Simultaneous bioethanol distillery wastewater treatment and xylanase production by the phyllosphere yeast Pseudozyma antarctica GB-4(0)

Abstract

Bioethanol production using lignocellulosic biomass generates lignocellulosic bioethanol distillery wastewater (LBDW) that contains a large amount of xylose, making it a potential inexpensive source of xylose for biomaterials production. The main goal of this study was the production of useful enzymes from LBDW during treatment of this wastewater. In this study, we found that xylose strongly induced two yeast strains, Pseudozyma antarctica T-34 and GB-4(0), to produce novel xylanases, PaXynT and PaXynG, respectively. The nucleotide sequence of PaXynT [accession No. DF196774 (GAC73192.1)], obtained from the genome database of strain T-34 using its N-terminal amino acid sequence, was 91% identical to that of PaXynG (accession No. AB901085), and the deduced amino acid sequence is 98% identical. The specific activities of the purified PaXynT and PaXynG were about 52 U/mg. The optimal pH and temperature for both enzymes’ activities were 5.2 and 50°C, respectively. They hydrolyzed xylan to xylose and neither had β-xylosidase (EC 3.2.1.37) activity, indicating that they are endo-β-xylanases (EC 3.2.1.8). With these results, we expect that PaXyns can be employed in saccharizing lignocellulosic biomass materials for the production of useful products just like other endoxylanases. After 72 h of LBDW fed-batch cultivation using a jar-fermentor, strain GB-4(0) produced 17.3 U/ml (corresponding to about 0.3 g/l) of PaXynG and removed 63% of dissolved organic carbon and 87% of dissolved total phosphorus from LBDW. These results demonstrate the potential of P. antarctica for xylanase production during LBDW treatment.

Deficiency of biodegradable plastic-degrading enzyme production in a gene-deletion mutant of phyllosphere yeast, Pseudozyma antarctica defective in mannosylerythritol lipid biosynthesis

“…This result suggested that PaE expression and/or secretion decreased with defective MEL production. On the other hand, strain GB-4(0) secretes large amounts of 33-kDa endo-β-xylanase in the presence of xylose (Watanabe et al 2015). We observed similar signal intensity corresponding to xylanase in the culture supernatants of ΔPa EMT1 and wild-type cells (Fig.…”

Innovations in CAZyme gene diversity and its modification for biorefinery applications

“…Similarly, secretome analysis of Kalmonozyma brasiliensis grown on distinct sources of carbon helped in identifying 20 CAZymes (13 GHs, 3 CEs and 4AAs), which can have significant biotechnological potentials [ 126 ]. Two strains of Moesziomyces antarcticus was shown to produce xylanase of 33 kDa and belonged to GH10 family [ 127 ], while M. aphidis strain was shown that the yeast produces amylase that catalyzes endohydrolysis of 1,4-α-D-glycoside linkage in polysaccharides [ 128 ]. Pectin degrading activity was identified in Moesziomyces antarcticus , Kalmonozyma fusiformata and Pseudozyma sp.…”

Parageobacillus thermantarcticus, an Antarctic Cell Factory: From Crop Residue Valorization by Green Chemistry to Astrobiology Studies

“…This strain was found to produce thermostable endoxylanase and beta-xylosidase. The beta-xylosidase was optimally active at pH 7.0 and 60 • C, while the endoxylanase was active over a broad range of pH (5.0-10.0) and temperatures ( Considering the Antarctic biodiversity, in literature, there are several examples of fungi able to produce cold-adapted xylanase [56] or examples of Antarctic yeast able to use as cheaper growth media the lignocellulosic bioethanol distillery wastewater, which contains a large amount of xylose, and concurrently able to produce endo-β-xylanases [57]. As regards the Antarctic bacterial microorganisms possessing xylanase activity, recently, a new haloalkaliphilic, non-endospore-forming actinobacterium, named Nesterenkonia aurantiaca, was isolated from a soil sample, collected at Cape King (Antarctica) [58], and it was found to be able to hydrolyse xylan on an agar plate.…”