Screening of iron-enriched fungus from natural environment and evaluation of organically bound iron bioavailability in rats

Abstract

Iron is an essential element for nearly all living organisms, and its deficiency is the most common form of malnutrition in the world. The organic forms of trace elements are considered more bioavailable than the inorganic forms. Although Saccharomyces cerevisiae can enrich metal elements and convert inorganic iron to organic species, its tolerability and transforming capacity are limited. The aim of this study was to screen higher biomass and other iron-enriched fungi strains besides Saccharomyces cerevisiae from the natural environment. A PDA medium containing 800 μg/mL iron was used for initial screening. Fifty strains that tolerated high iron concentration were isolated from the natural environment, and only one strain, No.BY1109, grew well at Fe (II) concentration of 10,000μg/ml. According to morphological characterization, 18S rDNA sequence analysis, and biophysical and biochemical characterization, the strain No.BY1109 was identified as Rhodotorula. The iron content of No.BY1109 (10 mg Fe/g dry cell) was determined using atomic absorption spectrometry. The results of distribution of iron in the cells showed that iron ion was mainly chelated in the cell walls and vacuoles. The bioavailability in rats confirmed that strain No.BY1109 had higher absorption efficiency than that of ferrous sulfate after single dose oral administration. The present study introduces new iron supplements, and it is a basis for finding new iron supplements from natural environment.Keywords: iron-rich fungus; screening and isolation; identification; cell-iron distribution; bioavailability.Practical Application: Iron is an essential element for nearly all living organisms, and its deficiency is the most common form of malnutrition in the world. The present study described the higher bioavailability of iron from natural environment grown in high iron medium. The result is interesting and shows some new data for finding new iron supplements from natural environment.

Effects of Fe-YM1504 on iron deficiency anemia in rats

“…16 It is well known that the iron ion(II) inhibits the growth of microorganisms. YM1504 was isolated from soil samples in different sites of an iron mine in Yuzhong County, Gansu province, China, according to our previously described screening method on highly iron-enriched microorganisms.…”

Foliar application of Fe resonates to the belowground rhizosphere microbiome in Andean landrace potatoes

“…In a heavy metal contaminated sediment the class Microbotryomycetes in phylum Basidiomycota was observed to be resistant to high levels of Fe and other heavy metals (Pb, Mn, Cd, Cu and Zn) (Abdel-Azeem et al, 2015). An Fe-enriched fungus was similarly isolated from a natural environment belonging to this class (Zhang et al, 2015). These results relate well to many of the OTUs in this class which had much greater relative abundance due to high Fe applications to leaf surfaces.…”

Improvement of selenium enrichment in Rhodotorula glutinis X-20 through combining process optimization and selenium transport

“…Yin et al also demonstrated that the optimal pH for selenium enrichment in S. cerevisiae was 5.822. Using Rhodotorula, the optimal pH for enrichment of other ions was also between 6.0 and 7.0 [25]. Efficient selenium enrichment at pH 7.0 implies an underlying difference in mechanism of selenium accumulation in R. glutinis X-20, which should be further examined.…”