Chemotaxis of bacteria

Chapman, P. A. "Chemotaxis of Bacteria" PhD Thesis, University of Minnesota, 1973. 

Berg, H.C. and Turner, L. (1990). Chemotaxis of bacteria in glass capillary arrays. Biophys. J. 58, 919-930. 

The results in Fig. 3 compare two cases a) the model takes into account the diffusion of bacteria b) the model takes into account chemotaxis of bacteria. It is noticed that in case of chemotaxis, amount of bacteria was higher concentrated in the places where hydrogen concentration is high compared to the case when the model uses diffusion of bacteria. This physically means that more the bacteria is concentrated faster the chemical reaction (1). As a result of this phenomena, the methane gas is generated in underground hydrogen storage. 

Rabitz et al. in their first articles assumed (Reuven et al. 1986 Smooke et al. 1988 Rabitz and Smooke 1988 Vajda et al. 1990 Vajda and Rabitz 1992 Mishra et al. 1994) that the similarity of sensitivity functimis is characteristic for flame models. Zsely et al. (Zsely and Turmyi 2003 Zsely et al. 2003, 2005 Zador et al. 2004) also found the similarity of sensitivity functions for models of homogeneous explosions for several chemical systems. More recently, the similarity of sensitivity functions was detected in several biological models. Lovrics et al. (2008), for example, found such similarities in the Chen et al. (2000) model of the cell cycle of budding yeast. Danis and Turanyi (2011) found such similarities in the Rao et al. (2004) model of the chemotaxis of bacteria E. coli and B. subtilis. In the following, the results of Lovrics et al. wiU be discussed in detail. 

Hoffman LR (1960) Chemotaxis of Oedogonium sperms. Southwestern Nat 5 111-116 Holmstrom C, James S, Egan S, Kjelleberg S (1996) Inhibition of common fouling organisms by marine bacterial isolates with special reference to the role of pigmented bacteria. Biofouling 10 251-259... 

The answer lies in the attraction of bacteria to compounds that they can metabolize. Bacteria will swim toward such compounds but away from repellent substances, a response known as chemotaxis. Cells of E. coli swim toward higher concentrations of L-serine (but not of D-serine), of L-aspartate, or of D-ribose. 

Standard models for bacterial chemotaxis are based on the behavior of nonmarine enteric bacteria.196 Chemotactic behavior of nonmarine bacteria consists of discrete steps of short runs interspersed with tumbling, resulting in the random repositioning of the cells, i.e., the classical random walk. As a consequence, the net speed up a chemical gradient via the random-walk response is only a few percent of the swimming speed. The relatively slow speed and mode of chemotaxis displayed by nonmarine enteric bacteria would restrict the ability of marine bacteria to respond to chemical gradients in the sea and hence cast doubt on the importance of chemotaxis for bacteria in turbulent marine environments. 

Dusenbery, D. B., Fitness landscapes for effects of shape on chemotaxis and other behaviors of bacteria, J. Bacteriol., 180, 5978, 1998. 

Blackburn, N. and Fenchel, T., Influence of bacteria, diffusion and shear on micro-scale nutrient patches, and implications for bacterial chemotaxis, Mar. Ecol. Prog. Ser., 189, 1, 1999. 

Young, L. Y. and Mitchell, R., Negative chemotaxis of marine bacteria to toxic chemicals, Appl. Microbiol., 25, 972, 1973. 

Rgure 10. Capillary assay for positive chemotaxis. (a) A capillary containing a chemoattractant [reddish color) is placed within a bacterial suspension (the bacteria are represented by short lines). Initially the bacteria are randomly distributed In the suspension and their density is equal throughout. With time the cells concentrate near the capillary opening and then (usually after 30-60 min from the initiation of the assay in the case of E. coli and similar bacteria) they accumulate within the capillary, (b) Number of bacteria in the capillary as a function of the concentrations of a chemoattractant and of an inert chemical. 

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