Enhancing untargeted metabolomics using metadata-based source annotation

Human untargeted metabolomics studies annotate only ~10% of molecular features. We introduce reference-data-driven analysis to match metabolomics tandem mass spectrometry (MS/MS) data against metadata-annotated source data as a pseudo-MS/MS reference library. Applying this approach to food source data, we show that it increases MS/MS spectral usage 5.1-fold over conventional structural MS/MS library matches and allows empirical assessment of dietary patterns from untargeted data

Implications of new research and technologies for malolactic fermentation in wine

The initial conversion of grape must to wine is an alcoholic fermentation (AF) largely carried out by one or more strains of yeast, typically Saccharomyces cerevisiae. After the AF, a secondary or malolactic fermentation (MLF) which is carried out by lactic acid bacteria (LAB) is often undertaken. The MLF involves the bioconversion of malic acid to lactic acid and carbon dioxide. The ability to metabolise L-malic acid is strain specific, and both individual Oenococcus oeni strains and other LAB strains vary in their ability to efficiently carry out MLF. Aside from impacts on acidity, LAB can also metabolise other precursors present in wine during fermentation and, therefore, alter the chemical composition of the wine resulting in an increased complexity of wine aroma and flavour. Recent research has focused on three main areas: enzymatic changes during MLF, safety of the final product and mechanisms of stress resistance. This review summarises the latest research and technological advances in the rapidly evolving study of MLF and investigates the directions that future research may take.Krista M. Sumby, Paul R. Grbin, Vladimir Jirane

Bioethanol synthesis for fuel or beverages from the processing of agri-food by-products and natural biomass using economical and purposely modified biocatalytic systems

This review describes the role of suitable and modified microorganisms as economical biocatalysts in the processing of by-products generated in industries and agriculture, which are cheaply available globally as renewable resources. Since the microbial processing can be economically used to produce a variety of value-added products, by employing specific species of microorganisms as biocatalysts; but to be specific to the title of this review the information included in this article has only emphasized on one important consumer-product bioethanol. The conclusion of the information gathered in this review is that, the selection and modification of a microbial biocatalyst should be strategically done. For example: employing an yeast strain of Saccharomyces or a non-Saccharomyces culture, is important in bioethanol synthesis; the optimisation of biocatalyst is also important according to the type of material being processed in the system as it could be a by-product or waste residue of agriculture, food & beverage industry or simply the seasonal locally available fruits. The other information, which has been included in this review, is on the modification of biocatalysts and important factors influencing the efficiency of bioprocessing, for the necessity of economical yield of bioethanol