Multiple nutrient limited growth

The metabolic response of P. putida KT2442 producing high levels of poly-hydroxyalkanoate under single- and multiple-nutrient-limited growth highlights from a multi-level omics approach. Micrafe. Cell Fact, 11, 34. 

In the case of mcZ-PHAs, a Swiss group reports the continuous, growth-associated production of poly(3-hydroxyalkanoate-co-3-hydroxyalkenoates) in one-stage chemostat cultures of Pseudomonas putida ATCC 29147 in a single CSTR. The applied substrates encompassed 5-phenylvalerate, octanoate and 10-undecenoate. Multiple nutrient limited growth conditions were chosen at a dilution rate of D = 0.1 h . Different mixtures of the substrates in the feed resulted in the formation of copolyesters with varying compositions and different amounts of aromatic and unsaturated side chains that make the products accessible for further modification. Based on the results, the authors conclude that the steady state conditions in a continuous culture provide a strategy especially suited for the production of tailored PHA copolymers [117]. 

Klausmeier, C. A., and Litchman, E. (2004). Phytoplankton growth and stoichiometry under multiple nutrient limitation. Limnol. Oceanogr. 49, 1463—1470. 

Zinn M, Witholt B, Egh T (2001) Occurrence, synthesis and medical application of bacterial polyhydroxyalkanoate. Adv Drug DeUv Rev 53 5-21 Zinn M, Hartmann R, Pletscher E, Geiger T, Witholt B, EgU T (2002) Tailored biosynthesis of polyhydroxyalkanoate under multiple-nutrient-Umited growth conditions Zinn M, Witholt B, Egli T (2004) Dual nutrient limited growth models, experimental observations, and applications. J Biotechnol 113 263-279... 

Finally, cell-quota theory treats the entire cellular content of a nutrient as being the pool controlling growth rate (under limiting conditions), and deals with multiple nutrient interactions empirically. At the third level of description, MECHANISTIC models aim to embody realistic accounts of the main biochemical processes and pools within cells. A recent example (Flynn Hipkin, 1999 Flynn, 2001) deals with nitrogen, phosphorus, silicon and iron as well as the carbon content of cells, photosynthesis, and the uptake competition between ammonium and nitrate. However, the model embodies many parameters and there is currently insufficient information to use it to distinguish between groups or species of phytoplankters. Its characteristic nutrient quota parameters are included in Table 9.3 except for those for silicon, which are cell-based. 

These equations are based on the assumption that at any given moment the population of micro-organisms (bacteria) in a culture will multiply as long as either there is nutrient available or, the concentration of the inhibitory product is not limiting. The rate of multiplication within the biofilm will vary according to these criteria. Belkhadir et al [1988] described the fundamental growth phases in a biofilm. The growth of active biomass is assumed to have an order of zero in relation to the nutrient and an order of unity in relation to the active bacteria so that ... 

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