Coenzyme Q10 (CoQ10), an important antioxidant molecule playing a major role in electron transport chain, has been commercially produced by fermentation process for the use in oral nutraceutical formulations. Construc...Coenzyme Q10 (CoQ10), an important antioxidant molecule playing a major role in electron transport chain, has been commercially produced by fermentation process for the use in oral nutraceutical formulations. Constructing the high-yielding CoQ10 producing strains is a pre-requisite for cost-effective production. A superior mutant strain P-87 generated from Paracoccus denitrificans ATCC 19367, which showed 1.25-fold improvement in specific CoQ10 content higher than the wild type strain at shake flask level, was selected to carry out the studies on CoQ10 yield improvement through fermenter process optimization. In the course of study, initially the cane-molasses-based medium and fed-batch fermentation strategy using pHBA in combination with sucrose were standardized in shake flask using wild type strain. This strategy was subsequently translated at 2 L laboratory fermenter while optimizing the fermentation process parameters using improved mutant strain P-87. Under optimized fermentation condition, mutant strain P-87 produced 49.85 mg/L of CoQ10 having specific content of 1.63 mg/g of DCW, which was 1.36 folds higher than the specific CoQ10 content of wild-type strain under similar optimized condition. The temperature and DO were found to be critical parameters for CoQ10 production by mutant strain P-87. The optimum temperature was found to be 32°C and the optimum DO concentration to be maintained throughout the fermentation cycle was found to be 30% of air saturation. Overall, a new cost-effective process has been established for the production of CoQ10 using the cheaper substrate “cane molasses” and higher CoQ10 producing mutant strain P-87.展开更多
1 Introduction Radioactive pollution is increasingly serious and radioactive pollution can not be repaired immediately once it breaks out.Strontium contamination is a research hot point as one of the typical radioacti...1 Introduction Radioactive pollution is increasingly serious and radioactive pollution can not be repaired immediately once it breaks out.Strontium contamination is a research hot point as one of the typical radioactive pollution,and展开更多
从实验室定向驯化的活性污泥中分离筛选出一株具有异养硝化-好氧反硝化功能的菌株TS-1.通过生理生化及16S r RNA基因序列鉴定其为脱氮副球菌,通过单因素和正交实验对其去除NH4+-N的最佳条件进行优化,并通过对比进一步探究其在不同氮源...从实验室定向驯化的活性污泥中分离筛选出一株具有异养硝化-好氧反硝化功能的菌株TS-1.通过生理生化及16S r RNA基因序列鉴定其为脱氮副球菌,通过单因素和正交实验对其去除NH4+-N的最佳条件进行优化,并通过对比进一步探究其在不同氮源条件下对各形态无机氮的去除规律.结果表明该菌株最适碳源为丁二酸钠,最佳C/N为15,最佳接种量为5%,最适温度为30℃、p H为8.0.以初始浓度约为100 mg/L的NH4+-N、NO3--N和NO2--N分别为单一氮源时,菌株TS-1对各形态氮的去除率为97.49%、100%和95.94%;维持各形态氮初始浓度不变,将其两两混合时发现混合氮源中若包含NO2--N会使菌株OD600值达到最大值所用时间延长,氮源中含有NH4+-N会降低菌株对其他形态氮源的去除率,以及NO3--N的添加会使菌株对NH4+-N的去除能力降低;3种形态氮源同时存在的条件下,该菌对各氮源去除能力由强至弱为NO2--N>NH4+-N>NO3--N.本研究从活性污泥中分离筛选出一株具有高效异养硝化-好氧反硝化功能的菌株TS-1,通过研究碳源、氮源、温度、p H得到了最佳降解条件,可为废水短程脱氮提供参考.(图9表4参37)展开更多
文摘Coenzyme Q10 (CoQ10), an important antioxidant molecule playing a major role in electron transport chain, has been commercially produced by fermentation process for the use in oral nutraceutical formulations. Constructing the high-yielding CoQ10 producing strains is a pre-requisite for cost-effective production. A superior mutant strain P-87 generated from Paracoccus denitrificans ATCC 19367, which showed 1.25-fold improvement in specific CoQ10 content higher than the wild type strain at shake flask level, was selected to carry out the studies on CoQ10 yield improvement through fermenter process optimization. In the course of study, initially the cane-molasses-based medium and fed-batch fermentation strategy using pHBA in combination with sucrose were standardized in shake flask using wild type strain. This strategy was subsequently translated at 2 L laboratory fermenter while optimizing the fermentation process parameters using improved mutant strain P-87. Under optimized fermentation condition, mutant strain P-87 produced 49.85 mg/L of CoQ10 having specific content of 1.63 mg/g of DCW, which was 1.36 folds higher than the specific CoQ10 content of wild-type strain under similar optimized condition. The temperature and DO were found to be critical parameters for CoQ10 production by mutant strain P-87. The optimum temperature was found to be 32°C and the optimum DO concentration to be maintained throughout the fermentation cycle was found to be 30% of air saturation. Overall, a new cost-effective process has been established for the production of CoQ10 using the cheaper substrate “cane molasses” and higher CoQ10 producing mutant strain P-87.
基金supported by the National Natural Science Foundation of China“The study on size effect of respirable mineral fine particles and common bacteria research (No. 40072020)
文摘1 Introduction Radioactive pollution is increasingly serious and radioactive pollution can not be repaired immediately once it breaks out.Strontium contamination is a research hot point as one of the typical radioactive pollution,and