Flagella-generated fluid stirring has been suggested to enhance nutrient uptake for sufficiently large micro-organisms, and to have played a role in evolutionary transitions to multicellularity. A corollary to this predicted size-dependent benefit is a propensity for phenotypic plasticity in the flow-generating mechanism to appear in large species under nutrient deprivation. We examined four sp...

Cellular nutrient consumption is influenced by both the nutrient uptake kinetics of an individual cell and the cells' spatial arrangement. Large cell clusters or colonies have inhibited growth at the cluster's center due to the shielding of nutrients by the cells closer to the surface. We develop an effective medium theory that predicts a thickness ℓ of the outer shell of cells in the cluster t...

Bacteria often encounter environments where nutrient availability is limited, and they must adapt accordingly. To identify Pasteurella multocida genes that are differentially expressed during nutrient limitation, we utilized whole-genome microarrays to compare levels of gene expression during growth in rich and minimal media. Our analysis showed that the levels of expression of a total of 669 g...

The application of controlled-release fertilizers (CRF) at the time of planting offers a means to improve the establishment of forest tree seedlings. As compared to conventional fertilizers, the gradual pattern of nutrient release from CRF may better coincide with plant needs, minimize leaching, and improve fertilizer use efficiency. Many different CRF types are available and products differ in...

Modeling under the framework of ecological stoichiometric allows the investigation of the effects of food quality on food web population dynamics. Recent discoveries in ecological stoichiometry suggest that grazer dynamics are affected by insufficient food nutrient content (low phosphorus (P)/carbon (C) ratio) as well as excess food nutrient content (high P:C). This phenomenon is known as the "...

The use of nitrogen in nutrient media is essential for growth and helps identify highly productive media for potato (Solanum tuberosum L.) micropropagation and adventitious shoot formation. Three potato cultivars (Agria, Marfona and Savalan cultivars) were examined for their growth response with medium containing four different levels of KNO3 (1, 1.25, 1.5 and 1.75 times as much 1.9 g l-1) and ...