In this paper, in order to get the target microbe which has high cellulose bio-degradation ability, we collected soil samples from environment rich in cellulose. Carboxymethyl cellulose sodium gel plate and filter pap...In this paper, in order to get the target microbe which has high cellulose bio-degradation ability, we collected soil samples from environment rich in cellulose. Carboxymethyl cellulose sodium gel plate and filter paper plate were used for microbe screening, and finally we got a strain named MI which has the highest cellulase producing ability, and it has been identified as Penicilium oxalicum by morphological and molecular biological identification. We have studied cellulose degradation ability of this strain under different conditions such as pH value, temperature and inoculating time. The results showed that CMCase which belongs to acid enzyme, could achieve its maximum enzyme activity 489.96 U/ml when the optimal pH value was 4. The FPAase could achieve its maximum enzyme activity 1,595.45 U/ml when the optimal pH value was 4, too. The optimal ferment temperature of CMCase is 50℃ when achieved the maximum of enzyme activity at the second day, whereas the FPAase could reach its tip top on the third day, So the optimal ferment temperature of FPAase is also 50℃.展开更多
The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mat...The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mature or over-mature source rock） to form large petroleum reservoirs. However, gas source correlation indicates that the natural gas in the Jingbian gas field does receive contribution from marine source rocks. In order to determine the effect of Carboxylate salts （or called as organic acid salts） on TOC in highly mature source rocks with low TOC value, we sampled the Ordovician marine source rock and the Permian transitional facies source rock in one drilled well in the southern Ordos Basin and performed infrared and GC-MS analysis. It is found that both kerogen-derived organic acids and carboxylate salt-conversed organic acids exist in both marine and transitional facies source rocks. The carboxylate salt-conversed organic acids mainly come from the complete acidification of carboxylate salts, which confirms the presence of carboxylate salts in the marine source rocks. Although the C16：o peak is the main peak for the organic acids both before and after acidification, the carboxylate salt-conversed organic acids have much less relative abundance ahead of C^6：o compared with that of the kerogen-based and free organic acids. This observation suggests that the kerogen-based and free organic acids mainly decarboxylate to form lower carboxylic acids, whereas the carboxylate salt-conversed organic acids mainly break down into paraffins. By using calcium hexadecanoate as the reference to quantify the kerogen-derived and carboxylate salt-conversed organic acids, the high TOC （〉2.0%） marine source rocks have low carboxylate salt content and the low TOC （0.2%-0.5%） marine source rocks contain high content of carboxylate salt. Therefore, for the marine source rocks with 0.2%-0.5% TOC, the carboxylate salts may be a potential gas source at high maturity stage.展开更多
文摘In this paper, in order to get the target microbe which has high cellulose bio-degradation ability, we collected soil samples from environment rich in cellulose. Carboxymethyl cellulose sodium gel plate and filter paper plate were used for microbe screening, and finally we got a strain named MI which has the highest cellulase producing ability, and it has been identified as Penicilium oxalicum by morphological and molecular biological identification. We have studied cellulose degradation ability of this strain under different conditions such as pH value, temperature and inoculating time. The results showed that CMCase which belongs to acid enzyme, could achieve its maximum enzyme activity 489.96 U/ml when the optimal pH value was 4. The FPAase could achieve its maximum enzyme activity 1,595.45 U/ml when the optimal pH value was 4, too. The optimal ferment temperature of CMCase is 50℃ when achieved the maximum of enzyme activity at the second day, whereas the FPAase could reach its tip top on the third day, So the optimal ferment temperature of FPAase is also 50℃.
基金supported by National Natural Science Foundation of China(Grant Nos.41173035&41322016)National Key Foundational Research and Development Project(Grant No.2012CB214800)the National Science & Technology Special Project(Grant No.2011ZX05005-004-004)
文摘The total organic carbon （TOC） in the marine source rock of the Ordos Basin mostly ranges from 0.2% to 0.5%. The industrial standard commonly states that the TOC value has to be no less than 0.5% （0.4% for high mature or over-mature source rock） to form large petroleum reservoirs. However, gas source correlation indicates that the natural gas in the Jingbian gas field does receive contribution from marine source rocks. In order to determine the effect of Carboxylate salts （or called as organic acid salts） on TOC in highly mature source rocks with low TOC value, we sampled the Ordovician marine source rock and the Permian transitional facies source rock in one drilled well in the southern Ordos Basin and performed infrared and GC-MS analysis. It is found that both kerogen-derived organic acids and carboxylate salt-conversed organic acids exist in both marine and transitional facies source rocks. The carboxylate salt-conversed organic acids mainly come from the complete acidification of carboxylate salts, which confirms the presence of carboxylate salts in the marine source rocks. Although the C16：o peak is the main peak for the organic acids both before and after acidification, the carboxylate salt-conversed organic acids have much less relative abundance ahead of C^6：o compared with that of the kerogen-based and free organic acids. This observation suggests that the kerogen-based and free organic acids mainly decarboxylate to form lower carboxylic acids, whereas the carboxylate salt-conversed organic acids mainly break down into paraffins. By using calcium hexadecanoate as the reference to quantify the kerogen-derived and carboxylate salt-conversed organic acids, the high TOC （〉2.0%） marine source rocks have low carboxylate salt content and the low TOC （0.2%-0.5%） marine source rocks contain high content of carboxylate salt. Therefore, for the marine source rocks with 0.2%-0.5% TOC, the carboxylate salts may be a potential gas source at high maturity stage.
