The effectiveness of current control measures against Aedes mosquitoes remains low, resulting in persistent epidemics in urban areas. The emergence of resistant mosquito populations to chemical insecticides highlights...The effectiveness of current control measures against Aedes mosquitoes remains low, resulting in persistent epidemics in urban areas. The emergence of resistant mosquito populations to chemical insecticides highlights the need for novel, environmentally friendly, cost-effective control strategies. This study explored the potential of environmental bacterial isolates to biocontrol wild Aedes larvae. Initially, we collected bacterial samples from infectious masses of Aedes fluviatilis larvae. The isolated bacteria were identified using biochemical, enzymatic, and molecular methods, including 16S rRNA sequencing and MALDI-TOF. Previously, Aeromonas hydrophila and Bacillus thuringiensis isolated from these infectious masses showed limited Aedes larval inhibition. Consequently, we screened additional environmental isolates from the bacteriotheque. Six isolates previously identified were tested: Chromobacterium violaceum, Enterobacter cloacae, Bacillus cereus, Bacillus sphaericus, and two strains of Bacillus thuringiensis israelensis. Among these strains, B. thuringiensis and C. violaceum exhibited significant inhibitory activities against wild Aedes larvae. Bacillus thuringiensis cultures grown under daylight conditions showed a slight ability to inhibit Aedes larvae. The potential of B. thuringiensis and C. violaceum strains studied, along with optimized culture growth conditions, will be further investigated to develop bioinsecticide products to provide safer and more sustainable alternatives for controlling larvae of Aedes mosquitoes.展开更多
为了筛选对瓜类果斑病(acterial fruit blotch,BFB)具有良好拮抗效果的生防细菌,本研究从黑龙江马铃薯根际土壤中分离得到一株对西瓜噬酸菌Acidovorax citrulli具有显著抑制效果的生防菌株ZF509。经形态学观察、生理生化特征、Biolog测...为了筛选对瓜类果斑病(acterial fruit blotch,BFB)具有良好拮抗效果的生防细菌,本研究从黑龙江马铃薯根际土壤中分离得到一株对西瓜噬酸菌Acidovorax citrulli具有显著抑制效果的生防菌株ZF509。经形态学观察、生理生化特征、Biolog测定和多基因系统发育树分析,鉴定菌株ZF509为防御假单胞Pseudomonas protegens。经抑菌谱分析,菌株ZF509对4种病原细菌、8种病原真菌具有显著拮抗作用。经酶活检测和抑菌物质分析,ZF509具有溶磷能力,可分泌蛋白酶,合成生物膜,产生氢氰酸,具备2-羟基、2,4-DAPG、藤黄绿脓菌素以及吡咯菌素4种抑菌物质的合成编码基因。盆栽试验结果表明,接种ZF509的处理果斑病发病的病情指数显著降低,防效可达73.46%,显著优于对照药剂噻霉酮处理。综上所述,菌株ZF509对瓜类细菌性果斑病具有良好的生防潜力和应用前景。展开更多
产铁载体细菌通过与病原菌竞争铁元素而具有良好的生防效果。本研究从人参根组织及根际土壤中分离细菌,对其抑菌作用和产铁载体能力进行筛选,并对所筛选的1株菌株进行发酵条件的单因素和响应面优化。结果表明,共分离得到细菌菌株207株,...产铁载体细菌通过与病原菌竞争铁元素而具有良好的生防效果。本研究从人参根组织及根际土壤中分离细菌,对其抑菌作用和产铁载体能力进行筛选,并对所筛选的1株菌株进行发酵条件的单因素和响应面优化。结果表明,共分离得到细菌菌株207株,其中8株菌株既具有产铁载体的能力又对人参黑斑、根腐和锈腐病菌具有良好抑制作用;经筛选发现菌株GR-39在限铁、富铁培养基上对黑斑病菌抑菌作用差异显著,并鉴定该菌株为普城沙雷氏菌Serratiaplymuthica。通过单因素试验确定菌株GR-39在蔗糖、蛋白胨5 g/L、温度34℃、p H 8时产铁载体相对含量为74.6%;通过响应面法建立了铁载体量与自变量的回归模型,得出最佳发酵条件为蔗糖6 g/L、蛋白胨5 g/L、p H 8时铁载体产量最大达77.13%。研究表明,菌株GR-39具有较强产铁载体能力并且对人参黑斑病菌防效显著,可为多功能微生物菌剂研制提供良好菌种资源。展开更多
