棉花黄萎病拮抗细菌产铁载体测定及其对抑菌活性的影响

Determination of the siderophore produced by antagonistic cotton Verticillium wilt bacteria and its effect on antibacterial activity

摘要:

【背景】棉花是新疆农业的支柱产业，棉花黄萎病严重影响棉花产量和纤维品质，有效的防治途径是目前解决的首要任务。【目的】探究Bacillus velezensis BHZ-29、Bacillus atrophaeus SHZ-24、Bacillus subtilis SHT-15、Bacillus vanillea SMT-24菌株产铁载体能力及其对抑菌活性的影响。【方法】MKB-CAS双层平板检测铁载体，Arnow法与高氯酸铁法鉴定铁载体类型，CAS染液定量铁载体，琼脂扩散法测定低铁条件下铁载体对抑菌物质的影响。【结果】MKB-CAS固体平板菌体周围出现橙紫色显色反应，Arnow 实验4株拮抗菌反应液颜色为红色，高氯酸铁实验反应液颜色为黄色；BHZ-29、SHZ-24、SHT-15、SMT-24菌株铁载体定量活性单位最大值分别为8.27%±0.61%、31.80%±2.06%、16.06%±3.61%、15.53%±0.51%，吸光度值As/Ar比值最小分别为0.917±0.092、0.682±0.021、0.845±0.005、0.846±0.008。BHZ-29、SHZ-24、SMT-24菌株含铁离子浓度0、10、20 μmol/L 3组处理发酵无菌滤液均未出现抑菌圈，SHT-15菌株3组处理出现抑菌圈，抑菌圈直径大小无差异性。【结论】4株拮抗菌株均产铁载体，铁载体类型为儿茶酚型，4株拮抗菌株整体产铁载体能力较低，最高达31.80%±2.06%，产铁能力As/Ar比值高于0.682时，BHZ-29、SHZ-24、SMT-24菌株含铁离子浓度0、10、20 μmol/L 3组处理发酵无菌滤液对抑菌活性无影响，SHT-15菌株3组不同铁离子浓度处理对抑菌物质影响差异不显著。

Abstract:

[Background] Cotton plays a key role in Xinjiang’s agriculture, but cotton production and fiber quality are seriously affected by Verticillium dahliae, effective prevention and control approaches are the primary tasks to be solved. [Objective] To study the ability of Bacillus velezensis BHZ-29, Bacillus atrophaeus SHZ-24, Bacillus subtilis SHT-15 and Bacillus vanillea SMT-24 to produce siderophore and siderophore’s effects on antibacterial activity. [Methods] MKB-CAS double-layer plate was used to detect siderophore, Arnow method and iron perchlorate method were used to identify the type of siderophore, CAS dye liquid quantitative siderophore and agar diffusion method was used to determine the effect of siderophore on antibacterial substances under low iron conditions. [Results] An orange-purple color appeared around the bacteria on the MKB-CAS solid plate, Solutions color of the four antagonistic antibiotics in the Arnow experiment was red and perchlorate reaction solutions was yellow. The maximum values of quantitative activity units of siderophore of BHZ-29, SHZ-24, SHT-15 and SMT-24 strains were 8.27%±0.61%, 31.80%±2.06%, 16.06%±3.61%, and 15.53%±0.51%, respectively, the absorbance values of As/Ar the smallest ratios were 0.917±0.092, 0.682±0.021, 0.845±0.005 and 0.846±0.008, respectively. No inhibitory zone appeared in the 0, 10 and 20 μmol/L iron ion treatment groups of BHZ-29, SHZ-24 and SMT-24 strains, in three treatment groups of SHT-15 strains had inhibition zones, but there was no difference in the diameter of the inhibition zone. [Conclusion] The four strains of antagonistic bacteria were all siderophore-producing, the type of siderophore was catechol, and the four antagonistic strains had low siderophore-producing ability, with a maximum of 31.80%±2.06%, when the siderophore-producting capacity of As/Ar ratio was higher than 0.682, BHZ-29, SHZ-24 and SMT-24 fermentation sterile filtrates with 0, 10 and 20 μmol/L iron ions, had no effect on the antibacterial activity, SHT-15 fermentation sterile filtrates with 0, 10 and 20 μmol/L had no significant difference in the effect of antibacterial substances.