Button D K, Robertson B R
Institute of Marine Science, University of Alaska, Fairbanks 99775.
Cytometry. 1989 Sep;10(5):558-63. doi: 10.1002/cyto.990100511.
The two primary kinetic constants for describing the concentration dependency of nutrient uptake by microorganisms are shown to be maximal rate of substrate uptake and, rather than the Michaelis constant for transport, specific affinity. Of the two, the specific affinity is more important for describing natural aquatic microbial processes because it can be used independently at small substrate concentrations. Flow cytometry was used to evaluate specific affinities in natural populations of aquatic bacteria because it gives a convenient measure of biomass, which is an essential measurement in the specific-affinity approach to microbial kinetics. Total biomass, biomass in various filter fractions, and the specific affinity of the bacteria in each fraction were determined in samples from a near-arctic lake. The partial growth rate of the pelagic bacteria from the 25 micrograms/liter of dissolved amino acids present (growth rate from the amino acid fraction alone) was determined to be 0.78 per day. By measuring activity in screened and whole-system populations, the biomass of the bacteria associated with particles was computed to be 427 micrograms/liter.
描述微生物对营养物质摄取的浓度依赖性的两个主要动力学常数分别是底物摄取的最大速率，以及比亲和力，而非转运的米氏常数。在这两者中，比亲和力对于描述天然水生微生物过程更为重要，因为在低底物浓度下它可以独立使用。流式细胞术被用于评估水生细菌自然种群中的比亲和力，因为它能方便地测量生物量，而生物量是微生物动力学比亲和力方法中的一项基本测量指标。在取自近北极湖泊的样本中，测定了总生物量、不同过滤级分中的生物量以及各部分细菌的比亲和力。根据存在的25微克/升溶解氨基酸计算得出的远洋细菌的部分生长速率（仅来自氨基酸部分的生长速率）为每天0.78。通过测量筛选种群和整个系统种群中的活性，计算得出与颗粒相关的细菌生物量为427微克/升。
