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Background Thermostable microorganisms are extremophiles. They have a special genetic background and metabolic pathway and can produce a variety of enzymes and other active substances with special functions. Most thermo-tolerant microorganisms from environmental samples have resisted cultivation on artificial growth media. Therefore, it is of great significance to isolate more thermo-tolerant microorganisms and study their characteristics to explore the origin of life and exploit more thermo-tolerant enzymes. Tengchong hot spring in Yunnan contains a lot of thermo-tolerant microbial resources because of its perennial high temperature. The ichip method was developed by D. Nichols in 2010 and can be used to isolate so-called “uncultivable” microorganisms from different environments. Here, we describe the first application of modified ichip to isolate thermo-tolerant bacteria from hot springs. Results In this study, 133 strains of bacteria belonging to 19 genera were obtained. 107 strains of bacteria in 17 genera were isolated by modified ichip, and 26 strains of bacteria in 6 genera were isolated by direct plating methods. 25 strains are previously uncultured, 20 of which can only be cultivated after being domesticated by ichip. Two strains of previously unculturable Lysobacter sp., which can withstand 85 °C, were isolated for the first time. Alkalihalobacillus, Lysobacter and Agromyces genera were first found to have 85 °C tolerance. Conclusion Our results indicate that the modified ichip approach can be successfully applied in a hot spring environment.

Under the circumstances that the demand is uncertain, furthermore, the demand sometimes cannot be satisfied by the production, the paper studies the production and maintenance control problem of failure prone production systems. For the hybrid system, a so-called double level hedging point control policy considering purchasing extra production or maintenance capacity is presented, which has strong dynamic characteristics. By the method that studies the problem from over the finite horizon to over the infinite horizon, meanwhile, utilizing a decomposition method, the corresponding hedging points are obtained respectively. The numerical comparison specifies and to some extent testifies the method.

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