绿汁发酵液及青贮苜蓿中乳酸菌的分离筛选及鉴定

苜蓿较难青贮,用青贮接种剂可提高苜蓿青贮的质量。本研究以pH的降低程度及稳定性,乳酸积累量多,产生香甜气味为指标,通过连续限制性培养,从绿汁发酵液、青贮苜蓿中共筛选出3株乳酸球菌和3株乳酸杆菌;该6株菌在72 h内均能使MRS液体培养基pH下降至3.2左右并维持稳定,在MRS固体培养基中培养散发出香甜气味,此6株菌可供开发苜蓿青贮接种剂作进一步研究。     

玉米秸秆和白菜尾菜混贮料的乳酸菌多样性及耐高温优良菌株筛选

通过形态特征、生理生化特性及16S rRNA序列分析方法对玉米(Zea mays)秸秆和白菜(Brassica pekinensis)尾菜混贮料中的乳酸菌多样性进行分析,并以温度和p H为限制因素筛选优良乳酸菌菌株。结果表明,分离得到的12株乳酸菌分属于乳杆菌属(Lactobacillus)和片球菌属(Pediococcus)。其中,1株(LB-1)为植物乳杆菌(Lactobacillus plantarum),6株(LB-2、LB-4、LB-7、LB-8、LB-9和LB-11)为戊糖片球菌(Pediococcus pentosaceus),3株(LB-5、LB-6和LB-12)为短乳杆菌(Lactobacillus brevis),2株(LB-3和LB-10)为类干酪乳杆菌(Lactobacillus paracasei)。菌株LB-3和LB-8表现出优良的耐高温、耐酸碱特性,且具有较强的产乳酸能力,二者可作为青贮饲料的乳酸菌添加剂。     

苜蓿青贮乳酸菌的筛选及其对苜蓿青贮发酵的影响

为获得苜蓿青贮用乳酸菌,本研究从苜蓿附生乳酸菌中通过抑菌活性、酸化苜蓿粉及结构性糖代谢中间产物的性能指标筛选优良菌株,并研究其对苜蓿(Medicago sativa)青贮发酵的影响。结果表明,1)筛选到抑菌活性较高、酸化苜蓿粉及结构性糖代谢中间产物综合性能较好的菌株ZZU A341,被鉴定为植物乳杆菌(Lactobacillus plantarum);2)青贮90 d,添加该菌株的处理组pH、氨态氮含量低于添加商业菌株(YX)的处理组,显著低于自然青贮(P <0.05)。综上所述,使用该筛选方法获得的优良乳酸菌可有效改善苜蓿发酵品质。     

苜蓿青贮乳酸菌的筛选及应用研究进展

苜蓿青贮是草食动物重要的粗饲料,调制并生产优质的苜蓿青贮对畜牧业尤其是奶牛行业的发展具有重要作用。青贮添加剂种类多样,乳酸菌是苜蓿青贮中的一种核心菌种,也是一种常见的青贮添加剂,它可以改善苜蓿青贮的发酵环境和有氧稳定性,从而提升其发酵质量和营养品质。本文对苜蓿青贮乳酸菌的筛选及其应用进行了归纳和阐述,以期为发掘适合苜蓿青贮的乳酸菌提供科学依据。     

西藏青贮用乳酸菌筛选分离及应用研究进展

西藏自治区地处青藏高原,虽然饲料原料资源丰富,但整体利用率不高。青贮处理可以有效贮存饲料,既可以节约饲料资源,也可以保存饲料中的营养成分。目前,西藏地区关于青贮用乳酸菌的研究已经由从传统乳制品中分离乳酸菌过渡到从多种天然青贮饲料中分离乳酸菌。对西藏地区青贮用乳酸菌的筛选分离及应用研究进展进行了综述,以期为加快以青贮分离乳酸菌菌株为来源的高原青贮用乳酸菌制剂的研发提供参考。     

甘蔗尾中乳酸菌的分离筛选和鉴定

该研究利用传统培养法从0–90 d打包青贮发酵的甘蔗(Saccharum sinense)尾中分离得到20株乳酸菌。通过形态学观察、API 50 CH生化试剂盒鉴定及16S rDNA基因序列分析法对分离纯化的菌株进行鉴定,并测定其产酸能力。结果显示,菌株Y42是干酪乳杆菌(Lactobacillus casei),菌株Y32、Y59是副干酪乳杆菌(L. paracasei),其余的17株是植物乳酸杆菌(L. plantarum);分离的20株菌株在培养18 h后,菌株发酵液的pH可降低至3.70以下,Y67菌株的pH最低,为3.57。从甘蔗尾中分离的20株乳酸菌产酸能力均较强,具备良好的青贮潜力,可作为制备青贮饲料发酵剂的菌种。     

地源性优势青贮发酵乳酸菌的筛选与鉴定

为了获得饲料青贮发酵优势乳酸菌株,用其研制高效青贮微生物添加剂.通过产酸和抑菌效果试验,对前期分离得到的6株地源性乳酸菌进行检测,然后采用PCR技术和最适生长条件试验,将产酸和抑菌效果均优良的乳酸菌株作进一步鉴定筛选.结果表明,6株地源性乳酸菌菌(编号为F1、F2、F3、T1、T2、T3)中的F1和T2株产酸效果最好(...     

