Fermenting, pectolytic yeasts were isolated from a massive commercial outbreak of softening and gas-pocket formation in olives that had been stored in acidified, low-salt brines in an attempt to reduce the problem of brine disposal. The suspected yeasts represented three different species: Saccharomyces oleaginosus, S. kluyveri, and Hansenula anomala var. anomala. All pectolytic cultures produced pectin esterase and polygalacturonase but no pectic acid transeliminase when grown in nutrient glucose broth. Crude, cell-free dialyzed enzyme preparations measured viscosimetrically exhibited optimal activity on sodium polygalacturonate at pH 6.0 and 45 C and were active in the range of pH 4.0 to 9.0 and 10 to 60 C.

In sporulating cells of Clostridium botulinum type A (NCA strain 78A), formation of exosporia was initiated laterally in the sporangia before the synthesis of the spore cortex. Mature spores were enveloped by multilayered exosporia; the layers were uniform in appearance, approximately 3 nm thick, with a center-to-center distance of 7 nm.

No abstract

A triple fixation method using a sequential application of 15 or 30% formaldehyde, 6% glutaraldehyde, and 1% osmium tetroxide resulted in excellent fixation of mature spores of Clostridium botulinum.

The ultrastructure of spores of Clostridium botulinum strains 78A, 17B (nonproteolytic), and C51C3 was investigated. Electron photomicrographs revealed the following: strain 78A: the oval spores, enveloped by multilayered exosporia, were normally found within swollen sporangia. The spore coat contained a distinct outer layer and a thicker inner coat. Strain 17B: the oval spores were covered by open-ended, sheath-like exosporia. Some spores were enclosed within slightly swollen sporangia, while most were present as free spores. A layered, electron-translucent outer coat and an electron-dense inner coat comprised the spore coat. Strain C51C3: the oval to cylindrical spores were seldom found within intact sporangia. The spore coat was a single, thin, electron-dense layer. Exosporial layers were in apposition to the spore coat.