饲用枯草芽孢杆菌SR096产孢培养基及培养条件的优化

试验旨在为了降低枯草芽孢杆菌SR096的工业生产成本和提高发酵液的芽孢含量,采用单因素试验和响应面法试验设计对菌株SR096的培养条件和发酵培养基组分优化,优化后的培养基组分为:葡萄糖7.5 g/L、玉米粉15.7 g/L、黄豆粉45.0 g/L、柠檬酸钠4.5 g/L、碳酸钙2.0 g/L、硫酸镁1.0 g/L,经验证在5 L发酵罐中以接种量3%、37℃、250 r/min条件下培养30 h,枯草芽孢杆菌SR096发酵液的活菌含量为1.67×10^10 CFU/mL,芽孢含量为1.56×10^10 CFU/mL,芽孢率为93.3%,为枯草芽孢杆菌SR096后期的产业化放大和推广应用奠定基础。     

枯草芽孢杆菌发酵黄芪提取液培养基优化研究

为了研究枯草芽孢杆菌发酵黄芪提取物的最佳培养基以及防腐剂对枯草芽孢杆菌存活率的影响,试验采用正交设计对培养基配方进行优化,并进行了扩大培养试验;用单因子试验法测定了枯草芽孢杆菌存活率。结果表明:培养基黄芪生药含量为0.5 g/mL,每100 mL培养基中含豆粕2.0 g、玉米2.0 g、麸皮2.5 g时枯草芽孢杆菌活菌数最多,可达到8.34×10~8cfu/mL,芽孢率大于90%。与摇瓶培养相比,发酵罐培养可以明显提高枯草芽孢杆菌的活菌数,为1.86×10~9cfu/mL。发酵液中添加一定量的防腐剂,经长时间保存后枯草芽孢杆菌的存活率均较高,约为95%。     

枯草芽孢杆菌YT168-6产抗菌肽sublancin的发酵工艺优化及培养基筛选的研究

研究旨在探索枯草芽孢杆菌YT168-6产抗菌肽sublancin的最适发酵条件和最适培养基组成,以期提高发酵液中sublancin含量。试验先通过单因素试验筛选出最适发酵条件,确定发酵培养基需要的无机盐、碳源、氮源,再通过正交试验、最陡爬坡试验、Box-Behnken设计的响应面分析方法确定最适发酵培养基组成。结果表明：枯草芽孢杆菌YT168-6产抗菌肽sublancin的最适发酵条件为菌种接种量1.0%、发酵温度37℃、发酵液初始pH 7.0;最适发酵培养基为K₂HPO₄ 5 g/L、KH₂PO₄ 5 g/L、MgSO₄ 10 g/L、可溶性淀粉30.2 g/L、蛋白胨23.6 g/L、玉米浆18.2 g/L;优化后sublancin产量由756 μg/mL提到1 581 μg/mL,是优化前的2.09倍。综上所述,本研究所筛选的最适发酵条件和最适培养基可为枯草芽孢杆菌YT168-6菌株工业化生产sublancin提供技术参考。     

一株饲用枯草芽孢杆菌CCAM080032固态发酵工艺的研究

为了提高一株饲用枯草芽孢杆菌CCAM 080032的芽孢产量,研究通过单因素试验及正交试验方法,确定了该枯草芽孢杆菌的最优培养基为:稻草粉:麸皮2:8、葡萄糖50 g、胰蛋白胨20 g、NH4NO3 15 g、KH2PO4 10 g、H2O 1 500 g,37℃培养48 h,芽孢产量达到7.90×1010 CFU/g。     

地衣芽孢杆菌TS-01发酵培养基的优化

通过正交实验对地衣芽孢杆菌TS-01的发酵培养基在摇瓶中进行了优化。研究发现:当培养基中葡萄糖为20g/l、豆饼粉为70g/l、玉米浆为7g/l时,发酵液中活菌数高于其它配比的培养基,达9.6×108cfu/ml。     

一株枯草芽孢杆菌发酵培养基的优化

采用正交试验对1株枯草芽孢杆菌的发酵培养基进行优化。确定了最佳的培养基配方为:葡萄糖25g/L,豆粕粉60g/L,玉米浆8g/L,在接种量为2%的情况下,发酵温度37℃,发酵时间24h,所获得活菌数约为5.3×109CFU/mL。     

