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1.
试验研究了芽孢乳酸菌的生长特性、泌酸能力、高温耐受性、耐酸性、胆盐耐受性和抑菌能力,旨在为微生态饲料添加剂的研发提供试验依据。结果表明,芽孢乳酸菌在30 h时菌体质量浓度达到最高值,在32 h时产酸量最高,最后在pH 3.80左右趋于稳定;芽孢乳酸菌经90℃处理10 min后存活率达到73.47%,pH 2.0及1.0%胆盐处理3 h后存活率分别为54.69%、24.36%;芽孢乳酸菌对大肠杆菌、沙门氏菌、金黄色葡萄球菌均具有较好的抑菌性能,抑菌圈直径分别为18.38、19.76、17.42 mm。结果说明,芽孢乳酸菌具备良好的生物学特性,是一株优异的益生菌株。  相似文献   

2.
为筛选可提升高寒地区菊芋(Helianthus tuberosus)青贮发酵品质的耐低温乳酸菌,本研究以‘青芋2号’菊芋青贮物料为材料,利用平板培养法分离乳酸菌株,分析菌株生理生化特性,并通过16S rRNA测序进行菌株种属鉴定。结果表明,菊芋青贮物料中共分离得到34株乳酸菌株,经低温及生理生化筛选获得13株耐低温乳酸菌株,包括11株同型发酵乳酸菌和2株异型发酵乳酸菌,其耐酸性和耐盐性均较强;经产酸和生长能力对比,GN02菌株生长最快(OD=2.63),GN10菌株具有更强的产酸能力(pH=3.59),XN25菌株兼具较强的生长和产酸能力;16S rRNA测序鉴定出9株植物乳杆菌(Lactiplantibacillus plantarum)、1株戊糖乳杆菌(Lactiplantibacillus pentosus)、1株棒状乳杆菌(Lactiplantibacillus coryniformis)、1株短乳杆菌(Lactiplantibacillus brevis)及1株无法鉴定。本研究筛选出适合高寒地区菊芋青贮发酵的耐低温植物乳杆菌、戊糖乳杆菌、短乳杆菌各1株。  相似文献   

3.
为获得性能优异的乳酸菌,对一些饲料原料中乳酸菌进行了筛选和鉴定,共获得了105株乳酸菌,通过形态学观察,16S rRNA基因序列分析以及生理生化试验等手段获取了有代表性的16株乳酸菌,通过产酸性能、酸耐受性、耐胆盐能力和抑菌效果等试验测定,共获得了2株性能优异的乳酸菌P16和C20。经鉴定,P16为戊糖片球菌(Pediococcus pentosaceus),对大肠杆菌K88(Escherichia coli CVCC 225)的抑菌能力较强,12 h发酵液pH值为3.36, 0.3%胆盐处理2 h存活率为82.00%;C20为希氏肠球菌(Enterococcus hirae)对指示菌金黄色葡萄球菌(Staphylococcus aureus ATCC 25923)的抑菌效果较好,发酵液12 h pH值为3.88,0.3%胆盐处理2 h存活率为97.67%;此外,P16和C20酸耐受性也相对较强,具备一定应用潜力。  相似文献   

4.
为了筛选出适用于多花黑麦草青贮发酵的优良乳酸菌菌株,从自然青贮多花黑麦草中分离乳酸菌,筛选并鉴定生长快速且产酸效率高的菌株,分析其生理生化特征以及对多花黑麦草青贮品质的影响。利用传统的平板培养法,从自然青贮多花黑麦草中分离获得180株乳酸菌。其中,5株乳酸菌生长快速且产酸能力强,均能够在NaCl浓度为3.0%,温度为15~35 ℃,pH为3.5~7.0的MRS液体培养基中良好生长。经16S rRNA基因序列比对鉴定,菌株PR_LAB_9、PR_LAB_34、PR_LAB_67和PR_LAB_86为植物乳杆菌,PR_LAB_76为戊糖片球菌。对菌株进行生长曲线和产酸性能测定,该5株乳酸菌均能够在12 h内快速繁殖和产酸,菌株PR_LAB_76在24 h内生长速率和产酸效率均优于其他4株乳酸菌。进一步分析添加该5株乳酸菌对多花黑麦草青贮发酵品质、营养成分、微生物数量的影响,发现该5株乳酸菌均能提高多花黑麦草的青贮品质,包括显著降低青贮料pH和氨态氮含量,减少干物质损失,提高可溶性碳水化合物含量。其中,菌株PR_LAB_76处理组多花黑麦草青贮品质最优,干物质含量、粗蛋白含量、乳酸含量、乳酸菌数量显著高于其他4株乳酸菌处理组,且pH值、酵母菌数量显著低于其他4株乳酸菌处理组。综上,戊糖片球菌PR_LAB_76可作为多花黑麦草青贮的备选菌株。  相似文献   

