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18 Graphical abstract 19 Highlights: Starch under hydration at ambient conditions was studied by synchrotron

Thermostable p-nitrophenylphosphatase from Bacillus Stearothermophilus (Bs-TpNPPase) is involved in the Mg(2+)-dependent hydrolysis of the phosphoenzyme at an optimum reaction temperature of 55°C. Bs-TpNPPase has been cloned and overexpressed in the E.coli M15 strain. Based on the conserved active sites, the protein was suggested to be a member of the haloalkanoate dehalogenase (HAD) superfamily. Two site-specific point mutants of Bs-TpNPPase were prepared by changing the catalytic Asp10 and Thr43 to Ala10 and Ala43, respectively. The activity of the two mutants further confirms Bs-TpNPPase as a member of the HAD superfamily. HAD superfamily can be divided into the four subfamilies and play several biochemical roles such as DNA repair, signal transduction and secondary metabolism. To understand the relationship between structure and thermostability in HAD superfamily, Bs-TpNPPase from Bacillus Stearothermophilus was selected. The X-ray crystal structure of Bs-TpNPPase was determined at 1.5A resolution using the molecular replacement phasing method. The structure of Bs-TpNPPase has been deposited and the PDB code is 4KN8. Compared with Bsp, a mesophilic prokaryotic putative p-nitrophenyl phosphatase from Bacillus Subtilis, Bs- TpNPPase showed highly homology but variations in the level of leucine content, aromatic clusters, cation-Pi and hydrophobic interaction. These differences may affect the thermal stability of the protein. The crystal structure of Bs-TpNPPase described herein may serve as a guide to better understand the mechanism of thermostability and provide insights for further mutation work.

The main resources needed for human survival are water, energy and food, and the research on the relationship among the three resources has become the research topic. Due to the shortage of natural resources, research on the efficiency of water–energy–food (WEF) nexus has become a hot issue among scholars and governments all over the world. The simple models cannot study the correlation among them; the methods of WEF nexus gradually shift from single to integrated model. The data envelopment analysis (DEA) model is the most simple and effective model, which can measure the efficiency value of each decision-making unit (DMU) and overcomes the shortcoming that the evaluation index system needs to give the weight. The DEA can calculate the efficiency value, but it cannot improve the efficiency value of DMU by changing the input. In this paper, the zero-sum gain (ZSG) DEA model is constructed based on zero-sum game theory. The initial efficiency values of 30 provinces in China are calculated, and each DMU is proportionally allocated according to the proportional subtractive method. After several iterations, the efficiency values of all DMUs reach 1, indicating that global optimization has been achieved. Under the condition of effectiveness, the initial input water resources are reconfigured. Finally, some conclusions are made, and optimization strategies are proposed for 30 provinces in China with low water resource utilization efficiency.