Bioprocessing

The energy crisis triggers the use of energy sources that are renewable, such as biomass made from lignocellulosic materials, to produce various chemical compounds for food ingredients and biofuel. The efficient conversion of lignocellulosic biomass into products with added value involves the activity of microorganisms, such as yeasts. For the conversion, microorganisms must be able to use various sugars in lignocellulosic biomass, including pentose sugars, especially xylose. This study aims to isolate xylose-utilizing yeasts and analyze their fermentation activity to produce xylitol and ethanol, as well as their ability to grow in liquid hydrolysate produced from pretreated lignocellulosic biomass...

In the context of the rapid development of low-carbon economy, there has been increasing interest in utilizing naturally abundant and cost-effective one-carbon (C1) substrates for sustainable production of chemicals and fuels. Moorella thermoacetica, a model acetogenic bacterium, has attracted significant attention due to its ability to utilize carbon dioxide (CO2 ) and carbon monoxide (CO) via the Wood-Ljungdahl (WL) pathway, thereby showing great potential for the utilization of C1 gases. However, natural strains of M...

Functional lipids, primarily derived through the modification of natural lipids by various processes, are widely acknowledged for their potential to impart health benefits. In contrast to chemical methods for lipid modification, enzymatic catalysis offers distinct advantages, including high selectivity, mild operating conditions, and reduced byproduct formation. Nevertheless, enzymes face challenges in industrial applications, such as low activity, stability, and undesired selectivity. To address these challenges, protein engineering techniques have been implemented to enhance enzyme performance in functional lipid synthesis...

During the ex vivo expansion of umbilical cord-derived mesenchymal stem cells (hUCMSCs) in a stirred tank bioreactor, the formation of cell-microcarrier aggregates significantly affects cell proliferation and physiological activity, making it difficult to meet the quantity and quality requirements for in vitro research and clinical applications. In this study, computational fluid dynamic (CFD) simulations were used to investigate the effect of an impeller structure in a commercial spinner flask on flow field structure, aggregate formation, and cellular physiological activity...

Because of its potent antioxidant effects, lycopene has been used in various industries including, but not limited to, food, medical, and cosmetic industries. Yarrowia lipolytica, a non-conventional yeast species, is a promising chassis due to its natural mevalonate (MVA) pathway, abundant precursor acetyl coenzyme A content, and oleaginous properties. Several gene editing tools have been developed for Y. lipolytica along with engineering strategies for tetraterpenoid production. In this study, we engineered Y...

A significant portion of the human diet is comprised of fruits, which are consumed globally either raw or after being processed. A huge amount of waste and by-products such as skins, seeds, cores, rags, rinds, pomace, etc. are being generated in our homes and agro-processing industries every day. According to previous statistics, nearly half of the fruits are lost or discarded during the entire processing chain. The concern arises when those wastes and by-products damage the environment and simultaneously cause economic losses...

Ulva is one of the main green algae causing green tide disasters. Ulvan is the primarily component polysaccharide of the cell wall of Ulva and its complex structure and monosaccharide composition resulted in various biological activities. However, the high-value and effective utilization of extracted ulvan have been obstructed by limitations ranging from large molecular weight and low solubility to poor bioavailability. Ulva oligosaccharide obtained by degrading ulvan can not only ideally retain the various biological activities of ulvan very well but also effectively solve the problems of low solubility and poor bioavailability...

Trehalose is a functional sugar that has numerous applications in food, cosmetic, and pharmaceutical products. Production of trehalose from maltose via a single-step enzymatic catalysis using trehalose synthase (TreS) is a promising method compared with the conventional two-step process due to its simplicity with lower formation of byproducts. In this study, a cold-active trehalose synthase (PaTreS) from Pseudarthrobacter sp. TBRC 2005 was heterologously expressed and characterized. PaTreS showed the maximum activity at 20 °C and maintained 87% and 59% of its activity at 10 °C and 4 °C, respectively...

β-Elemene, an active ingredient found in medicinal plants like turmeric and zedoary, is a sesquiterpene compound with antitumor activity against various cancers. However, its current mode of production through plant extraction suffers from low efficiency and limited natural resources. Recently, there has been an increased interest in establishing microbial cell factories to produce germacrene A, which can be converted to β-elemene by a one-step reaction in vitro. In this study, we constructed an engineered Pichia pastoris cell factory for producing germacrene A...

Hydrolysis at changing hydraulic retention time, recirculation, bedding straw content in the feed, bioaugmentation and the impact of those changes on gradient formation in the liquid phase in plug-flow reactors (PFRs) was examined. The pH-value, conductivity and oxidation-reduction potential (ORP) were monitored at three spots along the PFRs to study potential correlations to process performance during a total process time of 123 weeks. The on-line monitoring showed good correlations to acidogenesis: namely, the pH and ORP to the acidification, to butyric (and lactic) acid concentration and to the acid yield...

Cell-free protein synthesis (CFPS) system is an ideal platform for fast and convenient protein research and has been used for macromolecular assembly, unnatural amino acid embedding, glycoprotein production, and more. To realize the construction of an efficient eukaryotic CFPS platform with the advantages of low cost and short time, a CFPS system based on the yeast Pichia pastoris was built in this study. The internal ribosomal entry site (IRES) can independently initiate translation and thus promote protein synthesis...

