BioChem - DOS

Efficient conversion of mannitol derived from brown seaweed to fructose for fermentation with a thraustochytrid

Journal of bioscience and bioengineering

Tajima, Takahisa; Tomita, Kousuke; Miyahara, Hiroyuki; Watanabe, Kenshi; Aki, Tsunehiro; Okamura, Yoshiko; Matsumura, Yukihiko; Nakashimada, Yutaka; Kato, Junichi

<P>Macroalgae are a promising biomass feedstock for energy and valuable chemicals. Mannitol and alginate are the major carbohydrates found in the microalga <I>Laminaria japonica</I> (<I>Konbu</I>). To convert mannitol to fructose for its utilization as a carbon source in mannitol non-assimilating bacteria, a psychrophile-based simple biocatalyst (PSCat) was constructed using a psychrophile as a host by expressing mesophilic enzymes, including mannitol 2-dehydrogenase for mannitol oxidation, and NADH oxidase and alkyl hydroxyperoxide reductase for NAD<SUP>+</SUP> regeneration. PSCat was treated at 40 &deg;C to inactivate the psychrophilic enzymes responsible for byproduct formation and to increase the membrane permeability of the substrate. PSCat efficiently converted mannitol to fructose with high conversion yield without additional input of NAD<SUP>+</SUP>. <I>Konbu</I> extract containing mannitol was converted to fructose with hydroperoxide scavenging, inhibiting the mannitol dehydrogenase activity. <I>Auranthiochytrium</I> sp. could grow well in the presence of fructose converted by PSCat. Thus, PSCat is a potential carbohydrate converter for mannitol non-assimilating microorganism.</P> <P><B>Highlights</B></P> <P> <UL> <LI> PSCat efficiently converted mannitol to fructose without additional input of NAD<SUP>+</SUP>. </LI> <LI> <I>Konbu</I> extract with mannitol was converted to fructose, scavenging hydroperoxide. </LI> <LI> <I>Auranthiochytrium</I> sp. grew well in the presence of fructose converted by PSCat. </LI> <LI> PSCat is a potential carbohydrate converter for mannitol non-assimilating bacteria. </LI> </UL> </P>

2018

Elsevier

publisher-specific-oa

1389-1723

1347-4421

125

2

pp.180-184

10.1016/j.jbiosc.2017.09.002

http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=05787966&target=NART&cn=NART80069457

http://manuscript.elsevier.com/S1389172317304413/pdf/S1389172317304413.pdf

Biomass; Fructose; Mannitol; Psychrophilic bacteria; NAD+ regeneration