Comparison of Quasielastic Light Scattering and Laser Diffractometry as Nondestructive Probes into the Structure of Bacillus sphaericus Spores Produced at Different Temperatures.

Volume 62, no. 5, p. 1702, column 2, equation 3: the equation should read as follows. g(sup1)((tau)) = [g(sup2)((tau)) - 1](sup1/2) = exp[-K(sup2)(D(inf1) cos(sup2)(alpha) + D(inf2) sin(sup2)(alpha))(tau)] (3) [This corrects the article on p. 1699 in vol. 62.].

Comparison of Quasielastic Light Scattering and Laser Diffractometry as Nondestructive Probes into the Structure of Bacillus sphaericus Spores Produced at Different Temperatures.

Quasielastic light scattering (QLS) and laser diffractometry (LD) are relatively novel nondestructive procedures for estimating the sizes of bacterial spores in suspension. This study for the first time directly compared the two with a destructive procedure, namely, scanning electron microscopy (SEM), for quasispherical spores of Bacillus sphaericus. Because of the different physical aspect measured, the sizes derived by QLS and LD are, as could be expected for spores with an exosporium, significantly different. The larger estimates obtained by QLS (1.70, 1.58, and 1.14 (mu)m for spores produced at 15(deg)C [BS15], 20(deg)C [BS20], and 30(deg)C [BS30], respectively) than by LD (0.56 [BS15], 0.58 [BS20], and 0.52 [BS30] (mu)m) and SEM (0.64 [BS15], 0.58 [BS20], and 0.70 [BS30] (mu)m) are explained in terms of the detection by QLS, LD, and SEM of different spore layers and the degree of nonsphericity of the latter.

The application of laser diffractometry to study the water content of spores of Bacillus sphaericus with different heat resistances.

The distribution of water in the protoplast and integument of three populations of Bacillus sphaericus spores was determined by laser diffractometry together with the sizes of their integuments and protoplasts. The spores were produced at 15, 20 and 30 degrees C. Spores grown at 15 degrees C had protoplast and integument water contents similar to those produced at 20 degrees C, while those grown at 30 degrees C had significantly lower water contents than the other two populations. The inner (or protoplast) radii of the spores produced at 15, 20 and 30 degrees C were 0.41 +/- 0.02 microns, 0.42 +/- 0.01 microns and 0.38 +/- 0.02 microns whilst the outer (or whole spore) radii were 0.56 +/- 0.01 microns, 0.58 +/- 0.01 microns and 0.52 +/- 0.02 microns respectively. The ratios of integument to protoplast radius were 0.40 +/- 0.02, 0.43 +/- 0.07 and 0.41 +/- 0.03 respectively.