In the present study, beta-d-galactosidase from Bacillus circulans was proved to be a suitable biocatalyst for the production of lactosucrose (beta-d-Galp-(1-->4)-alpha-d-Glcp-(1-->2)-beta-d-Fruf, I) and its analogues from lactose and sucrose. During the hydrolysis of lactose, the formation of four transfer products was followed by high performance liquid chromatography with refraction index detector. In addition, the transfer products were isolated from the reaction mixture and identified to be I, beta-d-Galp-(1-->3)-alpha-d-Glcp-(1-->2)-beta-d-Fruf (II), beta-d-Galp-(1-->4)-beta-d-Galp-(1-->4)-alpha,beta-d-Glcp (III), and beta-d-Galp-(1-->4)-beta-d-Galp-(1-->4)-alpha-d-Glcp-(1-->2)-beta-d-Fruf (IV) by mass spectrometry with an electrospray ionization source and nuclear magnetic resonance spectroscopy. The order for the production of the transfer products was III > I > IV > II in the initial stage of the reaction, and the same relationship was also observed for the hydrolytic rates of transfer products. Furthermore, the effects of synthetic conditions including reaction temperature, reaction time, concentration of substrate, molar ratio of donor/acceptor, and enzyme concentration on the formation of transfer products were examined. We found that the optimal synthetic conditions were different for the production of I and II. Under the optimal conditions, the amount of total transfer products kept increasing during the early 4 h incubation, and a maximum yield of 146 g/L for total transfer products was obtained at 4 h of reaction.
PurposeImproving the agricultural products market integration is conducive to developing provincial comparative advantage, optimization of agricultural and industrial organization and enhanced competitiveness. The relationship between the emergencies and the agricultural products market integration in the production and consumption provinces is of great significance for stabilizing market prices and improving the efficiency of agricultural resource allocation.Design/methodology/approachThe authors reviewed the literature on the market integration of agricultural products. Then, they adopted a two-way fixed effect model to investigate the impact of emergencies on the poultry market integration in the production and consumption provinces in China.FindingsHighly pathogenic avian influenza (HPAI) caused abnormal fluctuations in the poultry market price and decreased the poultry market integration. The negative impact of HPAI on poultry market integration was strengthened in the main production provinces and weakened in the main consumption provinces.Originality/valueThis is the first study that applies empirical analysis to identify the emergencies’ impact on the poultry market integration considering production and consumption characteristics. The results indicate that the impact of avian influenza is more serious in production provinces than in consumption provinces. Due to the heterogeneity of production and consumption provinces, the government implements precise compensation policies to resume production quickly after the disaster. It can be conductive to market integration and promote the development of agricultural products market.
Using detailed survey data on broiler growers, we tested for the existence of holdup problems in the broiler industry in Jiangsu Province, China. We found that growers' investments in chicken houses, which are assets with a high degree of physical and location specificity, increased along with the number of potential buyers (integrators) nearby. Such an effect was particularly strong in proximity to leading industry buyers. These results support the existence of hold-ups in the Chinese broiler industry. However, we failed to find evidence that a longer-term contract led to higher grower investments in chicken houses, possibly because of the lack of a minimum purchase guarantee in a typical contract. A key policy implication of this study is that subsidies to growers, from the government or buyers, can alleviate the underinvestment problem caused by hold-ups.
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