%0 Journal Article %A Martin, Steven M. %A Bushell, Michael E. %T Effect of hyphal micromorphology on bioreactor performance of antibiotic-producing Saccharopolyspora erythraea cultures %D 1996 %J Microbiology, %V 142 %N 7 %P 1783-1788 %@ 1465-2080 %R https://doi.org/10.1099/13500872-142-7-1783 %K hyphal micromorphology %K eryrhromycin %K antibiotic production %K bioreactor performance %K secondary metabolism %I Microbiology Society, %X When Saccharopolyspora erythraea biomass from submerged culture was filtered (100-120 μn sintered glass filter) the antibiotic yield of the retentate (mean hyphal particle diameter 103 μm) was significantly higher [1.740 mg (mg biomass)-1] than that of the filtrate [1.286 mg (mg biomass)-1; mean hyphal particle diameter 88 μn]. A hypothesis to explain this is that there is a critical hyphal particle diameter, below which the particle is incapable of producing antibiotic. This would be a consequence of the site of antibiotic production occurring at a fixed distance from the growing hyphal tip. A protocol is proposed for calculation of the hypothetical critical hyphal diameter (88 μm in this case). The proportion of retentate (more productive) fraction of biomass varied between 60% and 30% during the course of a batch culture. Bioreactor stirrer speed significantly affected mean hyphal particle diameter (70 fim at 1500 r.p.m.; 124 μm at 750 r.p.m.) and antibiotic productivity [0.867 mg (mg biomass)-1 at 1500 r.p.m.; 0.913 mg (mg biomass)-1 at 750 r.p.m.]. %U https://www.microbiologyresearch.org/content/journal/micro/10.1099/13500872-142-7-1783