High gravity lignocellulose bioprocess development for ethanol and lactic acid production by multi-feed simultaneous saccharification and fermentation
Konferensbidrag (offentliggjort, men ej förlagsutgivet), 2017

Second generation bioethanol production is becoming established in production plants across the world. The process can also be viewed as a model biorefinery concept for biotechnological conversion of recalcitrant lignocellulosic raw materials to chemicals and other products. We have developed a Multi-Feed SSCF process: a systematic, model-driven design of fed-batch simultaneous saccharification and co-fermentation of steam-pretreated lignocellulosic materials in standard stirred tank reactors. The design includes feeding of solid substrate, enzymes, and active, robust cell factories adapted to the present substrate. The concept has been applied not only to ethanol production with S. cerevisiae, but also to lactic acid production from wheat straw by the thermophilic, cellulolytic strain Bacillus coagulans MA-13, isolated from bean processing waste. High Gravity operation, i.e. fermentation at high concentrations of water insoluble solids (WIS), pushes the process towards higher product concentrations and productivities, and improved energy and water economy. By using the multi-feed SSCF approach, the ethanol process was pushed towards final product concentrations above 60 g/L, at about 90% of the theoretical yields on consumed substrate, using 22% w/w accumulated WIS additions of acid- and steam explosion-pretreated wheat straw. Bacillus coagulans MA-13 was found to secrete cellulolytic enzymes and ferment lignocellulose-derived sugars to lactic acid; thus, it may be a potential platform for consolidated bioprocessing of lactic acid. We investigated its performance in multi-feed SSF and found that pre-adaptation of cells to the liquid fraction of the steam-pretreated lignocellulosic material improves lactate productivity and reduces the SSF time from 33 to 12 hours.


kinetic modeling

lactic acid

high gravity





Carl Johan Franzén

Chalmers, Biologi och bioteknik, Industriell bioteknik

Ruifei Wang

Chalmers, Biologi och bioteknik, Industriell bioteknik

David Benjamin Nickel

Chalmers, Biologi och bioteknik, Industriell bioteknik

Lisbeth Olsson

Chalmers, Biologi och bioteknik, Industriell bioteknik

Salvatore Fusco

Chalmers, Biologi och bioteknik, Industriell bioteknik

Martina Aulitto

Chalmers, Biologi och bioteknik, Industriell bioteknik

Simonetta Bartolucci

Patrizia Contursi

Oral presentation at: Recent Advances in Fermentation Technology, RAFT12. Oct 29 - Nov 1, Bonita Springs, FL, USA.


Hållbar utveckling


Industriell bioteknik



Livsvetenskaper och teknik (2010-2018)

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