Research On PVA Biodegradation And Cadmiums Biosorption Of Pseudomonas Pseudoalcaligenes

Microorganism is a commonly employed remediation technologyfor degrading PVA and restoring hevay mental pollution, which are twohotspots in environmental science. Under the catalysis of enzymedegradation, the molecular chain of PVAwas ruptured angian and angian,and then become lots of fragments with low relative molecular mass, atlast PVA fragments were absorbed into microbes’ body or digestion.Microorganism has great potential in environmental management andgetting more and more attention as it can be less expensive, highefficient and environmentally friendly.This article combined with PVAdegradation and heavy metal pollution problem, used the characteristicsthat PVA can be used as the sole carbon source for microbail growth,studies pseudomonas pseudoalcaligenes characteristics of PVAdegradation and cadmium biosorption. And used ultraviolet (UV)mutagenesis and HNO2treatments to promote the ability ofheavy-metal-resistant and cadmium-resistant.In order to solve thewaste that PVA can not be recycle used, relieve the pressure of PVAwaste on the environment, at the same time, it’s a kind way for cadmiumpollution. Which can double repair the ecological environment with lowenergy consumption and waste recycling.The research was focused ontwo directions as aforementioned, and the main content included asfollows:1. Consulted Finley method and spectrophotometric analysismethod to analysis PVA degradation. The suitable culture conditionwere(g/L): PVA17991，Yeast extract0.1,(NH4)2SO40.1，KH2PO40.24，K2HPO40.04，MgSO4·7H2O0.035，NaCl0.01，FeSO40.001,pH7.0.The PVAdegradation rate could reached94.09%.2. Dicussed the effect of osmotic pressure, heavy metal ions andother factors on PVA degradation.Geted the following conclusion:pseudomonas pseudoalcaligenes does not have the ability to resistance inhigh osmotic pressure and it can resistance in Cd environment when theCd concentration under the low of100mg/L. Other heavy metal ionslike Cu、Mg、Mn can be used to promote the rate of PVA degradation enzyme production. Ni and Co would restrain the growths of strains.3. Pseudomonas pseudoalcaligenes was single immobilized onbio-ceramic to adsorb cadmium ion. The biosorptions both of batch andreactor confirmed that immobilized microbes could removecadmium.The removal rates were37.4%and19.6%.The result ofFourier Transform Infrared Spectrum (FTIR) showed that the cell wallsof pseudomonas pseudoalcaligenes mutant contain a lot of potentialmetal-binding functional groups like O-H、N-H、C-N、PO3-4、HPO2-4、P-N,etc.4. After ultraviolet (UV) mutagenesis and HNO2treatment, theability of heavy-metal-resistant and cadmium-resistant were improved.When the pseudomonas pseudoalcaligenes was exposed to UV light for7min and HNO2treatment for20min, the minimal inhibitoryconcentration (MIC) to cadmium for the ZYB-6and YYB-2mutantwere60mmol/L and45mmol/L. The rates of remove cadmium waspromoved to54.4%and49.7%.class producing alkali pseudomonas,after uv and nitrous acid induced mutant strain resistance to cadmiumand other heavy metal resistance are. Scanning electron microscopy(SEM) spectrum and FTIR analysis showed that cadmium didn’t causemajor damage to the mutation bacterias cell structures when dealed withthe concentration of4mmol/L cadmium. The functional groups whichparticipate in cadmium adsorption reaction such as O-H、N-H、PO3-4、HPO2-4、P-O were more active.