沼泽红假单胞菌富硒发酵条件的研究

通过对沼泽红假单胞菌富硒发酵条件的研究,确定最优的富硒培养方式。采用单一因素变量法,利用微波消解与紫外分光光度法测定沼泽红假单胞菌在不同发酵条件下的生物量变化与富硒效果,确定其最佳培养方式。结果表明,最佳富硒培养条件为:培养温度30℃,环境硒浓度100μg/mL,培养基初始pH为7,硒添加方式应为梯度分次添加,添加时间应为培养周期的第3天、第4天。利用得到的富硒菌种,在最优条件下培养7 d后,测得环境硒浓度下降为10.9μg/mL,硒的转化率为89.1%,菌体富硒量可达到73.54 mg/g(干菌种),其中有机硒含量为97.1%。利用沼泽红假单胞菌生产有机硒具有可行性,富硒菌体可以作为动物饲料添加剂,也可以为人类提供富含有机硒的食品。在以后的实验中,将进一步进行验证和工业化应用。

Selenium-Enriching Fermentation Conditions of Rhodopseudomonas palustris

Culture conditions for selenium-enriched Rhodopseudomonas palustris were optimized using single factor variable method in the process,with microwave digestion and ultraviolet spectrophotometry to determine the biomass changes and selenium enrichment results under different fermentation conditions.The result showed that the optimum fermentation conditions are as followed： temperature was 30 ℃,the initial pH was 7.0,the selenium concentration in medium was 100 μg/mL,the selenium was added by gradient and batches method,and added at the third and fourth day of the cultivation period.Seven days after the culture under the optimized conditions,selenium concentrations decreased to 10.9 μg/mL,the selenium conversion rate was 89.1%,The thalamus selenium content reached as high as 73.54 mg/g（dry cell）,and the organic selenium content was 97.1%.Therefore,it was feasible to use Rhodopseudomonas palustris to produce organic selenium.The selenium-enriched thallus could be used as feed additive for animals,it could also provide as the selenium-enriched food for human being.There will be further test and verification for industrial application in the future.