A mini review on biotransformation of coal to methane by enhancement of chemical pretreatment

Lignocellulose is the most abundant renewable natural resource on earth and has been successfully used for the production of biofuels. A significant challenge is to develop cost-effective, environmentally friendly and efficient processes for the conversion of lignocellulose materials into suitable substrates for biotransformation. A number of approaches have been explored to convert lignocellulose into sugars, e.g. combining chemical pretreatment and enzymatic hydrolysis. In nature, there are organisms that can transform the complex lignocellulose efficiently, such as wood-degrading fungi (brown rot and white rot fungi), bacteria (e.g. Clostridium thermocellum), arthropods (e.g. termite) and certain animals (e.g. ruminant). Here, we highlight recent case studies of the natural degraders and the mechanisms involved, providing new utilities in biotechnology. The sugars produced from such biotransformations can be used in metabolic engineering and synthetic biology for the complete biosynthesis of natural medicine. The unique opportunities in using lignocellulose directly to produce natural drug molecules with either using mushroom and/or ‘industrial workhorse’ organisms (Escherichia coli and Saccharomyces cerevisiae) will be discussed.

Download Full-text

Valorization of sugarcane bagasse by chemical pretreatment and enzyme mediated deconstruction

Scientific Reports ◽

10.1038/s41598-019-52347-7 ◽

2019 ◽

Vol 9 (1) ◽

Cited By ~ 7

Author(s):

Vihang S. Thite ◽

Anuradha S. Nerurkar

Keyword(s):

Cell Wall ◽

Sugarcane Bagasse ◽

Structural Changes ◽

Enzymatic Saccharification ◽

Dry Weight ◽

Gravimetric Analysis ◽

Chemical Pretreatment ◽

Cell Wall Degrading Enzymes ◽

First Time ◽

Soluble Components

Abstract After chemical pretreatment, improved amenability of agrowaste biomass for enzymatic saccharification needs an understanding of the effect exerted by pretreatments on biomass for enzymatic deconstruction. In present studies, NaOH, NH4OH and H2SO4 pretreatments effectively changed visible morphology imparting distinct fibrous appearance to sugarcane bagasse (SCB). Filtrate analysis after NaOH, NH4OH and H2SO4 pretreatments yielded release of soluble reducing sugars (SRS) in range of ~0.17–0.44%, ~0.38–0.75% and ~2.9–8.4% respectively. Gravimetric analysis of pretreated SCB (PSCB) biomass also revealed dry weight loss in range of ~25.8–44.8%, ~11.1–16.0% and ~28.3–38.0% by the three pretreatments in the same order. Release of soluble components other than SRS, majorly reported to be soluble lignins, were observed highest for NaOH followed by H2SO4 and NH4OH pretreatments. Decrease or absence of peaks attributed to lignin and loosened fibrous appearance of biomass during FTIR and SEM studies respectively further corroborated with our observations of lignin removal. Application of commercial cellulase increased raw SCB saccharification from 1.93% to 38.84%, 25.56% and 9.61% after NaOH, H2SO4 and NH4OH pretreatments. Structural changes brought by cell wall degrading enzymes were first time shown visually confirming the cell wall disintegration under brightfield, darkfield and fluorescence microscopy. The microscopic evidence and saccharification results proved that the chemical treatment valorized the SCB by making it amenable for enzymatic saccharification.

Download Full-text

Treatment of a complex landfill leachate with peat

Canadian Journal of Civil Engineering ◽

10.1139/l78-010 ◽

1978 ◽

Vol 5 (1) ◽

pp. 83-97 ◽

Cited By ~ 13

Author(s):

Robert D. Cameron

Keyword(s):

Chemical Oxygen Demand ◽

Ferric Chloride ◽

Landfill Leachate ◽

Metal Removal ◽

Oxygen Demand ◽

Treatment Method ◽

Manganese Concentration ◽

Chemical Pretreatment ◽

Iron Manganese

The use of cheap, locally available peat as a treatment method for landfill leachate was investigated by passing leachate through plexiglass columns filled with an amorphous-granular peat. Preliminary adjustment of pH showed that reducing pH to 4.8 dramatically reduced adsorption. Increasing the pH to 8.4, metal removal was increased owing to filtration of precipitated metals. The best adsorption of metals occurred at the 'natural' pH of 7.1. Manganese was found to be the limiting pollutant. At the 0.05 mg/ℓ maximum acceptable manganese concentration 94% of the total metals were removed, requiring 159 kg of peat per 1000 ℓ of leachate.Resting the peat for 1 month did significantly increase removal capacity.Desorption of some contaminants occurred when water was percolated through the peat. The desorption test effluent was not toxic to fish although iron, lead and COD (chemical oxygen demand) exceeded acceptable values.Chemical pretreatment using lime and ferric chloride achieved significant iron, manganese and calcium removals. Chemical pretreatment followed by peat adsorption offered no advantage other than reducing toxicity to fish.Peat treatment alone was effective in reducing concentrations to a level that was non-toxic to fish.

