Improved β-glucan yield using an Aureobasidium pullulans M-2 mutant strain in a 200-L pilot scale fermentor targeting industrial mass production

Abstract

-(1→3)-D-glucans with -(1→6)-glycosidic linked branches are known to be immune activation agents and are incorporated in anti-cancer drugs and health-promoting supplements. -Glucan concentration was 9.2 g/L in a 200-L pilot scale fermentor using mutant strain Aureobasidium pullulans M-2, which was from an imperfect fungal strain belonging to A. pullulans M-1. The culture broth of A. pullulans M-2 had a faint yellow color, whereas that of the wild-type had an intense dark green color caused by the accumulation of melanin-like pigments. -Glucan produced by A. pullulans M-2 was identified as a polysaccharide of D-glucose monomers linked by -(1→3, 1→6)-glycosidic bonds through GC/MS and NMR analysis. When a conventional medium was used in the culture of A. pullulans M-2 in a 3-L jar fermentor, -glucan concentration was 1.4-fold that produced by the wild-type. However, when medium optimized by statistical experimental design was used with dissolved oxygen at 10%, the -glucan concentration was 9.9 g/L with yield of 0.52 (g -glucan/g consumed sucrose), which was 2.9-fold that of the wild-type. This level of productivity was reproduced when the fermentation was scaled up 200-L. The industrial production of high -glucan without melanin-like pigments is highly expected as a health-promoting supplement or functional food.

Yeasts found in vineyards and wineries

“…Other potential appications of A. pullulans include the production of several polysaccharides, such as β-(1 → 3)-d-glucans and pullulan (α-1,6 linked maltotriose), which are used as food additives, functional foods and raw materials for the medical, pharmaceutical and cosmetic industries (Moriya et al, 2013;Iyer et al, 2005;Kuan-Chen et al, 2010;Leathers, 2003). A. pullulans has also shown potential for phenol bioremediation of industrial effluents (dos Santos et al, 2009).…”

Stimulation of Macrophages with the β-Glucan Produced by Aureobasidium pullulans Promotes the Secretion of Tumor Necrosis Factor-Related Apoptosis Inducing Ligand (TRAIL)

“…Previous report has demonstrated that both soluble and particulate β-glucans are able to bind to dectin-1, but dectin-1 mediated signaling pathway is not activated by soluble β-glucans [ 34 , 35 ]. Curdlan is a particulate β-glucan [ 35 , 36 ], whereas AP-PG is water soluble [ 8 , 9 ]. Futher, it has been reported that AP-PG does not exhibit binding activity to dectin-1 [ 37 ], while curdlan is known to be an agonist for dectin-1 and is recognized by dectin-1 [ 38 , 39 ].…”

“…Black yeast, Aureobasidium Pullulans produces a water soluble β-glucan (AP-PG) in growth medium under certain conditions [ 8 , 9 ]. AP-PG is characterized by being more highly branched with β-(1,6)-D-glycosidic linked glucose residues than β-glucans derived from other organisms [ 9 , 10 ].…”

“…Black yeast, Aureobasidium Pullulans produces a water soluble β-glucan (AP-PG) in growth medium under certain conditions [ 8 , 9 ]. AP-PG is characterized by being more highly branched with β-(1,6)-D-glycosidic linked glucose residues than β-glucans derived from other organisms [ 9 , 10 ]. Overall, the effects of AP-PG in mammals are assumed to be the same as those of β-glucans derived from other organisms, and actually, anti-tumor, anti-allergy, and anti-infectious disease effects of AP-PG have been identified under experimental conditions [ 11 – 15 ].…”

Oral administration of the Aureobasidium pullulans-derived β-glucan effectively prevents the development of high fat diet-induced fatty liver in mice

“…Black yeast, Aureobasidium pullulans is widely used in industrial production of pullulan by fermentation 9 . Further, A. pullulans extracellularly produces soluble β-glucan consisting of a β-(1,3)-linked glucose main chain and β-(1,6)-linked glucose branches under specific growth conditions 10 11 . The A. pullulans -cultured fluid containing the β-glucan as a main component exhibits immune stimulatory activity, and is consumed as a supplement in many countries, as well as A. pullulans -cultured fluid is believed to exhibit beneficial effects in delaying the onset a number of diseases, and has been reported to exhibit anti-tumor 12 13 , anti-allergy 14 , and also anti-infectious disease 15 16 17 activities in mouse models.…”