There is an urgent need to improve the infrastructure supporting the reuse of scholarly data. A diverse set of stakeholders—representing academia, industry, funding agencies, and scholarly publishers—have come together to design and jointly endorse a concise and measureable set of principles that we refer to as the FAIR Data Principles. The intent is that these may act as a guideline for those wishing to enhance the reusability of their data holdings. Distinct from peer initiatives that focus on the human scholar, the FAIR Principles put specific emphasis on enhancing the ability of machines to automatically find and use the data, in addition to supporting its reuse by individuals. This Comment is the first formal publication of the FAIR Principles, and includes the rationale behind them, and some exemplar implementations in the community.

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The extracellular lipase from Acinetobacter calcoaceticus BD413 was purified to homogeneity, via hydrophobic-interaction fast performance liquid chromatography (FPLC), from cultures grown in mineral medium with hexadecane as the sole carbon source. The enzyme has an apparent molecular mass of 32 kDa on SDS-polyacrylamide gels and hydrolyses long acyl chain p-nitrophenol (pNP) esters, like pNP palmitate (pNPP), with optimal activity between pH 7.8 and 8.8. Additionally, the enzyme shows activity towards triglycerides such as olive oil and tributyrin and towards egg-yolk emulsions. The N-terminal amino acid sequence of the mature protein was determined, and via reverse genetics the structural lipase gene was cloned from a gene library of A. calcoaceticus DNA in Escherichia coli phage M13. Sequence analysis of a 2.1 kb chromosomal DNA fragment revealed one complete open reading frame, lipA, encoding a mature protein with a predicted molecular mass of 32.1 kDa. This protein shows high similarity to known lipases, especially Pseudomonas lipases, that are exported in a two-step secretion mechanism and require a lipase-specific chaperone. The identification of an export signal sequence at the N-terminus of the mature lipase suggests that the lipase of Acinetobacter is also exported via a two-step translocation mechanism. However, no chaperone-encoding gene was found downstream of lipA, unlike the situation in Pseudomonas. Analysis of an A. calcoaceticus mutant showing reduced lipase production revealed that a periplasmic disulphide oxidoreductase is involved in processing of the lipase. Via sequence alignments, based upon the crystal structure of the closely related Pseudomonas glumae lipase, a model has been made of the secondary-structure elements in AcLipA. The active site serine of AcLipA was changed to an alanine, via site-directed mutagenesis, resulting in production of an inactive extracellular lipase.

Acinetobacter calcoaceticus BD413, when grown in batch culture in nutrient broth, produces both extracellular lipase activity and cell-bound esterase activity during and after the transition between exponential growth and the stationary phase. From a library of A. calcoaceticus DNA in Escherichia cofi, plasmids were isolated that enabled E. coli to grow on media with tributyrin as the sole carbon source. Assays with model substrates classified the product of the cloned gene as an esterase. Via deletion analysis, the esterase gene was mapped on a 1.8 kbp chromosomal DNA fragment. This fragment was sequenced and found to contain one open reading frame, termed estA, which encodes a protein of 40.0 kDa. The amino acid sequence of this protein shows homology to a number of lipolytic enzymes, most notably to esterases. Deletion of estA only partially abolished cell-bound esterase activity in A. calcoaceticus, indicating that BD413 forms at least two esterases. Both esterases show the same temporal regulation of expression. /?-Galactosidase activity was measured in strains in which a promoterless lac2 gene was inserted into estA. Induction of lac2 expression in these strains also occurred at the end of exponential growth in batch cultures, indicating that production of the esterase is regulated at the genetic level.

For specific detection of the probiotic Bifidobacterium sp. strain LW420 in infant feces and for rapid quality control of this strain in culture, three strain-specific 16S rRNA gene-targeted primers have been developed. These primers allow specific detection of the organism via PCR. Specificity of the primers was determined in DNA samples isolated from single-strain and mixed cultures of bifidobacteria and in heterogenous fecal samples. The feasibility of this method for use in specific detection of probiotic strains was investigated through addition of Bifidobacterium sp. strain LW420 to infant instant milk formula (IMF) and PCR analyses of bacterial DNA isolated from feces of 17 newborn IMF-fed infants. In feces of all nine babies that had been fed with the probiotic IMF, the strain-specific PCR signal could be detected. No signal was found in feces of the eight infants that had been fed with a nonprobiotic IMF, demonstrating the specificity of the PCR method. All 17 infants developed a major fecal Bifidobacterium population already after 3 days, as determined through genus-specific and strain-specific PCR. Phenotypical screening of Bifidobacterium sp. strain LW420 and analysis of homology of the 16S rRNA gene sequence of this strain with that of other bifidobacteria deposited in databases do not allow positive classification of LW420 among the currently known species of Bifidobacterium.