Team:SZU-China/Demonstrate

Demonstrate

We wonder if the products made from recombinant Metarhizium anisopliae are convenient and useful. For this reason, we have taken a step forward to verify the function of the modified strain and determine the suitable production method.

According to Professor Wang Zhongkang's suggestion, we chose emulsifiable powder as the product dosage form and non-woven fabric as the carrier of the product. Both of the above have the following advantages:

1. Compared with dry spores and water-dispersing agents, the emulsifiable powder has stronger storage stability, UV resistance and thermal stability.

2. Compared with spore spray, non-woven fabric use less material and small-scale use.

In order to ensure that we can produce emulsifiable powder in large quantities, Professor Wang took us to visit the Chinese largest fungal pesticide factory. The production process is shown in the fig 1.

Fig 1: The emulsifiable powder production flow chart

It can be used after the emulsifiable powder is produced and brushed on the non-woven fabric. But we found problems: the non-woven fabric is so light that it maybe fly away. And the emulsifiable powder exposure to light may die easier.

To solve this problem, we designed the GreenGround series, which has 3 generations of products (please click on Applied Design for details). We finally chose the third generation and patented it. In order to test the effect of the box on the killing effect, we did a comparative experiment and the results are as follows.(Table 1)(Fig 2)

With box Without box
Group 1 10 4
Group 2 9 2
Group 3 12 5
Mean 9.5 3.0
Variance 2.3 2.3
Mortality 34.44% 12.22%
Fig 2: Mortality with or without box

This shows that our GreenGround can maintain the lethal effect of Metarhizium anisopliae, so it’s necessary to use.(Fig 3)

Fig 3：The third generation of GreenGround

In wild type M.anisopliae group, we used 10^9 emulsifiable powder 10μl to infects 17 cockroaches individually. While, in transformant group, we user 10^9 emulsifiable powder 10μl to infects 10 cockroaches individually. The results showed that wild-type M.anisopliae toke effect after two days, while transformant took effects less than one day. For mortality each day, transformant showed above two times significantly higher (P <0.05) mortality than wild-type. Two groups reached stationary state after four days, above 20% mortality in wild-type, while 50% in transformant.(Table 2)(Fig 4)(Fig 5)

Table 2: Experimental data of cockroaches infection experiment. * Table shows the number of cockroaches alive.
Fig 4: Mortality of cockroaches between wild type M.anisopliae and transformant.
Fig 5：The cockroach which covered by spores

Reference：

[1]Yin Youping, Wang Zhongkang, Xie Ning, et al. 2009. Insecticidal fungi emulsifiable powder:, CN101564047[P].