5.
筛选分解利用葡聚糖或木聚糖的乳酸菌作为饲料作物青贮添加剂。从30株供试乳酸菌中筛选能够利用葡聚糖或木聚糖产酸的菌株。通过抑菌活性、生长情况、碳源发酵及利用饲料作物粉产酸试验研究菌株的特性,结合形态学特征和16S rRNA序列分析鉴定菌种。筛选得到1株利用葡聚糖及木聚糖产酸效果较好的乳酸菌ZZU 360;该菌株对G+及G-细菌均具有较好的抑菌活性,在45和50℃及pH 3.5、4.0和4.5环境条件下生长较好,能够耐受6.5%盐溶液,利用碳源种类比较广泛,对40%干物质的苜蓿粉、饲料桑粉及饲料槐粉均具有较好的酸化作用,菌株ZZU 360被鉴定为戊糖片球菌。该菌株在可溶性糖短缺的饲料作物青贮中具有潜在的应用价值。  相似文献   

6.
刘悦  字学娟  陈婷  孙蓉  李茂  汤凯 《草地学报》2022,30(10):2819-2826
为筛选适合热带牧草的高温发酵优良乳酸菌,改善青贮发酵品质,本试验从海南岛不同气候区采集野生草本植物斑茅(Saccharum arundinaceum)、蔓生莠竹(Microstegium vagans)和木本植物银合欢(Leucaena leucocephala)、构树(Broussonetia papyrifera),青贮60 d后分离纯化乳酸菌,以培养36 h条件下最终发酵液pH≤4且OD(Optical density,吸光度)≥2作为条件初筛乳酸菌。用温度T=40℃,45℃,50℃和pH=3.0,3.5,4.0,6.0,8.0,9.0进行复筛,选取OD值较高的菌株作为优势菌株,再对其进行16S rDNA序列分析、生长和产酸速率测定以及生理生化实验。结果表明,本试验共分离到98株天然乳酸菌,经筛选得到4株优良乳酸菌(15B,10D,13C,14B)。经鉴定,10D,13C,14B为植物乳杆菌(Lactobacillus plantarum),15B为乳酸片球菌(Pediococcus acidilactici)。菌株15B,10D,13C,14B均耐酸、耐高温、且生长及产酸性能优良,具有良好的青贮潜力并对致病菌具有良好的抑制作用,可作为热带地区制备青贮添加剂的备选菌种。  相似文献   

7.
为筛选出能改善燕麦低温青贮发酵品质的潜力乳酸菌菌株,对青藏高原不同海拔地区种植的燕麦表面附着乳酸菌资源进行了采集,通过限制性培养方法筛选耐低温菌株,对其耐酸性和耐盐性、产酸速率和生长速度进行分析比较,并用16S rDNA序列分析方法进行了鉴定。结果表明:从不同海拔地区的燕麦植株上初步分离到232株乳酸菌,经进一步革兰氏染色、镜检观察和过氧化氢酶试验筛选,获得56株菌株,对其进行低温筛选,共得到18株耐低温乳酸菌资源,均能在5~20 ℃、3.0%和6.0% NaCl以及pH为3.0~5.0条件下生长,其中14株为同型发酵乳酸菌,4株为异型发酵乳酸菌。14株同型发酵乳酸菌中,OCPP3、OL3、OL8、OL25、OL36、OL54、OL77和OL122的产酸和生长速率较高,3株(OCPP3、OL36和OL77)为戊糖片球菌,2株(OL3和OL54)为戊糖乳杆菌,3株(OL8、OL25和OL122)为植物乳杆菌。在培养25 h后,菌株OL77的OD值在所有培养菌株中最高(2.52),其次为OL54(2.50)。从耐低温、产酸速率和生长速率及多样性角度综合考虑,戊糖片球菌OL77、戊糖乳杆菌OL54和植物乳杆菌OL122适宜作为青藏高原地区燕麦低温青贮的备选添加菌株。  相似文献   