苜蓿青贮饲料中优良乳酸菌菌株的筛选

本研究从苜蓿（Medicago sativa L.）青贮饲料中分离得到若干株乳酸菌,对所有菌株进行生长曲线和产酸速率测定,发现其中8个菌株产酸速率较快,能于24h内将培养基pH值降至4.0以下。根据形态、生化鉴定及16S rDNA同源性序列分析,鉴定4株为植物乳杆菌（Lactobacillus plantarum）,2株为戊糖片球菌（Pediococcus pentosaceus）,1株为类植物乳杆菌（Lactobacillus paraplantarum）,1株为副干酪乳杆菌（Lactobacillusparacasei）。通过适当的工艺处理其有望作为乳酸菌添加剂单独或混合添加入青贮中以提高青贮饲料品质。     

青贮用乳酸菌的分离鉴定及生物学特性评价

本研究旨在从构树青贮、玉米青贮及饲喂构树青贮的羔羊粪便中分离鉴定可饲用乳酸菌,为开发构树青贮用乳酸菌提供试验材料。以构树青贮、玉米青贮以及饲喂构树青贮的羔羊粪便为菌株分离来源,使用含有1%碳酸钙的MRS琼脂培养基分离纯化乳酸菌,获得菌株经16S rRNA测序鉴定后对其中可饲用菌株进行生长、产酸性能的筛选,评估在pH 3.0、3.5、4.0条件下存活率和对大肠杆菌、金黄色葡萄球菌和沙门氏菌的抑制能力,并对筛选菌株进行菌株之间拮抗性测定。结果表明：获得可饲用乳酸菌共37株,包括植物乳杆菌(Lactobacillus plantarum)、布氏乳杆菌(Lactobacillus buchneri)、副干酪乳杆菌(Lactobacillus paracasei)、粪肠球菌(Enterococcus faecalis)4种,不同的菌株在生长和产酸性能上表现出差异,在不同pH中存活率和抑菌性能也具有菌株特异性。综合比较不同菌株之间的生物学特性,植物乳杆菌GQ-3-2、GQ-3-29及GQ-5-4具有良好的生长、产酸及抑菌性能;粪肠球菌Y-3-15在发酵2 h进入对数生长期,能够为植物乳杆菌的大量繁...     

青贮菌剂在苜蓿裹包青贮中的应用效果

在苜蓿裹包青贮中添加3种不同青贮菌剂JD6、MMD3、X3Q2,分析青贮苜蓿的营养品质,微生物数量以及瘤胃降解率的变化,以研究3种青贮菌剂在裹包青贮条件下对苜蓿青贮的影响。结果表明,青贮5个月后,添加青贮菌剂可以显著降低pH值(P<0.05)、NH3/TN值(P<0.05),减少丁酸含量(P<0.01),有利于保存青贮物的营养成分,提高青贮品质。添加青贮菌剂对青贮物的NDF、ADF含量没有影响,对青贮产物干物质和NDF的瘤胃降解率没有影响。添加青贮菌剂可以提高青贮产物中乙酸含量(P<0.05),减少酵母菌和霉菌数量(P<0.05)。3种青贮菌剂在苜蓿裹包青贮试验中,有利于抑制有害微生物,保存苜蓿营养成分,提高苜蓿青贮品质和有氧稳定性。     

不同发酵类型青贮菌制剂对青贮发酵的影响

在许多国家,青贮饲料是牲畜的重要饲料形式.不同发酵类型的青贮菌制剂会对青贮发酵产物的营养品质、有氧稳定性和动物采食量产生重要的影响.笔者就青贮发酵菌制剂的筛选标准,同型、异型乳酸发酵菌种组成做了介绍,主要就同型、异型和混合3种乳酸发酵对青贮产物的品质影响及作用机理进行分析和综述.     

