyceps militaris morphology and exo-biopolymer production was investigated in a 5 litre stirred vessel using a six-blade Rushton turbine impeller. Methods and Results:,The mycelial morphology of C. militaris was characterized by means of image analysis, which included mean diameter, circularity, roughness and compactness of the pellets. The morphological parameters of the pellets grown under different stirring conditions were significantly different, which correspondingly altered exo-biopolymer production yields. Conclusions:,The compactness of the pellets was found to be the most critical parameter affecting exo-biopolymer biosynthesis; more compact pellets were formed at 150 rev min,1 with maximum exo-biopolymer production (15 g l,1). Significance and Impact of the Study:,The results of this study suggest that morphological change of pellets is a good indicator for identifying the cell activity for exo-biopolymer production. [source] Isolation of Sporothrix schenckii from the environmental sources of cutaneous sporotrichosis patients in Himachal Pradesh, India: results of a pilot studyMYCOSES, Issue 6 2007Karan Inder Singh Mehta Summary Himachal Pradesh, India is a known endemic area for cutaneous sporotrichosis. No attempt has been made to isolate Sporothrix schenckii, the causative fungus, from environmental sources in this region or in India as such. This prospective study was carried out to isolate Sporothrix schenckii from different environmental samples collected from the vicinity of cutaneous sporotrichosis patients. All patients of cutaneous sporotrichosis diagnosed during March 2005,February 2006 were studied. Twenty-one biopsy specimens and 62 environmental samples of soil, various thorns, corn-stalk, grass-blades and sphagnum moss were subjected to mycologic culture on Sabouraud's glucose agar. Sporothrix schenckii was identified by colony characteristics, lacto-phenol cotton blue mounts and demonstration of temperature dimorphism. These patients (F : M 15 : 6) were between 12 and 72 years of age and had cutaneous lesions for 45 days to 4 years. Lymphocutaneous and fixed cutaneous sporotrichosis was seen in 14 (66.6%) and 7 (33.3%) patients respectively. Extremities were involved in 16 (76.2%); and 5 (23.8%) patients had facial lesions. Ten (47.4%) biopsy specimens and six environmental (three soil, three corn-stalk) samples were culture-positive, which showed morphological characteristics suggesting Sporothrix schenckii. No variation in colony characteristics and mycelial morphology was observed in growth isolates from clinical or environmental samples. Temperature dimorphism was observed in all the 10 isolates obtained from the clinical specimens and in two isolates cultured from corn-stalk. Corn-stalks are evidently important sources of Sporothrix schenckii infection although subsequent contamination of wounds appears more important for development of clinical disease. Culture of Sporothrix schenckii from environmental sources may not be always possible to correlate with profile of injuries. [source] Dependence of Apparent Viscosity on Mycelial Morphology of Streptomyces fradiae Culture in Various Nitrogen SourcesBIOTECHNOLOGY PROGRESS, Issue 4 2000Du Bok Choi To examine what causes increased viscosity in culture broth in Streptomyces fradiae culture, various natural nitrogen sources were investigated. Extracellular protease activity increased with culture time and decomposed the natural nitrogen source into amino acids. In the case of gluten meal, after a culture time of 5 d, concentrations of glutamic acid and aspartic acid had increased to 600 and 200 mg/L, respectively, which were about 3- and 2-fold as high as levels in cultures under similar conditions using Pharmamedia. For various amino acids tested, the addition of glutamic acid or aspartic acid mixture to the culture medium raised the apparent viscosity to its highest demonstrated value, 260 mPa·s after 5 d of culture, which was 3-fold higher than without amino acids. Consumption of the decomposed glutamic acid and aspartic acid was dependent on the activities of glutamate dehydrogenase and aspartate aminotransferase, respectively. When ammonium ion was used as the nitrogen source, cell concentration reached 1.75 g/L measured as an intracellular nucleic acid concentration,which was about 2.3-fold higher than that with any other natural nitrogen source. However, apparent viscosity was only 75 mPa·s, a value one-third that of the amino acid mixture, and 70% of the pellets were bigger than 1.2 × 104 ,m2. In the case of gluten meal or the amino acid mixture, pellets bigger than 1.2 × 104 ,m2 comprised only 8%. This demonstrates that consumption of some amino acids affected the formation of filamentous morphology, which caused an increase in the apparent viscosity of the culture broth, and the apparent viscosity was not caused by the mycelial concentration but the mycelial morphology. [source] | ||||||||||