MULTIPHASIC KINETICS FOR D-GLUCOSE UPTAKE BY ASSEMBLAGES OF NATURAL MARINE-BACTERIA
MULTIPHASIC KINETICS FOR D-GLUCOSE UPTAKE BY ASSEMBLAGES OF NATURAL MARINE-BACTERIA
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DOI：
10.3354/meps006213
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发表时间：
1981-01-01
影响因子：
2.5
通讯作者：
HODSON, RE
中科院分区：
文献类型：
--
作者：
AZAM, F;HODSON, RE
D-葡萄糖-6-[3 H]海洋微生物组合的吸收动力学是多相的动力学时，确定了一个广泛的浓度范围（10-9至10-3 M）。最大摄取速率（Vmax）和1/2饱和常数（Kt）与环境葡萄糖浓度（Sn）之和（Kt + Sn）随葡萄糖浓度范围的增大而逐渐增大。在所有检验的海水样品中，最低（Kt + Sn）值为2-5 × 10 - 6。10-9 M;最高值高达5.9 × M。10-4 M.简单的扩散进入藻类或细菌不能解释动力学曲线的非线性。去除大多数藻类细胞并不改变动力学模式，并且扩散到细菌中的间接估计太小而不能极大地改变1 × 10 - 5中的摄取。10-9-1 ×10-5葡萄糖的M范围。海洋细菌组合的动力学多样性的循环中的溶解的有机物在不同的浓度制度可能存在于生产微区的影响。葡萄糖池在高浓度下的周转时间约为101-103 h，表明在显著吸收之前，偶发性高浓度底物将扩散出生产微区。持续的浓度梯度可能会吸引高Kt高Vmax的细菌，这些细菌可能会占据生产区内相当大一部分的底物。所观察到的动力学多样性点需要一个修改的动力学方法来解释的多样性Kt和Vmax。
D-Glucose-6-[3H] uptake kinetics for marine microbial assemblages were multiphasic when the kinetics were determined over a broad concentration range (10-9 to 10-3 M). Maximum uptake velocity (Vmax) and the sum of 1/2 saturation constant (Kt) and ambient glucose concentration (Sn), (Kt + Sn), increased gradually as the range of glucose concentration was increased. In all seawater samples examined the lowest (Kt + Sn) values were 2-5 .times. 10-9 M; highest values were as high as 5.9 .times. 10-4 M. Simple diffusion into algae or bacteria can not explain the non-linearity of kinetics curves. Removal of most algal cells did not change the kinetic pattern and indirect estimates of diffusion into bacteria were too small to have greatly changed the uptake in 1 .times. 10-9-1 .times. 10-5 M range of glucose. The kinetic diversity of marine bacterial assemblages has implications in the cycling of dissolved organic matter in the varied concentration regimes presumably present in production microzones. Turnover times of the glucose pool at elevated concentrations were in the order of 101-103 h, suggesting that episodic high concentrations of substrate would diffuse out of the production microzones before significant uptake. Sustained concentration gradients might attract high Kt high Vmax bacteria which might take up a significant fraction of substrate within the production zone. The observed kinetic diversity points to the need for a modified kinetic approach to account for the diversity of Kt and Vmax.