A green pathway for lignin valorization: Enzymatic lignin depolymerization in biocompatible ionic liquids and deep eutectic solvents.

Lignin depolymerization, which enables the breakdown of a complex and heterogeneous aromatic polymer into relatively uniform derivatives, serves as a critical process in valorization of lignin. Enzymatic lignin depolymerization has become a promising biological strategy to overcome the heterogeneity of lignin, due to its mild reaction conditions and high specificity. However, the low solubility of lignin compounds in aqueous environments prevents efficient lignin depolymerization by lignin-degrading enzymes.

Comparison of hydrothermolysis and mild-alkaline pretreatment methods on enhancing succinic acid production from hydrolyzed corn fiber.

In the present work, mild alkaline pretreatments using either sodium hydroxide (0.05 g/g corn fiber) or calcium hydroxide (lime) (0.05 g/g corn fiber) were optimized and compared with hydrothermolysis pretreatment to enhance bioproduction of succinic acid from hydrolyzed corn fiber.

A lack of an association between COVID-19 vaccination and corneal graft rejection: results of a large multi-country population based study.

Purpose: The aim of the study was to present the rates of corneal transplant rejection from 2018 to 2022 at both Moorfields Eye Hospital UK, and Ospedali Privati Forli (OPF) "Villa Igea", Italy and evaluate the purported association between COVID-19 vaccination and rejection.

Methods: We performed a retrospective review of rejection cases presenting to the two units. Monthly rates were correlated against regional vaccination programme rates.

A review on strategies to reduce ionic liquid pretreatment costs for biofuel production.

Worldwide demand for renewable energy has promoted the considerable exploration of biofuel production from lignocellulosic biomass. Ionic liquid pretreatment is of great interest to render biomass amenable for biofuel production, however, its unaffordable cost stimulates significant attention to the feasibility of commercialization. This review aims to compile the latest advances with respect to reducing production costs for ionic liquids-based biorefineries.

Rhodopseudomonas palustris: A biotechnology chassis.

Rhodopseudomonas palustris is an attractive option for biotechnical applications and industrial engineering due to its metabolic versatility and its ability to catabolize a wide variety of feedstocks and convert them to several high-value products. Given its adaptable metabolism, R. palustris has been studied and applied in an extensive variety of applications such as examining metabolic tradeoffs for environmental perturbations, biodegradation of aromatic compounds, environmental remediation, biofuel production, agricultural biostimulation, and bioelectricity production.

'Posture-Less' DMEK: Is Posturing After Descemet Membrane Endothelial Keratoplasty Actually Necessary?

Purpose: To evaluate the clinical results of Descemet membrane endothelial keratoplasty (DMEK) without any intraoperative or postoperative posturing.

Design: Retrospective, noncomparative, and interventional case series.

Methods: One hundred thirty-four (134) consecutive eyes of 101 patients requiring DMEK for any cause of endothelial failure were included.

Heterologous phasin expression in CGA009 for bioplastic production from lignocellulosic biomass.

CGA009 is a metabolically robust microbe that can utilize lignin breakdown products to produce polyhydroxyalkanoates (PHAs), biopolymers with the potential to replace conventional plastics. Our recent efforts suggest PHA granule formation is a limiting factor for maximum production of the bioplastic poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) by The Phap1 phasin () from the PHB-producing model bacterium H16 was expressed in with the aim of overproducing PHBV from the lignin breakdown product coumarate by fostering smaller and more abundant granules. Expression of yielded PHBV production from aerobically (0.

Synergistic experimental and computational approach identifies novel strategies for polyhydroxybutyrate overproduction.

Polyhydroxybutyrate (PHB) is a sustainable bioplastic produced by bacteria that is a potential replacement for conventional plastics. This study delivers an integrated experimental and computational modeling approach to decipher metabolic factors controlling PHB production and offers engineering design strategies to boost production. In the metabolically robust Rhodopseudomonas palustris CGA009, PHB production significantly increased when grown on the carbon- and electron-rich lignin breakdown product p-coumarate (CHO) compared to virtually no PHB titer from acetate (CHNaO).

Exploring lignin depolymerization by a bi-enzyme system containing aryl alcohol oxidase and lignin peroxidase in aqueous biocompatible ionic liquids.

Enzymatic depolymerization of lignin to produce low molecular weight products requires mild reaction conditions and exhibits higher selectivity compared to thermochemical lignin depolymerization. However, it remains challenging to depolymerize lignin enzymatically, partially due to the low solubility of lignin in aqueous phase. This study aimed to develop a novel approach to combine aqueous lignin extraction with enzymatic lignin depolymerization in biocompatible ionic liquids.

One step forward, two steps back: Transcriptional advancements and fermentation phenomena in Actinobacillus succinogenes 130Z.

