Whole conversion of agro-industrial wastes rich in galactose-based carbohydrates into lipid using oleaginous yeast Aureobasidium namibiae

Background Raw materials composed of easily assimilated monosaccharides have been employed as carbon source for production of microbial lipids. Nevertheless, agro-industrial wastes rich in galactose-based carbohydrates have not been introduced as feedstocks for oleaginous yeasts. Results In this study, Aureobasidium namibiae A12 was found to efficiently accumulate lipid from soy molasses and whey powder containing galactose-based carbohydrates, with lipid productions of 5.30 g/L and 5.23 g/L, respectively. Over 80% of the fatty acids was C16:0, C18:0, C18:1, and C18:2. All kinds of single sugar components in the two byproducts were readily converted into lipids, with yields ranging between 0.116 g/g and 0.138 g/g. Three α-galactosidases and five β-galactosidases in the strain were cloned and analyzed. Changes of transcriptional levels indicated GalB and GalC were key α-galactosidases, and GalG was key β-galactosidase. In 10 L fermentor, lipid production from SM and WP achieved 6.45 g/L and 6.13 g/L, respectively. β-galactosidase was responsible for lactose hydrolysis; sucrase and α-galactosidase both contributed to the efficient hydrolysis of raffinose and stachyose in a cooperation manner. Conclusions This is a new way to produce lipids from raw materials containing galactose-based carbohydrates. This finding revealed the significance of sucrase in the direct hydrolysis of galactose-based carbohydrates in raw materials for the first time and facilitated the understanding of the efficient utilization of galactose-based carbohydrates to manufacture lipid or other chemicals in bioprocess. Graphic abstract

Directional Synthesis of Furfural Compounds From Holocellulose Catalyzed by Sulfamic Acid

The coproduction of 5-hydroxymethylfurfural (5-HMF) and furfural (FUR) via the direct hydrolysis of holocellulose analogue composed of cellulose and hemicellulose was investigated. The effects of catalyst amount, solvent type and amount, reaction temperature and time using sulfamic acid with dual active sites as catalyst were also studied. The yields of 5-HMF and FUR at 37.2% and 62.0% were obtained with the volume ratio of γ-valerolactone to water of 25:1 at 180 oC for 3 h. The conversion of corn cob holocellulose and wheat straw holocellulose to furfural compounds was then carried out under the identical conditions. Yields of 5-HMF at 26.6% and 28.5%, and yields of FUR at 34.5% and 26.1% were obtained, respectively. A possible mechanism for the coproduction of 5-HMF and FUR from holocellulose was proposed. It is believed that there is a synergistic effect between the hydrolysis of cellulose and hemicellulose during the conversion of holocellulose.

Whole Conversion of Agro-Industrial Wastes Rich in Galactose-Based Carbohydrates into Lipid Using Oleaginous Yeast Aureobasidium Namibiae

BackgroundRaw materials composed of easily assimilated monosaccharides have been employed as carbon source for production of microbial lipids. Nevertheless, agro-industrial wastes rich in galactose-based carbohydrates have not been introduced as feedstocks for oleaginous yeasts. ResultsIn this study, Aureobasidium namibiae A12 was found to efficiently accumulate lipid from soy molasses and whey powder containing galactose-based carbohydrates, with lipid productions of 5.30 g/L and 5.23 g/L, respectively. Over 80% of the fatty acids was C16:0, C18:0, C18:1, and C18:2. All kinds of single sugar components in the two byproducts were readily converted into lipids, with yields ranging between 0.116 g/g and 0.138 g/g. Three α-galactosidases and five β-galactosidases in the strain were cloned and analyzed. β-galactosidase was responsible for lactose hydrolysis; sucrase and α-galactosidase both contributed to the efficient hydrolysis of raffinose and stachyose in a cooperation manner. ConclusionsThis is a new way to produce lipids from raw materials containing galactose-based carbohydrates. This finding revealed the significance of sucrase in the direct hydrolysis of galactose-based carbohydrates in raw materials for the first time and facilitated the understanding of the efficient utilization of galactose-based carbohydrates to manufacture lipid or other chemicals in bioprocess

Synthesis, structures and reduction chemistry of monophthalocyanine scandium hydroxides

The preparation and structural characterization of a pair of scandium(III) phthalocyanine hydroxide complexes were achieved by reaction of PcScCl with alkali metal alkoxides, likely via hydrolysis of soluble PcSc-alkoxide intermediates. A Sc[Formula: see text]Li[Formula: see text]-OH)[Formula: see text] cubane supported by two distorted Pc rings of the form (PcSc)[Formula: see text]-OH)[Formula: see text]Li[Formula: see text](THF)(DME) was isolated from the reaction of PcScCl with LiO[Formula: see text]Pr, while a simpler alkali-metal-free [Pc[Formula: see text]Sc[Formula: see text]-OH)[Formula: see text](THF)] was obtained from addition of NaO[Formula: see text]Bu; both structures are reminiscent of bent metallocenes, with dihedral angles between the two Pc rings of 50.8 and 37.7[Formula: see text]respectively. A soluble PcScOH material can also be obtained directly via hydrolysis of insoluble PcScCl in approximately 95:5 THF:water. Reduction of the Pc ring of PcScCl using KC[Formula: see text] is reversible and generates Pc[Formula: see text] and Pc[Formula: see text]-containing materials that were characterized via UV-vis spectroscopy and, where appropriate EPR and [Formula: see text]H NMR spectroscopy; analogous reductions of the PcScOH-based species were irreversible. Exposure of the air-sensitive, reduced PcScCl-based species to ambient atmosphere generated PcScOH materials analogous to the direct hydrolysis route.

Analysis of Glutamine Deamidation: Products, Pathways, and Kinetics

This manuscript examines glutamine deamidation, which is a spontaneous chemical modification similar to the much more thoroughly characterized asparagine deamidation. Although both processes share similarities and are known to occur in long-lived proteins, here we establish that important differences exist as well. For example, the distribution of isomers generated following glutamine deamidation contains far fewer D-residues. Furthermore, with the exception of QG motifs, glutamine deamidation occurs primarily by direct hydrolysis and produces less isoglutamic acid as a result. In addition, we demonstrate that radical-directed dissociation generates abundant, characteristic, fragment ions that can be used to easily distinguish glutamic acid from isoglutamic acid.

Analysis of Glutamine Deamidation: Products, Pathways, and Kinetics

This manuscript examines glutamine deamidation, which is a spontaneous chemical modification similar to the much more thoroughly characterized asparagine deamidation. Although both processes share similarities and are known to occur in long-lived proteins, here we establish that important differences exist as well. For example, the distribution of isomers generated following glutamine deamidation contains far fewer D-residues. Furthermore, with the exception of QG motifs, glutamine deamidation occurs primarily by direct hydrolysis and produces less isoglutamic acid as a result. In addition, we demonstrate that radical-directed dissociation generates abundant, characteristic, fragment ions that can be used to easily distinguish glutamic acid from isoglutamic acid.