Environmental and Advanced Parasitology and Vector Control Biotechnology Laboratories, Department of Zoology, Dayalbagh Educational Institute, Dayalbagh, Agra, 282 005, India.
Parasitol Res. 2010 Nov;107(6):1329-36. doi: 10.1007/s00436-010-2003-y. Epub 2010 Aug 6.
Chrysosporium keratinophilum is known to be a keratinophilic fungus and an effective mosquito control agent. This fungus was grown on Sabauraud dextrose broth in the laboratory at 25°C, while the relative humidity was maintained at 75 ± 5% for 15 days. Filtration process of metabolites was done using whatman-1 filter paper, column chromatography and flash, chromatography. Larvicidal efficacy was performed against all instars of Culex quinquefasciatus. Larvicidal efficacy was performed at six different concentrations with different effective ratios (ethanol/metabolites: 9:1, 8:2, 7:3, 6:4, 5:5, 4:6, 3:7, 2:8, and 1:9). The mortality values were then subjected by the probit analysis. The larval mortalities were observed for a period of 24, 48, and 72 h, respectively. The first and second instars were highly susceptible to 2:8 ratio. In the first instar after column chromatography, LC(50) =26.66 ppm, LC(90) =121.96 ppm, LC(99) =231.86 ppm were observed after 72 h, while after flash chromatography the LC(50) =20 ppm, LC(90) =123.02 ppm, LC(99) =281.83 ppm were observed after 48 h. In the second instar after column chromatography, LC(50) =18.19 ppm, LC(90) =102.32 ppm, LC(99) =162.18 ppm were observed after 72 h, while doing flash chromatography 100% mortality could be recorded after 24 h. In the third instar after column chromatography, the LC(50) =38.01 ppm, LC(90) =131.82 ppm, LC(99) =245.47 ppm were observed after 72 h, while after flash chromatography the LC(50) =17.78 ppm, LC(90) =100 ppm, LC(99) =151.35 ppm. In the fourth instar, LC(50) =61.65 ppm, LC(90) =181.97 ppm, LC(99) =436.51 ppm, while after flash chromatography LC(50) =40 ppm, LC(90) =120 ppm, and LC(99) =223.87 ppm were observed after 72 h. The extracellular metabolites of C. keratinophilum could be a fungal based larvicides resource for the control of C. quinquefasciatus larvae. This could be another agent for biotechnological exploitation, if found suitable in field trials.
嗜角蛋白真菌 Chrysosporium keratinophilum 是一种角蛋白亲和真菌，也是一种有效的蚊虫控制剂。该真菌在 25°C 的实验室条件下于 Sabauraud 葡萄糖肉汤中生长，相对湿度保持在 75±5%，持续 15 天。采用 Whatman-1 滤纸、柱层析和快速层析对代谢产物进行过滤处理。采用不同有效比例（乙醇/代谢物：9:1、8:2、7:3、6:4、5:5、4:6、3:7、2:8 和 1:9）的 6 个不同浓度对所有龄期的致倦库蚊进行了杀幼虫效果测试。将死亡率值通过概率单位分析进行处理。在 24、48 和 72 小时分别观察幼虫的死亡率。1 龄和 2 龄对 2:8 比例的幼虫高度敏感。经过柱层析处理后，在 72 小时后观察到第一龄幼虫的 LC50 值为 26.66 ppm，LC90 值为 121.96 ppm，LC99 值为 231.86 ppm；而经过快速层析处理后，在 48 小时后观察到 LC50 值为 20 ppm，LC90 值为 123.02 ppm，LC99 值为 281.83 ppm。经过柱层析处理后，在 72 小时后观察到第二龄幼虫的 LC50 值为 18.19 ppm，LC90 值为 102.32 ppm，LC99 值为 162.18 ppm；而经过快速层析处理后，在 24 小时即可记录到 100%的死亡率。经过柱层析处理后，在 72 小时后观察到第三龄幼虫的 LC50 值为 38.01 ppm，LC90 值为 131.82 ppm，LC99 值为 245.47 ppm；而经过快速层析处理后，在 72 小时后观察到 LC50 值为 17.78 ppm，LC90 值为 100 ppm，LC99 值为 151.35 ppm。第四龄幼虫的 LC50 值为 61.65 ppm，LC90 值为 181.97 ppm，LC99 值为 436.51 ppm；而经过快速层析处理后，在 72 小时后观察到 LC50 值为 40 ppm，LC90 值为 120 ppm，LC99 值为 223.87 ppm。C. keratinophilum 的细胞外代谢产物可能是一种基于真菌的杀幼虫剂资源，可用于控制致倦库蚊幼虫。如果在田间试验中被证明合适，这可能成为另一种生物技术利用的制剂。
