Background The biomanufacturing of d-glucaric acid has attracted increasing interest because it is one of the top value-added chemicals produced from biomass. Saccharomyces cerevisiae is regarded as an excellent host for d-glucaric acid production. Results The opi1 gene was knocked out because of its negative regulation on myo-inositol synthesis, which is the limiting step of d-glucaric acid production by S. cerevisiae. We then constructed the biosynthesis pathway of d-glucaric acid in S. cerevisiae INVSc1 opi1Δ and obtained two engineered strains, LGA-1 and LGA-C, producing record-breaking titers of d-glucaric acid: 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L d-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in fed-batch fermentation mode, respectively. However, LGA-1 was preferable because of its genetic stability and its superior performance in practical applications. There have been no reports on d-glucaric acid production from lignocellulose. Therefore, the biorefinery processes, including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated and compared. CBP using an artificial microbial consortium composed of Trichoderma reesei (T. reesei) Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high d-glucaric acid titers and yields after 7 d of fermentation, 0.54 ± 0.12 g/L d-glucaric acid from 15 g/L Avicel and 0.45 ± 0.06 g/L d-glucaric acid from 15 g/L steam-exploded corn stover (SECS), respectively. In an attempt to design the microbial consortium for more efficient CBP, the team consisting of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be the best, with excellent work distribution and collaboration. Conclusions Two engineered S. cerevisiae strains, LGA-1 and LGA-C, with high titers of d-glucaric acid were obtained. This indicated that S. cerevisiae INVSc1 is an excellent host for d-glucaric acid production. Lignocellulose is a preferable substrate over myo-inositol. SHF, SSF, and CBP were studied, and CBP using an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be promising because of its relatively high titer and yield. T. reesei Rut-C30 and S. cerevisiae LGA-1were proven to be the best teammates for CBP. Further work should be done to improve the efficiency of this microbial consortium for d-glucaric acid production from lignocellulose.

The biomanufacturing of D-glucaric acid has been attracted increasing interest and the industrial yeast Saccharomyces cerevisiae is regarded as an excellent host for D-glucaric acid production. Here we constructed the biosynthetic pathway of D-glucaric acid in S. cerevisiae INVSc1 whose opi1 was knocked out and obtained two engineered strains, LGA-1 and LGA-C, producing record breaking titers of D-glucaric acid, 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L D-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in the mode of fed-batch fermentation, respectively. Due to the genetic stability and the outperformance in subsequent applications, however, LGA-1 was a preferable strain. As one of the top chemicals from biomass, there have been no reports on D-glucaric acid production from lignocellulose, which is the most abundant renewable on earth. Therefore, the biorefinery processes of lignocellulose for D-glucaric acid production including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated in this work and CBP by an artificial microbial consortium composed of Trichoderma reesei Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high D-glucaric acid titers and yields after 7 d fermentation, 0.54 ± 0.12 g/L D-glucaric acid from 15 g/L Avicel, and 0.45 ± 0.06 g/L D-glucaric acid from 15 g/L steam exploded corn stover (SECS), respectively. In attempts to design the microbial consortium for more efficient CBP the team consisted of the two members, T. reesei Rut-C30 and S. cerevisiae LGA-1, was found to be the best with excellent work distribution and collaboration.This desirable and promising approach for direction production of D-glucaric acid from lignocellulose deserves extensive and in-depth research.

Background The biomanufacturing of D-glucaric acid has been attracted increasing interest and the industrial yeast Saccharomyces cerevisiae is regarded as an excellent host for D-glucaric acid production. Results Here we constructed the biosynthetic pathway of D-glucaric acid in S. cerevisiae INVSc1 whose opi1 was knocked out and obtained two engineered strains, LGA-1 and LGA-C, producing record breaking titers of D-glucaric acid, 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L D-glucaric acid from 30 g/L glucose and 10.8 g/L myo -inositol in the mode of fed-batch fermentation, respectively. Due to the genetic stability and the outperformance in subsequent applications, however, LGA-1 was a preferable strain. As one of the top chemicals from biomass, there have been no reports on D-glucaric acid production from lignocellulose, which is the most abundant renewable on earth. Therefore, the biorefinery processes of lignocellulose for D-glucaric acid production including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated in this work and CBP by an artificial microbial consortium composed of Trichoderma reesei Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high D-glucaric acid titers and yields after 7 d fermentation, 0.54 ± 0.12 g/L D-glucaric acid from 15 g/L Avicel, and 0.45 ± 0.06 g/L D-glucaric acid from 15 g/L steam exploded corn stover (SECS), respectively. Conclusions In attempts to design the microbial consortium for more efficient CBP the team consisted of the two members, T. reesei Rut-C30 and S. cerevisiae LGA-1, was found to be the best with excellent work distribution and collaboration. This desirable and promising approach for direction production of D-glucaric acid from lignocellulose deserves extensive and in-depth research.

Background: The biomanufacturing of D-glucaric acid has been attracted increasing interest because it is one of the top value-added chemicals produced from biomass. Saccharomyces cerevisiae is regarded as an excellent host for D-glucaric acid production. Results: The opi1 gene was knocked out because of its negative regulation on myo-inositol synthesis, which is the limiting step of D-glucaric acid production by S. cerevisiae. Then we constructed the biosynthetic pathway of D-glucaric acid in S. cerevisiae INVSc1 opi1Δ and obtained two engineered strains, LGA-1 and LGA-C, producing record breaking titers of D-glucaric acid, 9.53 ± 0.46 g/L and 11.21 ± 0.63 g/L D-glucaric acid from 30 g/L glucose and 10.8 g/L myo-inositol in the mode of fed-batch fermentation, respectively. However, LGA-1 was more preferable because of the genetic stability and the outperformance in applications. So far, there have been no reports on D-glucaric acid production from lignocellulose. Therefore, the biorefinery processes including separated hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and consolidated bioprocessing (CBP) were investigated and compared. CBP by an artificial microbial consortium composed of Trichoderma reesei Rut-C30 and S. cerevisiae LGA-1 was found to have relatively high D-glucaric acid titers and yields after 7 d fermentation, 0.54 ± 0.12 g/L D-glucaric acid from 15 g/L Avicel, and 0.45 ± 0.06 g/L D-glucaric acid from 15 g/L steam exploded corn stover (SECS), respectively. In attempts to design the microbial consortium for more efficient CBP the team consisted of the two members, T. reesei Rut-C30 and S. cerevisiae LGA-1, was found to be the best with excellent work distribution and collaboration.Conclusions: Two engineered S. cerevisiae strains, LGA-1 and LGA-C, with high titers of D-glucaric acid were obtained. This indicates that S. cerevisiae INVSc1 was an excellent host. Lignocellulose is a more preferable substrate than myo-inositol. SHF, SSF and CBP were studied and CBP by an artificial microbial consortium of T. reesei Rut-C30 and S. cerevisiae LGA-1 was found to be promising because of the relatively high titer and yield. T. reesei Rut-C30 and S. cerevisiae LGA-1were proved to be the best teammates for CBP. Further work should be done to improve the efficiency of this microbial consortium for D-glucaric acid production from lignocellulose.