Bacteria spores

In adverse conditions, some bacteria can enter a dormant state known as a spore. Spores can remain dormant for decades and can survive under extreme temperatures and other adverse environmental conditions. Unlike fungi (Chapter 20), formation of spores is not related to reproduction and is done strictly as a protective mechanism. Upon reactivation, each spore produces a single active bacteria. Spores are normally spherical or oval and are only a fraction of the size of the active (i.e., vegetative) cell. 

Surface disinfectants Compounds containing phenolics, chlorhexidine (not effective against bacteria spores), quaternary ammonium salts (additional activity if bis-n-tributyltin oxide present), hypochlorites such as household bleach, alcohols such as 70-95% ethanol and isopropyl (not effective against bacteria spores), potassium peroxymonosulfate, hydrogen peroxide, iodine/iodophores, and triclosan. 

Fig. 15.26 The effect of applying positive (A) and negative (B) potential to the metal layer of the MCLW sensor on deposition and repulsion of different concentrations of BG bacteria spores. Reprinted from Ref. 22 with permission. 2008 The Royal Society of Chemistry...

The integrated system has been tested for enhancement of bacterial capturing by introducing a solution of bacteria spores (concentration of 106 cells per mL) at 200 pL min 1 flow rate into the flow cell. Here, a small number of spore clumps were observed forming in the central region of the chamber when the ultrasound (0.5 V at 1.92-MHz frequency) was turned on. The clumps were held stationary... 

The peroxygen compounds, hydrogen peroxide and peracetic acid, have high killing activity and a broad spectrum against bacteria, spores, viruses, and fungi when used in appropriate concentration. They have the advantage that their decomposition products are not toxic and do not injure the environment. They are powerful oxidizers that are used primarily as disinfectants and sterilants. 

Examples of especially dry environments on Earth include the Atacama Desert of northern Chile and the Dry Valleys of Antarctica. Dose et al. (2001) exposed spores, conidia, and cells of several microbes to 15 months of desiccation in the dark at two locations of the Atacama Desert. Bacillus subtilis (bacteria) spores (survival 15%) and Aspergillus niger (fungi) conidia (survival 30%) outlived other species. Deinococcus radiodurans (bacteria) did not survive the desert exposure because they were readily killed at RH between 40% and 80%, which occurred during desert nights (Dose et al. 2001). 

Raman spectroscopy can be used to analyse aqueous biological and bio-organic samples e.g., bacteria, spores, diseased tissues, neurotransmitters,... 

Bacterial resistance to antibiotics and biocides is essentially of two types, intrinsic and acquired. Whilst the latter is of greater significance clinically with antibiotics, specific examples of intrinsic resistance to both antibiotics, e.g. mycobacteria, and biocides (e.g. mycobacteria, Gram-negative bacteria, spores) are also of importance. 

Same laser for Raman and one optical tweezers 785 nm 2,6-pyridine dicarboxylic acid (Ca-DPA) in bacteria spores Ca-DPA at 1,017 cm Raman spectra of the Ca-DPA peak can be used as quantitative standard measure to reveal concentration and characteristic spore information... 

Chlorocresol is used as an antimicrobial preservative in cosmetics and pharmaceutical formulations. It is generally used in concentrations up to 0.2% in a variety of preparations except those intended for oral administration or that contact mucous membrane. Chlorocresol is effective against bacteria, spores, molds, and yeasts it is most active in acidic media. Preservative efficacy may be reduced in the presence of some other excipients, particularly nonionic surfactants, see Sections 10 and 12. 

Chlorhexidine has broad-spectrum antibacterial activity hut is not active against acid-fast bacteria, spores, or viruses. It has been used for such topical uses as preoperative. skin disinfection, wound irrigation, mouthwashes, and general sanitiration. Chlorhexidine is not absorbed through skin or mucous membranes and docs not cause systemic toxicity. 

UV can cause permanent inactivation of virus, bacteria, spores, fungi and other pathogens. UV irradiation disinfection requires no additional chemicals. Unlike chlorination disinfection, it does not produce odor it is usually deemed as the best choice with very low or no DBFs and no residual toxicity. In addition, it is able to kill some chlorine-resistant pathogens such as Cryptosporidium and Giardia. Compared with other disinfection alternatives, UV is a cost-effective, clean, and simple approach. UV disinfection system does not require the transportation, storage, and handling of regulated chemicals such as chlorine. 

Giant DRV Liposome Entrapped particulate material is separated from nonentrapped Separation from material (bacteria spores, etc.) by sucrose gradient centrifugation. 

Shortly after their development in the 1940s, antibiotics were used in veterinary medicine, first to prevent or treat mastitis in cows and later for the treatment of other diseases. Initial concern about antibiotic residues in milk was not a public health issue but came from dairy processors who noticed inhibition of starter cultures used in the production of cheese and yogurt, thus generating a need for screening tests to examine milk for antibiotic residues. " Since inhibition of starter cultures by penicillin in milk was the main problem, the earliest microbial inhibition assays were based on growth inhibition of lactic acid bacteria. Spores of Bacillus species were also utilized spores are easier to handle and far more stable than the vegetative cells. 

Despite the ongoing evolution of paper machine technology no engineering solution has yet been found for the problem of deposits. Part of the problem is that paper is still made predominantly from the pulping of trees and water from a nearby source. Even after pulping and bleaching, the fibres can still have pitch particles associated with them and similarly, untreated water may contain bacteria, spores and fungi. 

Enfors, S.O. and Molin, G. The influence of high concentrations of carbon dioxide on the germination of bacteria spores, J. Appl. BacterioL, 45, 279,1978. 

---