猪源枯草芽孢杆菌HEW-B113的鉴定及发酵工艺优化

研究从猪肠道中获得一株疑似枯草芽孢杆菌,通过形态特征、生理生化鉴定和16S r DNA分子鉴定确定其为枯草芽孢杆菌,并采用液体发酵法,以发酵液中活菌数和芽孢数为指标,通过单因素试验和正交试验对枯草芽孢杆菌HEW-B113的培养基和发酵条件进行优化。确定其最佳培养基配方为玉米淀粉2%、葡萄糖1%、豆粉1%、硫酸锰0.2%和硫酸铁0.15%;最佳发酵条件为初始p H 7.1、接种量0.8%、发酵摇瓶装液量100 m L/500 m L、转速200 r/min、发酵温度35℃及发酵时间40 h。采用枯草芽孢杆菌的最优发酵工艺可以降低成本,提高质量,为枯草芽孢杆菌的扩大化生产提供理论依据。     

枯草芽孢杆菌固态发酵花生粕的条件优化

文章旨在研究枯草芽孢杆菌固态发酵花生粕的条件优化.试验以枯草芽孢杆菌为主要发酵菌种,以发酵花生粕中多肽含量为优化目标,使用单因素试验与正交试验考察枯草芽孢杆菌接种量、发酵温度、发酵时间对发酵花生粕中多肽含量的影响.结果 显示,枯草芽孢杆菌固态发酵花生粕的最佳发酵参数为枯草芽孢杆菌接种量为150 g、发酵温度38℃、发酵...     

饲用枯草芽孢杆菌高产芽孢工艺优化及菌剂制备

为提高枯草芽孢杆菌SR096发酵液中芽孢含量,本研究通过单因素试验和响应面法试验对SR096发酵培养基中的碳源、氮源以及无机盐体系等组分进行了优化。最终确定发酵培养基组成为:葡萄糖7.5 g/L、玉米粉12.69 g/L、酵母粉10.66 g/L、黄豆粉20 g/L、柠檬酸钠4.46 g/L、碳酸钙1.5 g/L、硫酸镁2 g/L,优化后的发酵培养基在37℃、180 r/min条件下摇瓶培养48 h,枯草芽孢杆菌SR096菌株发酵液中芽孢含量可达7.978×10~9 cfu/mL,制备的益生菌剂具有耐热、耐酸、耐胆盐的优点并能在常温下长期贮存。     

地衣芽孢杆菌产芽孢培养基和培养条件的优化

本研究以地衣芽孢杆菌CICC 20514为对象,芽孢数和芽孢率为目标参数,采用单因素、正交试验方法对培养基配方进行筛选,并在此配方基础上对培养条件进一步优化。结果表明：最终产芽孢发酵培养基的最佳组合为20 g/L果糖、20 g/L豆粕、5 g/L K₂HPO₄、7 g/L NaCl、0.8 g/L CaCO₃和0.8 g/L MgSO₄;产芽孢最佳培养条件为37℃,220 r/min,接种量5%,装样量20%,初始pH 6.5～7.5,发酵培养时间48 h。优化后的地衣芽孢杆菌CICC 20514培养基芽孢数及芽孢率均具有良好的稳定性,发酵液芽孢数达5.8×10⁹CFU/mL,比优化前提高了58倍。     

Phase I evaluation of CCNU (lomustine) in tumor-bearing cats

1-(2-Chloroethyl)3-cyclohexyl-1-nitrosourea (CCNU) is an alkylating agent in the nitrosourea subclass. A prospective evaluation of CCNU was done to determine the maximally tolerated dosage of CCNU in tumor-bearing cats. Response data were obtained when available. Twenty-five cats were treated with CCNU at a dosage of 50-60 mg/m3 body surface area. Complete hematologic data were available for 13 cats. Neutropenia was the acute dose-limiting toxicity. The median neutrophil count at the nadir was 1,000 cells/microL (mean, 2,433 cells/microL; range, 0-9,694 cells/microL). The time of neutrophil nadir was variable, occurring 7-28 days after treatment, and counts sometimes did not return to normal for up to 14 days after the nadir. Based on these findings, a 6-week dosing interval and weekly hematologic monitoring after the 1st treatment with CCNU are recommended. The nadir of the platelet count may occur 14-21 days after treatment. The median platelet count at the nadir was 43,500 cells/microL. No gastrointestinal, renal, or hepatic toxicities were observed after a single CCNU treatment, and additional studies to evaluate the potential for cumulative toxicity should be performed. Five cats with lymphoma and 1 cat with mast cell tumor had measurable responses to CCNU. Phase II studies to evaluate antitumor activity should be completed with a dosing regimen of 50-60 mg/m3 every 6 weeks.     

