Dissertation > Industrial Technology > Chemical Industry > Other chemical industries > Fermentation industry > Enzyme preparation ( enzyme )

Screening and Characterization of Bio-scouring on Solar Energy

Author XuChunYuan
Tutor ZhengLaiJiu
School Dalian University of Technology
Course Textile Engineering
Keywords Enzyme Wool scouring Bacteroidetes Sphingobacterium sp. Processoptimization Energy consumption and income
Type Master's thesis
Year 2012
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Chemical method is mainly used in the initial processing of wool fiber materials. The using of surfactants and inorganic salts results in the left of chemicals on the surface of fiber. The scouring wastewater is discharged into nature, resulting in serious environmental pollution. And, the chemical method requires higher temperature and strong mechanical action, consuming large number of energy. In order to solve the above problems, this paper studied on screening ang identification of bio-scouring, the optimization of bacteria growth condition, the optimization of microbial fermentation conditions, the optimization of bio-scouring process and the consumption and benefit analysis of solar energy hot water system.The two strains having a higher yield of lipase were isolated from the dirt on the surface of raw wool fiber. By Rhodamine B chromogenic medium fluorescence experiments, the H/C of1#is2(H/C is the ratio of Fluorescent ring diameter and colony diameter), the H/C of2#is1.5. By the strain morphological, physiological and biochemical test and16S rDNA identification, the1#lipase producing strain was identified as Bacteroides, the2#lipase producing strain was identified as Sphingobacterium sp..Their16S rDNA were registered in GenBank, the accession number were NC016001and FJ859899, respectively.To further enhance the enzymatic activity of the two screened strains, the fermentation medium and conditions of the strains were also optimized. Bacteroidetes can grow well in the medium contain:glucose10g/L, beef extract10g/L, NaCl5g/L, pH is7.5, culured at28℃. Meanwhile, for Sphingobacterium sp, the medium contain:soluble glucose lOg/L, beef extract20g/L, NaCl5g/L, pH is7.5, temperature is30℃. The fermentation conditions of the two Lipase overproducing strains, Bacteroidetes and Sphingobacterium sp. were optimized. The optimum medium conditions of Bacteroidetes were as follows:beef extract10g/L.(NH4)2SO410g/L, MgSO4·7H2O0.5g/L, K2HPO4,1g/L, pH7.5,1%inoculum,30mL liquid volumed in250mL flask,180r/min, cultured for28h on28℃. The optimized medium conditions of Sphingobacterium sp. were as follows:beef extract5g/L,(NH4)2SO420g/L, MgSO4·7H2O0.5g/L, K2HPO4,1g/L, pH7.5,1%inoculum,40mLliquid volumed in 250mL flask,180r/min, cultured for36h on30℃.After training under the above conditions, the optimization of enzymatic wool scouring was studied. The lipase solution of Bacteroidetes and Sphingobacterium sp.was mixed with the best ratio of3:1. The best scouring process conditions were as follows:7%enzyme dosage, liquor ratio is1:35, temperature is35℃, pH is7.5, scouring for20h. Relative to the scouring process before optimization, the fat ratio of scoured fiber was significantly reduced. Meanwhile compared to the conventional scoured wool, enzymatic scoured wool is lower fracture strength and increased elongation, but little effect on the whiteness of scoured wool.Bio-enzymatic wool scouring needs moderate conditions, relatively lower requirements on the heat source. Using the selected lipase-producing strains, solar hot water system can meet the needs of the enzymatic wool scouring. Therefore, the results of this paper provide certain theory basis for the industry of the green wool scouring production.

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