Effects of dietary Clostridium butyricum and rumen protected fat on meat quality,oxidative stability,and chemical composition of finishing goats

Background Clostridium butyricum(CB)is a probiotic that can regulate intestinal microbial composition and improve meat quality.Rumen protected fat(RPF)has been shown to increase the dietary energy density and provide essential fatty acids.However,it is still unknown whether dietary supplementation with CB and RPF exerts beneficial effects on growth performance and nutritional value of goat meat.This study aimed to investigate the effects of dietary CB and RPF supplementation on growth performance,meat quality,oxidative stability,and meat nutritional value of finishing goats.Thirty-two goats(initial body weight,20.5±0.82 kg)were used in a completely randomized block design with a 2 RPF supplementation(0 vs.30 g/d)×2 CB supplementation(0 vs.1.0 g/d)factorial treatment arrangement.The experiment included a 14-d adaptation and 70-d data and sample collection period.The goats were fed a diet consisted of 400 g/kg peanut seedling and 600 g/kg corn-based concentrate(dry matter basis).Result Interaction between CB and RPF was rarely observed on the variables measured,except that shear force was reduced(P<0.05)by adding CB or RPF alone or their combination;the increased intramuscular fat(IMF)content with adding RPF was more pronounced(P<0.05)with CB than without CB addition.The pH24h(P=0.009),a*values(P=0.007),total antioxidant capacity(P=0.050),glutathione peroxidase activities(P=0.006),concentrations of 18:3(P<0.001),20:5(P=0.003)and total polyunsaturated fatty acids(P=0.048)were increased,whereas the L*values(P<0.001),shear force(P=0.050)and malondialdehyde content(P=0.044)were decreased by adding CB.Furthermore,CB supplementation increased essential amino acid(P=0.027),flavor amino acid(P=0.010)and total amino acid contents(P=0.024)as well as upregulated the expression of lipoprotein lipase(P=0.034)and peroxisome proliferator-activated receptorγ(PPARγ)(P=0.012),and downregulated the expression of stearoyl-CoA desaturase(SCD)(P=0.034).The RPF supplementation increased dry matter intake(P=0.005),averaged daily gain(trend,P=0.058),hot carcass weight(P=0.046),backfat thickness(P=0.006),concentrations of 16:0(P<0.001)and c9-18:1(P=0.002),and decreased the shear force(P<0.001),isoleucine(P=0.049)and lysine content(P=0.003)of meat.In addition,the expressions of acetyl-CoA carboxylase(P=0.003),fatty acid synthase(P=0.038),SCD(P<0.001)and PPARγ(P=0.022)were upregulated due to RPF supplementation,resulting in higher(P<0.001)content of IMF.Conclusions CB and RPF could be fed to goats for improving the growth performance,carcass traits and meat quality,and promote fat deposition by upregulating the expression of lipogenic genes of Longissimus thoracis muscle.

Clostridium difficile infection following colon subtotal resection in a patient with gallstones: A case report and review of literature

BACKGROUND Clostridium difficile(C.difficile)infection(CDI)is a rare clinical disease caused by changes in the intestinal microenvironment,which has a variety of causes and a poor prognosis,and for which there is no standardized clinical treatment.CASE SUMMARY A patient experienced recurrent difficulty in bowel movements over the past decade.Recently,symptoms worsened within the last ten days,leading to a clinic visit due to constipation.The patient was subsequently referred to our depart-ment.Preoperatively,the patient was diagnosed with obstructed colon accom-panied by gallstones.Empirical antibiotics were administered both before and after surgery to prevent infection.On the fourth day post-surgery,symptoms of CDI emerged.Stool cultures confirmed the presence of C.difficile DNA.Treatment involved a combination of vancomycin and linezolid,resulting in the patient's successful recovery upon discharge.However,the patient failed to adhere to the prescribed medication after discharge and was discovered deceased during a follow-up two months later.CONCLUSION CDI is the leading cause of nosocomial post-operative care,with limited clinical cases and poor patient prognosis,and comprehensive clinical treatment guidelines are still lacking.This infection can be triggered by a variety of factors,including intestinal hypoxia,inappropriate antibiotic use,and bile acid circulation disorders.In patients with chronic bowel disease and related etiologies,prompt preoperative attention to possible CDI and preoperative bowel preparation is critical.Adequate and prolonged medication should be maintained in the treatment of CDI to prevent recurrence of the disease.

