This study was conducted to investigate the effects of traditional Chinese medicine compounds(TCMC)on rumen fermentation, methane emission and populations of ruminal microbes using an in vitro gas production technique...This study was conducted to investigate the effects of traditional Chinese medicine compounds(TCMC)on rumen fermentation, methane emission and populations of ruminal microbes using an in vitro gas production technique. Cablin patchouli herb(CPH), Atractylodes rhizome(AR), Amur Cork-tree(AC) and Cypsum were mixed with the weight ratios of 1:1:1:0.5 and 1:1:1:1 to make up TCMC1 and TCMC2,respectively. Both TCMC were added at level of 25 g/kg of substrate dry matter. In vitro gas production was recorded and methane concentration was determined at 12 and 24 h of incubation. After 24 h, the incubation was terminated and the inoculants were measured for pH, ammonia nitrogen, volatile fatty acids(VFA). Total deoxyribonucleic acid of ruminal microbes was extracted from the inocula, and populations were determined by a real-time quantitative polymerase chain reaction. Populations of total rumen methanogens, protozoa, total fungi, Ruminococcus albus, Fibrobacter succinogenes and Ruminococcus flavefaciens were expressed as a proportion of total rumen bacterial 16 S ribosomal deoxyribonucleic acid. Compared with the control, the 2 TCMC decreased(P < 0.05) total VFA concentration,acetate molar proportion, acetate to propionate ratio, gas and methane productions at 12 and 24 h,hydrogen(H) produced and consumed, and methanogens and total fungi populations, while the 2 TCMC increased(P < 0.05) propionate molar proportion. Traditional Chinese medicine compound 1 also decreased(P ≤ 0.05) R. flavefaciens population. From the present study, it is inferred that there is an effect of the TCMC in suppressing methanogenesis, probably mediated via indirect mode by channeling H2 utilized for methanogenesis to synthesis of propionate and direct action against the rumen microbes involved in methane formation. In addition, the relative methane reduction potential(RMRP) of TCMC2 was superior to that of TCMC1.展开更多
[Objective] The aim was to study the influence factors of membrane fouling in A/O-MBR system,so as to control membrane fouling better,prolong the service life of membrane,further reduce the cost of water treatment and...[Objective] The aim was to study the influence factors of membrane fouling in A/O-MBR system,so as to control membrane fouling better,prolong the service life of membrane,further reduce the cost of water treatment and promote the popularization of membrane bioreactor(MBR) effectively.[Method] Based on small A/O-MBR device,an orthogonal test with three factors(including aeration intensity,pump-stop ratio and mixed liquor suspended solid) and three levels was designed to optimize three parameters,and the effects of factors on membrane fouling and their mechanisms were studied through single-factor analysis.[Result] The order of operation parameters affecting membrane fouling in A/O-MBR was aeration intensity>pump-stop ratio>mixed liquor suspended solid(MLSS),and the optimum operating parameters were composed of 1.6 m3/h of aeration intensity,4 500 mg/L of MLSS and 9:2 of pump-stop ratio.With the increase of running time,soluble microbial product(SMP) and extracellular polymeric substance(EPS) accumulated gradually in the reactor,and EPS accumulated more rapidly than SMP;meanwhile,membrane fouling was accelerated.Therefore,EPS was the priority factor for membrane fouling compared with SMP.In addition,membrane fouling was accelerated gradually with the increase of protein content in EPS,while the variation of polysaccharides content in EPS had no obvious effect on membrane fouling,so protein content in EPS was the main factor for membrane fouling.[Conclusion] The study could provide theoretical references for the choice of parameters,operation and running in practical engineering.展开更多
从分离自南大西洋深海沉积物的细菌中筛选出一株产脂肪酶菌株FE10,通过16S rRNA序列分析,对FE10进行分子鉴定和系统发育分析,初步确定其为海杆菌属(Marinobacter)。对菌株FE10所产脂肪酶进行酶学性质初步研究表明:在实验温度条件下所产...从分离自南大西洋深海沉积物的细菌中筛选出一株产脂肪酶菌株FE10,通过16S rRNA序列分析,对FE10进行分子鉴定和系统发育分析,初步确定其为海杆菌属(Marinobacter)。对菌株FE10所产脂肪酶进行酶学性质初步研究表明:在实验温度条件下所产脂肪酶40℃、p H 7时酶活最高,p H 9时酶活几乎消失。展开更多