Within the field of bioproduction, non-model organisms offer promise as bio-platform candidates. Non-model organisms can possess natural abilities to consume complex feedstocks, produce industrially useful chemicals, and withstand extreme environments that can be ideal for product extraction. However, non-model organisms also come with unique challenges due to lack of characterization.

Fed-batch production of Thermothelomyces thermophilus lignin peroxidase using a recombinant Aspergillus nidulans strain in stirred-tank bioreactor.

Enzymatic lignin depolymerization is considered a favorable approach to utilize lignin due to the higher selectivity and less energy requirement when compared to thermochemical lignin valorization. Lignin peroxidase (LiP) is one of the key enzymes involved in lignin degradation and possesses high redox potential to oxidize non-phenolic structures and phenolic compounds in lignin. However, the production of LiP is mainly from white-rot fungi at small scales.

Fed-batch polyhydroxybutyrate production by Paraburkholderia sacchari from a ternary mixture of glucose, xylose and arabinose.

Polyhydroxybutyrate (PHB) is a biodegradable bioplastic that is comparable with many petroleum-based plastics in terms of mechanical properties and is highly biocompatible. Lignocellulosic biomass conversion into PHB can increase profit and add sustainability. Glucose, xylose and arabinose are the main monomer sugars derived from upstream lignocellulosic biomass processing.

Process optimization and scale-up production of fungal aryl alcohol oxidase from genetically modified Aspergillus nidulans in stirred-tank bioreactor.

Microbial production of aryl alcohol oxidase (AAO) has attracted increasing attention due to the central role of AAO in enzymatic lignin depolymerization. However, large-scale production of AAO has not been reached because of the low yield and inefficient fermentation process. This study aims to optimize the process parameters and scale-up production of AAO using Aspergillus nidulans in a stirred-tank bioreactor.

Optimization of process parameters and fermentation strategy for xylanase production in a stirred tank reactor using a mutant strain.

The present work studied the optimization of aeration rate, agitation rate and oxygen transfer and the use of various batch fermentation strategies for xylanase production from a recombinant strain in a 3 L stirred tank reactor. Maximum xylanase production of 1250 U/mL with productivity of 313 U/mL/day was obtained under an aeration rate of 2 vvm and an agitation rate of 400 rpm using batch fermentation. The optimum volumetric oxygen transfer coefficient (ka) for efficient xylanase production was found to be 38.

Recent advances in polyhydroxyalkanoate production: Feedstocks, strains and process developments.

Polyhydroxyalkanoates (PHAs) have been actively studied in academia and industry for their properties comparable to petroleum-derived plastics and high biocompatibility. However, the major limitation for commercialization is their high cost. Feedstock costs, especially carbon costs, account for the majority of the final cost.

Development of a cost-effective medium for submerged production of fungal aryl alcohol oxidase using a genetically modified Aspergillus nidulans strain.

Aryl alcohol oxidase (AAO), an extracellular HO-providing enzyme, plays a central role in lignin depolymerization. Cost-effective production of AAO has not been achieved, due to the low yield of enzyme-producing microorganisms and the high cost of fermentation media. This study aims to develop a cost-effective medium for high-yield production of AAO in submerged culture using a recombinant Aspergillus nidulans strain.

Fed-batch cultivation and adding supplements to increase yields of polyhydroxybutyrate production by Cupriavidus necator from corn stover alkaline pretreatment liquor.

The aim of this study was to evaluate polyhydroxybutyrate (PHB) production and productivity with supplements under fed-batch cultivation at bioreactor scale (1.3 L). In this study, multiple supplements including oxidative enzyme, mediators, surfactants and silicon nanoparticles were added to Cupriavidus necator culture growing on alkaline pretreatment liquor (APL).

Heterologous expression and functional characterization of a GH10 endoxylanase from var. with potential biotechnological application.

Xylanases decrease the xylan content in pretreated biomass releasing it from hemicellulose, thus improving the accessibility of cellulose for cellulases. In this work, an endo-β-1,4-xylanase from var. (AFUMN-GH10) was successfully expressed.

Flow cytometry for quantitation of polyhydroxybutyrate production by Cupriavidus necator using alkaline pretreated liquor from corn stover.

Alkaline pretreated liquor (APL) from lignocellulosic feedstock pretreatment is a lignin-rich stream. Polyhydroxybutyrate (PHB), a biodegradable polymer, has been previously synthesized from APL. It is of interest to monitor PHB production and cell number from APL rapidly for process control.

Optimization of polyhydroxybutyrate production by experimental design of combined ternary mixture (glucose, xylose and arabinose) and process variables (sugar concentration, molar C:N ratio).

Conversion of lignocellulosic feedstocks to polyhydroxybutyrate (PHB) could make lignocellulosic biorefineries more profitable and sustainable. Glucose, xylose and arabinose are the main sugars derived from pretreatment and hydrolysis of herbaceous feedstocks. Burkholderia sacchari DSM 17165 is a bacterium that can convert these sugars into PHB.