Growth and morphogenesis inStreptomyces

Abstract

In this report we propose a model of apical growth for streptomycetes. The apical tip is considered as a multilayered wall that expands by an inside-to-outside mechanism of growth. It is also assumed that each layer is made up of peptidoglycan blocks, each of them being the result of the biosynthetic activity of a wall-synthesizing unit or membrane-associated growth zone. According to our model, apical growth occurs as follows: as a consequence of the hydrostatic pressure and the cleavage of some bonds, the layers are pushed and forced to slide (one with respect to the other), migrating from the center of the tip (at the inside of the wall) towards a peripheral location (at the outside of the wall). The model also incorporates a mechanism by which apical growth can be regulated and coordinated with the replication of the chromosome.

Cloning and characterization of a Streptomyces antibioticus ATCC11891 cyclophilin related to Gram negative bacteria cyclophilins

“…Streptomyces is a mycelial bacterium whose natural habitat is the soil, where it carries out a notable degradative activity on organic substrates. Its developmental cycle is highly complex and involves programmed cell‐death processes that are central to the differentiating cycle of the bacterium [30,31]. The signals that induce these phenomena are unknown, though stress conditions are known to induce these processes [A. Manteca and J. Sanchez, unpublished data and [32]].…”