Bacterial sporulation

DipicolinicAcid(DPA) Detection Bacillus and Clostridia species have been found to contain 5%-14% dipicolinic acid (DPA dry weight) this compound has been found to be characteristic to sporulated bacterial cultures. Beverly and coworkers have reported a 10 min detection protocol from B. anthracis cultures using in situ derivatization with Py-MS [43]. 

Pedraza-Reyes, M., Gutierrez-Corona, E, and Nicholson, W.L., Temporal regulation and forespore-specific expression of the spore photoproduct lyase gene by o-G RNA-polymerase during Bacillus subtilis sporulation, /. Bacterial., 176, 3983,1994. 

Bacillus thuringiensis produces a variety of organic compounds which are toxic to the larvae of certain susceptible insect hosts. Among the toxic entities are proteinaceous crystals, probably three soluble toxins, and certain enzymes. The protein material is the major toxin active in killing lepidopterous larvae. The protein is formed by the cells apparently in close synchrony with sporulation, and its nature is a constant function of bacterial strain. The mode of action of the protein is under study. The sequence of events in the pathology observed is probably solubilization of the crystal (enzymatic or physical)—>liberation of toxic unit—>alteration of permeability of larval gut wall— change in hemolymph pH—>invasion of hemolymph by spores or vegetative cells of the bacterium. 

The bacterial culture converts a portion of the supplied nutrient into vegetative cells, spores, crystalline protein toxin, soluble toxins, exoenzymes, and metabolic excretion products by the time of complete sporulation of the population. Although synchronous growth is not necessary, nearly simultaneous sporulation of the entire population is desired in order to obtain a uniform product. Depending on the manner of recovery of active material for the product, it will contain the insolubles including bacterial spores, crystals, cellular debris, and residual medium ingredients plus any soluble materials which may be carried with the fluid constituents. Diluents, vehicles, stickers, and chemical protectants, as the individual formulation procedure may dictate, are then added to the harvested fermentation products. The materials are used experimentally and commercially as dusts, wettable powders, and sprayable liquid formulations. Thus, a... 

Mycobacteria are more resistant than other non-sporulating bacteria to a wide range of biocides. Examples of such organisms axe Mycobacterium tuberculosis, theM avium-intracellulare (MAI) group andM. chelonae (M. chelonei). Of the bacteria, however, the most resistant of all to biocides are bacterial spores, e.g. Bacillus subtilis, B. cereus. 

Spore formation is limited almost entirely to two genera of rodshaped bacteria Bacillus (aerobic or facultatively anaerobic), and Clostridium (anaerobic or aerotolerant). With one possible exception, the common spherical bacteria do not sporulate. Some spore-bearing species can be made to lose their ability to produce spores. When the ability to produce spores is once lost, it is seldom regained. SporMation is not a process to increase bacterial numbers because a cell rarely produces more than one spore. 

PHAs are synthesized as intracellular energy and carbon storage materials. Therefore, bacterial cells with a high content of poly(3HB) are better able to survive than cells with a low poly(3HB) content [15]. Poly(3HB) also serves as an endogenous carbon and energy source for sporulation in Bacillus species and cyst formation in Azobacter species [16-18] and the majority of bacteria investigated accumulate PHAs in response to a nutrient limitation. The reported... 

McCormick JR, Losick R, Cell division gene jfeQis required for efficient sporulation but not growth and viability in Streptomyces coelicolor A3 2), J Bacterial 178 5295-5301, 1996. 

Reserving DNA in Bacterial Endospores Bacterial endospores form when the environment is no longer conducive to active cell metabolism The soil bacterium Bacillus subtilis, for example, begins the process of sporulation when one or more nutrients are depleted. The end product is a... 

A striking accumulation of Mn2+ often occurs within bacterial spores (Chapter 32). Bacillus subtilus absolutely requires Mn2+ for initiation of sporulation. During logarithmic growth the bacteria can concentrate Mn2+ from 1 pM in the external medium to 0.2 mM internally during sporulation the concentrations become much higher.593... 

Sporulation. Bacteria of the genera Bacillus and Clostridium form metabolically inert spores when deprived of adequate nutrients (Fig. 32-1L83,203,20 1 Bacterial spores are remarkably resistant to heat and can survive boiling water for prolonged periods. 

Some bacterial and fungal strains are capable of differentiation (sporulation, filamenta-tion). This property can affect product formation and the physical properties of the fermentation broth. Some enzymes are synthesized as secondary products and their production does not appear to be growth associated. Production strains are distinguished on the basis of their fermentation behavior such as viscosity or recoverability. They can also be distinguished by patent or proprietary... 

The first stage in the action of an antibiotic or biocide on a bacterial cell involves interaction between the chemical and the biological entity. Adsorption of a variety of biocides into bacterial cells has been described [33] but this, per se, does not necessarily provide information about the mechanism or site of action of the antibacterial compound. However, resistant cells would usually (but not necessarily) be expected to adsorb less of a chemical than sensitive cells. In non-sporulating bacteria, changes to the outer layers of cells may follow the initial binding to the cell surface or there may be diffusion across the cell envelope in either case, an antibiotic or biocide will penetrate the cell to reach the primary site of action at the cytoplasmic membrane or within the cytoplasm. Little is known about the penetration of antibacterial agents into bacterial spores. 

Bacillus anthracis can remain for extended periods of time in soil. The mechanism responsible for its persistence is unclear. Therefore, persistence may involve multiplication cycles and sporulation. It may involve multiplication of the organism in the soil or bacterial amplification in infected animals prior to soil contamination by the carcass. Spores may germinate simply upon application of water to soil (Hanna and Ireland, 1999 Oncul et al, 2002). 

The uptake of aluminum, cadmium, chromium, cobalt, cop-per, iron, lead, magnesium, manganese, molybdenum, nickel, silver, tin, and zinc by B. subtilis Strain 168 is reported. These data were obtained during the lag phase, exponential phase, stationary phase, and the sporulation phase of the maturation cycle of this bacterial strain. Nonflame atomic absorption spectrometry was the method of analysis for all the metals except calcium, which was determined by flame atomic absorption spectrometry. The complete microbiological and analytical procedures are described. Uptake curves as a function of moles per cell, of moles per dry weight of a cell, and of percent available are reported. The data show that these metals seem to be required for growth. No attempts were made to postulate the roles played by these metals. 

In a few bacterial genera, notably Bacillus and Clostridium, a unique process takes place in which the vegetative cell undergoes a profound biochemical change to give rise to a specialized structure called an endospore or spore (Fig. 3.6). This process of sporulation is not part of a reproductive cycle,... 

Bacterial spores of the genera Bacillus and Clostridium are invariably the most resistant of all types of bacteria to biocides. Many biocides, e.g. biguanides and QACs, will kill (or at low concentrations be bacteriostatic to) non-sporulating bacteria but not bacterial spores. Other biocides such as alkaline glutaraldehyde are sporicidal, although higher concentrations for longer contact periods may be necessary than for a bactericidal effect. 

Response to a biocide depends upon the cellular stage of development. Sporulation, a process in which a bacterial spore develops from a vegetative cell, involves seven stages (I—VII Chapter 3) of these, stages IV-VII (cortex and coat development) are the most important in relation to the development of biocide resistance. Resistance to biocidal agents develops during sporulation and may be an early, intermediate or late/very late event. For example, resistance to chlorhexidine occurs at an intermediate stage, at about the same time as heat... 

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