乳酸菌和纤维素酶对直穗鹅观草青贮的改善效果

本试验以直穗鹅观草(Roegneria turczaninovii)为材料,研究了乳酸菌和纤维素酶单独添加或以不同比例混合添加对鹅观草青贮发酵品质和营养价值的改善效果。处于抽穗期的直穗鹅观草经刈割切短后,分别添加纤维素酶0.06 g·kg-1 (CF),乳酸菌0.01 g·kg-1 (LD1)、0.02 g·kg-1 (LD2),纤维素酶+乳酸菌(0.06+0.01) g·kg-1 (CF+LD1)和(0.06+0.02) g·kg-1 (CF+LD2),并设置无添加剂组为对照(CK),每个处理3个重复。真空密封条件下贮藏90 d后,所有添加剂处理组pH值、丙酸、丁酸和氨态氮含量均显著低于对照组（P<0.05）,乳酸、乙酸、粗蛋白（CP）和可溶性糖水化合物(WSC)含量均显著高于对照组（P<0.05）,且CF、CF+LD1和CF+LD2处理的中性洗涤纤维（NDF）和酸性洗涤纤维（ADF）含量显著低于对照（P<0.05）。由此可见,添加乳酸菌和纤维素酶使直穗鹅观草青贮饲料的发酵品质和营养价值均得到了改善,且以混合添加0.06 g·kg-1的纤维素酶和0.02 g·kg-1的乳酸菌制剂的效果最好。     

Isolating and evaluating lactic acid bacteria strains for effectiveness on silage quality at low temperatures on the Tibetan Plateau

Four lactic acid bacteria (LAB) strains isolated from straw silages on the Tibetan Plateau were characterized, and their effects on the fermentation quality of Italian ryegrass (Lolium multiflorum Lam.) at different temperatures (10°C, 15°C and 25°C) were studied. These LAB isolates were evaluated using the acids production ability test, morphological observation, Gram staining, physiological, biochemical and acid tolerance tests. All the isolates (M1, LM8, LO7 and LOG9) could grow at 5‐20°C, pH 3.5‐7.0 and NaCl (3.0%, 6.5%). Strains M1, LM8, LO7 and LOG9 were identified as Lactobacillus plantarum, L. coryniformis, Pediococcus pentosaceus and P. acidilactici, respectively, by sequencing 16S ribosomal DNA. The four isolates were added to Italian ryegrass for ensiling for 30 days at various temperatures. Compared with the corresponding control, inoculating with isolates M1, LM8 and LO7 could improve the silage quality of Italian ryegrass at low temperatures, indicated by significantly (P < 0.05) higher lactic acid (LA) contents and ratios of lactic acid/acetic acid (LA/AA), and significantly (P < 0.05) lower pH and ammonia nitrogen/total nitrogen (AN/TN). Compared with other isolates, LM8 performed better at 10°C and 15°C, indicated by the higher (P < 0.05) LA content and ratio of LA/AA, and the lower (P < 0.05) pH and AN/TN.     

Characterization and application of lactic acid bacteria for tropical silage preparation

Strains TH 14, TH 21 and TH 64 were isolated from tropical silages, namely corn stover, sugar cane top and rice straw, respectively, prepared in Thailand. These strains were selected by low pH growth range and high lactic acid‐producing ability, similar to some commercial inoculants. Based on the analysis of 16S ribosomal RNA gene sequence and DNA‐DNA relatedness, strain TH 14 was identified as Lactobacillus casei, and strains TH 21 and TH 64 were identified as L. plantarum. Strains TH 14, TH 21, TH 64 and two commercial inoculants, CH (L. plantarum) and SN (L. rhamnosus), were used as additives to fresh and wilted purple Guinea and sorghum silages prepared using a small‐scale fermentation method. The number of epiphytic lactic acid bacteria (LAB) in the forages before ensilage was relatively low but the numbers of coliform and aerobic bacteria were higher. Sorghum silages at 30 days of fermentation were all well preserved with low pH (3.56) and high lactic acid production (72.86 g/kg dry matter). Purple Guinea silage inoculated with LAB exhibited reduced count levels of aerobic and coliform bacteria, lower pH, butyric acid and ammonia nitrogen and increased lactic acid concentration, compared with the control. Strain TH 14 more effectively improved lactic acid production compared with inoculants and other strains. © 2016 Japanese Society of Animal Science     

饲料乳酸菌冻干工艺的探究

通过离心条件的选择,获得最大浓度的乳酸菌,进而利用正交试验设计,确定适合植物乳杆菌和肠膜状明串株葡聚糖亚种的最佳保护剂配方.试验结果表明,两株菌均在5000 r/min的条件下离心10 min,所得的活菌数最多.试验确定植物乳杆菌的最佳保护剂配方为:脱脂乳15%、海藻糖6%、甘油2%、抗坏血酸3%;肠膜状明串株葡聚糖亚种的最佳保护剂配方为:脱脂乳15%、海藻糖6%、甘油1%、抗坏血酸2%.     