文摘The effectiveness of current control measures against Aedes mosquitoes remains low, resulting in persistent epidemics in urban areas. The emergence of resistant mosquito populations to chemical insecticides highlights the need for novel, environmentally friendly, cost-effective control strategies. This study explored the potential of environmental bacterial isolates to biocontrol wild Aedes larvae. Initially, we collected bacterial samples from infectious masses of Aedes fluviatilis larvae. The isolated bacteria were identified using biochemical, enzymatic, and molecular methods, including 16S rRNA sequencing and MALDI-TOF. Previously, Aeromonas hydrophila and Bacillus thuringiensis isolated from these infectious masses showed limited Aedes larval inhibition. Consequently, we screened additional environmental isolates from the bacteriotheque. Six isolates previously identified were tested: Chromobacterium violaceum, Enterobacter cloacae, Bacillus cereus, Bacillus sphaericus, and two strains of Bacillus thuringiensis israelensis. Among these strains, B. thuringiensis and C. violaceum exhibited significant inhibitory activities against wild Aedes larvae. Bacillus thuringiensis cultures grown under daylight conditions showed a slight ability to inhibit Aedes larvae. The potential of B. thuringiensis and C. violaceum strains studied, along with optimized culture growth conditions, will be further investigated to develop bioinsecticide products to provide safer and more sustainable alternatives for controlling larvae of Aedes mosquitoes.
基金云南省万人计划“云岭学者”项目(YNWR-YLXZ-2018-018)国际原子能机构(International Atomic Energy Agency)项目“An IntegrativeApproach to Enhance Disease Resistance Against Fusarium Wilt(Foc TR4)in Banana–Phase II”(D23033-26673)。
文摘为了筛选对瓜类果斑病(acterial fruit blotch,BFB)具有良好拮抗效果的生防细菌,本研究从黑龙江马铃薯根际土壤中分离得到一株对西瓜噬酸菌Acidovorax citrulli具有显著抑制效果的生防菌株ZF509。经形态学观察、生理生化特征、Biolog测定和多基因系统发育树分析,鉴定菌株ZF509为防御假单胞Pseudomonas protegens。经抑菌谱分析,菌株ZF509对4种病原细菌、8种病原真菌具有显著拮抗作用。经酶活检测和抑菌物质分析,ZF509具有溶磷能力,可分泌蛋白酶,合成生物膜,产生氢氰酸,具备2-羟基、2,4-DAPG、藤黄绿脓菌素以及吡咯菌素4种抑菌物质的合成编码基因。盆栽试验结果表明,接种ZF509的处理果斑病发病的病情指数显著降低,防效可达73.46%,显著优于对照药剂噻霉酮处理。综上所述,菌株ZF509对瓜类细菌性果斑病具有良好的生防潜力和应用前景。
文摘产铁载体细菌通过与病原菌竞争铁元素而具有良好的生防效果。本研究从人参根组织及根际土壤中分离细菌,对其抑菌作用和产铁载体能力进行筛选,并对所筛选的1株菌株进行发酵条件的单因素和响应面优化。结果表明,共分离得到细菌菌株207株,其中8株菌株既具有产铁载体的能力又对人参黑斑、根腐和锈腐病菌具有良好抑制作用;经筛选发现菌株GR-39在限铁、富铁培养基上对黑斑病菌抑菌作用差异显著,并鉴定该菌株为普城沙雷氏菌Serratiaplymuthica。通过单因素试验确定菌株GR-39在蔗糖、蛋白胨5 g/L、温度34℃、p H 8时产铁载体相对含量为74.6%;通过响应面法建立了铁载体量与自变量的回归模型,得出最佳发酵条件为蔗糖6 g/L、蛋白胨5 g/L、p H 8时铁载体产量最大达77.13%。研究表明,菌株GR-39具有较强产铁载体能力并且对人参黑斑病菌防效显著,可为多功能微生物菌剂研制提供良好菌种资源。
