ABSTRACT
In order to increase the production of insecticidal crystal proteins Cry1 and Cry2, firstly, Plack-ett-Burman design was applied to evaluate the effectiveness of the related nutrition factors; it was found that the soybean powder and MnSO4?H2O were significant factors for Cry1 production, but the yield of Cry2 wasn’t effected remarkably in such medium. Then the steepest ascent experiment was adopted to approach the optimal region of the medium composition. Lastly, the optimal concentration of the soybean powder and MnSO4?H2O was 11.5 and 0.02 g/L, obtained by response surface methodology (RSM). The final yields of Cry1 and Cry2 was 0.32 mg/mL and 0.11 mg/mL, increasing twice more than that in the medium optimized before. The median lethal concentration (LC50) of optimal medium was 1.09 ?L/mL. The toxicity to Heli-coverpa armigera was significantly enhanced than the old one.
ABSTRACT
Two high protease producing strains, whic h are desi gnated Aspergillus oryzae AS100 and AS102, were screened and applied as main fermentation strains of swine blood meal. A Saccharomyces cerevisiae Y113 and a Bacillus Asp007 were also used as assistant fermentation strains. The enzyme production abilities we re studied,and a series of parameters of the fermentation technology were deter mined. Through swine blood meal fermentation, a high-protein fermented feed wa s produced, which is strong soy flavor and was rich in protein(69%), free amino acid, vitamin such as VitD 3 and niacin and organic elements such as Fe. It is a kind of high-protein feed for animals and it could be used as feedstuff addi tive.
ABSTRACT
Along with the development of computer techniques and the dissemination of Internet,many investigators of microorganisms already can acquire a lot of knowledge of many fields on microbe via Internet,extremely including the whole genome of a certain microbe. This was considered unimaginable in the past.Rapid collection of information also to a great extent expands the researching ranges and researching ability of microbial researcher,and at one time,the highly developed Internet provides a unprecedented opportunity for intercommunication of information?share of resources and international cooperations of microbiology.