Thursday, 30th August Australian and New Zealand Metabolomics Conference 2018

Sonic stimulation can affect the growth and production of volatile metabolites of yeasts

Alastair Harris ¹ , Melodie Lindsay ¹ , Silas Villas-Boas ¹

1. University of Auckland, Auckland, New Zealand

An organism’s phenotype is dependent upon the environmental stimuli to which it is exposed during growth. Traditionally, this phenotypic plasticity has been ascribed to factors such as pH, temperature, nutrient availability, and redox potential. However, in recent years the biological effect of other environmental conditions have become an area of interest. Through the manipulation of factors such as sound, fermentation parameters can be influenced to greatly affect the levels of different metabolites. In microorganisms, audible sound waves can be generated as a result of internal motion produced by cellular processes, such as the activity of molecular motors and protein folding. The combination of these motions result in the global vibration of cells and intracellular components at species, and environmental specific frequencies. The nanomechanical motion of Saccharomyces cerevisiae, for example, was demonstrated to range from 0.9-1.6kHz, depending upon the temperature of growth. These vibrations were sufficiently strong (~10nN) to affect the cell membrane and propagate into surrounding media. We have shown previously that the growth and metabolic profile of S. cerevisiaecan affected by sonic stimuli. Sound could therefore also significantly affect the volatile composition of a fermentation broth with important implications in fermented beverage production. In this present work, we focused on the effect of audible range sonic stimuli upon beer-like fermentations, with an emphasis on volatile compounds, which could affect the flavour of the resulting beverage. The growth rate of fermentations exposed to both high and low frequency sound stimuli was increased by 22.7% compared to that of silence. Furthermore, the profile of volatile metabolites in the ferments was dependent upon the frequency of sonic stimuli applied. Therefore, we demonstrate that the aroma compounds in ‘beer-like’ media could be manipulated through the use of sonic stimuli. These compounds are important as they directly influence the flavour of the final beverage.

Introduction to metabolomics:

Part 1: Metabolomics Overview and Best Practices

Dr Farhana Pinu (Plant and Food Research Ltd, New Zealand) and Dr Dan A. Dias (RMIT University, Australia)

The introduction of metabolomics session is mainly aimed to those who are relatively new to the field of metabolomics. The first part of this session will provide an overview and best practices used in metabolomics. Other topics that will be presented include a simplified metabolomics workflow, experimental design, sample preparation, data acquisition and the importance of quality control. Finally, the most recent developments in the field of metabolomics will be discussed.

Part 2: Targeted and Untargeted Metabolomics (Instrumentation)

Dr David Beale (CSIRO Land and Water, Australia) and Dr Devin Benheim (Latrobe University, Australia)

Metabolomics workflows can be characterised into three distinct strategies: untargeted, semi-targeted or targeted analyses. Common analytical platforms include, but is not limited to, Gas and Liquid-based Chromatography, and Fourier Transform infrared (FTIR) and Nuclear Magnetic Resonance (NMR) spectroscopy.  In this session, we will illustrate the major points of difference among each of these approaches and discuss future analytical developments, highlighting the types of instrumentation used and their workflow challenges when utilised within metabolomics-based studies.

Part 3: Data processing and Analysis

Dr Beatrix Jones (University of Auckland, New Zealand) and Dr Konstantinos Kouremenos (University of Melbourne, Australia)

Data analysis is one of the most important and challenging task for any metabolomics research. In this session, insights will be provided on basic steps of metabolomics data processing including normalisation, batch effects, identifying likely contaminants, basic univariate tests and controlling the false discovery rate. We will also be discussing different data processing strategies (including databases) for untargeted metabolomics studies. The focus for this will be on open-access packages, as they are comprehensive and free for users - these include: MzMINE, XCMS, MS-DIAL, METLIN, Massbank, LIPIDMAPS, Metaboanalyst, HMDB etc.

Part 4: Lipidomics and Fluxomics

Dr Damien Callahan (Deakin University, Australia and Dr Greg Kowalski (Deakin University, Australia)

This is the last part of the introduction of metabolomics session where we will be presenting two different omics approaches including lipidomics and fluxomics.

The main aim of lipidomics is to study all lipids within a biological system. However, their analysis not a trivial task mainly due to the diverse chemical nature of lipid molecules. This presentation will provide a short overview of the typical mass spectrometry (MS) approaches used for the analysis of lipids and will also highlight some of the challenges.

Widely used within the field of system biology, fluxomics deals with the determination of metabolic reactions within a biological entity and is becoming an important tool to understand dynamic process of metabolism. Here, we will provide the details of different MS based approaches that are used for the analysis of metabolic fluxes. In addition, highlights will also be provided on most recent developments within this area. 

• We all like sheep – and worms, bugs, and maths. NMR-based metabolomics, systems biology and genome-scale modelling in livestock science, insects, and C. elegans. - Horst Joachim Schirra
• Livestock Metabolomics and the Livestock Metabolome Database - Seyed Ali Goldansaz
• Metabolite profiling of Scyralidium parasiticum (Sp) fractions against Ganoderma boninense - Kamalrul Azlan Azizan
• Effect of fodder beet or ryegrass diets during pregnancy on lamb growth, carcass characteristics, meat quality and meat metabolites - Linda M Samuelsson
• Metabolomics Across the Value-Chain - From Farm to Fork - Karl Fraser