Alan Wheals's research while affiliated with University of Bath and other places

... For molecular typing, the following molecular markers were used: interdelta analysis ( Legras and Karst, 2003), minisatellites analysis (AGA1, DAN4, HSP150, SED1 genes) ( Mannazzu et al., 2002;Marinangeli et al., 2004) and mtDNA-RFLP with restriction endonucleases Hae III, Hinf I, Rsa I. Fingerprinting images were analysed using the Bionumerics software, version 5.1 (Applied Maths, Kortrijk, Belgium). Similarities among patterns were assessed by means of Bionumerics software. ...

... (Chandrasena et al., 2006). Studies conducted worldwide have revealed that many beneficial yeast strains are possible to be isolated from various fermented foods (Dubash et al., 2010;Gana et al.;Moreira et al., 2001;Obasi et al 2014). But, so far only a limited number of research studies have been carried out in Sri Lanka to isolate yeasts from locally fermented foods and to screen them for their beneficial properties in a broad way. ...

... The nutrients for cell growth and ethanol production are present in the must, which is normally composed of concentrated sugarcane juice or molasses diluted with sugarcane juice or water in sufficient proportions to obtain a substrate concentration (total reducing sugars, TRS: free and potential glucose plus fructose from sucrose hydrolysis) of around 250 g L −1 (substrate concentration in the must, C SM ) [13]. The inoculum has a cell concentration in the range from 60 to 100 g L −1 , with no substrate [13,14]. Therefore, the profile of substrate concentration ( C S ) over time starts with C S0 =0.0 g L −1 and increases as the must is fed, until reaching the useful volume of the vat (at the end of the fed-batch stage). ...

... Coffee is produced from a pair of seeds found in the center of the coffee cherry. Following the removal of the exocarp, mesocarp, and mucilage layer, which is a colorless and viscous pectin layer lying under the mesocarp, coffee cherries are processed following one of the two processes suggested by Schwan and Wheals, depending on the place of production and species [14]. ...

... According to the great specificity and sensitivity of this method here described, as well as the development of a pre-treatment with no requirement of DNA extractions steps in the B. bruxellensis diagnosis, it may be considered as a routine, simple test to include in the winery laboratories. Comparing our method to that described by Hulin et al. (2014), ours may have some methodological advantages in terms of the simplicity of sampling processing. The main advantage here is the analysis of the pre-treated wine samples, without any microbial culture step. ...

... There is substantial evidence that hybridisation is also frequent in the Zygosaccharomyces genus, which comprises twelve formally described species (Hulin and Wheals 2014), at least three of which are interspecies hybrids (Figure 6). Z. bailii and Z. rouxii are the two most studied species because of notable tolerance to adverse environmental conditions and their close association with food. ...

... Contrary to the present multiplex PCR, these multiplex methods have been designed for safety purposes only, targeting biogenic amine-forming LAB (Coton et al., 2010) or spoilage bacteria such as Zymomonas mobilis (Coton et al., 2005). Some other PCR have been set up to differentiate yeasts, such as Saccharomyces -the main yeast responsible for ethanol production in cider (De Melo Pereira et al., 2010;Josepa et al., 2000;Sharpe et al., 2014) -or Brettanomyces/Dekkera, involved in cider and wine spoilage (Cocolin et al., 2004;Hulin et al., 2014). All these studies confirmed the use of a multiplex PCR as a powerful identification tool for food isolates. ...

... Potential pectinolytic activity was determined using the methods described by Hankin & Lacy (1984) and Schwan et al. (1997). Isolated yeasts and bacteria were cultured at 30 °C for four days with 12 h photoperiods on plates with mineral medium containing 5 g/L polygalacturonic acid (MP5) at pH 5.5 for detecting polygalacturonase (PG) activity and mineral medium containing 5 g/L pectin (MP7) at pH 7.2 for detecting pectin lyase (PL) activity (Hankin & Lacy, 1984).The mineral medium contained 5 g/L glucose, 6 g/L KH 2 PO 4 , 1 g/L yeast extract, 2 g/L (NH 4 )2SO 4 , 15 g/L agar and 0.1 ml/L solutions of 0.1 g/L FeSO 4 , 20 g/L MgSO 4 , 0.1 g/L CaCl 2 , 0.2 g/L H 3 BO 3 , 0.2 g/L MnSO 4 , 1.4 g/L ZnSO 4 .7H 2 O, 1 g/L CuSO 4 .5H 2 O, and 0.2 g/L MoO 3 (Carrim et al., 2006;Silva et al., 2008a). ...

... Several yeast species isolated from cocoa bean fermentations are pectinolytic and are considered to have an important role in degradation and solubilization of the pulp, especially during the first 24 h (Carr 1982;Cascante et al. 1994;Schwan et al. 1997). Hydrolysis of pectin requires several enzymes, including polygalacturonase, pectin methylesterase, and pectin lyase, as described previously (Roelofsen 1953;Schwan et al. 1996;Silva et al. 2005). This activity decreases the viscous nature of the bean mass and facilitates its mixing and penetration of air (oxygen) that encourages the growth of AAB. S. cerevisiae, Candida saitoana, K. marxianus, and Pichia norvegensis are pectinolytic yeasts that were isolated from cocoa fermentations in the Ivory Coast (Sanchez et al. 1984). ...

... Strains BY4742 (MATα) and BY4743 (MATa) were used as internal controls. Hybrids were validated by PCR-RFLP analysis of ITS1 spacer with HaeIII enzyme (Thermo Fisher Scientific, Waltham, MA, USA) [54] and PCR amplifications of FSY1 and MEX67 genes using species-specific primers [55]. Genotyping of hybrids after genome stabilization was done by (GTG) 5 fingerprinting assay according to Dakal et al. [56]. ...