| As an essential nutrient,the iron is closely related to many basic physiological activities in human and animal life activities.It is a component of myoglobin,hemoglobin and other substances.Iron deficiency can cause immunodeficiency,iron deficiency anemia and other related diseases,thus can even seriously affect human health.According to statistics data,the average incidence of iron deficiency anemia of various groups reached 20.1% in China,moreover,the incidence of anemia of women,children and the elderly population are higher than average level.Iron supplements are main drugs in the treatment for iron deficiency anemia.Using the microbe strain conversion of inorganic iron into organic iron,it is the most important attempt and measure to obtain organic iron and develop new type of iron supplements for improving utilization rate of iron.Our previous results suggested that there are some microorganisms in natural environment,they can grow in the high-iron environment,and have better ability of transformation and enrichment.Therefore,in the present study,the high iron-enrich microorganism was further used to investigate its mechanism of transformation and absorption,all of which would obtain a new theory for its further applications.The main results are as follows:The screening and identification of high iron-enriched strains and siderophore producing strains.In the present study,136 high iron-enriched strains provided by the laboratory through primary screening was investigated.Our results showed that 22 colonies including 16 Fungi,2 bacteria and 4 actinomyces can survive in medium with Fe2+10000?g/m L.By the screening of 22 colonies on CAS blue solid plate,14 strains including 10 fungi,1 bacteria and 3 actinomycetes can product siderophores.Further,by the Arow experiment,Csaky experiment,iron perchlorate experiment and Fe Cl3 experiment,the type of 14 siderophores was determined as following: 10 strain was catechins,2 strain was hydroxyl oxime acids.Moreover,one strain exists two type of siderophore at the same time,and one type of another siderophore is uncertain.The study suggested that the transformation of high iron-enrich microorganism growing in high-iron environment is related to siderophores.Screening and identification of siderophore production of high activity predominant strain and preliminary purification of its siderophores.According to the determination of intracellular iron content,the CAS content and the cell biomass,it suggested that the intracellular iron content of high iron-enrich microorganism is related to siderophores.The strain T-G-G-Y producing siderophore with better activity was obtained and further named its siderophore as TZT-11.The different condition of strain producing siderophores are optimized,and the results showed thatthe optimal fermentation condition of the strain is initial p H 6.0 with Fe2+ 8000?g/m L for 24 h.By morphology and molecular biology identification,the results showed that the 18 s r DNA and 26 s r DNA sequence of the strain are similar to Aspergillus fumigatus with 100% homology.The results of separation and purification of the siderophre suggested that activated carbon and macroporous resin is unsuitable for separstion,however,Anion exchange resin and cation exchange resin have better adsorption effect on siderophores because the CAS content of supernatant has decreased significantly after 15 min.The transformation activity of siderophore on Saccharomyces cerevisiae.In order to evaluate the transformation activity,the 14 siderophore from high iron-enrich microorganism were added into saccharomyces cerevisiae,and the revelant intracellular iron content and the cell biomass was determinated.The results showed that the iron conversion rate is highest after adding the siderophore named as TZT-12 from strain YP-12 with the best concentration(24?g/m L),and the intracellular iron content and the cell biomass increase 126.57% and 248.3%,respectively.Subsequently,the different condition of strain YP-12 producing siderophores are optimized,the content of siderophore is higest when the optimal fermentation condition is initial p H 6.0 with Fe2+ 8000?g/m L for 72 h.Based on the morphology,molecular biology and the content of G+C mol %,the results showed that the partial26 S r DNA sequence of the strain are similar to Rhodotorula mucilaginosav with 97%homology,the G+C content was 87.4833%,and the strain have difference on lactose and galactose with R.mucilaginosa in Carbon source assimilation and trace biochemical pipe identification.Finally the strain was preliminary identificated as a new strain.Preparation of iron-enriched yeast with adding siderophore TZT-12 and its efficacy evaluation in anemia model mice.In the present study,by adding siderophore TZT-12,the iron-enriched yeast was obtained and the intracellular iron concentration was 59.399 mg/g.The effect of iron-enriched yeast and ferrous sulfate iron on iron deficiency anemia mice was investigated,and the index of the blood indices,the organ coefficients,body weight,the iron content of organ were determinated.The results showed that iron-enrich yeast can significantly improve the effect of iron deficiency anemia compared with ferrous sulfate group.Our results suggested the iron-enrich yeast produced by adding siderophore TZT-12 would be safe and effective iron supplements,our findings would provide a new idea for preparation of organic trace elements iron. |
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