Genetic Studies on Microbial Cross Resistance to Toxic Agents I. ,

Inhibition of the biosynthesis of cell-wall mucopeptides by the penicillins. A study of penicillin-sensitive and penicillin-resistant strains of Staphylococcus aureus

“…when growing in broth. In order to select pencillin-resistant substrains, two techniques were used: (a) the gradient plate technique of Szybalski & Bryerson (1952) and (b) the selection of colonies from heavily inoculated agar plates containing sufficient penicillin almost to inhibit growth completely. As an example, a plate eontaining, say, 0-036 ,ug.…”

Experimental and Simulation Efforts in the Astrobiological Exploration of Exooceans

“…Plate diffusion methodologies owe much to the pioneer works of Beijerinck, and later works that resulted in the development of the ingenious wedge plate technique by Szybalski and Bryson (Szybalski 1951;Szybalski and Bryson 1952) and the steady-state twodimensional gradient plate (Caldwell and Hirsch 1973), which constituted two major breakthroughs in this field. Further studies by Wimpenny and colleagues (Peters et al 1991;Wimpenny 1993, 1996b,a;Wimpenny andWaters 1984, 1987;Wimpenny et al 1981) perfected the wedge plate technique and even permitted the establishment of multidimensional systems (i.e., systems where several parameters are varied simultaneously).…”

The use of two-dimensional gradient plates in determining the responses of non-sulphur purple bacteria to pH and NaCl concentration

“…It was possible to divide the strains into 3 separate groups. Those (1-3) capable of growth at more than 5.6% (w/v) NaC1, an intermediate group (4)(5)(6) which were inhibited between 3.5-4.3% (w/v) NaC1, and a third group (7)(8)(9) which was inhibited by about 3% (w/v) NaC1. 2 strains (8 and 9) from this latter group were incapable of growth below about pH 7.0 whilst the middle group could tolerate pH 6.0-6.4, and the most salt-resistant set were also the most acid-tolerant, growing at down to pH 5.3 to 5.9 depending on the strain.…”

“…A steady-state 2-dimensional diffusion plate was described in 1973 [2,3] but has not been developed further. A technique for preparing one-dimensional gradients on agar Petri dishes was used by Szybalski and coworkers [4][5][6] to investigate the responses of bacteria to antibiotic gradients. This wedge plate technique was later applied to the preparation of pH gradient plates [7] and to following growth on double ended one-dimensional gradients of metal ion versus antibiotic concentration [8].…”