Bio‐based succinic acid is a potential building block for the production of renewable chemicals and polymers. The use of hemicellulosic hydrolyzate from sugarcane bagasse allows production of succinic acid without competing with food chains and increasing the biomass ‐aggregated value. This work assesses the economic impacts of integrating the production of ‐succinic acid on an optimized sugarcane biorefinery with the production of first‐generation ethanol and electricity. Process simulation was performed to obtain mass and energy balances of the entire process, from bagasse pre‐treatment to pentose fermentation and succinic acid recovery, using several pieces of technical information and data taken from the scientific literature. After ‐assessing the impacts of key economic variables through risk analysis, the obtained results were benchmarked against those of an optimized ethanol distillery. Calculated succinic acid production cost was US$ 2.32/kg, comparable to costs related to less expensive sugar sources. The integrated succinic acid biorefinery presented a slightly lower internal rate of return (IRR) compared to an ‐ethanol distillery. However, even when considering uncertainties, succinic acid production has a strong probability (84.6%) of achieving an IRR higher than 12%. © 2017 Society of Chemical Industry and John Wiley & Sons, Ltd

This article gives an overview of high-cell-density cultures for polyhydroxyalkanoate (PHA) production and their modes of operation for increasing productivity. High cell densities are very important in PHA production mainly because this polymer is an intracellular product accumulated in various microorganisms, so a high cellular content is needed for the polymer production. This review describes relevant results from fed-batch, repeated batch, and continuous modes of operation without and with cell recycle for the production of these polymers by microorganisms. Finally, recombinant microorganisms for PHA production, as well future directions for PHA production, are discussed.

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Alcoholic fermentation of released sugars in pretreatment and enzymatic hydrolysis of biomass is a central feature for second generation ethanol (E2G) production. Saccharomyces cerevisiae used industrially in the production of first generation ethanol (E1G) convert sucrose, fructose, and glucose into ethanol. However, these yeasts have no ability to ferment pentose (xylose). Therefore, the present work has focused on E2G production by Scheffersomyces stipitis and Spathaspora passalidarum. The fermentation strategy with high pitch, cell recycle, fed-batch mode, and temperature decrease for each batch were performed in a hydrolyzate obtained from a pretreatment at 130°C with NaOH solution (1.5% w/v) added with 0.15% (w/w) of anthraquinone (AQ) and followed by enzymatic hydrolysis. The process strategy has increased volumetric productivity from 0.35 to 0.38 g · L · h (first to third batch) for S. stipitis and from 0.38 to 0.81 g · L · h for S. passalidarum (first to fourth batch). Mass balance for the process proposed in this work showed the production of 177.33 kg ethanol/ton of sugar cane bagasse for S. passalidarum compared to 124.13 kg ethanol/ton of sugar cane bagasse for S. stipitis fermentation. The strategy proposed in this work can be considered as a promising strategy in the production of second generation ethanol. Biotechnol. Bioeng. 2017;114: 2211-2221. © 2017 Wiley Periodicals, Inc.