8.
本研究旨在探寻益生特性优良、可作为抗生素替代品的乳酸菌,并为后续应用于畜禽养殖提供理论依据。本试验以青海黑藏羊和西藏白绒山羊瘤胃内容物为菌株分离来源,采用含有碳酸钙的MRS固体培养基分离纯化乳酸菌,经生理生化和16S rRNA测序鉴定及产酸产气试验分离得到22株同型发酵乳酸菌,测定并评价其生长速率、产酸能力、耐酸和耐胆盐性能、抑菌能力、自凝集率及抗生素敏感性。综合比较不同菌株之间的生物学特性,分别在片球菌属、肠球菌属、乳杆菌属中筛选获得2株戊糖片球菌、1株海氏肠球菌、2株戊糖乳杆菌。结果表明:2株戊糖片球菌均在4 h后进入对数生长期,16 h达到稳定期,24 h后菌液pH达到4.0以下,能耐受pH 3.0和0.3%的胆盐环境;1株海氏肠球菌在2 h后进入对数生长期,12 h达到稳定期,24 h后pH达到4.5以下,能耐受pH 4.0和0.3%的胆盐环境;2株戊糖乳杆菌均在2 h后进入对数生长期,16 h达到稳定期,16 h后pH达到4.0以下,能耐受pH 3.0和0.3%的胆盐环境,5株乳酸菌自凝集率、抑菌能力及安全性均表现优良。综上所述,本试验筛选获得的5株不同种属乳酸菌生物学特性良好,可作为后续开发微生物发酵饲料及动物微生态制剂的菌种来源。  相似文献   

9.
研究从青贮饲料中分离筛选获得3株乳酸菌,通过产酸试验、不同温度和pH培养试验及对糖类利用及抑菌试验,筛选出1株适合作为青贮接种剂的优良菌种,通过形态学、生理生化和分子鉴定相结合的方法对获得的菌株进行鉴定,最终确定菌株P1为乳酸片球菌,为青贮接种剂提供优良菌株。  相似文献   

10.
为筛选出适合于青藏高原青稞秸秆青贮用的优良乳酸菌菌株,研发新型青贮添加剂。分离了青藏高原青稞(Hordeum vulgare)秸秆青贮饲料中的乳酸菌,利用传统微生物培养法和16S rRNA序列分析法对乳酸菌进行鉴定,探讨其生物学特性,并筛选出优良的乳酸菌菌株。共分离获得4株同型发酵乳酸菌菌株,其中HG24,LH2为植物乳杆菌(Lactobacillusp lantarum),LH9为乳酸片球菌(Pediococcusacidi lactici),LH7为戊糖片球菌(Pediococcusp entosaceus)。分离出的乳酸菌菌株均能在5~30℃,pH 3.5~7.0及3.0%和6.5% NaCl培养基中生长良好,其中HG24,LH2在pH值为3的培养基中仍能生长,体现出分离的乳酸菌菌株具有耐低温、耐酸性和耐盐性强的特征。4株乳酸菌菌株中HG24和LH2产酸能力强、生长速率快,最适宜于用作青贮乳酸菌菌种。  相似文献   

11.
The purpose of the experiment was to screen psychrotrophic lactic acid bacteria with strong stress-resistant growth ability,acid production ability and good bacteriostatic characteristics in vitro,and analyze its related biological characteristics,so as to provide excellent psychrotrophic lactic acid bacteria resources for low temperature silage in Northeast China.The culture condition of 10 ℃ was used to screen the psychrotrophic lactic acid bacteria.After the determination of the growth characteristics of Lactobacillus under different pH,temperature and salinity conditions,the species identification of the candidate strains was carried out,and the growth curve,acid production curve,acid and bile salt resistance,bacteriostatic performance and feeding test of mice were conducted for the candidate strains.The results showed that 11 strains of psychrotrophic lactic acid bacteria could grow well at 10 ℃.The strains C37,C34 and C4212 were identified as Lactobacillus plantarum by 16S rRNA sequencing analysis.The pH of C37,C34 and C4212 decreased to below 4.25 after 7 days of culture.In addition,C37,C34 and C4212 could grow well at 4 ℃,45 ℃,pH 3.0 and 6.5% NaCl.The analysis of growth curve showed that the three strains of Lactobacillus all had a fast growth rate,entered the logarithmic growth period at 4 h,and entered the stable growth period in 10-12 h after inoculation.In the aspect of acid production rate,C37,C34 and C4212 could reduce pH below 4.04 at 24 h of culture.At pH 3.0,C37 and C4212 had a high survival rate,they all had a certain tolerance to 0.5% bile salt,and the survival rate was more than 80%.C37,C34 and C4212 had inhibitory effect on enterotoxin producing Escherichia coli,Salmonella Typhimurium,Staphylococcus aureus and Salmonella Enteritis,and the animal test of three Lactobacillus plantarum were safe.Based on the results of this experiment,Lactobacillus C37,C34 and C4212 were screened and identified from the forest soil of Changbai Mountain,which could provide excellent lactic acid bacteria resources for low temperature silage in winter in Northeast China.  相似文献   

