2-Carbomethoxynorbornene is identified as a more effective transient mediator to promote a Pd(II)-catalyzed meta-C(sp2)–H alkylation of amides with various alkyl iodides as well as arylation with previously incompatible aryl iodides. The use of a tailor-made quinoline ligand is also crucial for this reaction to proceed.

Biochar is widely used as a soil amendment. Enzyme activity is an important factor that reflects soil metabolic activity, and is involved in biochemical processes such as organic matter decomposition and nutrient cycling in soils. However, the effects of biochar prepared for different straw materials on soil enzyme activity and soil nutrients are rarely studied. Through pot experiments, the effects of different straw (wheat, rice, maize) biochars (obtained by pyrolysis at 500 °C) on soil organic carbon, nitrogen, available phosphorus, and enzyme activity were studied in paddy soil. The results showed that the addition of biochar increased the soil organic carbon content, which gradually decreased with the extension of the rice growth period. The soil ammonium nitrogen content gradually decreased as the rice growth period continued; however, the soil nitrate nitrogen content first decreased and then increased over the rice growth period. Soil invertase, phosphatase, and urease activity first increased and then decreased, and the enzyme activity was the highest at the heading stage of rice. At this time, there were also significant correlations between enzyme activity and carbon, nitrogen, and phosphorus levels, except in the case of soil urease activity. The geometric mean of the investigated enzyme activities was the highest after amendment with rice straw biochar. These results indicate that the response of enzyme activity to biochar depends on the biochar feedstock and the rice growth stage. Biochar has been suggested as a suitable material for soil remediation to improve soil structure, soil moisture retention, soil carbon sequestration and greenhouse gas emissions reductions 1-5. However, the mechanism of soil change due to the addition of biochar are not clear. Some researchers have shown that the response of the soil environment to the addition of biochar depends on the properties of the biochar 6,7. Feedstock and pyrolysis temperatures are key factors influencing biochar performance 7-9. Straw, as an agricultural residue, contains abundant nutrients. Thus, straw incorporation could maintain and potentially improve the contents of soil nutrients. If straw is directly applied to the soil, microorganisms decompose it rapidly and generate gases such as CO 2 , CH 4 , and N 2 O,resulting in nutrient losses. Biochar applications can affect various biogeochemical processes in the soil, including carbon (C), phosphorus (P), and nitrogen (N) cycling 10-12. The addition of biochar can promote the stabilization of soil organic carbon (SOC) 13 , and the ability of soil to maintain N and P 10,14,15. Biochar addition alters the form of N, the subsequent N stabilization and N transformation within the soil 16. Tan et al. demonstrated that when one form of nitrogen was contained within biochar residue another form was released into the soil after biochar addition 12. Biochar-amended soil can affect organic N by converting it into mineral N (ammonium and nitrate) which is directly taken up by the plant. Biochar can serve as...

The presence and phylogeny of methylotrophs, including methanotrophs, in a deep-sea sediment of a tropical west Pacific Warm Pool site WP was investigated by molecular marker-based analysis of mxaF, pmoA and archaeal 16S rRNA genes. MxaF amino acid sequence analysis revealed that microbes belonging to the K-Proteobacteria and most related to Hyphomicrobium and Methylobacterium were the dominant aerobic methylotrophs in this deep-sea sediment ; also, a small percentage of type II methanotrophs, closely related to Methylocystis and Methylosinus, were detected in this environment. On the other hand, the use of a pmoA gene marker could not demonstrate the presence of any methanotrophs in this environment, suggesting that the mxaF gene probe is a more suitable marker in this deep-sea sediment for the detection of methylotrophs (including methanotrophs). mxaF quantitative polymerase chain reaction results showed that the west Pacific WP sediment contained approximately 3U10 4À5 methylotrophs per gram sediment, 10^100 times more than the samples collected from several other deep-sea Pacific sediments, but, on the other hand, about 10 times less than the amounts present in samples collected from rice and flower garden soil. Archaeal diversity as analyzed by 16S rRNA gene sequences indicated that a nonthermophilic marine group I crenarchaeote was the major archaeal group present in the west Pacific WP.

An efficient fermentation-strengthening approach was developed to improve the anaerobic production of propionic acid and vitamin B12 by co-fermentation with Propionibacterium freudenreichii. Vitamin B12 production from glucose resulted in relatively high productivity (0.35 mg/L h) but a low propionic acid yield (0.55 g/g). By contrast, glycerol gave a high propionic acid yield (0.63 g/g) but low productivity (0.16 g/L h). Co-fermentation of glycerol and glucose with a gradual addition strategy gave high yields (propionic acid: 0.71 g/g; vitamin B12: 0.72 mg/g) and productivities (propionic acid: 0.36 g/L h; vitamin B12: 0.36 mg/L h). Finally, the integrated feedstock and fermentation system strengthening strategy was demonstrated as an efficient method for the economic production of bio-based propionic acid and vitamin B12.