Biodiversity and ITS-RFLP Characterisation of Aspergillus Section Nigri Isolates in Grapes from Four Traditional Grape-Producing Areas in Greece

A study on the occurrence of Aspergillus section Nigri species on grapes from four traditional grape-producing areas in Greece during the 2011/2012 vintage, and their capability to produce OTA was conducted. One hundred and twenty-eight black aspergilli isolates were characterised at the species level initially by the use of morphological criteria in accordance with appropriate keys, followed by molecular characterisation performed with Polymerase Chain Reaction–Restriction Fragment Length Polymorphism (PCR-RFLP) of the 5.8 ribosomal RNA gene Internal Transcribed Spacer region (5.8 rRNA ITS). Restriction enzyme digestion of the ITS amplicons using the HhaI, HinfI and RsaI, endonucleases distinguished eleven different patterns of restriction fragment length polymorphism (RFLP), four for each of the HhaI and RsaI digests and three for HinfI. From a total number of 128 individual isolates, 124 were classified into four Aspergillus species corresponding to A. carbonarius, A. tubingensis, A. japonicus and A. ibericus, and the remaining 4 were classified as members of the A. niger aggregate. A. carbonarius and A. tubingensis being the main representative species were equally counted, with higher geographical representation of the former in southern and the latter in northern regions, respectively. All isolates were tested for their ochratoxigenic potential by use of High Performance Liquid Chromatography (HPLC) and Enzyme Linked Immuno Sorbent Assay (ELISA), resulting in significant interspecies differences in OTA production

Application of Non-Saccharomyces Yeasts in Wine Production

In the past, Saccharomyces spp. yeasts were almost the only option for use in modern winemaking due to their unparalleled ability to metabolize all grape juice sugar into ethanol. For that reason, until some years ago, all commercial dry yeasts were Saccharomyces spp. For several years, non-Saccharomyces were forgotten at industrial level, and even some of them were considered as spoilage microorganisms. Non-Saccharomyces only played a significant role in limited productions that perform spontaneous fermentations following organic polities. However, during the last decade, several researchers have proved numerous non-Saccharomyces to be able to improve wine quality and to solve some modern enology challenges. Some of the factors that can improve are acidity, aromatic complexity, glycerol content, ethanol reduction, mannoproteins, anthocyanins, and polysaccharide concentrations. They can also decrease the concentrations of unwanted compounds that affect food safety, such as ochratoxin A, ethyl carbamate, and biogenic amines. Due to all those scientific advances, the main manufacturers have just started to commercialize dry non-Saccharomyces such as Torulaspora delbrueckii, Schizosaccharomyces pombe, Metschnikowia pulcherrima, Lachancea thermotolerans, and Pichia kluyveri. Other non-Saccharomyces species with special enology abilities such as Candida zemplinina, Kloeckera apiculata, Hanseniaspora vineae, Hanseniaspora uvarum, C. stellata, Kazachstania aerobia, or Schizosaccharomyces japonicus could follow a similar progress. The aim of the chapter is to show which are the main abilities and advantages of these non-Saccharomyces in modern winemaking.Depto. de Genética, Fisiología y MicrobiologíaFac. de Ciencias BiológicasTRUEpu