摘要
【目的】当前,养殖业的臭气污染已成为行业的痛点和难点,氨气(NH3)作为臭气污染贡献率高的重要有害气体,其减排已成为亟待解决的首要问题。通过筛选高效除氨菌株并对其进行条件优化,为除臭菌剂的研发提供优良菌种。【方法】选择养殖场排污口沉积的粪污作为菌株分离来源,采用NH3富集培养基进行富集、分离和纯化,并采用NH3降解培养基对已纯化菌株进行降解能力测定,筛出高效降解菌株,再通过形态学(菌落形态和革兰氏染色)和16S rRNA测序对高效菌株进行鉴定,然后进一步研究不同pH(5.0、6.0、7.0、8.0和9.0)、碳源(葡萄糖、蔗糖、果糖、麦芽糖和木糖)、盐度(0%、0.5%、1.0%、1.5%和2.0%)和接种量(1.0%、5.0%、10%、15%和20%)对高效除氨菌株生物量的影响,确定其最优生长条件。【结果】(1)通过富集培养共分离出12株疑似NH3降解菌株(命名C1-C12),其中菌株C5具有较高的NH3降解能力,该菌株的对数生长期为2—20 h,降解率随菌体生长而增加,培养24 h时降解率达60.70%,48 h高达75.49%,显著高于同时期的其他11株菌(P<0.05)。通过形态学和16S rRNA鉴定,菌株C5呈粗短杆状,两端钝圆,无夹膜,革兰氏染色阴性,结合基因测序结果和系统发育树,确定该菌株为肺炎克雷伯氏菌(Klebsiella pneumoniae)。(2)不同pH、碳源、盐度和接种量对菌株C5培养48 h的菌液浓度产生不同的影响。初始pH为7.0时,菌液浓度高于pH5.0、pH6.0和pH9.0,差异达显著水平(P<0.05);相比其他碳源,葡萄糖作为碳源的条件下,培养8—48 h的菌液浓度最高;不同盐度和接种量条件下,菌液浓度组间均表现出显著性差异(P<0.01),1.5%盐度的菌液浓度最高,培养40 h时,菌液浓度达峰值,另外,该菌接种量为1.0%时,菌株生长最快,菌液浓度最高。可见,菌株C5生长的适宜条件:pH 7.0、碳源葡萄糖、盐度1.5%和接种量1.0%,此条件下菌株生长最快,生物量最大。【结
【Objective】Odor pollution from animal industry has become a pain point and a difficulty in recent years.Ammonia(NH3)is an important harmful gas with great contribution rate to odor pollution,and its cutting emission becomes an urgent task.The objective of this study was to isolate the efficient NH3-removing strains and to optimize its cultivated conditions,which would provide excellent strains for developing deodorizers.【Method】Manure deposited in the sewage outlet of the farm was collected as the source of strain isolation.The NH3-removing strains were enriched,separated,and purified using NH3 enrichment culture medium.Then,the degradation ability of purified bacteria above was determined using NH3-degradating culture medium,and the efficient NH3-removing strains were screened.The isolated strains were identified by morphology(colony morphology and Gram staining)and 16S rRNA sequencing method.Further,the effects of various cultivated conditions on biomass of the strains,including pH(5.0,6.0,7.0,8.0,and 9.0),carbon sources(xylose,sucrose,fructose,maltose,and glucose),salt contents(0%,0.5%,1.0%,1.5%,and 2.0%),and inoculum amounts(1.0%,5.0%,10%,15%,and 20%),were performed,and the optimal conditions were determined.【Result】(1)A total of 12 suspected NH3-degrading strains were isolated by enrichment culture(named as C1-C12),among of which,the strain named C5 had efficient NH3-removing ability.The logarithmic growth period of the strain C5 was 2 to 20 h.During the period,the degradation rate of C5 increased with the growing bacteria biomass,reaching 60.70%at 24 h and 75.49%at 48 h of culture,respectively,which was greater than that of the other 11 strains in the same time(P<0.05).From morphology and 16S rRNA identification,the C5 was characterized by stubby-and rod-shaded,pointless round at both ends,and no capsule,as well as Gram-negative bacteria.Combined with gene sequencing results and phylogenetic tree,the C5 was determined to be Klebsiella pneumoniae.(2)Various pH values,carbon sources,salt content,a
作者
董晴
宋连杰
张洪伟
苏东遥
张澳
张璐
张会文
李伯森
高玉红
孙新胜
DONG Qing;SONG LianJie;ZHANG HongWei;SU DongYao;ZHANG Ao;ZHANG Lu;ZHANG HuiWen;LI BoSen;GAO YuHong;SUN XinSheng(College of Animal Science and Technology,Hebei Agricultural University,Baoding 071000,Hebei;Chengde Academy of Agriculture and Forestry,Chengde 067000,Hebei;Veterinary Drug Administration,Chengde 067000,Hebei;College of Information and Technology,Hebei Agricultural University,Baoding 071001,Hebei)
出处
《中国农业科学》
CAS
CSCD
北大核心
2024年第21期4367-4375,共9页
Scientia Agricultura Sinica
基金
河北省自然科学基金(C2023204024)
河北省重点研发计划项目(22326603D)
河北省羊产业体系(HBCT2023200202,HBCT2024250403)。
关键词
氨气
筛选
降解率
肺炎克雷伯氏菌
条件优化
ammonia
screening
degradation rate
Klebsiella pneumoniae
condition optimization
