Metarhizium robertsii protease and conidia production, response to heat stress and virulence against Aedes aegypti larvae

AMB Express

Table 6 Cumulative mortality of Aedes aegypti larvae after treatment with Metarhizium robertsii ARSEF 2575

Treat	Stress	SUPPL	UNSUPPL	Treat	Stress	SUPPL	UNSUPPL	Treat	Stress	SUPPL	UNSUPPL
		Mortality (%)				Mortality (%)				Mortality (%)
		3 days				5 days				10 days
Crude extract	None	66.7 ± 8.8^Aa	80.0 ± 5.8^Aa	Crude extract	None	90.0 ± 5.8^Aa	96.7 ± 3.3^Aa	Crude extract	None	100 ± 0^Aa	100.0 ± 0^Aa
Conidia	None	60.0 ± 5.8^Aa	66.7 ± 12.0^Aa	Conidia	None	80.0 ± 100 ^Aa	90.0 ± 5.8^Aa	Conidia	None	100 ± 0^Aa	96.7 ± 3.3^Aa
Supernatant	None	15.0 ± 5.0^Ab	15.0 ± 5.0^Ab	Supernatant	None	15.0 ± 5.0^Ab	20.0 ± 0^Ab	Supernatant	None	30.0 ± 10.0^Ab	35.0 ± 5.0^Ab
Crude extract	Heat	60.0 ± 5.8^Aa	50.0 ± 5.8^Aab	Crude extract	Heat	76.0 ± 3.3^Aa	83.3 ± 120 ^Aa	Crude extract	Heat	93.3 ± 3.3^Aa	96.7 ± 3.3^Aa
Conidia	Heat	53.3 ± 3.33^Aa	66.7 ± 6.7^Aa	Conidia	Heat	83.3 ± 6.7^Aa	90.0 ± 5.8^Aa	Conidia	Heat	100 ± 0^Aa	96.7 ± 3.3^Aa
Supernatant	Heat	70.0 ± 20.0^Aa	15.0 ± 15.0^Bb	Supernatant	Heat	70.0 ± 20.0^Aa	25.0 ± 15^Bb	Supernatant	Heat	90.0 ± 0^Aa	45.0 ± 5.0^Bb
Control		0 ± 0		Control		10 ± 3.3		Control		10 ± 3.3

After twenty days of solid fermentation, rice was washed with Tween 80® (0.1% v/v). One part of crude extract was kept and the other part was centrifuged and filtered. Conidia were resuspended in Tween 80® (0.1% v/v) and supernatant stored. The three treatments (crude extract. conidia and supernatant) were separated into two subgroups: one kept at 27 ± 1 °C and the other exposed to 45 ± 0.2 °C for 2 h. Larvae were treated with the three types of treatments after biphasic fermentation in media supplemented (SUPPL) with riboflavin and sodium nitrate or unsupplemented media (UNSUPPL). The same treatments produced in different culture media or different treatments submitted to the same stress conditions were compared. Larvae were incubated at 25 ± 1 °C. Relative humidity greater than 75% and 12 h photoperiod for 10 days
Equal capital letters in the same row indicate no significant difference and equal lower-case letters in the same column indicate no significant difference according to Tukey's test (P < 0.05)