In this paper, two statistical methods were applied to optimize medium components to improve the production of the milk-clotting enzyme by Bacillus amyloliquefaciens D4. First, wheat bran juice, skim milk powder, and Na2HPO4 were shown to have significant effects on D4 enzyme production using the Plackett-Burman experimental design. Subsequently, an optimal medium was obtained using the Box-Behnken method, which consisted of 3.31 g/l of skim milk powder, 5.0 g/l of sucrose, 0.1 g/l of FeSO4·7H2O, 0.1 g/l of MgSO4·7H2O, 0.1 g/l of MnSO4·2H2O, 0.1 g/l of ZnSO4·7H2O, 1.52 g/l of Na2HPO4, and 172.45 g/l of wheat bran juice. With this optimal medium, the milk-clotting enzyme production was remarkably enhanced. The milk-clotting enzyme activity reached 3,326.7 SU/ml after incubation of 48 h, which was 1.76-fold higher than that of the basic medium, showing that the Plackett-Burman design and Box-Behnken response surface method are effective to optimize medium components, and B. amyloliquefaciens D4 possessed a high rennet-producing capacity in the optimal medium.

A series of poly (N-isopropylacrylamide-co-glycyrrhetinic acid) (P(NIPAAm-co-GA)) microgels were prepared by dispersion copolymerization. The morphologies of the microgels were observed by field scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM). The temperature sensitivity of microgels was examined by measuring the optical transmittance of the microgel aqueous solution. Cytotoxicity of the microgels was investigated by MTT assay. The results indicated that microgel particles had a regular spherical shape of about 500 nm with narrow size distributions. Moreover, P(NIPAAm-co-GA) microgels exhibited good temperature sensitivity and low toxicity. This novel microgel could be expected as good candidate for controlled growth factor release.Intorduction

Based on the velocity contrast of rocks, the seismic logging is to study the relationship of the velocity-depth by using the seismic wave data acquired in borehole. The concept of average velocity used in conventional method of seismic logging data may lead to a wrong interpretation. With help of the raytracing technique, This paper deals with the seismic logging data by Fast Reconstruction (FR) technique to obtain a fine velocity structure in borehole. The results from numerical modeling show that the method can be used in complicated structure with a fast computation and high accuracy.

This paper makes the operational capability of enterprise production planning system as the research object, in which the four operation modules access to information, scheduling, report processing, system tools are analysised in failure mode. Frequency analysis and entropy method are applied to determine the weight of factors of subordinate operation module, and evaluation matrix is applied to determine the operation ability level. The results of the weighting analysis in a large manufacturing group 8 regional branch 2011 annual production planning system operation module, it finds out the key influence factors of subordinate operation module, which can provide the reference for enterprise to promote production planning system operational ability .

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