Osteoarthritis (OA) of the knee is a common degenerative articular disorder and is one of the main causes of pain and functional disability. Cartilage damage is frequently linked to elevated osteoarthritis incidence. Supercritical carbon dioxide (scCO2 ) decellularized cartilage graft produced from the porcine cartilage is an ideal candidate for cartilage tissue engineering. In the present study, we derived collagen type II (Col II) solution from the scCO2 decellularized porcine cartilage graft (dPCG) and compared its efficacy with hyaluronic acid (HA) in the surgical medial meniscectomy (MNX) induced post-traumatic osteoarthritis (PTOA) model...

This study aimed to produce bioactive peptides from navy-bean protein with alcalase and pepsin enzymes (30-300 min) and to load them into a nanoliposome system to stabilize and improve their bioavailability. The degree of hydrolysis and biological activities (scavenging of DPPH, OH, and ABTS free radicals, reducing power, and chelating metal ions) of navy-bean protein were affected by the type of enzyme and hydrolysis time. The average particle size (83-116 nm), PDI (0.23-0.39), zeta potential (- 13 to - 20 mV), and encapsulation efficiency (80-91%) of nanoliposomes were influenced by the type and charge of peptides...

In Germany alone, more than 5·106 tons of municipal green waste is produced each year. So far, this material is not used in an economically worthwhile way. In this work, grass clippings and tree pruning as examples of municipal green waste were utilized as feedstock for the microbial production of platform chemicals. A pretreatment procedure depending on the moisture and lignin content of the biomass was developed. The suitability of grass press juice and enzymatic hydrolysate of lignocellulosic biomass pretreated with an organosolv process as fermentation medium or medium supplement for the cultivation of Saccharomyces cerevisiae, Lactobacillus delbrueckii subsp...

The natural product pneumocandin B0 is the precursor of the antifungal drug caspofungin. To explore the relationship between pneumocandin B0 and oil. We found that the addition of 1 g/L of oil to the fermentation medium is more conducive to the production of pneumocandin B0 . The metabolic reaction mechanism was explored using different fatty acids and the results showed that stearic acid and acetic acid increased the total production of pneumocandin B0 by 22.98% and 9.08%, respectively, as well as increasing the content of intracellular lipid droplets...

Unspecific peroxygenases (UPOs) are glycosylated enzymes that provide an efficient method for oxyfunctionalizing a variety of substrates using only hydrogen peroxide (H2 O2 ) as the oxygen donor. However, their poor heterologous expression has hindered their practical application. Here, a novel UPO from Marasmius fiardii PR910 (MfiUPO) was identified and heterologously expressed in Pichia pastoris. By employing a two-copy expression cassette, the protein titer reached 1.18 g L-1 in a 5 L bioreactor, marking the highest record...

High-performance electrical Joule heaters with high mechanical properties, low driving voltage, rapid response, and flexibility are highly desirable for portable thermal management. Herein, by using aligned bacterial cellulose (BC) and silver nanowire (AgNW), we fabricated a novel film heater based on Joule heating phenomena. The aligned BC film prepared by stretching BC hydrogel and hot-pressing drying technology showed outstanding mechanical properties and flexibility. The ultrahigh strength of up to 1018 MPa and the toughness of 20 MJ/m3 were obtained for the aligned BC film with 40% wet-stretching (BC-40)...

Tobacco polysaccharides were extracted by hot water extraction, and purified and separated using DEAE-52 cellulose chromatography columns, and three purified polysaccharide fractions, YCT-1, YCT-2, and YCT-3, were finally obtained. The physicochemical properties of the three fractions were analyzed by ultraviolet spectroscopy, high-performance liquid chromatography and high-performance gel chromatography. The in vitro antioxidant activity of tobacco polysaccharides was compared among different fractions by using DPPH radical, hydroxyl radical scavenging assay and potassium ferricyanide method...

This study investigated, if a mixed electroactive bacterial (EAB) culture cultivated heterotrophically at a positive applied potential could be adapted from oxidative to reductive or bidirectional extracellular electron transfer (EET). To this end, a periodic potential reversal regime between - 0.5 and 0.2 V vs. Ag/AgCl was applied. This yielded biofilm detachment and mediated electroautotrophic EET in combination with carbonate, i.e., dissolved CO2 , as the sole carbon source, whereby the emerged mixed culture (S1) contained previously unknown EAB...

Monoclonal antibodies (mAbs) require a high level of purity for regulatory approval and safe administration. High-molecular weight (HMW) species are a common impurity associated with mAb therapies. Hydrophobic interaction chromatography (HIC) resins are often used to remove these HMW impurities. Determination of a suitable HIC resin can be a time and resource-intensive process. In this study, we modeled the chromatographic behavior of seven mAbs across 13 HIC resins using measurements of surface hydrophobicity, surface charge, and thermal stability for mAbs, and hydrophobicity and zeta-potential for HIC resins with high fit quality (adjusted R2  > 0...