添加乳酸菌制剂和麸皮对去穗玉米秸秆青贮质量的影响

为阐明乳酸菌制剂和麸皮对去穗玉米秸秆在不同装填时间青贮质量的影响,利用自制青贮发酵桶研究了乳酸菌制剂Sila-Max、Sila-Mix及麸皮和在2种装填时间(1次和3次装填)条件下对去穗玉米秸秆青贮的发酵参数、营养组成、发酵后干物质含量、干物质损失率以及48 h体外干物质消化率的影响。结果表明:密封发酵45 d后,各试验组玉米秸秆青贮质量良好,未添加组中,3 d延迟装填使发酵产物的乙酸、氨氮、粗蛋白、酸性洗涤纤维、木质素、钙及干物质损失率分别提高了22.05%、50.00%、10.34%、5.19%、10.92%、20.51%和48.37%,干物质含量降低了7.37%,差异显著(P<0.05);1次装填,同时添加麸皮和Sila-Max组与未添加组相比,使发酵产物的乳酸、粗脂肪和干物质含量分别提高了22.98%、12.46%和5.57%,干物质损失率降低了39.27%,差异显著(P<0.05),添加Sila-Max组干物质含量提高了6.41%,干物质损失率降低了45.80%,差异显著(P<0.05),添加麸皮使粗蛋白含量降低了9.17%,差异显著(P<0.05);3次装填,添加Sila-Max组相比未添加组,使发酵产物的乙酸和木质素含量分别提高10.94%和9.14%,粗脂肪含量降低了11.29%,差异显著(P<0.05),添加麸皮组,使乙酸含量提高10.94%,粗脂肪含量降低了11.29%,差异显著(P<0.05),同时添加麸皮和Sila-Max使产物乙酸、木质素和干物质含量分别提高9.67%、12.13%和6.23%,粗脂肪含量和干物质损失率分别降低了15.81%和26.73%,差异显著(P<0.05);所有处理均未对去穗玉米秸秆青贮的48 h体外干物质消化率产生显著影响(P>0.05)。可见,延迟装填会使去穗玉米秸秆青贮的干物质含量降低,有氧发酵增加,降低发酵品质,增加干物质损失率,1次装填添加Sila-Max及其与麸皮混合添加均可以提高发酵品质,减少营养物质损失,3次装填同时添加Sila-Max和麸皮,不能提高发酵品质,但可以减少营养物质损失。     

Fermentation quality and chemical composition of shrub silage treated with lactic acid bacteria inoculants and cellulase additives

Effects of lactic acid bacteria (LAB) inoculants and cellulase additives on fermentation quality and chemical compositions of shrub silages were studied by using a small‐scale fermentation system. Two LAB inoculants of Qingbao (Lactobacillus plantarum, Pediococcus acidilacticii, Lactobacillus casei and Clostridium phage) and Caihe (Lactobacillus plantarum, Lactobacillus brevis and Pediococcus acidilactici) and a commercial cellulase made from Trichoderma reesei were used as additives for intermediate pea‐shrub, rush bushclover, arborescent ceratoides and shrubby silage preparation. The crude protein, neutral detergent fiber and water‐soluble carbohydrate contents of the four shrub materials were 10.1–14.2, 62.6–67.2 and 1.9–3.5% on a dry matter basis, respectively. All shrub silages had pH 3.40–4.43, ammonia‐N 0.1–0.2% g/kg and lactic acid 1.3–2.9% on a fresh matter basis. The silage quality of LAB‐inoculated silages did not have a greater effect than control silages, except shrubby silage preparation. Silages treated with the cellulase, the pH of rush bushclover and shrubby sweetvetch silage were significantly (P < 0.05) lower and the lactic acid content were significantly (P < 0.05) higher than the control silages. The results confirmed that shrub contained a relatively high content of crude protein; its silages can be preserved in good quality, and they are new potential resources for livestock feed.     

复方中药预防肉鸡腹水综合征效果的观察

为了研究不同时间投喂复方中药预防肉鸡腹水综合征的效果,检测肉鸡肺动脉压(mPAP)和体重变化的比例,试验结果表明10日龄肉鸡投喂不同种复方中药后,阻止肉鸡形成肺动脉高压的作用,效果显著(P0.05)。10日龄肉鸡投喂不同种复方中药后,肉鸡体重均匀度显著提高(P0.05);17日龄投喂本试验中药复方后,肉鸡体重均久度与对照组相比显著提高(P0.05);这说明不同时间投喂复方中药预防肉鸡腹水综合征的效果不同。