Screening,Identification,Function Optimization And Hemp Rain Degumming Effect Of Pectobacterium Aroidearum WNH

In order to isolate and screen high-efficiency pectinase strains for hemp biological degumming,a medium PMAS with citrus pectin as the sole carbon source was used,and a high-activity pectinase strain was obtained by plate dilution method.Single colonies on PMAS solid medium were yellow,opaque,nearly round,with irregular edges.The taxonomic status of the strain WNH was determined by 16 s r DNA sequence alignment,and it was preliminarily confirmed as Pectobacterium aroidearum,and initially named as P.aroidearum WNH.P.aroidearum WNH can appear transparent circle after staining with Congo red,and the circle diameter ratio is 6.06±0.53.The pectinase activity of strain WNH was determined by the DNS method to be 85.05 U/m L.The second degumming treatment of hemp bast was carried out by inoculating P.aroidearum WNH,and the control group was not inoculated.the degumming rate of bast fibers in the experimental group is 27.18%,which is 15.50-42.00% higher than that in the control group.To further optimize the enzyme-producing ability of P.aroidearum WNH,in a constant temperature incubator at 27℃,the initial p H=7.0,the inoculum volume was 10%,and after culturing at 160 r/min for 16 h,the pectinase activity was 155.03 U/m L,which was higher than that before optimization.Increased by 82%.In order to verify the effect of P.aroidearum WNH in the natural hemp retting of hemp,four groups of treatments were set up: natural rain retting(CK1),enhanced rain retting(T1),natural stacking retting(CK2)and enhanced stacking retting(T2).Among them,the T1 group had the highest numbness rate of stem stems of 18.51%,and the lowest rate of bast glue residues of29.70±0.01%.The residual gum rate of the inoculated treatment group was significantly better than that of the non-inoculated group,and the residual gum rate of the flat-bed retted hemp was significantly better than that of the stacked-type retted hemp.The results showed that spraying P.aroidearum WNH was helpful to improve the effect of natural rain and dew retting,but it had no obvious effect on the hemp yield of dry stems;the flat laying treatment was more suitable for the rain and dew retting treatment than the stacking treatment.