PubMed Health⌕ Search

PubMed · 15975231

Preparative SEC column packed with microporous particles prepared from cellulose.

Abstract

New microporous particles with large pore size (mean pore diameter of 820 nm) are successfully prepared from a mixture of cellulose and konjac glucomannan (RC-KGM3) in 1.5 M NaOH-0.65 M thiourea aqueous solution by coagulating with 5 weight percentage (wt%) CaCl(2), and then 2 wt% HCl aqueous solution. A preparative size-exclusion chromatographic (SEC) column packed with the gel particles is used for the fractionation of a dextran in water. The exclusion limit and fractionation range of the stationary phase are molecular masses of 125 yen 104 g/mol and 5.6 yen 104 to 125 yen 104 g/mol, respectively. The dextran [dextran 50, weight-average molecular mass (M(w)) = 40.1 yen 104 g/mol, polydispersity index (d) = 3.5] is fractionated by the preparative SEC column to obtain six fractions, and four of them are refractionated twice by the same preparative SEC column. The refractionated samples F-3-3 and F-4-3 are characterized by analytical SEC combined with laser light scattering and light scattering to obtain M(w) of 91.8 and 61.9 yen 104 g/mol, as well as d of 1.3 and 1.4, respectively. The results indicate that the fractions having narrow molecular mass distribution are satisfactorily prepared with the SEC column. The described SEC column can be successfully used to fractionate polymers in aqueous solution.

Explore related subjects

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Yanwei Wu, Bingren Xiang, Jin Yang, Jingjuan Fu, Jianhua Jiang. 2005. Preparative SEC column packed with microporous particles prepared from cellulose.. https://pubmed.ncbi.nlm.nih.gov/15975231/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

Compost microbiomes as reservoirs of cellulolytic microorganisms for cellulosic textile degradation.

Cellulosic textiles, constituting over 30% of global fibre production, are biodegradable but remain challenging to recycle at scale owing to their high crystallinity, chemical finishes, and heterogeneous waste streams. Although microorganisms drive cellulose turnover in natural ecosystems, their potential for transforming anthropogenic cellulosic waste remains largely unexplored. In this study, composting was evaluated both as a sustainable approach to textile biodegradation and a reservoir of cellulolytic microorganisms with biotechnological potential. Biodegradation assays of cotton and lyocell were integrated with shotgun metagenomics and targeted cultivation to identify microbial taxa and enzymes involved in cellulose degradation. Composting trials showed that degradation was strongly influenced by both composting system and fibre composition. Community composting achieved near-complete textile disintegration, while shredded textiles exhibited the highest degradation rates, reaching up to 97%. Shotgun metagenomic revealed a bacterial-dominated community enriched in Actinomycetota and Bacillota and characterised by an abundance of glycoside hydrolases. Culture-based screening recovered 62 microbial isolates, of which Neurospora and Aspergillus exhibited the highest cellulolytic activity (>60%). In vitro assays further showed that cotton was more readily degraded than lyocell, with several isolates achieving >70% mass loss. Metagenomic approach revealed a predominantly bacterial composting community at the sampled stage, whereas cultivation preferentially recovered fungi that, despite their low relative abundance in situ, exhibited strong cellulolytic potential. These findings highlight the potential of composting as a sustainable end-of-life strategy for cellulosic textiles and identify compost microbiomes as valuable reservoirs of cellulolytic microorganisms for the development of sustainable bioprocesses for textile waste treatment.

Cellulose↗

Optimization of enzyme complexes for lignocellulose hydrolysis.

The ability of a commercial Trichoderma reesei cellulase preparation (Celluclast 1.5L), to hydrolyze the cellulose and xylan components of pretreated corn stover (PCS) was significantly improved by supplementation with three types of crude commercial enzyme preparations nominally enriched in xylanase, pectinase, and beta-glucosidase activity. Although the well-documented relief of product inhibition by beta-glucosidase contributed to the observed improvement in cellulase performance, significant benefits could also be attributed to enzymes components that hydrolyze non-cellulosic polysaccharides. It is suggested that so-called "accessory" enzymes such as xylanase and pectinase stimulate cellulose hydrolysis by removing non-cellulosic polysaccharides that coat cellulose fibers. A high-throughput microassay, in combination with response surface methodology, enabled production of an optimally supplemented enzyme mixture. This mixture allowed for a approximately twofold reduction in the total protein required to reach glucan to glucose and xylan to xylose hydrolysis targets (99% and 88% conversion, respectively), thereby validating this approach towards enzyme improvement and process cost reduction for lignocellulose hydrolysis.

Cellulose↗

Wax removal for accelerated cotton scouring with alkaline pectinase.

A rational approach has been applied to design a new environmentally acceptable and industrially viable enzymatic scouring process. Owing to the substrate specificity, the selection of enzymes depends on the structure and composition of the substrate, i.e. cotton fibre. The structure and composition of the outer layers of cotton fibre has been established on the basis of thorough literature study, which identifies wax and pectin removal to be the key steps for successful scouring process. Three main issues are discussed here, i.e. benchmarking of the existing alkaline scouring process, an evaluation of several selected acidic and alkaline pectinases for scouring, and the effect of wax removal treatment on pectinase performance. It has been found that the pectinolytic capability of alkaline pectinases on cotton pectin is nearly 75% higher than that of acidic pectinases. It is concluded that an efficient wax removal prior to pectinase treatment indeed results in improved performance in terms of hydrophilicity and pectin removal. To evaluate the hydrophilicity, the structural contact angle (theta) was measured using an auto-porosimeter.

Cellulose↗