Latest Research on cellulose : Dec 2021

Cellulose chemistry and its applications

Twenty-one chapters cover various aspects of cellulose chemistry, including: chemistry fundamentals and structure; intercrystalline swelling; cellulose in solution; decomposition by chemical, physical, mechanical and biochemical means; photochemistry and radiation chemistry of cellulose; cellulose esters and ethers; cross-linking of cellulose; cellulose fibers and their properties. The chapter on photochemistry and radiation chemistry is indexed separately.[1]


Cellulose

The natural polymer cellulose is intimately connected with the history of man. Civilizations and cultures can be measured in terms of man’s ability to produce cellulosic substrates for writing and printing. The modern science and technology of cellulose probably began with Anselme Payen. The term cellulose was first used in the literature in 1839 in a report of the French Academy, which evaluated Payen’s work. At present, though plant sources of cellulose are the most known and sought after, there are bacterial, fungal, and algal systems and even animals that depend on and use cellulose in their life cycle. The amount of cellulose in different species of plants varies greatly. Never found alone, it is always associated with many other plant substances. Cellulose synthesis in human beings is still a controversial matter. The impact of cellulose on world biomass economics is to be noted. Commercial cellulose from higher plant life supplies an annual world consumption of about 150 million tons of fibrous raw material. The proofs of cellulose structure proceeded along two separate lines: classical organic chemistry, on the one hand, and embryonic polymer studies, on the other. [2]


Semimicro determination of cellulose inbiological materials

A semimicro method is described for the determination of cellulose inmicrobial cultures, other biological materials, or pulp and paper products. Lignin, hemicellulose, and xylosans are extracted with acetic acid/nitric acid reagent, and the remaining cellulose is dissolved in 67% H2SO4 and determined by the anthrone reagent. The method gives quantitative recovery of purified cellulose from microbiological culture media, and also appears to be satisfactory for cellulose from paper pulp.[3]


The Characterization of Bacterial Cellulose Produced by Acetobacter xylinum and Komgataeibacter saccharovorans under Optimized Fermentation Conditions

Aims: studying the biological activities of A. xylinum ATCC 10245 (as reference strain) and K. saccharivoransPE5 for bacterial cellulose production (B.C) under optimized fermentation conditions and the structural characteristics of cellulose produced.

Study Design: The production of bacterial cellulose under optimal fermentation conditions by investigated strains then the purified cellulose was characterized by different techniques.

Place and Duration of Study: Agric. Microbiology Dept., Fac. of Agriculture, Ain Shams Univ., Cairo, Egypt.

Methodology: A. xylinum ATCC 10245 and K. saccharivorans PE5 strain were used as producers of bacterial cellulose. These strain were grown on productive medium under optimal fermentation conditions. The parameters of growth and B.C production were determined during the fermentation period. The specific growth rate, doubling time. Multiplication rate and generation number were calculated during the exponential phase of growth. Purified polymers were characterized and the properties of paper sheet were detected.

Results: Results indicated that the exponential phase of Komagataeibacter saccharivorans PE 5 and Acetobacter xylinum ATCC 10245 growth was detected during the first 48 to 144 hrs and during 168 hrs in productive media, respectively. The highest cellulose concentration and yield were obtained after 336 hrs by both tested strains being 11.11 gl-1 & 74.1% for Acetobacter xylinum ATCC 10245 and being 12.61 gl-1 & 84.11% for Komgataeibacter saccharivorans PE 5. The structure of BC produced from the tested strains was assayed by scanning electron microscope, fourier transform- infrared spectrum (FT-IR) and x-ray diffraction. It was revealed the diameter of thin ribbons ranged from 34.34 nm to 39.16 nm and the shape of FT-IR spectra for the two stains is similar to pure cellulose. The crystalinity index of A. xylinum ATCC 10245 is 54.14% and 52.76% for K. saccharivorans PE 5. Also, the properties of paper sheet from K. saccharivoransPE 5 cellulose increased about 1.19, 1.25, 1.33, 1.91 and 1.27 fold for wet tensile strength, dry tensile strength, degree of polymerization, brightness and opacity, respectively than A. xylinum ATCC 10245 cellulose. [4]


Chromium (VI) Ions Removal from Tannery Effluent using Chitosan-Microcrystalline Cellulose Composite as Adsorbent

The bio-adsorbent chitosan-microcrystalline was synthesized from waste materials of shrimp processing industries, and waste cotton rags of garments industries for removal of chromium (VI) ion from tannery effluent. The chitosan was extracted from shrimp shell through the deproteinization, demineralization and deacetylation steps and microcrystalline cellulose was extracted from waste cotton rags by acid hydrolysis. The composite was prepared by simple solution evaporation method. The functional groups, responsible for adsorption and the chemical interaction in the composite formation were evidenced from FTIR results. The observed SEM results indicate that the prepared composite has a rough and porous surface. Batch adsorption experiments were conducted and removal of Cr(VI) was found to be reliant on pH and maximum adsorption was observed at pH 5.0. For 2 ppm Cr(VI) stock solution, the optimum dose and contact time treatment was 2 g/L and 240 minutes respectively and the maximum removal efficiency of chromium was found 93%. Tannery effluent was treated with optimum conditions required for maximum removal of Cr(VI). Langmuir isotherm and Freundlich isotherm model were plotted against the adsorption data and found that Langmuir Isotherm was well fitted with R2 value of 0.997.[5]
Reference

[1] Nevell, T.P. and Zeronian, S.H., 1985. Cellulose chemistry and its applications.

[2] Marchessault, R.H. and Sundararajan, P.R., 1983. Cellulose. In The polysaccharides (pp. 11-95). Academic press.

[3] Updegraff, D.M., 1969. Semimicro determination of cellulose inbiological materials. Analytical biochemistry, 32(3), pp.420-424.

[4] Hassan, E.A., Abdelhady, H.M., Abd El-Salam, S.S. and Abdullah, S.M., 2015. The characterization of bacterial cellulose produced by Acetobacter xylinum and Komgataeibacter saccharovorans under optimized fermentation conditions. Microbiology Research Journal International, pp.1-13.

[5] Yasmeen, S., Kabiraz, M.K., Saha, B., Qadir, M.R., Gafur, M.A. and Masum, S.M., 2016. Chromium (VI) ions removal from tannery effluent using chitosan-microcrystalline cellulose composite as adsorbent. International Research Journal of Pure and Applied Chemistry, pp.1-14.

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