The spores of Penicillium chrysogenum are of the noncoagulating type, and after spore germination a culture of disperse mycelia is obtained. In this study, it is shown that when the hyphal elements increase in size, they may agglomerate, and depending on the operating conditions, these agglomerates may develop into pellets with a dense core. The influence of initial spore concentration and agitation rate on agglomeration, leading to pellet formation, was studied. For a low concentration of spores in the inoculum, only a few hyphal elements agglomerate and pellets with a small diameter are obtained. At higher spore concentrations, many hyphal elements agglomerate and develop into large diameter pellets. Finally, at a very high spore concentration in the inoculum, the final hyphal element size is small and agglomerates therefore are not formed. With a high agitation rate, the agglomeration of hyphal elements is reduced. In a repeated fed-batch cultivation, where there was a shift from pellet morphology to disperse mycelia, it was found that there is no relation between macroscopic morphology and penicillin production by P. chrysogenum. The morphology was quantified throughout the repeated fed-batch cultivation, and both the pellet diameter and the concentration of pellets were affected by the agitation rate.

Culture Media↗

PubMedDate not supplied

Increased lymphatic flow from the liver in different intra- and extrahepatic diseases demonstrated by CT.

Increase in the production of hepatic lymph is a compensatory mechanism known to occur in cirrhosis, neoplasia of the liver, biliary obstruction, and right-sided cardiac decompensation with elevated hepatic venous pressure. In hepatic lymphostasis, dilated hepatic lymphatics are reflected on CT as low attenuation rims--perivascular lucencies (PVLs)--surrounding the portal veins and the intrahepatic vena cava. In this study, CT scans of the livers of normal controls and patients in each of the four disease categories mentioned above were evaluated for the presence of PVLs; the presence/absence of PVLs was correlated with other CT findings and various biochemical and pathophysiologic parameters. The PVLs were seen with some frequency in patients in each of the four disease categories (12-52%) but in none of the normal controls. In patients with tricuspid incompetence, the presence of PVLs correlated perfectly with the presence of mottled enhancement of the hepatic parenchyma (evidence of sinusoidal stasis). The presence of PVLs was associated with elevation of certain biochemical parameters, but no common biochemical marker was observed across the disease categories. Perivascular lucencies on CT reflect altered hepatic lymphatic dynamics; in the absence of impaired efferent lymph drainage, they reflect increased lymphatic flow. However, the sensitivity of the finding--the relationship of the presence/absence of PVLs on CT to the degree of alteration of the lymphatic dynamics--has yet to be assessed.

Adolescent↗