Therapeutics involved in managing initial and recurrent Clostridium difficile infection:An updated literature review

Clostridium difficile infection(CDI)has been increasing due to the effect of recurrent hospitalizations.The use of antibiotics has been shown to alter the gut microbiome and lead to CDIs.The treatment is limited to three major antibiotics;however,the incidence of recurrent CDIs has been increasing and drug resistance is a major concern.This aspect is a growing concern in modern medicine especially in the elderly population,critical care patients,and immunocompromised individuals who are at high risk of developing CDIs.Clostridium difficile can lead to various complications including septic shock and fulminant colitis that could prove to be lethal in these patients.Newer modalities of treatment have been developed including bezlotoxumab,a monoclonal antibody and fecal microbiota transplant.There have been studies showing asymptomatic carriers and drug resistance posing a major threat to the healthcare system.Newer treatment options are being studied to treat and prevent CDIs.This review will provide an insight into the current treatment modalities,prevention and newer modalities of treatment and challenges faced in the treatment of CDIs.

响应面法优化Clostridium beijerinckii木糖发酵产丁醇培养基的研究

采用响应面法对Clostridium beijerinckii利用木糖发酵生产丁醇的培养基进行了优化,建立了回归方程,得到了Cl·beijerinckii木糖发酵的优化培养基组成为:木糖26·6g/L,酵母浸粉1·38g/L,维生素液5·55mL/L,微量元素液9·67mL/L。在此优化条件下发酵,丁醇产量提高了18·4%,达到6·69g/L。

Clostridium saccharobutylicum利用玉米秸秆水解液发酵生产燃料丁醇

以Clostridium saccharobutylicum DSM 13864为丁醇生产菌株,采用正交优化法确定了以玉米秸秆水解液为底物的最优培养基配方:CaCO32.0 g/L,(NH4)2SO41.0 g/L,K2HPO40.5 g/L,玉米浆干粉15 g/L,MnSO4.H2O 0.01 g/L。采用该最优培养基配方,在3 L发酵罐中发酵培养40 h后,总溶剂为16.1 g/L,其中丁醇10.59 g/L,发酵强度为0.40 g/(L·h),生产率为0.33 g/g。通过对发酵过程进行变温调控证实低温有利于溶剂积累,总溶剂由17.01 g/L提高至19.98 g/L。在稀释率为0.1 h-1的变温连续发酵过程中,从80 h开始进入稳定产溶剂状态并持续至269 h,该阶段平均总溶剂为12.28 g/L(其中丁醇8.50 g/L),发酵强度为1.23 g/(L·h),是变温分批发酵(D方式)的4.92倍。

基于比较基因组学的Clostridium kluyveri己酸代谢途径关键酶生物信息学分析

对3株白酒来源重要的己酸生产菌株Clostridium kluyveri(NBRC 12016、JZZ和DSM 555)全基因组信息进行比较基因组学分析,聚焦于己酸代谢途径核心催化酶,发现NBRC 12016的己酸代谢途径未得到有效注释,JZZ的己酸代谢途径核心催化酶酰基辅酶A脱氢酶存在注释错误。进一步对C. kluyveri模式菌株DSM 555己酸代谢途径的关键酶硫解酶ThlA进行生物信息学分析,发现DSM 555携带3拷贝的ThlA,且具有序列多态性,可能与催化脂肪酸代谢链延长的底物特异性相关。结构分析和分子对接表明,硫解酶Thl A1的底物催化属于氧化还原开关调控机制,并预测了酶的关键催化位点和具体的催化过程。上述分析结果有助于为后续进一步改进菌株的己酸生产性能和更好地应用于白酒酿造提供依据。

