Nutrient limitations

Smith, S. V., Kimmerer, W. J., and Walsh, T. W. (1986). Vertical flux and biogeochemical turnover regulate nutrient limitation of net organic production in the North Pacific Gyre. Limnol. Oceanogr. 31, 161-167. 

The majority of PH As biosynthesis is performed by various microorganisms, especially bacteria. They can produce PHAs from a number of substrates and accumulate in their cells as carbon source and energy reserve under imbalanced growth conditions such as nutrient limitation. Fig.7 shows PHA accumulated in their cells that are characterized by transmission electron microscopic (TEM) technique. 

Kluiyama H. Slaughter J.C. (1995) Control of cell morphology of die yeast Saccharomyces cerevisiae by nutrient limitation in continuous culture. LettApplMicrobiol, 20, 37-40. 

Apart from nutrient limitation and diminished growth rates, another reason for this decreased susceptibility is the prevention of access of a biocide to the underlying cells. Thus, in this mechanism, the glycocalyx as well the rate of growth of the biofilm micro-eolony in relation to the diffusion rate of the biocide across the biofilm, can affect susceptibility. A possible third mechanism involves the increased production of degra-dative enzymes by attached cells, but the importance of this has yet to be determined. 

The role of Cu, Ni, Mo, and W are discussed in the context of metalloenzymes in Chapter 3, Part 5. Only two examples of the importance of nutrient limitation in determining the realization of biodegradation are noted here ... 

Lewis DL, HP Kollig, RE Hodson (1986) Nutrient limitation and adaptation of microbial populations to chemical transformations. Appl Environ Microbiol 51 598-603. 

What the UDC-GV model has shown is that plants grown in nutrient-limited conditions could downregulate their growth rate in response to nutrient deficiency and still produce predictions that validate the model at least as well as the original analysis. It is extremely unlikely that the very simple and direct... 

In order to understand current approaches for prevention and control of biofilms, we must first consider the reasons for the failure of conventional antimicrobial protocols. There are thought to be three main reasons as to why biofilm bacteria out-survive their planktonic counterparts during antimicrobial treatments (reviewed by McBain et a/.16).These are i) poor penetration of antimicrobial compounds due to the presence and turn-over of exopolymer slime (glycocalyx) ii) the imposition of extreme nutrient limitation within the depths of the biofilm community and the co-incident expression of metabolically-dormant, recalcitrant phenotypes and (iii) the expression of attachment-specific phenotypes that are radically different and intrinsically less susceptible than unattached ones. 

Mills and colleagues58 describe the use of these formulations to predict aerobic biodegradation in surface waters and present methods of adjusting for temperature and nutrient limitations. This approach to predicting biodegradation is problematic because it is difficult to obtain empirical coefficients in the deep-well setting. 

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... 

The polymerase can occur in either a soluble (hydrophilic) or a granule-bound (hydrophobic) form, depending on prevailing conditions of life. During growth under carbon substrate limitation, the enzyme exists mainly in the soluble state, and after transfer to nutrient-limiting conditions, e.g., ammonium limitation, the granule-associated polymerase appears (for review see [25]). 

Oligotroph an organism with optimal growth in nutrient-limited conditions. 

Giisewell S (2004) N P ratios in terrestrial plants variation and functional significance. New Phytol 164 243-266. doi http //www.blackwell-synergy.com/doi/abs/10. Ill 1/j. 1469-8137.2004.01192.x Giisewell S, Bailey KM, Roem WJ, Bedford BL (2005) Nutrient limitation and botanical diversity in wetlands can fertilisation raise species richness Oikos 109 71-80. doi http //www.black-well-synergy.com/doi/abs/10.1111/j.0030-1299.2005.13587.x Halsted M, Lynch J (1996) Phosphorus responses of C3 and C4 species. J Exp Bot 47 497-505. 

It is often necessary to dose nutrients into the bioprocess to achieve a good performance. However, this leads to nutrients entering the whitewater system with the reused water. As microbial activities in the whitewater systems are generally nutrient limited, the increased supply of nutrients may lead to a considerably increased growth of microorganisms and increased slime problems, rather than the decrease that is the aim of biotreatment [81]. 

Button, D. K. (1985). Kinetics of nutrient-limited transport and microbial-growth,... 

Morgenroth E, Schroeder ED, Chang DPY, et al. 1996. Nutrient limitation in a compost biofilter degrading hexane. J Air Waste Management Association 46 300-308. 

Nostoc was attributed to a putative antibiotic released during the stationary phase of colony growth, suggesting that this may be an inducible allelopathic response to nutrient limitation (Schagerl et al. 2002). 

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