Inokuma Kentaro, Hasunuma Tomohisa, Kondo Akihiko
Graduate School of Science, Technology and Innovation, Kobe University, 1-1 Rokkodai, Nada, Kobe, 657-8501, Japan.
Biomass Engineering Program, RIKEN, 1-7-22 Suehiro-cho, Tsurumi-ku, Yokohama, Kanagawa, 230-0045, Japan.
AMB Express. 2016 Dec;6(1):83. doi: 10.1186/s13568-016-0267-z. Epub 2016 Oct 3.
N-acetyl-D-glucosamine (GlcNAc) is the building block of chitin, which is one of the most abundant renewable resources in nature after cellulose. Therefore, a microorganism that can utilize GlcNAc is necessary for chitin-based biorefinery. In this study, we report on the screening and characterization of yeast strains for bioethanol production from GlcNAc. We demonstrate that Scheffersomyces (Pichia) stipitis strains can use GlcNAc as the sole carbon source and produce ethanol. S. stipitis NBRC1687, 10007, and 10063 strains consumed most of the 50 g/L GlcNAc provided, and produced 14.5 ± 0.6, 15.0 ± 0.3, and 16.4 ± 0.3 g/L of ethanol after anaerobic fermentation at 30 °C for 96 h. The ethanol yields of these strains were approximately 81, 75, and 82 % (mol ethanol/mol GlcNAc consumed), respectively. Moreover, S. stipitis NBRC10063 maintained high GlcNAc-utilizing capacity at 35 °C, and produced 12.6 ± 0.7 g/L of ethanol after 96 h. This strain also achieved the highest ethanol titer (23.3 ± 1.0 g/L) from 100 g/L GlcNAc. To our knowledge, this is the first report on ethanol production via fermentation of GlcNAc by naturally occurring yeast strains.
N-乙酰-D-葡萄糖胺（GlcNAc）是几丁质的组成成分，几丁质是自然界中仅次于纤维素的最丰富的可再生资源之一。因此，对于基于几丁质的生物炼制来说，一种能够利用GlcNAc的微生物是必不可少的。在本研究中，我们报告了用于从GlcNAc生产生物乙醇的酵母菌株的筛选和特性。我们证明了树干毕赤酵母（Scheffersomyces (Pichia) stipitis）菌株可以将GlcNAc用作唯一碳源并生产乙醇。树干毕赤酵母NBRC1687、10007和10063菌株消耗了提供的50 g/L GlcNAc中的大部分，并在30°C厌氧发酵96小时后分别产生了14.5±0.6、15.0±0.3和16.4±0.3 g/L的乙醇。这些菌株的乙醇产量分别约为81%、75%和82%（每消耗1摩尔GlcNAc产生的乙醇摩尔数）。此外，树干毕赤酵母NBRC10063在35°C时保持了较高的GlcNAc利用能力，并在96小时后产生了12.6±0.7 g/L的乙醇。该菌株还从100 g/L GlcNAc中获得了最高的乙醇滴度（23.3±1.0 g/L）。据我们所知，这是关于天然酵母菌株通过发酵GlcNAc生产乙醇的首次报道。