Download Full-text

Valorization of Byproducts of Hemp Multipurpose Crop: Short Non-Aligned Bast Fibers as a Source of Nanocellulose

Molecules ◽

10.3390/molecules26164723 ◽

2021 ◽

Vol 26 (16) ◽

pp. 4723

Author(s):

Sara Dalle Vacche ◽

Vijayaletchumy Karunakaran ◽

Alessia Patrucco ◽

Marina Zoccola ◽

Loreleï Douard ◽

...

Keyword(s):

Infrared Spectroscopy ◽

Thermogravimetric Analysis ◽

Cannabis Sativa ◽

Crystallinity Index ◽

Residual Lignin ◽

Chemical Pretreatment ◽

X Ray Diffraction ◽

X Ray ◽

Bast Fibers ◽

Seed Maturity

Nanocellulose was extracted from short bast fibers, from hemp (Cannabis sativa L.) plants harvested at seed maturity, non-retted, and mechanically decorticated in a defibering apparatus, giving non-aligned fibers. A chemical pretreatment with NaOH and HCl allowed the removal of most of the non-cellulosic components of the fibers. No bleaching was performed. The chemically pretreated fibers were then refined in a beater and treated with a cellulase enzyme, followed by mechanical defibrillation in an ultrafine friction grinder. The fibers were characterized by microscopy, infrared spectroscopy, thermogravimetric analysis and X-ray diffraction after each step of the process to understand the evolution of their morphology and composition. The obtained nanocellulose suspension was composed of short nanofibrils with widths of 5–12 nm, stacks of nanofibrils with widths of 20–200 nm, and some larger fibers. The crystallinity index was found to increase from 74% for the raw fibers to 80% for the nanocellulose. The nanocellulose retained a yellowish color, indicating the presence of some residual lignin. The properties of the nanopaper prepared with the hemp nanocellulose were similar to those of nanopapers prepared with wood pulp-derived rod-like nanofibrils.

Download Full-text

Study of the chemical pretreatment of a nonconventional low-cost biosorbent (Callitriche obtusangula) for removing an anionic dye from aqueous solution

Euro-Mediterranean Journal for Environmental Integration ◽

10.1007/s41207-021-00265-4 ◽

2021 ◽

Vol 6 (2) ◽

Author(s):

Khaled Benabbas ◽

Nacéra Zabat ◽

Imene Hocini

Keyword(s):

Aqueous Solution ◽

Low Cost ◽

Chemical Pretreatment ◽

Anionic Dye

Download Full-text

SUITABILITY OF ACID-SOLUBLE AND ACID-INSOLUBLE LEATHER FRACTIONS IN RADIOCARBON DATING

Radiocarbon ◽

10.1017/rdc.2020.93 ◽

2020 ◽

pp. 1-8

Author(s):

Alyssa M Tate ◽

Brittany Hundman ◽

Jonathan Heile

Keyword(s):

Radiocarbon Dating ◽

Insoluble Fraction ◽

Economic Life ◽

Chemical Pretreatment ◽

Acid Base ◽

The Past ◽

Acid Soluble Collagen ◽

Method Of Production ◽

Insight Into

ABSTRACT Leather has been produced by a variety of methods throughout human history, providing researchers unique insight into multiple facets of social and economic life in the past. Archaeologically recovered leather is often fragile and poorly preserved, leading to the use of various conservation and restoration efforts that may include the application of fats, oils, or waxes. Such additives introduce exogenous carbon to the leather, contaminating the specimen. These contaminants, in addition to those accumulated during interment, must be removed through chemical pretreatment prior to radiocarbon (14C) dating to ensure accurate dating. DirectAMS utilizes organic solvents, acid-base-acid (ABA) and gelatinization for all leather samples. Collagen yield from leather samples is variable due to the method of production and the quality of preservation. However, evaluating the acid-soluble collagen fraction, when available, provides the most accurate 14C dates for leather samples. In instances where gelatinization does not yield sufficient material, the resulting acid-insoluble fraction may be dated. Here we examine the effectiveness of the combined organic solvent and ABA pretreatment with gelatinization for leather samples, as well as the suitability of the acid-insoluble fraction for 14C dating.

Download Full-text