Furosemide continuous rate infusion in the horse: evaluation of enhanced efficacy and reduced side effects

Continuous rate infusion (CRI) of furosemide in humans is considered superior to intermittent administration (IA). This study examined whether furosemide CRI, compared with IA, would increase diuretic efficacy with decreased fluid and electrolyte fluctuations and activation of the renin-angiotensin-aldosterone system (RAAS) in the horse. Five mares were used in a crossover-design study. During a 24-hour period, each horse received a total of 3 mg/kg furosemide by either CRI (0.12 mg/kg/h preceded by a loading dose of 0.12 mg/kg IV) or IA (1 mg/kg IV q8h). There was not a statistically significant difference in urine volume over 24 hours between methods; however, urine volume was significantly greater after CRI compared with IA during the first 8 hours ([median 25th percentile, 75th percentile]: 9.6 L [8.9, 14.4] for CRI versus 5.9 L [5.3, 6.0] for IA). CRI produced a more uniform urine flow, decreased fluctuations in plasma volume, and suppressed renal concentrating ability throughout the infusion period. Potassium, Ca, and Cl excretion was greater during CRI than IA (1,133 mmol [1.110, 1,229] versus 764 mmol [709, 904], 102.7 mmol [96.0, 117.2] versus 73.3 mmol [65.0, 73.5], and 1,776 mmol [1,657, 2.378] versus 1,596 mmol [1,457, 1,767], respectively). Elimination half-lives of furosemide were 1.35 and 0.47 hours for CRI and IA, respectively. The area under the excretion rate curve was 1,285.7 and 184.2 mL x mg/mL for CRI and IA, respectively. Furosemide CRI (0.12 mg/kg/h) for 8 hours, preceded by a loading dose (0.12 mg/kg), is recommended when profound diuresis is needed acutely in horses.     

Prevalence of gastric lesions in racing Alaskan sled dogs

Human and equine athletes are reported to have a high prevalence of gastric disease, and anecdotal evidence suggests a similar phenomenon applies to racing sled dogs. To investigate the prevalence of gastric disease in racing sled dogs, we conducted 2 gastroscopy studies on dogs competing in the annual Iditarod Sled Dog Race. A pilot study of dogs that were either dropped from the 2000 Iditarod Sled Dog Race because of illness or that finished the race indicated that, approximately 5 days after competing, 10 of 28 dogs (35%) had endoscopic evidence of gastric ulceration, erosion, or hemorrhage. The next year, an endoscopic study of 73 dogs participating in the 2001 Iditarod race was performed in order to evaluate a larger population of dogs. Data from 70 of these dogs could be used; 34 (48.5%) had ulceration, erosion, gastric hemorrhage, or some combination of these findings. When this group of 70 dogs was compared retrospectively to a control group of 87 dogs presented to the Texas A&M University (TAMU) Veterinary Medical Teaching Hospital, the Iditarod sled dogs had a significantly higher prevalence (P = .049) of gastric lesions. These findings suggest that, similar to athletes of other species, elite canine athletes have an increased prevalence of gastric disease compared to the canine population at large.     

Internal Parasites and Haematological Values in Cattle Slaughtered in Buea Subdivision of Cameroon

Tropical Animal Health and Production -     

The Epidemiology of Gastrointestinal Nematodes of Dairy Cattle in Central Kenya

The epidemiology of H. placei and of other gastrointestinal nematodes in yearling dairy cattle was examined on two farms in Kiambu District, central Kenya during each of 13 one-month periods from April 1993 to April 1994. On each farm, 32 newly weaned dairy calves were given a single dose of albendazole and then placed on experimental pastures. Twelve of the animals were designated for bi-monthly slaughter (n = 2) and analysis of worm population characteristics and 20 were designated for blood and faecal collection and for weighing. Two parasite-free tracer calves were grazed alongside the weaner calves each month throughout the study period and were also slaughtered for analysis of worm populations. Faecal egg counts, haematological and serum pepsinogen determinations, herbage larval counts, and animal live weight changes were recorded monthly. The study revealed that Haemonchus placei, Trichostrongylus axei, Cooperia spp. and Oesophagostomum radiatum were responsible for parasitic gastroenteritis and that H. placei was the predominant nematode present in the young cattle on both farms. Faecal egg counts from resident cattle and necropsy worm counts revealed that pasture larval levels were directly related to the amount of rainfall. The total worm burdens in the animals were highest during the rainy season (March–June and October–December) and lowest during the dry seasons (July–September and January–February). The very low recovery of immature larvae of H. placei from the tracer calves indicated that arrested development is not a feature of the life cycle of this parasite in central Kenya. The maintenance of the parasite population depended on continuous cycling of infection between the host and the pasture. The agroclimatic conditions of the study area were such that, in general, favourable weather conditions for the development and survival of the free-living stages of gastrointestinal nematodes existed all year round.     

