A Research Of Cr(?) Adsorption Characteristics And Whole Genomics Of Penicillium Janthinellum P1

Heavy metal chromium is very toxic to living organisms,carcinogenic and teratogenic,and it is difficult to treat heavy metal chromium pollution in the environment.Microbial repair technology should have the advantages of low cost,easy operation,and no introduction of secondary pollution,which has been favored by researchers.Many microorganisms have been found to adsorb heavy metal chromium ions.The ocean is a huge treasure trove,which contains a lot of microbial resources.The marine environment is rich and diverse,giving many characteristics of marine fungi.Compared with terrestrial fungi,marine fungi generally have the advantages of salt tolerance,low temperature resistance,high pressure resistance,strong UV exposure,high permeability,and heavy metal resistance.In this thesis,the marine fungus Penicillium janthinellum P1,which is highly resistant to heavy metal chromium,is used as the research object to explore the characteristics and mechanism of P1 adsorption of Cr(?).On this basis,the whole genome sequencing of P1 was carried out,and a research method combining the second and third generation sequencing technologies was used.Starting from whole-genome data,careful analysis and prediction of possible functional genes in the P1 genome,and analysis of genes related to high resistance to heavy metal chromium.Through the above research,the following results were obtained:(1)Under the optimal conditions of initial Cr(?)concentration of 250 mg/L,pH of 1,temperature of 30 ° C,biosorbent dose of 30 g/L,and adsorption time of 8 h,The maximum Cr(?)biosorption rate is about 87 %.Under the optimal conditions of an initial Cr(?)concentration of 100 mg/L,an initial pH of 1,a temperature of 30 ° C,a biosorbent dose of 3 g/L,and an adsorption time of 12 h,the P1 cells were inactivated.The maximum Cr(?)biosorption rate is about 58.6 %.(2)The biosorption process of Cr(?)follows a pseudo-second-order kinetic model,and the bioadsorption process fits well with Freundlich,Dubinin-Radushkevich(D-R)isotherms.The bioadsorption of Cr(?)on P1 cells is feasible,spontaneous and endothermic.SEM analysis revealed that a large amount of Cr(?)was adsorbed on the cell surface after Cr(?)treatment.FT-IR spectra and XPS spectra of C1 s before and after the adsorption of Cr(?)indicate that the amino,carboxyl,carbonyl,and hydroxyl groups present on the cell surface are involved in the adsorption of Cr(?).XPS studies have found that cells reduce the Cr(?)in aqueous solution to Cr(?)to achieve the purpose of Cr(?)adsorption.(3)The genome size is about 30 Mb,and a total of 29 contigs were generated.Contig N50 was 3088.6 kbp and GC content was 46.16 %.(4)10955 CDS were obtained from the tadpole genome,with an average CDS length of 1591 bp,a total of about 1.90 % of the sequences were repetitive,and 503 t RNAs and 70 rRNAs were annotated.(5)There are 574 carbohydrate active enzyme genes and 250 genes that may be related to heavy metal chromium resistance of P1 in the plutonium genome.The above research work has filled the gap in the research of P1 genome,and laid a foundation for further excavation and utilization of P1's high resistance to heavy metal chromium.