12.
The effects of freeze-thaw conditions on the fermentation quality and aerobic stability of oat silage were investigated. Four strains of freeze-thaw-resistant lactic acid bacteria(LAB)with rapid growth and efficient acid production were screened from 437 strains,which had been isolated from the Qinghai-Tibetan Plateau. Based on physiological and biochemical characteristics and 16S rRNA gene sequence alignment,the four strains were identified as Lactobacillus plantarum 157(LP157),L. plantarum 160(LP160),Lactobacillus brevis 248(LB248),and Lactobacillus pentosus 260(LPE260). In order to investigate their effects on the fermentation quality,nutrient composition,microbial counts and aerobic stability of oat silage under freeze-thaw conditions,seven treatments were tested as follows:1)LP157;2)LP160;3)LB248;4)LPE260;5)LP160+Lactobacillus rhamnosus 753 mixture (MIX);6)A commercial bacterial silage additive(COM);7)The same amount of sterilized distilled water(CK). All treatments were ensiled for 60 days at a constant temperature of 20 ℃ and under a 20 ℃/-5 ℃ regime alternating every 12 h(freeze-thaw). LP inoculation improved silage quality:The pH and dry matter loss in silages inoculated with LP157,LP160,LB248 and LPE260 were significantly lower than CK(P<0. 05)and lactic acid and acetic acid contents were significantly higher than CK(P<0. 05),and the growth of spoilage micro-organisms such as coliform bacteria,yeast and mold were inhibited,both with fermentation at constant 20 ℃ and under freeze-thaw conditions. After aerobic exposure for 5 days,the pH and NH3-N of silages treated with LP157,LP160,LB248 and LPE260 were significantly(P<0. 05) lower than CK,MIX and COM. The aerobic stability of oat silage was improved,especially when inoculated with LP160(70 h vs. CK 11 h). The results show that the four screened strains can be used as effective LAB inoculants for silage preparation in the freeze-thaw environment of the Qinghai-Tibetan Plateau. © 2022 Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   

13.
为探讨不同乳酸菌互作对苜蓿(Medicago sativa)青贮细菌群落结构的影响,以2种植物乳杆菌、乳酸片球菌、戊糖片球菌及凝结芽孢杆菌形成的6种乳酸菌组合按1.5 mL·kg-1的添加量制作苜蓿青贮,以等量蒸馏水替代添加剂作为对照,45 d后运用高通量测序分析细菌群落结构。结果表明,各苜蓿青贮的优势乳酸菌群均为厚壁菌门(Firmicates)的乳杆菌属(Lactobacillus)和片球菌属(Pediococcus),二者相对丰度之和为65.4%~79.0%,其中含植物乳杆菌处理高于对照和含凝结芽孢杆菌处理;与对照相比,乳酸菌组合处理提高了菌群Chao1和ACE指数但降低了Simpson和Shannon指数;6个乳酸菌组合处理中,含凝结芽孢杆菌处理组与对照相似性较高,对苜蓿青贮细菌群落影响较小;相关分析表明,苜蓿青贮菌群结构和多样性可较好地解释其营养品质的变化。综上,乳酸菌组合在一定程度上改善了苜蓿青贮的细菌群落结构,其中含植物乳杆菌的组合效果较好。  相似文献   

14.
为筛选出适用昆明地区全株玉米青贮发酵的优质乳酸菌菌株,探求其青贮效果,本研究以自然发酵60 d的全株玉米(Zea mays)、紫花苜蓿(Medicago sativa)、鸭茅(Dactylis glomerata)为试验材料,将继代培养、菌株分离和形态及基因序列鉴定等方式筛选的3株优质菌株制成菌液,单独或2种菌液按1∶1配比添加到全株玉米中,检测其对全株玉米发酵品质、营养品质及有氧稳定性的提升效果。结果表明:短乳杆菌B10、植物乳杆菌B16及戊糖片球菌C23是昆明地区3种青贮饲料中的优质本土乳酸菌;与自然发酵相比,同型发酵乳酸菌B16,C23单独添加或与异型发酵乳酸菌B10配合添加可显著提高青贮饲料中乳酸菌的数量(P<0.05);与商用复合乳酸菌相比,优质本土乳酸菌单一菌液或复合菌液的添加可更好的保存青贮饲料的DM及CP含量,但对青贮饲料有氧稳定性的提升效果相对较差。因此,添加本土优质乳酸菌可改善全株玉米青贮品质。  相似文献   

