title: Formation and regeneration of protoplasts of the actinorhizal nitrogen-fixing actinomycete frankia.
abstract: Procedures for forming and regenerating protoplasts of four Frankia strains are described. Cells obtained from growth medium containing 0.1% glycine were digested with lysozyme (250 mug/ml) in a medium containing 0.5 M sucrose, 5.0 mM CaCl(2), and 5.0 mM MgCl(2). Protoplasts were formed during 15 to 120 min of digestion at 25 degrees C. Optimum conditions for protoplast regeneration involved placing protoplasts on a layer of complex growth medium containing 0.3 M sucrose, 5.0 mM CaCl(2), and 5.0 mM MgCl(2) which was overlaid with a layer of 0.8% low-melting-point agarose containing 0.5 M sucrose, 5.0 mM MgCl(2), and 5.0 mM CaCl(2). The maximum regeneration efficiency was 36.9% for strain CpI1, 1.3% for strain ACN1, 27% for strain EAN1pec, and 20% for strain EuI1c.
authors.affiliation: Department of Bacteriology, University of Wisconsin, Madison, Wisconsin 53706.
authors.forename: L S
authors.initials: LS
authors.lastname: Tisa
authors.forename: J C
authors.initials: JC
authors.lastname: Ensign