Penicillium chrysogenum endophthalmitis

Infections caused byPenicillium chrysogenum are rare. The first case of posttraumatic endophthalmitis caused by this saprophytic fungus is reported. Therapy with amphotericin B and topical natamycin eradicated the organism.     

Mutagenesis and Enrichment of Auxotrophs in Penicillium chrysogenum

An efficient method for isolation of auxotrophs of Penicillium chyrysogenum involving mutagenesis with ethyl methanesulfonate followed by enrichment with sodium pentachlorophenate was developed. The auxotroph frequencies obtained were 30 to 40%.     

A cold-adapted endo-arabinanase from Penicillium chrysogenum

Previously, three arabinan-degrading enzymes were isolated from Penicillium chrysogenum 31B. Here we describe another arabinan-degrading enzyme, termed Abnc, from the culture filtrate of the same organism. Analysis of the reaction products of debranched arabinan by high-performance anion-exchange chromatography (HPAEC) revealed that Abnc cleaved the substrate in an endo manner and that the final major product was arabinotriose. The molecular mass of Abnc was estimated to be 35 kDa by SDS-PAGE. Enzyme activity of Abnc was highest at pH 6.0 to 7.0. The enzyme was stable up to 30 degrees C and showed optimum activity at 30 to 40 degrees C. Compared with a mesophilic counterpart from Aspergillus niger, Abnc exhibited a lower thermal stability and optimum enzyme activity at lower temperatures. Production of Abnc in P. chrysogenum was found to be strongly induced by arabinose-containing polymers and required a longer culture time than did other arabinanase isozymes in this strain.     

Ballistic Disruption of Penicillium chrysogenum Cells

The use of glass beads in a high-speed mixing device to rupture organisms was applied to molds. The use of a mixer in which the propellor shaft enters from the top into a metal mixing chamber made it possible to immerse the whole device in a salt water and ice mixture so that the temperature of the glass-bead slurry could be kept below 5 C without difficulty. Mycelia, glass beads, and buffer in a 1:2:3 (w/w) ratio gave above 95% breakage in 15 min with Penicillium chrysogenum cells and in 4 min with Rhizopus nigricans. Some of the factors influencing breakage are discussed.