Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes

Graphical abstract: Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes

Fermentation of hydrolysate detoxified by pervaporation through block copolymer membranes

 

The large-scale use of lignocellulosic hydrolysate as a fermentation broth has been impeded due to its high concentration of organic inhibitors to fermentation. In this study, pervaporation with polystyrene-block-polydimethylsiloxane-block-polystyrene (SDS) block copolymer membranes was shown to be an effective method for separating volatile inhibitors from dilute acid pretreated hydrolysate, thus detoxifying hydrolysate for subsequent fermentation. We report the separation of inhibitors from hydrolysate thermodynamically and quantitatively by detailing their concentrations in the hydrolysate before and after detoxification by pervaporation. Specifically, we report >99% removal of furfural and 27% removal of acetic acid with this method. Additionally, we quantitatively report that the membrane is selective for organic inhibitor compounds over water, despite water’s smaller molecular size. Because its inhibitors were removed but its sugars left intact, pervaporation-detoxified hydrolysate was suitable for fermentation. In our fermentation experiments, Saccharomyces cerevisiae strain SA-1 consumed the glucose in pervaporation-detoxified hydrolysate, producing ethanol. In contrast, under the same conditions, a control hydrolysate was unsuitable for fermentation; no ethanol was produced and no glucose was consumed. This work demonstrates progress toward economical lignocellulosic hydrolysate fermentation.

 

 

 
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Corresponding authors
a
Department of Chemical and Biomolecular Engineering, University of California, Berkeley, USA 
E-mail: nbalsara@berkeley.edu ;
Tel: +1 (510) 642-8937
b
Department of Bioengineering, University of California, Berkeley, USA 
E-mail: aparkin@lbl.gov ;
Tel: +1 (510) 643-5678
c
Energy Biosciences Institute, University of California, Berkeley, USA
d
Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, USA
e
Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, Berkeley, USA
Green Chem., 2014, Advance Article


DOI: 10.1039/C4GC00756E

 

 

 

 

 

 

 

 

 

 

Received 28 Apr 2014, Accepted 24 Jun 2014
First published online 11 Jul 2014

Hydrolysate was pervaporated with a block copolymer membrane, removing inhibitors but leaving sugars, creating a viable fermentation broth.

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Chiral Tin Participates in Radical Cyclizations

 

Chiral tin hydrides generate radicals and transfer chirality in the cyclization of aldehydes
This offers an insight for the future design of catalytic asymmetric radical reactions.

Read more

http://www.chemistryviews.org/details/ezine/5446641/Chiral_Tin_Participates_in_Radical_Cyclizations.html

Rapid Wolff-Kishner reductions in a silicon carbide microreactor

Green Chem., 2013, Advance Article
DOI: 10.1039/C3GC41942H, Paper
Stephen G. Newman, Lei Gu, Christoph Lesniak, Georg Victor, Frank Meschke, Lahbib Abahmane, Klavs F. Jensen
Wolff-Kishner reductions are performed continuously in a silicon carbide microreactor. Short reactions times and safe operation are achieved, giving high yields without reactor corrosion issues using just 1.5 equivalents of hydrazine.

Rapid Wolff-Kishner reductions in a silicon carbide microreactor

http://pubs.rsc.org/en/Content/ArticleLanding/2013/GC/C3GC41942H?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+rss%2FGC+%28RSC+-+Green+Chem.+latest+articles%29#!divAbstract

Wolff–Kishner reductions are performed in a novel silicon carbide microreactor. Greatly reduced reaction times and safer operation are achieved, giving high yields without requiring a large excess of hydrazine. The corrosion resistance of silicon carbide avoids the problematic reactor compatibility issues that arise when Wolff–Kishner reductions are done in glass or stainless steel reactors. With only nitrogen gas and water as by-products, this opens the possibility of performing selective, large scale ketone reductions without the generation of hazardous waste streams

Branched Enynenynols

“Old MacDonald Named a Compound: Branched Enynenynols”

that was originally published in the J. Chem. Ed. 74 (1997) 782, about what would happen if ‘Old MacDonald’ were a chemist, and made molecules that have the shapes of animals. Some are shown below.

http://pubs.acs.org/doi/abs/10.1021/ed074p782

Department of Chemistry, Hofstra University, Hempstead, NY 11590
J. Chem. Educ., 1997, 74 (7), p 782
DOI: 10.1021/ed074p782
Publication Date (Web): July 1, 1997

 

Selection of boron reagents for Suzuki-Miyaura coupling

Selection of boron reagents for Suzuki-Miyaura coupling


Chem. Soc. Rev.
, 2014, Advance Article
DOI: 10.1039/C3CS60197H, Review Article

Alastair J. J. Lennox, Guy C. Lloyd-Jones
School of Chemistry, University of Edinburgh, West Mains Road, Edinburgh, EH9 3JJ, UK
This review analyses the general physical and chemical properties of the seven main classes of boron reagent that have been employed for SM coupling
Suzuki–Miyaura (SM) cross-coupling is arguably the most widely-applied transition metal catalysed carbon–carbon bond forming reaction to date. Its success originates from a combination of exceptionally mild and functional group tolerant reaction conditions, with a relatively stable, readily prepared and generally environmentally benign organoboron reagent. A variety of such reagents have been developed for the process, with properties that have been tailored for application under specific SM coupling conditions. This review analyses the seven main classes of boron reagent that have been developed. The general physical and chemical properties of each class of reagent are evaluated with special emphasis on the currently understood mechanisms of transmetalation. The methods to prepare each reagent are outlined, followed by example applications in SM coupling.

Improved Continuous Flow Processing: Benzimidazole Ring Formation via Catalytic Hydrogenation of an Aromatic Nitro Compound

Figure

Improved Continuous Flow Processing: Benzimidazole Ring Formation via Catalytic Hydrogenation of an Aromatic Nitro Compound

Chemical Process Research and Development, Teva Pharmaceuticals, 383 Phoenixville Pike, Malvern, Pennsylvania 19355, United States
Org. Process Res. Dev., Article ASAP
Publication Date (Web): August 6, 2013 (Article)
DOI: 10.1021/op400179f
 In the development of a new route to bendamustine hydrochloride, the API in Treanda, the key benzimidazole intermediate 5 was generated via catalytic heterogeneous hydrogenation of an aromatic nitro compound using a batch reactor. Because of safety concerns and a site limitation on hydrogenation at scale, a continuous flow hydrogenation for the reaction was investigated at lab scale using the commercially available H-Cube. The process was then scaled successfully, generating kilogram quantities on the H-Cube Midi. This flow process eliminated the safety concerns about the use of hydrogen gas and pyrophoric catalysts and also showed 1200-fold increase in space–time yield versus the batch processing.