Study On Biological Characterization And Barren Soil Improvement Of An Oligotrophic Bacterium

The specific oligotrophic bacteria are possessed of the sbatle special functions through the long-term natural selection to adapt the adverse circumstances. This research based on a oligotrophic bacterium Bacillus subtilis P4 which was isolated from barren soil. By carrying on experiment of basic biological characteristics; structural characteristics of whole-genome sequencing; barren soil improved.Research result provides theoretical basis and technical reference on Oligotrophic microorganisms repair in desert ecosystem. The results are as follows:(1) Strain P4 can grow in the sugar concentration of 15mg/L to 10 g/L which indicate strain P4 is a kind of facultative oligotrophic bacterium. Optimum growth temperature of strain P4 was 30 ? and optimum growth pH value was 7.3. Strain P4 can grow normally in poor soil and the maximum biomass reached to 1.58 X 109cfu/g. Strain P4 has a strong salt-tolerance and the abilities of phosphorus-solubilizing and potassium-releasing. Besides, the strain has the ability of exoploysaccharide-producing.(2)Research sequence features as well as structural and functional annotations of the P4 genome were focused based on sequencing. The results showed that: The complete genomic information of Bacillus subtilis P4 is contained on a single circular chromosome of 3929791 bp with an average GC content of 46.5%. Which contains 4029 predicted protein-coding genes and 86 tRNAs. most genes are involved in amino acid transport and metabolism, carbohydrate metabolism,enzyme metabolism and own differentiation. The barley environment mechanism of the P4 strain analysis showed that: they are many forecast genes coding had important significance for starvation stress, oxidative stress, high temperature stress, osmotic stress and drought stress. We also found that 264 genes were involved in carbohydrate transport and metabolism. Because the key enzymes of gluconeogenesis pathway which are glucose-6-phosphatase and phosphoenolpyruvate carboxylase. There were 45 genes involved in amino sugar and nucleotide glucose metabolism pathway and we found five specific genes encoding polysaccharide synthesis. The number of 508 genome-specific genes of other four bacillus subtilis and the 878 common genes of the KNP414, then predicted protein analysis.(3)The content of available nutrient were marked higher than it of control. Effective N?Effective K and Effective P amplitude respectively 29.42 %-125 %?4.16%-14.15 % and 8.15 %-11.68 %. But there were no obviously increase on full nutrient and pH value, however the contents of soil organic matter were decreased. water retention were significantly increased. especially some soil water absorption were significantly increased both more than 30%. there were the significant positive among three kinds of enzyme activities. Holistically, the original patterns of barren soil nutrients and beneficial to surface soil moisture were changed by spraying the oligotrophic bacteria, provide nutrient to microorganisms and other plant. The barren soil has a certain improvement effect by Oligotrophic Bacteria.