Metabolic engineering strategies for consolidated production of lactic acid from lignocellulosic biomass. (4th February 2020)

• Record Type: Journal Article
• Authors: Mazzoli, Roberto
• Other Names: Mazzoli Roberto guestEditor.; Liu Cheng‐Guang guestEditor.
• Is Part Of: Biotechnology and applied biochemistry. Volume 67:Number 1(2020)
• Page Start: 61
• Page End: 72
• Publication Date: 2020-02-04
• Subjects: Bacillus -- consolidated bioprocessing -- Clostridium -- lactic acid bacteria -- Rhizopus; Biotechnology -- Periodicals; Biochemical engineering -- Periodicals; Biochemistry -- Periodicals; Biochemistry -- Periodicals; Genetic Techniques -- Periodicals; Microbiological Techniques -- Periodicals; 660.6
• DOI: 10.1002/bab.1869
• Languages: English
• ISSNs: 0885-4513

Abstract

Abstract: Lactic acid (LA) is one of the most desired molecules by the chemical industry. Current expansion of LA market is mainly driven by its application as building block for the synthesis of polylactide (PLA), that is, a family of biodegradable and biocompatible plastic polymers. PLA can potentially replace oil‐derived polymers as general purpose plastic, but current LA prices fails to make PLA cost‐competitive with traditional plastics. Nowadays, LA is mainly produced by fermentation of expensive starchy biomass. Hopefully, cheaper lignocellulosic feedstock could be used in future second‐generation biorefinery processes. However, most efficient natural LA producers cannot ferment lignocellulose without prior biomass saccharification. Metabolic engineering may develop improved microorganisms that feature both efficient biomass hydrolysis and LA production, thus supporting consolidated bioprocessing (CBP), that is, one‐pot fermentation, of lignocellulose to LA. CBP could dramatically reduce LA production cost, thus contributing to the expansion of more environmental sustainable plastics and commodity chemicals. This review presents an overview of "recombinant cellulolytic strategies", mainly consisting in introducing cellulase systems in native producers of LA, and "native cellulolytic strategies" aimed at improving LA production in natural cellulolytic microorganisms. Issues and perspectives of these approaches will be discussed. Abstract : Construction of recombinant microorganisms for direct fermentation of lignocellulose to lactic acid can be pursued through the native cellulolytic strategy, namely the improvement of lactic acid production in natural cellulolytic strains (left) or the recombinant cellulolytic strategy, that is, the introduction of designer cellulase systems in natural lactic acid producers (right).