Use of Bacillus subtilis minicells to demonstrate an antigenic relationship between the poles and lateral cylindrical regions of rod-shaped cells

Abstract

Purified minicells produced by Bacillus subtilis div IV-B1 mutants were used to immunize rabbits. Immune serum was obtained that agglutinated minicells and was able to form precipitin lines when reacted with minicell antigens in double-diffusion or immunoelectrophoretic procedures. Antiminicell serum agglutinated rod-shaped B. subtilis cells to long filaments produced by growth of a cell division-defective mutant at restrictive temperature. These findings indicate that minicells are immunogens capable of eliciting the production of antibodies that cross-react with the lateral, cylindrical regions of B. subtilis rods. It appears, therefore, that poles share a common antigen(s) with cylindrical regions of the cell.Rod-shaped bacteria consist of two geometrically distinct regions: cylindrical sides and hemispherical poles. During the growth cycle, cells elongate by the extension of the cylindrical region and then compartmentalize into two daughter cells by the construction of a septum. Division is completed by the differentiation of the septum into two poles. Each daughter cell consists of two poles, one of which is a generation older than the other, connected by a cylindrical region. Septum formation, and consequently pole production, is known to be under specific genetic control distinct from that which regulates cell growth by cylindrical length extension (7). It is of interest to determine whether the composition of the cell surface in the cylindrical portions of the cell is identical to that found in the poles. It has been demonstrated that wall regions isolated from the poles ofBacillus subtilis are more resistant to autolytic degradation than are wall regions from the cylindrical portion of the cell (3, 5). The reasons for this resistance are not clear since it has been reported that cell surface turnover occurs in cell pole regions, as well as in cylindrical portions of the cell (4).We have reported the isolation of a minicellproducing mutant of B. subtilis and have described the properties of purified minicells (8,9). Minicells consist entirely of cell pole surface and, thus, offer a system for investigating differences between poles and sides of rod-shaped bacteria (9). In this paper we report that mini-1 Present address: Department of Microbiology, University of Alabama in Birmingham, Birmingham, Ala. 35294. cells share a common antigen(s) found on cell cylindrical surfaces. MATERIALS AND METHODS Bacteria. Strain of B. subtilis and Escherichia coli used in these experiments are listed in Table 1. Media. Minimal medium consisted of: 0.0151 M (NH4)2S04, 0.0613 M K2HPO4-3H20, 0.0441 M KH2PO4, 0.0034 M sodium citrate 2H2O, 0.00081 M MgSO4-7H2O, and 0.0277 M glucose. Sterile supplements (20 ,ug/ml) were added as follows: thymine, isoleucine, and methionine for growth of CU403 cultures; thymine and methionine for growth of CU403 div IV-Bl and CU403 tms-12 cultures; and leucine, methionine, and adenine for growth of BC-101 cultures. Trypticase soy broth (BBL, Cockeysville, Md.; 30 g/liter) was supplemented with ...

Effective surface motion on a reactive cylinder of particles that perform intermittent bulk diffusion

“…Namely, the motors can fall off the cellular tracks and then rebind to the filament after a bulk excursion [16]. Outside of biological cells the exchange behavior between cell surface and surrounding bulk is influenced by bulk excursions, the cylindrical geometry being of relevance for a large class of rod-shaped bacteria (bacilli) and their linear arrangements [17].…”

Bulk-mediated Surface Diffusion on a Cylinder in the Fast Exchange Limit

“…Similarly, while molecular motors move actively along cylindrical filaments of the cellular skeleton, they regularly fall off the filaments and perform bulk mediated motion [17]. Finally, BMSD in cylindrical geometries occurs during the surface exchange of molecules with the vicinal bulk solution in rod-shaped cells such as bacilli and linear arrangements thereof [18].…”

Bulk-mediated surface diffusion along a cylinder: Propagators and crossovers

“…BMSD was revealed by NMR in porous glasses [1] and has relevance to numerous technological applications [2]. The particular case of BMSD on a cylindrical surface is of importance for facilitated diffusion in gene regulation [3,4], the net motion of motor proteins along cytoskeletal filaments [5], the transient binding of chemicals to nanotubes [6], or the exchange behavior between cell surface and surrounding bulk of rod-shaped bacteria (bacilli) and their linear arrangements [7] to name but a few examples.…”