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As the pervasive, standardized format for interchange and deposition of raw mass spectrometry (MS) proteomics and metabolomics data, text-based mzML is inefficiently utilized on various analysis platforms due to its sheer volume of samples and limited read/write speed. Most research on compression algorithms rarely provides flexible random file reading scheme. Database-developed solution guarantees the efficiency of random file reading, but nevertheless the efforts in compression and third-party software support are insufficient. Under the premise of ensuring the efficiency of decompression, we propose an encoding scheme "Stack-ZDPD" that is optimized for storage of raw MS data, designed for the format "Aird", a computation-oriented format with fast accessing and decoding time, where the core compression algorithm is "ZDPD". Stack-ZDPD reduces the volume of data stored in mzML format by around 80% or more, depending on the data acquisition pattern, and the compression ratio is approximately 30% compared to ZDPD for data generated using Time of Flight technology. Our approach is available on AirdPro, for file conversion and the Java-API Aird-SDK, for data parsing. [ABSTRACT FROM AUTHOR]

Trehalose synthase (TreS) converts maltose to trehalose, which has several important functions; therefore, enhancing TreS expression is desirable. Here, a recombinant Bacillus subtilis W800N (ΔamyE)-Pglv strain was constructed to achieve enhanced expression of TreS. Process optimization strategies were developed to improve the expression level of TreS in B. subtilis W800N (ΔamyE)-Pglv. Intracellular activity of TreS was induced using 60 g/L of maltose in shake flask culture. The protein activity reached 5211 ± 134 U/g at 33 °C and pH 7.0 in Luria-Bertani medium. A fed-batch fermentation strategy was applied in a 30 L fermenter containing 18 L terrific broth to achieve high cell density by replacing glycerol with high maltose syrup as a carbon source and an inducer. After 32 h of fermentation, recombinant B. subtilis W800N (ΔamyE)-Pglv activity reached 6850 ± 287 U/g dry cell weight. Our results demonstrate the efficiency of the Pglv promoter in increasing the expression of TreS in B. subtilis W800N (ΔamyE)-Pglv. [ABSTRACT FROM AUTHOR]