Challenges and prospects of xylitol production with whole cell bio-catalysis: A review

Abstract

Xylitol, as an alternative low calorie sweetener is well accepted in formulations of various confectioneries and healthcare products. Worldwide it is industrially produced by catalytic hydrogenation of pure d-xylose solution under high temperature and pressure. Biotechnological xylitol production is a potentially attractive replacement for chemical process, as it occurs under much milder process conditions and can be based on sugar mixtures derived from low-cost industrial and agri-waste. However, microbial fermentation route of xylitol production is not so far practiced industrially. This review highlights the challenges and prospects of biotechnological xylitol production considering possible genetic modifications of fermenting microorganisms and various aspects of industrial bioprocessing and product downstreaming.

A Bibliometric Study of Scientific Publications regarding Hemicellulose Valorization during the 2000–2016 Period: Identification of Alternatives and Hot Topics

“…The employment of microorganisms allows the direct conversion of xylose to xylitol without previous purification tasks and avoids the use of catalysts. Although some bacteria and fungi are able to produce xylitol from xylose, the relative low production of xylitol has not attracted too much interest in these organisms [228,229], and, as a consequence, yeasts are preferred. The organisms of genus Candida and Debaryomyces are among the best-known producers of xylitol, including species such as C. guilliermondii, C. pelliculosu, C. parapsilosis, C. tropicalis, C. pseudotropicalis, C. units, D. hansenii or D. nepalensis [229,230].…”

Xylitol production on sugarcane biomass hydrolysate by newly identified Candida tropicalis JA2 strain

“…Xylitol is industrially produced by catalytic hydrogenation of pure xylose solution under high temperature and pressure (Dasgupta, Bandhu, Adhikari, & Ghosh, ). This production process is expensive and presents low yields due to the complexity of the product recovery stages (Bier, Maranho, Azevedo, & da Silva, ).…”

“…The major drawback of microbial production processes employing lignocellulosic‐derived hydrolysates is the presence of inhibitory compounds in their composition, which may hinder yeast metabolism (Dasgupta et al, ). During pretreatment and hydrolysis of biomass, cellulose and hemicellulose are broken down, releasing monomeric sugars but also microbial‐inhibitory compounds, such as furaldehydes, phenolic compounds, and acetic acid (Almeida et al, ; Kumar & Sharma, ).…”

Identification of genes involved in xylose metabolism of Meyerozyma guilliermondii and their genetic engineering for increased xylitol production

“…The overall xylitol yields of the M. guilliermondii ATCC 6260 strain are intrinsically rather low compared to other xylitol producing yeasts or fungi (Pal et al 2016;Dasgupta et al 2017). Although total xylitol yield Table 3 Yields (after 72 h growth on 20 g l −1 glucose and 20 g l −1 xylose) and productivities of the strains used in this study remains within the single-digit gram per liter range, it could be substantially enhanced by overexpression of XR and knockout of XDH in M. guilliermondii ATCC 6260.…”

“…in (Granström et al 2007b) and (Jeffries and Jin 2004)). Whilst there are several attempts of genetic modification of Saccharomyces cerevisiae to produce xylitol (Jeppsson et al 2006;Dasgupta et al 2017), other, non-conventional yeasts, like amongst others Candida sp., Kluyveromyces sp. or Trichoderma reesei, are natural producers of this sugar alcohol (Winkelhausen and Kuzmanova 1998;Chen et al 2010;Venkateswar Rao et al 2015), and are therefore probably more promising candidates for biotechnological production of xylitol.…”