TY - JOUR
T1 - Quantifiation of autolysis in Penicillium chrysogenum by semiautomated image analysis
AU - McIntyre, M
AU - Eade, Jeremy
AU - Cox, Philip
AU - Thomas, Colin
AU - White, S
AU - Berry, DR
AU - McNeil, B
PY - 2001/1/1
Y1 - 2001/1/1
N2 - An image analysis method is described for the characterization of empty (autolyzed and inactive) regions within the mycelia of filamentous fungi. It extends a previous method that characterized only regions filled with cytoplasm or vacuoles (i.e., the active biomass). The method is semiautomatic, requiring some manual editing before automated measurements. When the method was used for samples from a batch fermentation of an industrial strain of Penicillium chrysogenum, the empty regions were observed to constitute up to 15% (by projected area) of the biomass during the growth phase. After nutrient exhaustion, however, the proportion of empty regions rose rapidly, eventually representing more than 50% of the biomass by the end of fermentation. The increase in the percentage of empty regions coincided with a decrease in biomass (as measured by dry cell weight) and a fall in penicillin titre. Further morphological analysis revealed that fragmentation of mycelia, particularly clumps, coincided with increases in the levels of empty regions. This new image analysis method gave additional information on hyphal differentiation and a measure of autolysis. It was also a useful indicator of the processes leading to autolysis.
AB - An image analysis method is described for the characterization of empty (autolyzed and inactive) regions within the mycelia of filamentous fungi. It extends a previous method that characterized only regions filled with cytoplasm or vacuoles (i.e., the active biomass). The method is semiautomatic, requiring some manual editing before automated measurements. When the method was used for samples from a batch fermentation of an industrial strain of Penicillium chrysogenum, the empty regions were observed to constitute up to 15% (by projected area) of the biomass during the growth phase. After nutrient exhaustion, however, the proportion of empty regions rose rapidly, eventually representing more than 50% of the biomass by the end of fermentation. The increase in the percentage of empty regions coincided with a decrease in biomass (as measured by dry cell weight) and a fall in penicillin titre. Further morphological analysis revealed that fragmentation of mycelia, particularly clumps, coincided with increases in the levels of empty regions. This new image analysis method gave additional information on hyphal differentiation and a measure of autolysis. It was also a useful indicator of the processes leading to autolysis.
UR - http://www.scopus.com/inward/record.url?scp=0034887468&partnerID=8YFLogxK
U2 - 10.1139/cjm-47-4-315
DO - 10.1139/cjm-47-4-315
M3 - Article
C2 - 11358171
SN - 1480-3275
VL - 47
SP - 315
EP - 321
JO - Canadian Journal of Microbiology
JF - Canadian Journal of Microbiology
IS - 4
ER -