The impacts of carbon emissions and voluntary carbon disclosure on firm value.

Investors and other stakeholders are starting to pay attention to firms' carbon emissions and carbon disclosure. This study investigated the effects of voluntary carbon disclosure information and carbon emissions on firm value from listed companies in the Shanghai and Shenzhen 300 (CSI 300) Index. We also apply the Probit model to predict the probability of voluntary carbon disclosure information. The results indicate that the increase in carbon emissions has a negative impact on firm value. The action that companies select to disclose carbon emissions has a positive impact on firm value. The effect of leverage ratio on VCDI is increasing year by year. What is more, the probability of the average size firm carbon disclosure was 30.73% in 2020. Company management needs to pay attention to the risks caused by carbon emissions and ensure the quality of carbon disclosure information, especially the authenticity and reliability of the information.

Energy Conservation and Carbon Flux Distribution During Fermentation of CO or H2/CO2 by Clostridium ljungdahlii.

Both CO and H2 can be utilized as energy sources during the autotrophic growth of Clostridium ljungdahlii. In principle, CO is a more energetically and thermodynamically favorable energy source for gas fermentation in comparison to H2. Therefore, metabolism may vary during growth under different energy sources. In this study, C. ljungdahlii was fed with CO and/or CO2/H2 at pH 6.0 with a gas pressure of 0.1 MPa. C. ljungdahlii primarily produced acetate in the presence of H2 as an energy source, but produced alcohols with CO as an energy source under the same fermentation conditions. A key enzyme activity assay, metabolic flux analysis, and comparative transcriptomics were performed for investigating the response mechanism of C. ljungdahlii under different energy sources. A CO dehydrogenase and an aldehyde:ferredoxin oxidoreductase were found to play important roles in CO utilization and alcohol production. Based on these findings, novel metabolic schemes are proposed for C. ljungdahlii growing on CO and/or CO2/H2. These schemes indicate that more ATP is produced during CO-fermentation than during H2-fermentation, leading to increased alcohol production.

Characterization of environmentally friendly nicotine degradation by Pseudomonas putida biotype A strain S16.

Nicotine and some related alkaloids in tobacco and tobacco wastes are harmful to health and the environment, and a major environmental requirement is to remove them from tobacco and tobacco wastes. In this study, an isolated strain, S16, identified as Pseudomonas putida biotype A, was used to investigate nicotine degradation. Possible intermediates were identified based on the results of NMR, Fourier-transform (FT)-IR and UV spectroscopy, GC-MS and high-resolution MS (HR-MS) analysis. The pathway of nicotine degradation in P. putida was proposed to be from nicotine to 2,5-dihydroxypyridine through the intermediates N-methylmyosmine, 2'-hydroxynicotine, pseudooxynicotine, 3-pyridinebutanal,C-oxo, 3-succinoylpyridine and 6-hydroxy-3-succinoylpyridine. N-Methylmyosmine, 2,5-dihydroxypyridine and succinic acid were detected and satisfactorily verified for the first time as intermediates of nicotine degradation. In addition, an alcohol compound, 1-butanone,4-hydroxy-1-(3-pyridinyl), was found to be a novel product of nicotine degradation. These findings provide new insights into the microbial metabolism of nicotine and the environmentally friendly route of nicotine degradation.

"Green" route to 6-hydroxy-3-succinoyl-pyridine from (S)-nicotine of tobacco waste by whole cells of a Pseudomonas sp.

A new technology for 6-hydroxy-3-succinoyl-pyridine (HSP) production from (S)-nicotine in tobacco waste by whole cells of a Pseudomonas sp. has been developed. When deionized water was used in the transformation reaction as a medium and the initial pH value of reaction mixture was adjusted to 7.0, 1.45 g/L HSP was produced from 3 g/L of nicotine in 5 h with 3.4 g/L of cells in a 5-L flask at 30 degrees C. HSP could be easily purified from the reaction without perplexing separation steps. A quantity of 1.3 g of HSP was recovered without impurity, and the overall yield of HSP was 43.8% (w/w), based on an initial concentration of 3.0 g/L of nicotine in reaction. This biotransformation made it possible to convert nicotine in tobacco wastes with high nicotine content into valuable compounds.