不同磷、硫及二氧化碳浓度对标志链带藻生长和碳水化合物积累的影响

Effects of phosphorus, sulfur and carbon dioxide concentrations on growth and carbohydrate accumulation of Desmodesmus insignis

摘要:

[目的]为了研究不同磷、硫及二氧化碳浓度对标志链带藻（Desmodesmus insignis）生长与碳水化合物积累的影响，本实验以改良BG11培养基为基础，设计了8种不同初始K₂HPO₄浓度、8种不同初始MgSO₄浓度及4种二氧化碳浓度培养标志链带藻。[方法]采用干重法和苯酚-硫酸法分别测定其生物质浓度与总碳水化合物的含量。[结果]实验结果显示，在高磷浓度（0.460 mmol/L）下生物量达到最高为6.37 g/L，磷浓度为0.230 mmol/L（对照组）时总碳水化合物含量及单位体积产率达到最高，分别为45.40%（%干重）和0.20 g/（L·d）。不同初始MgSO₄浓度实验结果显示，高硫浓度有利于标志链带藻生长及碳水化合物的积累，生物量、总碳水化合物含量及单位体积产率分别在硫浓度为1.217 mmol/L、0.609 mmol/L和1.824 mmol/L时达到最高，分别为7.02 g/L、51.6%（%干重）及0.26 g/（L·d）。当二氧化碳浓度为3%（V/V）时，标志链带藻生物量、总碳水化合物含量及单位体积产率均达到最高，分别为6.81 g/L、44.03%和0.20 g/（L·d）。[结论]因此，磷浓度为0.230 mmol/L、硫浓度为1.824 mmol/L和二氧化碳浓度为3%时最有利于标志链带藻生长及碳水化合物的积累。

关键词:标志链带藻;磷;硫;二氧化碳;生物质;碳水化合物

Abstract:

[Objective] To determine the effect of concentrations of P, S and CO₂ on the growth and total carbohydrate accumulation of Desmodesmus insignis, the algae were cultivated in modified BG-11 medium containing 8 different initial phosphorus and sulfur concentrations and 4 different carbon dioxide concentrations. [Methods] Biomass and total carbohydrate content were measured by dry weight and phenol-sulfuric acid method, respectively. [Results] The highest biomass concentration reached 6.37 g/L under 0.460 mmol/L K₂HPO₄ and the maximum content and productivity of carbohydrate was 45.40% of dry weight and 0.20 g/(L·d) under 0.230 mmol/L K₂HPO₄, respectively. High MgSO₄ concentration could promote the growth and carbohydrate accumulation of Desmodesmus insignis. The highest biomass concentration and the maximum content and productivity of carbohydrate were achieved at 1.217 mmol/L, 0.609 mmol/L and 1.824 mmol/L MgSO₄, which was 7.02 g/L, 51.60% of dry weight and 0.26 g/(L·d), respectively. In addition, the highest biomass concentration and the maximum content and productivity of carbohydrate were 6.81 g/L, 44.03% and 0.20 g/(L·d) when 3% (V/V) CO₂ was used. [Conclusion] Thus, the concentrations of P, S and CO₂ which were beneficial to the growth and carbohydrate accumulation were 0.230 mmol/L, 1.824 mmol/L and 3% (V/V), respectively.

Key words:Desmodesmus insignis;phosphorus;sulfur;carbon dioxide;biomass;carbohydrate