产氢菌Clostridium butyricum P22的分离鉴定及其产氢特性研究

从连续生物制氢反应器中分离得到高效产氢细菌P22,利用微生物自动鉴定仪并结合菌株16S rDNA序列分析,将其鉴定为Clostridium butyricum P22。同时还进一步研究了碳源、氮源、初始pH值和培养温度对菌株P22产氢活性的影响。结果表明:该菌株能利用多种碳源氮源产氢,当以葡萄糖作为产氢底物时,其最大产氢量和产氢速率分别为为301.7 mL/g-glucose(2.42 mol/mol-glucose)、31.1 mL(/g-glucose.h)。发酵液的初始pH和培养温度严重影响产氢菌活性,初始pH6.47、35℃培养为该菌种较为适宜的产氢条件。利用Arrehnius方程以葡萄糖为底物拟合得到该菌株产氢反应的活化能为70.7 kcal/mol。经能量分析,Clostridium butyricum P22产氢过程中葡萄糖能量回收率为20.6%。该菌株在生物制氢中具有很好的应用发展前景。

Clostridium autoethanogenum的生长培养基优化

Clostridium autoethanogenum是一种能将H2,CO以及CO2转变成乙醇和乙酸的特殊菌株。文章采用数值方法对C.autoethanogenum的生长培养基进行了优化。首先,用Plackett-Burman设计筛选出酵母膏是唯一影响C.autoethanogenum的显著因素,并得到11种组分的相对较优浓度。然后,用梯度试验进一步确定酵母膏的最佳浓度为1.5 g/L,从而最终确立改良的培养基配方。在试验条件下,优化的培养基能得到399.46 mg/L C.au-toethanogenum。此优化培养基能应用于两步CSTRs发酵合成气制乙醇。

低温蛋白酶产生菌Clostridium bifermentans B-25发酵条件优化

为提高低温蛋白酶产生菌Clostridium bifermentans B-25的产酶活性,通过单因子和正交试验,对其培养条件进行了优化。结果表明,其最佳培养基组成为酵母粉20.0 g/L、蛋白胨20.0 g/L、淀粉10.0 g/L、MgSO4 0.4 g/L、KH2PO40.2 g/L。最适培养条件为pH值7.5,最适温度16～30℃,最佳培养时间72 h。在最适培养条件下,采用优化培养基,低温蛋白酶产生菌B-25产酶活性达43.8 U/mL。

Recurrent Clostridium difficile infections:The importance of the intestinal microbiota

Clostridium difficile infections(CDI)are a leading cause of antibiotic-associated and nosocomial diarrhea.Despite effective antibiotic treatments,recurrent infections are common.With the recent emergence of hypervirulent isolates of C.difficile,CDI is a growing epidemic with higher rates of recurrence,increasing severity and mortality.Fecal microbiota transplantation(FMT)is an alternative treatment for recurrent CDI.A better understanding of intestinal microbiota and its role in CDI has opened the door to this promising therapeutic approach.FMT is thought to resolve dysbiosis by restoring gut microbiota diversity thereby breaking the cycle of recurrent CDI.Since the first reported use of FMT for recurrent CDI in 1958,systematic reviews of case series and case report have shown its effectiveness with high resolution rates compared to standard antibiotic treatment.This article focuses on current guidelines for CDI treatment,the role of intestinal microbiota in CDI recurrence and current evidence about FMT efficacy,adverse effects and acceptability.

Clostridium papyrosolvens厌氧发酵产氢研究

采用分批培养研究了从高浓度厌氧产氢活性污泥中筛选的优势菌种Clostridium papyrosolvens的发酵产氢能力.结果表明:该菌有较强的高糖耐受性和耐酸性,当葡萄糖浓度为30g/L、pH阶段性控制在4.5时,发酵44h葡萄糖消耗率为83.7%,总产气量达到3081.3mL/L,最高产气率为187.5mLL-1h-1,氢气含量为67.5%,比产氢率达1.06mol(H2)/mol(葡萄糖).研究中选用了廉价的发酵产氢培养基,以玉米浆为氮源,以还原铁粉作氧化还原电位控制剂,省去了牛肉膏、蛋白胨等昂贵氮源以及L-半胱氨酸、维生素、无机离子等高成本组分,显著降低了纯菌发酵的培养基成本,获得了较好的产氢效果.