Diversity of Ectoparasites in Sheep Flocks in Sa~o Paulo,Brazil

The occurrence of ectoparasites in sheep flocks is frequently reported but seldom quantified. Sheep production used to be a predominantly family activity in the state of Sa~o Paulo (Brazil), but it began to become a commercial activity in the past decade. Thus, information about the ectoparasites existing in sheep flocks has become necessary. The present data were obtained by means of questionnaires sent to all sheep breeders belonging to the `Associaça~o Paulista de Criadores de Ovinos' (ASPACO; Sa~o Paulo State Association of Sheep Breeders). Response reliability was tested by means of random visits paid to 10.6% of the respondents. Most of the properties (89.5%) reported the presence of one or more ectoparasites. Screw-worm (Cochliomyia hominivorax) was the most frequent ectoparasite (72.5%), followed by bot fly larvae (Dermatobia hominis, 45.0%), ticks (Amblyomma cajennense) and Boophilus microplus, 31.3%) and finally lice (Damalinia ovis, 13.8%). Combined infestations also occurred, the most common one being screw-worm with bot fly larvae (36.0%) followed by bot fly larvae with ticks (13.9%), screw-worm with ticks (9.3%), bot fly larvae with lice (6.9%), and ticks with lice (5.0%). The most common triple combination was screw-worm, bot fly larvae and ticks (12.8%). Breeds raised for meat or wool were attacked by bot fly larvae and ticks more often than other breeds. Lice were only absent from animals of indigenous breeds. The relationships among these ectoparasites are discussed in terms of sheep breeds, flock size, seasonality and the ectoparasitic combinations on the host.     

Chemotaxis of macrophage in inflammation

Our particular attention in this article was given to natural mediators for macrophages isolated from the sites of tissue injury. A number of chemotactic factors, which may satisfy many criteria making them acceptable as inflammatory leucocyte chemotactic factors, has been separated. Among them, our laboratory has isolated three macrophage (monocyte) chemotactic factors (MCF-a, -b and -c). Their purification, characterization and functional specificity are discussed.     

Evaluation of biohydrogenation rate of canola vs. soya bean seeds as unsaturated fatty acids sources for ruminants in situ

An experiment was conducted to study disappearance of C14 to C18 fatty acids, lag times and biohydrogenation (BH) rates of C18 fatty acids of ground soya bean and canola seeds in situ. Three ruminally fistulated Dallagh sheep were used to determine ruminal BH of unsaturated fatty acids (UFAs). Differences in the disappearance of fatty acids through the bags and lag times were observed between the oilseeds. We saw that the longer the incubation time of the oilseeds in the rumen, the lower the content of C18:2 and C18:3. Significantly higher lag times for both C18:2 and C18:3 were observed in ground canola compared to ground soya bean. BH rates of C18:2 and C18:3 fatty acids in soya bean were three times higher than those of canola. These results suggest that the fatty acid profile of fat source can affect the BH of UFAs by rumen micro‐organisms. So that UFAs of canola had higher ability to escape from ruminal BH. It seems that fatty acid profile of ruminant products is more affected by canola seed compared to soya bean seed.     

Serum biochemical values and mineral element contents of tissues in yaks

Serum biochemical values and the wet weight to dry weight ratios of tissues were determined in yaks in Shandan county of Gansu province. The liver, kidney, heart and muscle contents of seven elements in yaks were also analysed. Most serum biochemical values were similar to those of cattle, camels and sheep, but the calcium concentration was considerably above the normal range for other ruminants. The liver contained the highest concentrations of copper, manganese and cobalt and the kidney of selenium, iron and calcium.Abbreviations Alb albumin - ALT alanine aminotransferase - AST aspartate aminotransferase - BUN blood urea nitrogen - Chol cholesterol - Glob globulin - -GT -glutamyl transpeptidase - IP inorganic phosphorus - TP total protein