15.
为探究不同乳酸菌添加剂对苦荬菜(Lactuca indica)青贮品质的影响,本试验以‘蒙早’苦荬菜为原料,设置对照(CK组)、单独添加植物乳杆菌(LP组)、单独添加布氏乳杆菌(LB组)和混合添加植物乳杆菌和布氏乳杆菌(LP+LB组)4个处理,青贮60天后,进行营养成分、发酵品质和微生物数量的测定。结果表明:不同乳酸菌添加剂对苦荬菜青贮饲料的粗蛋白质和可溶性碳水化合物含量有显著影响(P<0.05);加入乳酸菌添加剂后苦荬菜青贮饲料的pH值显著低于CK组(P<0.05),乳酸菌数量均有所增加(P<0.05);LB组的酵母菌数量最少(P<0.05);LP组和LP+LB组的乳酸含量显著高于CK组和LB组(P<0.05);LB组的乙酸含量最高(P<0.05)。采用隶属函数法综合评价表明,LP组的青贮品质最好。综上所述,单独或混合添加不同发酵类型乳酸菌均能改善苦荬菜青贮饲料的发酵品质,其中植物乳杆菌更适宜用作添加剂调制苦荬菜青贮饲料。  相似文献   

16.
川西北高寒地区燕麦收获时含水量较高,环境温度较低,燕麦青贮品质不佳。本文为提高燕麦青贮品质,研究了自选乳酸菌发酵生物学特性,评价了麦麸和自选乳酸菌菌株对燕麦裹包青贮品质和有氧稳定性的影响,采用双因素试验设计:因素A,A0:0%麦麸;A1:30%麦麸;因素B,B0:对照;B1:Lactobacillus plantarum 160 (LP160);B2:Lactobacillus brevis 248 (LB248);B3:商业菌。每个裹包50 kg,每个处理3个重复。结果表明,自选菌株LP160和LB248在模拟冻融(20℃/-5℃)条件下生长迅速、产酸快。燕麦裹包青贮60 d后,添加麦麸后青贮干物质、粗蛋白、可溶性碳水化合物、乳酸显著增加(P<0.01),添加乳酸菌后青贮pH和氨态氮显著降低(P<0.01),其中A0B1组发酵品质最优,A1B1组营养品质最...  相似文献   

17.
To study the physicochemical properties extracted from koumiss of Lactobacillus plantarum DSM20174 bacteriocin,we purified the Lactobacillus plantarum DSM20174 bacteriocins and got the bacteriocin crude extractions after ammonium sulfate precipitation and dialysis.After purification with Sephadex G-100 gel column chromatography,bacteriocin specific activity apparently increased,reaching 154.70 AU/mL,yield was 43.5%.We detected the effects of purified Lactobacillus plantarum DSM20174 bacteriocin on bacteriostatic action of wild bovine pathogenic E.coli O78 by Oxford cup method under 3 different treatments.The results showed that:①In five groups of temperature treatments,the bacteriostatic action decreased with the increase of temperature,bacteriostatic actions of all groups were significantly different (P<0.05).Even after treatment at 121 ℃ 30 min,antimicrobial diameter was 14.90 mm.② After Lactobacillus plantarum DSM20174 bacteriocin were treated with pH 2.0 to pH 12.0,the higher of pH,the smaller of antibacterial diameter.The inhibitory effect of groups were significantly different (P<0.05) except pH 9.0 and pH 10.0.③Lactobacillus plantarum DSM20174 bacteriocins were treated by trypsin,pepsin and papain,antibacterial diameter apparently changed,bacteriostatic action was significantly different (P<0.05) before and after treatment.The results suggested that Lactobacillus plantarum DSM20174 bacteriocins were better antibacterial substances,but not thermal stability substances.It had a relatively wide pH range,and the smaller of pH,the stronger of its antibacterial activity,the antibacterial activity had been enhanced at optimum growth pH.It was not protease stability substances.  相似文献   

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