肿瘤治疗中Clostridium novyi-NT的研究

联合细菌的溶瘤治疗(combined bacteriolytic therapy,COBALT)策略在实体瘤治疗中方兴未艾。此策略是将专性厌氧菌Clostridium novyi-NT联合传统放化疗药物治疗实体瘤,现处于临床Ⅰ期试验阶段。本文分别从有效性及安全性等方面总结了抗肿瘤细菌应具有的标准,并简述了C.novyi-NT的溶瘤机制。

Clostridium difficile的中文翻译商讨

＂艰难梭菌＂是近几年来备受关注的专业词。但是,在大量资料上也有＂难辨梭菌＂一词,其使用频率似乎更高。两者均无英文对照,谈及内容极相似。原来两者均是Clostridium difficile的译名。

利用Clostridium saccharobutylicum DSM 13864连续发酵生产丁醇

为使用廉价糖质原料进行连续发酵生产丁醇提供理论依据和实验指导,以Clostridium saccharobutylicumDSM 13864为发酵菌种,考察了稀释率和温度等因素对以葡萄糖为原料的四级连续发酵生产丁醇的影响。结果表明:高稀释率有利于酸的积累和菌体的生长,低稀释率有利于溶剂的生产。当稀释率为0.05 h 1,4个发酵罐温度控制在37℃时,总溶剂产量为11.57 g/L,其中丁醇7.29 g/L,生产率为0.145 g/(L.h)。在0.05 h 1稀释率的条件下进行变温连续发酵证实低温有利于溶剂的积累,当一级和二级罐温度控制在37℃,三级和四级罐温度控制在33℃时总溶剂产量最高为13.69 g/L,其中丁醇为8.36 g/L,生产率为0.171 g/(L.h)。

Prevalence of diverticulosis in recurrent Clostridium difficile infection

AIM:To re-evaluate the theory that colonic diverticulosis is associated with relapse of Clostridium difficile associated disease (CDAD) in light of data suggesting increasing rates of CDAD infection and relapse.METHODS: Charts were reviewed for patients with recurrent CDAD who had also had a prior colonoscopy or flexible sigmoidoscopy. An age and gender matched control group was used to compare the prevalence of diverticulosis.RESULTS: Twenty-two patients met the study criteria, and the prevalence of diverticulosis in patients with CDAD relapse was 23% compared to 32% in age and sex matched controls (P=0.44). A significant proportion of patients with CDAD relapse had comorbidities associated with immune suppression.CONCLUSION: Diverticulosis does not appear to be associated with CDAD relapse.

Clostridium clariflavum DSM 19732木聚糖酶Xyn2441的克隆表达及条件优化

Clostridium clariflavum DSM19732是一种颇具应用价值的木质纤维素降解菌，尤其对半纤维素的降解能力非常高，国外学者已开始关注其中木质纤维素降解酶类的结构与功能，国内尚无相关报道。作者首次从复合菌系RXS基因组DNA中扩增出C．clariflavum DSM19732的一个表达双功能木聚糖酶（糖苷水解酶家族（glycosyl hydrolase family，GH）10和11的木聚糖酶）的基因Clocl-2441，并将其与载体pET28a（＋）连接，在大肠杆菌E．coli BL21（DE3）成功表达。重组菌最佳诱导表达条件为：添加诱导剂时的菌体量OD600值约为1．25、诱导剂IPTG浓度为0．5mmol／L、诱导时间7～8h及诱导温度25℃，此时胞内重组酶比酶活达到34．92U／mg。经镍柱初步分离纯化后比酶活达713．16U／mg，纯化倍数20．83倍，回收率27％。重组酶的最适反应温度和pH分别为70℃和6．5。

响应面分析法优化一株窖泥源酪丁酸梭菌（Clostridium tyrobutyricum）RL1菌株产丁酸发酵培养基

从某浓香型白酒窖泥中筛选出1 株高产丁酸的酪丁酸梭菌(Clostridium tyrobutyricum)RL1 菌株,采用响应面分析法对其产丁酸培养基进行优化研究。首先采用Plackett-Burman 设计对基础培养基中9 个主要因素进行筛选,确定出对丁酸产量影响显著的3 个因素,依次为葡萄糖、碳酸钙和蛋白胨。对上述显著因素利用最陡爬坡试验逼近最大产酸响应区域,最后通过Box-Behnken 设计及响应面分析确定最佳培养基总成分组成为:葡萄糖85.29 g/L,酵母粉7.5 g/L,蛋白胨9.37 g/L,氯化钠7.5 g/L,乙酸钠4.5 g/L,磷酸氢二钾2.5 g/L,七水合硫酸镁0.3 g/L,硫酸铵1.5 g/L,七水合硫酸亚铁0.015 g/L,硫代乙醇酸钠0.5 g/L,碳酸钙11.6 g/L。优化后培养基的丁酸浓度为22.96 g/L,较优化前的14.23 g/L提高了61.35 %。

