乳酸菌对海水中铅离子的吸附作用

Adsorption of Lead Ions in Seawater by Lactic Acid Bacteria

【目的】分析德式乳杆菌、嗜热链球菌及屎肠球菌3种不同乳酸菌对海水中铅离子的吸附作用影响。【方法】采用原子吸收分光光度计法测定海水中铅的含量,并通过计算乳酸菌对重金属铅的吸附率及单位菌体吸附量分析乳酸菌对铅的吸附性能。【结果】菌液加入海水6 h后,屎肠球菌的吸附率最大为80.85%,嗜热链球菌的吸附率最大为51.73%,德式乳杆菌的吸附率为19.97%;6~48 h内,随着吸附时间的延长,3种乳酸菌对海水中铅离子的吸附率和吸附量均呈先降后升的趋势。当投菌量为10 g/L时,屎肠球菌的吸附率和单位菌体吸附量分别为88.31%和2.48mg/g,增大投放量,吸附率上升不显著;当投菌量为40g/L时,屎肠球菌、德式乳杆菌及嗜热链球菌对铅离子的吸附率均达到最大,分别为95.04%、83.73%及83.25%。当铅离子浓度为150 mg/L时,德式乳杆菌的吸附率和单位菌体吸附量均较高时分别为40.18%和2.26mg/g;嗜热链球菌的吸附率和单位菌体吸附量均较高时分别为48.33%和8.15 mg/g;屎肠球菌的吸附率和单位菌体吸附量均较高时分别为62.90%和3.53 mg/g。【结论】屎肠球菌在3种乳酸菌中对铅的吸附效果最好,当屎肠球菌生物投放量为10g/L、海水中铅离子浓度为150mg/L,6 h后即可达到最大吸附量。

【Objective】The adsorption properties of lead ions in seawater by Lactobacillus delbrueckii,Streptococcus thermophilus and Enterococcus faecium were studied.【Method】The concentration of lead in seawater was detected by the atomic absorption spectrophotometer and the adsorption capacity of lactic acid bacteria to lead was analyzed by calculating the adsorption rate and adsorption capacity per unit of bacteria of heavy metal lead by lactic acid bacteria.【Result】The results showed that the maximum adsorption rates of Streptococcus thermophilus were 80.85%and 51.73%respectively within 6 hours since inocula was added to the seawater,and the adsorption rate of Lactobacillus delbrueckii was only 19.97%.The adsorption rate and adsorption capacity of lead ions by the three lactic acid bacteria decreased at first and then increased with the prolongation of adsorption time within 6—48 hours.The adsorption rate and unit bacterial adsorption capacity of Enterococcus faecium were 88.31%and 2.48 mg/g respectively,but the adsorption rate wasn’t significantly increased when the concentation of lactic acid bacteria was 10 g/L.The adsorption rates of lead ion by Enterococcus faecium,Lactobacillus delbrueckii and Streptococcus thermophilus reached the highest,which were 95.04%,83.73%and 83.25%respectively with the 40 g/L concentration of lactic acid bacteria.When the concentration of lead ion was 150 mg/L,the adsorption rate and unit bacterial adsorption capacity of Lactococcus faecium were 40.18%and 2.26 mg/g,and those of Streptococcus thermophilus 48.33%and 8.15 mg/g respectively,and those of Enterococcus faecium were 62.90%and 3.53 mg/g respectively when the adsorption rate and unit bacterial adsorption capacity of Enterococcus faecium were both higher.【Conclusion】Enterococcus faecium had the best adsorption effect on lead among the three kinds of lactic acid bacteria by comparing the adsorption properties of the three kinds of lactic acid bacteria.When the biomass of Enterococcus faecium was 10 g/L with the concentration of lead ion in seawater was 150 mg/L,the maximum adsorption capacity can be reached after 6 hours.