基金financially supported partly by Fundamental Research Funds for the Central Universities (XDJK2014C154)
文摘This study was conducted to investigate the effects of traditional Chinese medicine compounds(TCMC)on rumen fermentation, methane emission and populations of ruminal microbes using an in vitro gas production technique. Cablin patchouli herb(CPH), Atractylodes rhizome(AR), Amur Cork-tree(AC) and Cypsum were mixed with the weight ratios of 1:1:1:0.5 and 1:1:1:1 to make up TCMC1 and TCMC2,respectively. Both TCMC were added at level of 25 g/kg of substrate dry matter. In vitro gas production was recorded and methane concentration was determined at 12 and 24 h of incubation. After 24 h, the incubation was terminated and the inoculants were measured for pH, ammonia nitrogen, volatile fatty acids(VFA). Total deoxyribonucleic acid of ruminal microbes was extracted from the inocula, and populations were determined by a real-time quantitative polymerase chain reaction. Populations of total rumen methanogens, protozoa, total fungi, Ruminococcus albus, Fibrobacter succinogenes and Ruminococcus flavefaciens were expressed as a proportion of total rumen bacterial 16 S ribosomal deoxyribonucleic acid. Compared with the control, the 2 TCMC decreased(P < 0.05) total VFA concentration,acetate molar proportion, acetate to propionate ratio, gas and methane productions at 12 and 24 h,hydrogen(H) produced and consumed, and methanogens and total fungi populations, while the 2 TCMC increased(P < 0.05) propionate molar proportion. Traditional Chinese medicine compound 1 also decreased(P ≤ 0.05) R. flavefaciens population. From the present study, it is inferred that there is an effect of the TCMC in suppressing methanogenesis, probably mediated via indirect mode by channeling H2 utilized for methanogenesis to synthesis of propionate and direct action against the rumen microbes involved in methane formation. In addition, the relative methane reduction potential(RMRP) of TCMC2 was superior to that of TCMC1.
基金Supported by Science and Technology Key Project of Water Pollution Control and Management(2008ZX07314-003)
文摘[Objective] The aim was to study the influence factors of membrane fouling in A/O-MBR system,so as to control membrane fouling better,prolong the service life of membrane,further reduce the cost of water treatment and promote the popularization of membrane bioreactor(MBR) effectively.[Method] Based on small A/O-MBR device,an orthogonal test with three factors(including aeration intensity,pump-stop ratio and mixed liquor suspended solid) and three levels was designed to optimize three parameters,and the effects of factors on membrane fouling and their mechanisms were studied through single-factor analysis.[Result] The order of operation parameters affecting membrane fouling in A/O-MBR was aeration intensity>pump-stop ratio>mixed liquor suspended solid(MLSS),and the optimum operating parameters were composed of 1.6 m3/h of aeration intensity,4 500 mg/L of MLSS and 9:2 of pump-stop ratio.With the increase of running time,soluble microbial product(SMP) and extracellular polymeric substance(EPS) accumulated gradually in the reactor,and EPS accumulated more rapidly than SMP;meanwhile,membrane fouling was accelerated.Therefore,EPS was the priority factor for membrane fouling compared with SMP.In addition,membrane fouling was accelerated gradually with the increase of protein content in EPS,while the variation of polysaccharides content in EPS had no obvious effect on membrane fouling,so protein content in EPS was the main factor for membrane fouling.[Conclusion] The study could provide theoretical references for the choice of parameters,operation and running in practical engineering.
文摘以宋河酒厂窖泥、酒糟、酒厂废水为样品,从中分离出100株菌株,经初筛、复筛和酒精发酵试验,最终获得1株耐酒精度为18%vol酵母菌,编号为A16。通过单因素实验确定最佳发酵条件为:发酵温度30℃、p H值4.5、碳源为葡萄糖、氮源为复合氮源(酵母膏和蛋白胨的比例为2∶1)、无机盐为Mg SO4·7H2O、接种量为10%、转速100 r/min、装液量为150 m L/250 m L;通过正交试验确定培养基最佳配比为:葡萄糖25%,酵母膏2%,蛋白胨1%,Mg SO4·7H2O 1%,(NH4)2SO41%,KH2PO41%,菌株A16的酒精得率70%。
文摘从分离自南大西洋深海沉积物的细菌中筛选出一株产脂肪酶菌株FE10,通过16S rRNA序列分析,对FE10进行分子鉴定和系统发育分析,初步确定其为海杆菌属(Marinobacter)。对菌株FE10所产脂肪酶进行酶学性质初步研究表明:在实验温度条件下所产脂肪酶40℃、p H 7时酶活最高,p H 9时酶活几乎消失。
