The aim of this research was to study the production of humic acids (HA) by Trichoderma reesei from empty fruit bunches (EFBs) of palm oil processing, with a focus on the effects of lignocellulosic content and residual lipids. EFBs from two different soils and palm oil producers were previously characterized about their lignocellulosic composition. Submerged fermentations were inoculated with T. reesei spores and set up with or without residual lipids. The results showed that the soil and the processing for removal of the palm fresh fruits were crucial to EFB quality. Thus, EFBs were classified as type 1 (higher lignocellulosic and fatty acids composition similar to the palm oil and palm kernel oil) and type 2 (lower lignocellulosic content and fatty acids composition similar to palm oil). Despite the different profiles, the fungal growth was similar for both EFB types. HA production was associated with fungal growth, and it was higher without lipids for both EFBs. The highest HA productivity was obtained from type 1 EFB (approximately 90 mg L−1 at 48 h). Therefore, the lignocellulosic composition and the nature of the residual lipids in EFBs play an important role in HA production by submerged fermentation.
Microorganisms are found throughout every corner of nature, and vast number of microorganisms is difficult to cultivate by classical microbiological techniques. The advent of metagenomics has revolutionized the field of microbial biotechnology. Metagenomics allow the recovery of genetic material directly from environmental niches without any cultivation techniques. Currently, metagenomic tools are widely employed as powerful tools to isolate and identify enzymes with novel biocatalytic activities from the uncultivable component of microbial communities. The employment of next-generation sequencing techniques for metagenomics resulted in the generation of large sequence data sets derived from various environments, such as soil, the human body and ocean water. This review article describes the state-of-the-art techniques and tools in metagenomics and discusses the potential of metagenomic approaches for the bioprospecting of industrial enzymes from various environmental samples. We also describe the unusual novel enzymes discovered via metagenomic approaches and discuss the future prospects for metagenome technologies. 相似文献
The arene-perfluoroarene (ArH-ArF) interaction, which has been extensively studied in the field of solid-state chemistry, is exploited in the hierarchical self-assembly of oligo(para-phenylenevinylene)s (OPVs) with controlled longitudinal fiber growth that leads to gelation. The size of the self-assembled fibers of a pentafluorophenyl-functionalized OPV 5 could be controlled through C-FH--C hydrogen bonding and pi stacking. The ability of fluoroaromatic compounds to form excited-state complexes with aromatic amines has been utilized to form a supramolecular exciplex, exclusively in the gel state, that exhibits enhanced emission. Thus, the commonly encountered fluorescence quenching during the self-assembly of OPVs could be considerably prevented by exciplex formation with N,N-dimethylaniline (DMA), which only occurred for the fluorinated OPV and not for the non-fluorinated analogue 4. In the former case, a threefold enhancement in the emission intensity could be observed in the gel state, whereas no change in emission occurred in solution. Thus, the major limitations of spontaneous fiber growth and fluorescence self-quenching encountered in the self-assembly of OPVs could be controlled to a great extent by using the versatile ArH-ArF interaction. 相似文献
In recent years, growing attention has been focused on the use of lignocellulosic biomass as a feedstock for the production
of ethanol, a possible renewable alternative to fossil fuels. Several pretreatment processes have been developed for decreasing
the biomass recalcitrance, but only a few of them seem to be promising. In this study, effect of various organic solvents
and organic acids on the pretreatment of sugarcane bagasse was studied. Among the different organic acids and organic solvents
tested, formic acid was found to be effective. Optimization of process parameters for formic acid pretreatment was carried
out. The structural changes before and after pretreatment was investigated by scanning electron microscopy, X-ray diffraction
(XRD), and Fourier transform infrared (FTIR) analysis. The X-ray diffraction profile showed that the degree of crystallinity
was more for pretreated biomass than that of untreated. The FTIR spectra shown at the stretching of hydrogen bonds of pretreated
sugarcane bagasse arose at higher number. It also revealed that the cellulose content in the solid residue increased because
the hemicelluloses fraction in raw materials was released by acid hydrolytic reaction. 相似文献
The commercially available crystalline silicotitanate inorganic ion exchanger, IONSIV IE-911, and its parent precursor, TAM-5,
have been evaluated for the removal of 137Cs from nitric acid medium and simulated high-level liquid waste. The distribution coefficient (Kd) of cesium decreased with increasing nitric acid concentration and at 3.0 M nitric acid, a distribution coefficient of 1150
mL/g and 2600 mL/g were obtained for IONSIV IE-911 and TAM-5, respectively. Rapid uptake of cesium followed by the establishment
of equilibrium occurring within three hours. Loading of cesium in ion exchangers increased with the increase in the concentration
of cesium in aqueous phase and from Langmuir adsorption model the apparent capacity of cesium was 69 mg/g and 82 mg/g for
IONSIV IE-911 and TAM-5, respectively. The performance of the sorbent under dynamic conditions was assessed by following a
breakthrough (BT) curve up to C/Co = 1, where C and Co are the concentrations of cesium in the effluent and feed, respectively. 相似文献
Illuminating! Isolation of a π-core by covalently attached flexible hydrocarbon chains has been employed to synthesize blue-emitting oligo(p-phenylenevinylene) (OPV) liquids with tunable viscosity and optical properties. A solvent-free, stable, white-light emitting ink/paint, which can be applied onto various surfaces and even onto LEDs, was made by blending of liquid OPVs with emissive solid dopants. 相似文献