SUMMARY: An improved growth medium for lactobacilli is described. It supports good growth of lactobacilli generally and also is particularly useful for a number of fastidious strains which grow only poorly in other general media. In addition, tomato juice, a highly variable material, is not required. In a slightly modified form, it can also be used as a basal medium for fermentation tests.

A method is described for drawing up FHPN tables restricted to results with a defined minimal probability and containing 95 and 99% confidence limits calculated on the basis of probability histograms. Tables for 3, 5 and qO tubes, respectively, in three decimal dilutions and also a table for 5 tubes in the first dilution and q tube in two decimal dilutions are presented.Because microbiological standards for foods are becoming increasingly severe, in the future N]PN methods will probably often have to replace plate counts (Schmidt-Lorenz, 1974). The interpretation of N_P~ results has not always received the attention it deserves, however.Several authors have pointed out that it is important to provide not only the N_PN values themselves, but also confidence limits, e.g. for 95 or 99% probability; and in many tables at least approximate values for confidence limits are now mentioned.

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1. Of several ioas tested, only Fe+8, Cu+* and A]+# catalysed the decarboxylation of a-acetolactic add at pH 4.8.2. At pH 2.2, only Fk+a and Cu+* were active.3. Fe+8 and GI+* were shown to form complexes with a-acetolactic acid.4. Fe+8 and Cu+* not only dccarboxylatcd but also oxidized a-acetolactic add, with, as a r e d t , formation of diacetyl. 5. Decarboxylation o f a-acetdactic add by these ions is compatible with the mechanism suggested by Martell and Calvin. 6. adcetolactic add is d j e c t to autoxiciation. 2-Buteae-2,3diol may be an intermediebe product.* J. C. de Man and J. W. Pette, Int. dhiry Congress Pra. 14th h Q t . Rome 2/1. 89 (19%). 8 H. A. Krebs, Biochcm. J. 36. 303 (1942). 4 A. Kotnberg, S. Ochoa and A. H . MehJer, J. Biol. Chem. 174, 159 (1948).The formation of diacetyl and acetoin, etc.78 (1959) AECUEIL 481 E x p e r i m e n t a 1.

Currently, there is a lack of comprehensive data on the diversity of chemicals present in vaping liquids. To address this gap, a non-targeted analysis of 825 vaping liquids collected between 2017 and 2019 from Canadian retailers was conducted. Prior to mass spectrometry analysis, samples were diluted 1:500 v/v with methanol or acetonitrile. Chemical compound separation and analysis was carried out using gas chromatography and triple quadrupole mass spectrometry (GC-MS/MS) systems operated in the full scan mode and mass range of 35–450 m/z. Mass spectrum for each sample was obtained in electron ionization at 70 eV and processed. Non-targeted identification workflow included use of automated mass spectral deconvolution and identification system (AMDIS), where required, as well as a number of commercially available spectral libraries. In order to validate identities, an in-house database of expected compounds previously detected in vaping liquids was used along with genuine analytical standards for compounds of interest. This resulted in a dataset of over 1,500 unique detected chemicals. Approximately half of these chemical compounds were detected only once in a single product and not in multiple products analyzed. For any sample analyzed, on average, 40% of the chemical constituents appeared to have flavouring properties. The remainder were nicotine and related alkaloids, processing, degradation or indirect additives, natural extractives and compounds with unknown roles. Data published here from the project on the Open Characterization of vaping liquids is unique as it offers a detailed understanding of products’ flavour chemical profiles, the presence and frequency of chemicals of potential health concern, as well as trends and changes in products’ chemical complexity over a three-year period. Non-targeted chemical surveillance such as this present valuable tools to public health officials and researchers in responding to emergent issues such as vaping associated lung injury or informing chemical based strategies which may be aimed at addressing product safety or appeal.