Biodegradation of Structurally Diverse Phthalate Esters by a Newly Identified Esterase with Catalytic Activity toward Di(2-ethylhexyl) Phthalate.

Herein, we report a double enzyme system to degrade 12 phthalate esters (PAEs), particularly bulky PAEs, such as the widely used bis(2-ethylhexyl) phthalate (DEHP), in a one-pot cascade process. A PAE-degrading bacterium, sp. strain 5F, was isolated from soil polluted with plastic waste.

Efficient Degradation of Malathion in the Presence of Detergents Using an Engineered Organophosphorus Hydrolase Highly Expressed by Pichia pastoris without Methanol Induction.

The biodegradation of pesticides by organophosphorus hydrolases (OPHs) requires an efficient enzyme production technology in industry. Herein, a Pichia pastoris strain was constructed for the extracellular expression of PoOPH, an engineered malathion-degrading enzyme. After optimization, the maximum titer and yield of fermentation reached 50.

[Bioassay-guided isolation of functional components from hot water extract of Chlorella pyrenoidosa].

The main functional ingredients of hot water extract of Chlorella pyrenoidosa (CPE) were investigated through a bioassay-guided fractionation based on free radical scavenging and macrophage proliferation effects. The main functional ingredients of CPE were polysaccharides (PS) that were isolated by high pressure extraction, Sevag method, ethanol precipitation and ultrafiltration separation. Crude polysaccharides were further separated and purified by ion exchange chromatography DEAE52 and size exclusion chromatography Sephadex G-100.

[Response of Soil Respiration and Organic Carbon to Returning of Different Agricultural Straws and Its Mechanism].

Soybean, maize and rice straws were selected as raw materials to study the response of the soil respiration (SR) and soil organic carbon (SOC) to returning of different straws in the Chongming Dongtan area. The results showed that all of SR, SOC and the plant biomass of the lands with returning of different straws were higher than those of the controls. The soil with soybean straw returning possessed the lowest SR and highest SOC among the three kinds of straws, meaning its higher soil organic carbon sequestration capability than corn and maize straws returning.

[Potential Carbon Fixation Capability of Non-photosynthetic Microbial Community at Different Depth of the South China Sea and Its Response to Different Electron Donors].

The seawater samples collected from many different areas with different depth in the South China Sea were cultivated using different electron donors respectively. And the variation in the potential carbon fixation capability ( PCFC ) of non-photosynthetic microbial community (NPMC) in seawater with different depth was determined after a cycle of cultivation through the statistic analysis. In addition, the cause for the variation was clarified through analyzing key gene abundance regarding CO2 fixation and characteristics of seawater with different depth.

Similarity between segments in protein conformational epitopes and MHC II peptides.

In immune response, major histocompatibility complex class II (MHC II) molecules bind peptides derived from antigens and present them. The formation of MHC II-peptide complexes was a critical signal in inducing of antibodies production of B cells. In this research, we tried to investigate whether there was a similarity or relationship between the segments in B cell conformational epitopes and MHC II peptides.

Purification and in situ immobilization of papain with aqueous two-phase system.

Papain was purified from spray-dried Carica papaya latex using aqueous two-phase system (ATPS). Then it was recovered from PEG phase by in situ immobilization or preparing cross-linked enzyme aggregates (CLEAs). The Plackett-Burman design and the central composite design (CCD) together with the response surface methodology (RSM) were used to optimize the APTS processes.

[Breeding, optimization and community structure analysis of non-photosynthetic CO2 assimilation microbial flora].

Isolation and screening from sea water and sediments, and the optimization of electron donor and inorganic carbon source structure were performed for obtaining microbial flora with high efficient inorganic carbon fixation without the light and hydrogen. In addition, the structure of the microbial flora was studied through 16S rDNA sequence analysis and contrast for providing theoretical basis to improve carbon fixation efficiency through optimizing microbial flora structure. The result showed that non-photosynthetic microbial flora with the capacity of inorganic carbon fixation under the general aerobic and anaerobic conditions could be obtained from the sea by long-term domestication and isolation.

Refolding and purification of rhNTA protein by chromatography.

RhNTA protein is a new thrombolytic agent which has potential medicinal and commercial value. Protein refolding is a bottleneck for large-scale production of valuable proteins expressed as inclusion bodies in Escherichia coli. The denatured rhNTA protein was refolded by an improved size-exclusion chromatography refolding process achieved by combining an increasing arginine gradient and a decreasing urea gradient (two gradients) with a size-exclusion chromatography refolding system.

Improving the refolding of NTA protein by urea gradient and arginine gradient size-exclusion chromatography.

Inclusion body refolding processes play a major role in the production of recombinant proteins. Improvement of the size-exclusion chromatography refolding process was achieved by combining a decreasing urea gradient with an increasing arginine gradient (two gradients) for the refolding of NTA protein (a new thrombolytic agent) in this paper. Different refolding methods and different operating conditions in two gradients gel filtration process were investigated with regard to increasing the NTA protein activity recovery and inhibition of aggregation.

[The separation and identification of the flavonoids from the leaves of Bryophyllum pinnatum].

This study investigated the separation of the effective compositions containing quercetin derivatives from the leaves of Bryophyllum pinnatun by solvent extraction of methanol, polar adsorption by porous polymetric resins, mixed solvent extraction of methanol with chloroform and polyamide chromatography. The results indicated that the yield of product containing 51.23% quercetin in the form of quercetin derivatives was 0.