抑氨菌筛选鉴定、培养条件优化及在鸡粪除臭中的应用

目的筛选能抑制鸡粪中恶臭气体NH3释放的亚硝化、硝化细菌菌株。方法以亚硝化、硝化细菌培养基为筛选培养基筛选菌株,然后将菌株分别以10%(v/m,下同)的接种量接种到鸡粪中,测定其对鸡粪中NH3释放量的影响,从中筛选出可减少NH3释放的菌株。根据菌株的形态特征和16S rDNA序列分析对其进行鉴定。通过自动发酵系统对菌株培养温度、pH、通气量及转速四个因素进行正交优化。结果通过筛选得到两株细菌YF1和YS2,经鉴定分别为假单胞菌属(Pseudomonas sp.)和中华根瘤菌属(Sinorhizobium sp.)。菌株YF1最适培养条件为温度28℃,pH 7.0,通气量5 L/min,转速200 r/min;菌株YS2最适培养条件为温度30℃,pH6.5,通气量5 L/min,转速300 r/min。温度、pH、接种量和通气量对YF1、YS2影响均极显著(P0.01)。YF1和YS2单独按10%剂量接种分别使鸡粪中NH3的释放量降低26.0%和28.4%,而两菌1∶1混合接种可使NH3释放量降低75.6%。结论 YF1和YS2是抑制鸡粪中NH3释放的优良菌株。

Isolation,identification and optimization of culture condition of ammonia-reducing bacteria and its application in chicken manure deodorizing

Objective To screen nitrosobacteria and nitrobacteria which can reduce ammonia emission from chicken manure. Methods Selective media were used to screen the strains. The strains were then inoculated respectively in manure at an inoculum of 10%. The amount of ammonia emission was measured. The qualified strains were identified by morphological and 16S rDNA sequence analysis. The culture condition was optimized by orthogonal experiment, which included four factors： incubation temperature, pH, ventilation and ortation speed, in 10 L autofermentation system. Results Two strains were obtained and named YF1 and YS2, which were identified as Pseudomonas sp. and Sinorhizobium sp. respectively. The optimum culture conditions for strain YF1 were at 28℃, pH value of 7.0, aeration rate of 5 L/rain, and rotation speed of 200 rpm ; the optimum conditions for strain YS2 were at 30℃ , pH value of 6.5, aeration rate of 5 L/min, and rotation speed of 300 rpm. The four factors had significant effect （P 〈 0.01 ） on YF1 and YS2. Inoculum of 10% of YF1 and YS2 reduced the ammonia emission by 26.0% and 28.4% respectively ; Inoculation of the two strains mixed in 1 to 1 ratio reduced the ammonia emission by 75.6%. Conclusion YF1 and YS2 are excellent strains for inhibition of ammonia emission from manure.