초록
<P><B>Background</B></P><P>Natural bacterial consortia are considered a promising solution for one-step production of ethanol from lignocellulose because of their adaptation to a wide range of natural lignocellulosic substrates and their capacity for efficient cellulose degradation. However, their low ethanol conversion efficiency has greatly limited the development and application of natural bacterial consortia.</P><P><B>Results</B></P><P>In the present study, we analyzed 16 different natural bacterial consortia from a variety of habitats in China and found that the HP consortium exhibited relatively high ethanol production (2.06 g/L ethanol titer from 7 g/L α-cellulose at 55°C in 6 days). Further studies showed that <I>Pseudoxanthomonas taiwanensis</I> played an important role in the high ethanol productivity of HP and that this strain effectively boosted the ethanol production of various other natural bacterial consortia. Finally, we developed a new consortium, termed HPP, by optimizing the proportion of <I>P. taiwanensis</I> in the HP consortium to achieve the highest ethanol production reported for natural consortia. The ethanol conversion ratio reached 78%, with ethanol titers up to 2.5 g/L.</P><P><B>Conclusions</B></P><P>In the present study, we found a natural bacterial consortium with outstanding ethanol production performance, and revealed an efficient method with potentially broad applicability for further improving the ethanol production of natural bacterial consortia.</P><P><B>Electronic supplementary material</B></P><P>The online version of this article (doi:10.1186/s13068-014-0186-7) contains supplementary material, which is available to authorized users.</P>