Author: aaronwillium

Lignin for Sustainable Bioproducts and Biofuels

To meet the goal of replacing 30% of fossil fuel by biofuels around 2030, approximately 225 million tons of lignin will soon be produced beside the current production of between 40 and 50 million tons per year in the paper and pulp industry in the U.S. Yet only about 2% of the waste lignin is currently recycled into new products [1]. This is also the case for the rest of the world. One of the efficient routes of upgrading lignin is the fast pyrolysis, in which lignin molecules are decomposed to short chain molecules in the absence of oxygen producing vapor and char. After condensing the vapor bio-oil is formed. Depending on the type of biomass and pyrolysis conditions, bio-oil contains innumerous compounds including hydrocarbons of aromatics, aliphatic, and cyclic that includes phenols, ethers, aldehydes, ketones, carboxylic acids, pyridines, amines, and esters. Separation of phenols from lignin with polyaromatic nature can help achieve renewable, sustainable, and economical phenols, other chemicals, and fuels from lignin [2]. Since approximately 99 % of current phenol production originates from petroleum-based Cumene oxidation with rather low yield, lignin pyrolysis bio-oil can help reduce the dependence to fossil fuels for producing chemicals and fuels [2-4].

Carbon Catalysts for Biomass Conversion

The use of a supported heterogeneous catalyst makes the process more efficient and economically feasible in many applications. The support materials provide a physical surface for dispersion or binding of active catalyst components. The final catalytic properties depend on the combination of the type of catalyst components and supportive material. Lignocellulosic biomass is an alternative to petroleum for the production of biofuels and chemicals and is increasingly recognized as a valuable material; however, the high cost of conversion technologies hinders its use as an economical alternative to petroleum. One way to make the conversion process economical is to use catalysts during conversion reactions. For instance, furfural production from biomass has attracted a lot of attention in the last several years. Commercially, furfural is produced using mineral acids such as sulfuric acid and hydrochloric acid as homogeneous catalysts. Metal chlorides such as CrCl2 , ZnCl2 , MgCl2 , FeCl3 , and AlCl3 demonstrated the ability to catalyze xylose dehydration to produce furfural as alternative. However, both types of catalysts are homogeneous and have some limitations in terms of difficulties in separation and recyclability and high environmental and safety risks as use of mineral acids.

Hexanol, Model, Molecule, Carbon, 3D, Ball, Stick

Functional Application of Thermo- Alkali- Stable Lignocellulolytic Enzymes in Kraft-Pulp Industry and Development of Fermentation Process for Production

For many years, microbial enzymes are commercially used as biocatalysts and efficiently catalyze various processes in industries. Biocatalysts are less corrosive to industrial processing equipment and due to their substrate specificity, they produced less toxic wastes which promotes environmental sustainability. At present, thermostable and alkali tolerant lignocellulolytic enzymes have gain enormous attention to be used as biocatalyst due their stability and robustness at high temperature and alkaline milieu. In this review, the characteristic of the several thermo–alkali-stable lignocellulolytic enzymes such as thermo–alkali-stable cellulases, thermo–alkali-stable xylanases and thermo–alkali-stable laccases as biobleaching agents in Kraft-pulp industry are described. This article discusses the characteristics of these enzymes such as their molecular weight, thermo-stability, pH tolerance, solvents compatibility and their stability towards the presence of metal ions and other chemicals. This review also discusses the development of fermentation process for the production of thermo–alkali-stable lignocellulolytic enzymes focusing on microorganisms (i.e. strain selection and strains improvement via mutation and recombinant techniques), culture medium optimization (i.e carbon, nitrogen and minerals) and other fermentation parameters (i.e. inoculums size, temperature, pH, agitation rate, aeration rate, and dissolved oxygen tension). The performances of strain producers in bioreactors and different mode of operation (i.e submerged and solid state fermentation) are also compared and discussed in this paper.

Fluorescence Microsphere Immunoassay for Detection of Antibodies to Porcine Reproductive and Respiratory Syndrome Virus and Porcine Circovirus type 2 using Protein A, Protein G, and Protein A/G

The purpose of this study was the development of multiplex fluorescence microsphere immunoassay (FMIA) for the detection of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) specific IgG antibodies by incorporation of non-species-specific conjugates Protein A, G, and A/G in place of the secondary antibody. A total of 205 serum samples obtained from pigs experimentally infected with PRRSV and/or PCV2 were tested. For the production of recombinant antigens, PRRSV nucleoprotein (N) and PCV2 capsid protein (CP) were expressed in Escherichia coli and purified on a nickel affinity column. 

The Establishment of Realtime Fluorescent Quantitative Polymerase chain reaction (PCR) for Detection of Highly Pathogenic Avian Influenza Virus Subtype H5N1

Highly pathogenic strains of avian influenza virus (AIV), which are influenza A viruses, cause severe disease in domestic poultry and humans. The objective of this study was to establish a fluorescent quantitative RT-PCR assay for detection of highly pathogenic avian influenza virus (AIV) subtype H5N1. The H5 and N1 subtypespecific probe sets were developed based on avian influenza virus sequences detected in China. Two pairs of primers and two fluorescent probes were strictly designed and optimized in a reaction system. According to the amount of plasmid RNA extracted from H5N1 strains, the standard curve DWQBGWDWQBGW of fluorescent quantitative PCR was drawn and all of the specimens were then tested by means of Real-time PCR. The test of highly pathogenic AIV subtype H5N1 was identified to be specific and its sensitivity level was 102 ~103 copies/reaction. The standard curve was accomplished at 109 ～105 DNA copies/reaction. It took only three hours from viral RNA extraction through to completion of the test. The assay was easy to carry out and highly reproducible. In conclusion, fluorescent quantitative PCR, described here, provides a rapid, specific and sensitive method to detect not only the H5 but N1 genes as well.