牛粪堆肥中溶解性有机物对铜绿微囊藻生理生化及产毒特性的影响

Effects of DOM in compost of cattle's manure on the physiological and toxin–producing characteristics of Microcystis aeruginosa FACHB905

提取牛粪堆肥中的溶解性有机物(dissolved organic matter,DOM),并将DOM转移至含有铜绿微囊藻Microcystis aeruginosa FACHB905细胞的培养液中,DOM含量以溶解性有机碳(DOC)质量浓度进行衡量,分别控制培养液中DOC的终质量浓度为0、15、30、60、90、120 mg/L(分别记为CK、T1、T2、T3、T4、T5)。通过测定藻细胞密度、色素含量和藻毒素含量,研究DOM对铜绿微囊藻生理生化及产毒特性的影响。结果表明:1)M.aeruginosa FACHB905受DOM影响,在处理后第2天,各DOM处理的细胞密度与CK相比均有所增加,T4处理的细胞密度(5.97×106个/m L)最大,比CK增加了21.67%,处理后第4天,T1、T2、T3处理均能够促进细胞生长,T2处理的细胞密度(9.23×10~6个/m L)最大,比CK增加了15.27%,而T4、T5处理抑制细胞生长,处理后第6天,仅T1及T2处理能够促进细胞生长,T1处理的细胞密度(13.34×10~6个/m L)最大,比CK增加了10.35%,而T3、T4、T5处理抑制细胞生长;2)堆肥来源DOM能够抑制藻毒素的合成,单位细胞藻毒素Microcystin–LR含量在处理后第2天T5处理的最低,比CK下降了53.13%,而Dha7–Microcystin–LR含量在处理后第4天T5处理的最低,与CK比较下降了78.51%;3)各DOM处理对单位细胞内Chl–a和Carotenoid的合成没明显影响。

Dissolved organic matter （DOM） originated from compost of cattle manure had been extracted and added to Microcystis aeruginosa FACHB905 to study its effects on the physiological and toxin-producing characteristics via the determination of cell growth, pigments content and algal toxins content. The concentration of DOM was evaluated by using dissolved organic carbon （DOC）. The final concentrations of DOC designed for cultural medium, marked as CK, T1, T2, T3, T4 and T5, were 0, 15, 30, 60, 90 and 120 mg/L, respectively. The results showed that： 1）Cell density influenced by DOM increased in treatments T1 to T5 at day 2; The maximum growth rate occurred in treatment T4 （5.97×10^ cells/mL） at day 2, with a 21.67% increase than that of CK. DOM could increase cell growth in treatments T1 to T3 but inhibit cell density in treatments T4 and T5 at day 4, the maximum growth rate occurred in treatment T2 （9.23×10^6 cells/mL） with a 15.27% increase than that of CK. DOM could only promote the cell growth in treatments T1 and T2, but inhibit cell density in treatments T3 to T5 at day 6, the maximum growth rate occurred in treatment T1 （13.34×10^6 cells/mL） with a 10.35% increase than that of CK. 2）Compost source of DOM inhibited the synthesis of algal toxins, the lowest content of Microcystin-LR in cells was occurred in treatment T5 at day 2, with a 53.13% decrease than that of CK. The lowest content of Dha7-Microcystin-LR in cells was occurred in treatment T5 at day 4, with a 78.51% decrease than that of CK. 3）There was no significant effect among DOM treatments on the synthesis of Chl-a or carotenoid in cells.