Clostridium clariflavum GH10木聚糖酶的克隆表达、酶学性质及位点功能分析

首次将来源于Clostridium clariflavum的木聚糖酶基因Clocl-2441中的糖苷水解酶家族10(glycosyl hydrolase families,GH)结构域基因连接到pET28a(+)载体上,在E.coli BL21(DE3)成功异源表达。经镍柱和脱盐分离纯化达到电泳纯,并对其酶学性质进行解析。结果表明,重组木聚糖酶rXyn2441GH10最适温度和pH分别为70℃和7.0,属于中性嗜热木聚糖酶。rXyn2441GH10在65℃以下和pH 4.0~9.0范围比较稳定,金属离子中5 mmol/L的Mg^(2+)可以提高79.2%的酶活。以榉木木聚糖为底物重组酶的动力学参数,V_(max)为1 691.5μmol/(mg·min),K_m值为2.5 mg/mL,k_(cat)为1 236.4/s,k_(cat)/K_m为494.6 mL/(mg·s)。定点饱和突变表明209位点的组氨酸对酶活有重要的作用。

宁波沿海陆源排污口弓形杆菌属(Arobacter sp.)和梭菌属(Clostridium sp.)的分布特点

弓形杆菌属(Arobacter sp.)和梭菌属(Clostridium sp.)广泛存在于水体和寄生在动物体内,极易造成水体污染和人畜共患病。采用高通量454焦磷酸测序方法对宁波沿海2个重点排污口、8个一般排污口的20个站位水样进行分析,得到1年中的3月、5月、8月和10月份各排污口弓形杆菌属和梭菌属生物的分布情况。研究结果表明:弓形杆菌属检测出两个种,分别是嗜低温弓形杆菌(Arcobacter cryaerophilus)、布氏弓形杆菌(Arcobacter butzleri)。梭菌属共检测出12个种,其中产气荚膜梭菌(Clostridium perfringens)检出次数最高,丁酸梭菌(Clostridium butyricum)次之;排污口的类型是影响弓形杆菌属检出量的重要因素。弓形杆菌属主要分布在氮,磷含量较高的工业排污口和市政排污口,而梭菌属只在3月份的S7宁海西店崔家综合排污口呈现出相对较高的比例(7.5%),其它排污口检出量均在2%以下;弓形杆菌属和梭菌属在10个排污口20个站位4个月份的检出次数呈现正相关性;由季节性的变化引起的气温差异也是影响弓形杆菌属生长的重要因素,弓形杆菌属在5月份的时候检出次数最大,梭菌属适宜生长温度范围较广10—65°C,受温度影响较小。

Clostridium paraputrificum M-21发酵制氢培养条件研究

利用类腐败梭状芽孢杆菌M 2 1(ClostridiumparaputrificumM 2 1) ,在 37℃、15 0r min条件下发酵制氢 ,以葡萄糖为碳源 ,蛋白胨为氮源 ,1mol的葡萄糖可以产生 1 0 5mol的氢气 ,最终所产气体中有 70 %H2 和 30 %CO2 (体积百分数 )。最优初始pH范围为 7 0～ 7 5 ,少量乙酸的存在对氢气的生成有促进作用 ,若大量存在 ,会严重抑制菌的生长。在C N质量比为 1 0时 ,所产氢气体积最多 ,1g葡萄糖可产生 75mLH2 (常温常压 )。在高温 83℃下对种菌预处理 30s促进孢子的萌发 ,会缩短发酵产氢的时间。以淀粉为碳源 ,所产氢气体积略微高于葡萄糖 ,1g淀粉可产生 78mLH2 (常温常压 ) ;以蔗糖为碳源 ,所产氢气体积略微低于葡萄糖 ,1g蔗糖可产生 72mLH2 (常温常压 )。该菌不能降解利用羧甲基纤维素 ,木质素磺酸钠 ,及纸浆等。