Acorus calamus root extracts to control harmful cyanobacteria blooms

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• 作者：Sheng-hua Zhang^a ; ^{zhangshenghua@yahoo.com" class="auth_mail" title="E-mail the corresponding author} ; ^{shhzhang@aliyun.com" class="auth_mail" title="E-mail the corresponding author} ; Shi-yang Zhang^c ; Gu Li^b ; ^{ligu@yfi.ac.cn" class="auth_mail" title="E-mail the corresponding author}
• 关键词：Acorus calamus ; Microcystis aeruginosa ; Algal control ; Water quality
• 刊名：Ecological Engineering
• 出版年：2016
• 出版时间：September 2016
• 年：2016
• 卷：94
• 期：Complete
• 页码：95-101
• 全文大小：779 K

文摘

Small ponds often suffer from the overgrowth of harmful algae (including cyanobacteria), and few safe methods exist for the rapid suppression of these harmful algae blooms in situ. Since laboratory studies indicated that cyanobacteria could be inhibited by Acorus calamus roots extracts, we evaluated the application of the extracts in natural water column. Besides, we also considered the shifts of algal community structures in extracts-treated enclosures. There were 65 algal species existed in pond before the addition of extracts, which belonged to six phyla: Cyanophyta, Chlorophyta, Cryptophyta, Xanthophyta, Bacillariophyta and Euglenophyta. The water bloom belonged to Microcystis bloom because the algal community was dominated by Microcystis aeruginosa with the abundance of 23.3 × 10⁴ cells mL⁻¹. After A. calamus roots extracts addition, The total algal biomass decreased sharply. In the 20, 50 and 100 mg L⁻¹ extracts-treated enclosures, the removal percentages of the algae were 64.5%, 92.7% and 94.6% after 3 days, respectively. The total algal biomass and Chl a concentration decreased more than 90% for 7 days, and the decrease ratios lasted till the end of 30 days experiment. And at the end of 30 days experiment, the Simpson index (D), Shannon-Weaver index (H’) and Pielou index (E) of the algae community in three treatments were all higher than that of calculated in the controls. The predominant species in algal community shifted from cyanobacteria to Chlorophyta and Bacillariophyta in the extracts-treated enclosures. Furthermore, the biomass of cyanobacteria did not recover, while the Chlorophyta and Bacillariophyta showed slight recovery. During the first week, the COD_Mn increased obviously in the extracts-treated and control 2 (with ethanol) enclosures. Moreover, the concentration of TN increased slightly in the 50 and 100 mg L⁻¹ extracts-treated enclosures in the 1 st day. And in the end of the experiment, the concentrations of TN and I_Mn in the three extracts-treated enclosures tended to be consistent with two controls. The initial slight negative effects of the extracts on the water quality eliminated over time. Overall, the antialgal-activity of the extracts showing in pond is encouraging from the applied perspective of using A. calamus roots extracts as natural agent(s) to manage harmful cyanobacteria (Microcystis) blooms.