Penicillin-binding proteins of protoplast and sporoplast membranes of Streptomyces griseus strains

Membrane-bound penicillin-binding proteins (PBPs) of two Streptomyces griseus strains that sporulate well in liquid and solid medium have been investigated during the course of their life-cycle. The PBP patterns were analyzed by sodium dodecylsulphate polyacrylamide-gel electrophoresis and fluorography. One strain (No. 45 H) has only a single band (mol wt: 27,000) in early log phase, and two additional PBPs of higher mol wt (69,000 and 80,000) in the late log phase. The other strain (No. 2682) possessed two bands with mol wts 27,000 and 38,000 which did not change during its vegetative phase. In strain No. 2682, a new PBP with a mol wt of 58,000 appeared in spore membranes while one of those (mol wt 38,000) present in mycelial membranes disappeared. Our results suggest that appearance of the new PBP in the spore may be associated with the sporulation process. The major PBP band (mol wt: 27,000) present in all stages of the life cycle of these strains, may be characteristic of S. griseus while the other PBPs reflect certain stages of the life cycle. A new method was developed for the production of spore protoplasts by consecutive enzymatic treatments.Abbreviation PBP penicillin-binding protein     

Preparation and properties of pollen sporoplasts

Summary Methods for the removal of exine from mature, ungerminatedLilium longiflorum pollen and release of intact gametophytes (sporoplasts) have been developed. These methods rely on the low temperature solvolytic activity of 4-methylmorpholine N-oxide (MMNO), which allows partial or complete detachment of exine from intine during subsequent washing procedures. These methods are: aqueous MMNO combined with cyclohexylamine (method I), aqueous MMNO at alkaline pH (method II), and aqueous MMNO containing a high Ca²⁺ concentration with added cellulysin and macerase (method III). Sporoplasts produced by methods I and II are most frequently completely separated from exine and, as shown by histochemical tests, enveloped by the intine layer. Selected enzyme activities in method II sporoplasts are measurable but, as indicated by other tests, considerable damage to the plasma membrane accompanies this treatment. Sporoplasts produced by melhod III largely remain attached to their ruptured exine layer and retain substantial biological competence in terms of extractable enzyme activities, membrane integrity, and respiration.Abbreviations MMNO 4-methylmorpholine N-oxide - SEM scanning electron microscope - TEM transmission electron microscope