Project description:Consolidated bioprocessing (CBP) represents a promising approach to convert biomass into valuable chemicals by integrating the hydrolysis of cellulose and hemicellulose with microbial fermentation in a single step. This study investigates the potential of CBP technique for the efficient conversion of lignocellulosic biomass into malic acid using the thermophilic fungus Myceliophthora thermophila. Transcriptomic analysis and genetic studies indicated that efficient degradation of lignin is crucial for improving the overall efficiency of CBP, as it facilitates access to cellulose and hemicellulose while enabling the utilization of lignin-derived compounds. The assay of lignin degradation products revealed that M. thermophila can channel main lignin-derived components into the central metabolic pathway for malic acid production. The combined enhancement of lignin degradation capabilities and optimization of the cellodextrin utilization pathway in M. thermophila resulted in 52.9% increase in malic acid production, from 36.3 g/L to 55.5 g/L directly from raw corncob. In a bioreactor, malic acid titer reached 151.2 g/L by one-step bioconversion of plant biomass, with the productivity and yield of 1.09 g/L/h and 0.55 g/g raw corncob. Following separation and purification, the purity of malic acid reached 99%. This study underscores the viability of CBP as a sustainable approach for biobased chemical production and emphasizes the importance of optimizing both lignin degradation and product synthesis pathways to maximize the efficiency of biomass conversion processes.
Project description:Investigation of whole genome gene expression level changes in a Nitrosomonas europaea (ATCC 19718) wildtype and pFur::Kan mutant [kanamycin resistance cassette insertion in the promoter region of the fur gene (NE0616)] strains grown in Fe-replete and Fe-limited media. The Nitrosomonas europaea (ATCC 19718) wiltype cells grown in Fe-limited media were compared to cells grown in Fe-replete media to gain a better understanding of the metabolic changes occurring in response to iron stress. The Nitrosomonas europaea (ATCC 19718) pFur::Kan mutant strain grown in Fe-replete & Fe-limited media were compared to wildtype cells grown in Fe=replete & Fe-limited media to gain a better understanding of the role Fur (NE0616) plays in iron homeostasis control.
Project description:Lignin is a universal waste product of the agricultural industry and is currently seen as a potential feedstock for more sustainable manufacturing. While it is the second most abundant biopolymer in the world, most of it is currently burned as it is a very recalcitrant material. Many recent studies, however, have demonstrated the viability of biocatalysis to improve the value of this feedstock and convert it into more useful chemicals, such as polyhydroxybutyrate, and clean fuels like hydrogen and n-butanol. Rhodopseudomonas palustris is a gram-negative bacterium which demonstrates a plethora of desirable metabolic capabilities, including aromatic catabolism useful for lignin degradation. This study uses a multi-omics approach, including the first usage of CRISPRi in R. palustris, to investigate the lignin consumption mechanisms of R. palustris, the essentiality of redox homeostasis to lignin consumption, elucidate a potential lignin catabolic superpathway, and enable more economically viable sustainable lignin valorization processes.
Project description:Investigation of whole genome gene expression level changes in a Nitrosomonas europaea (ATCC 19718) wildtype and pFur::Kan mutant [kanamycin resistance cassette insertion in the promoter region of the fur gene (NE0616)] strains grown in Fe-replete and Fe-limited media. The Nitrosomonas europaea (ATCC 19718) wiltype cells grown in Fe-limited media were compared to cells grown in Fe-replete media to gain a better understanding of the metabolic changes occurring in response to iron stress. The Nitrosomonas europaea (ATCC 19718) pFur::Kan mutant strain grown in Fe-replete & Fe-limited media were compared to wildtype cells grown in Fe=replete & Fe-limited media to gain a better understanding of the role Fur (NE0616) plays in iron homeostasis control. A 4-plex 3 chip study using total RNA recovered from three separate wild-type cultures each of N. europaea grown in Fe-replete media and Fe-limited media and three seperate cultures each of N. europaea pFur::Kan mutant strain grown in Fe-replete and Fe-limited media. Each chip measures the expression level of 2368 genes from Nitrosomonas europaea (ATCC19718) with 4 X 72,000 60-mer 14 probe pairs per gene, with two-fold technical redundancy.
Project description:It includes analysis of different types of organic carbon
1 Model ligands and complexes
2 Lignin degradation materials
3 Quinones and adducts from biochars
4 Extraction and porewater of permafrost soils across the gradients of palsa-bog-fens
Project description:It includes analysis of different types of organic carbon
1 Model ligands and complexes
2 Lignin degradation materials
3 Quinones and adducts from biochars
4 Extraction and porewater of permafrost soils across the gradients of palsa-bog-fens