The objective of these studies were to identify ruminal yeast in varying ratios of roughage to concentrate in TMR diets in order to explore yeast diversity by using molecular technique with similarity of rDNA sequence...The objective of these studies were to identify ruminal yeast in varying ratios of roughage to concentrate in TMR diets in order to explore yeast diversity by using molecular technique with similarity of rDNA sequence. The experiment was assigned to four 98.6% of cross bred Holstein Friesian heifers with 2 levels and two replicates of roughage to concentrate ratios as： 10：90 （T1） and 50：50 （T2）. The experimental period was 14 days. Rumen fluid sample was collected by stomach tube for total DNA extraction by using silica gel method, and analysis of quantity and quality of DNA by Nanovue and agarose gel electrophoresis. The divergent DI/D2 domain of 26S rDNA was amplified by primers NL-1（5＇-GCA TAT CAA TAA GCG GAG GAA AAG-Y） and NL4 （5＇-GGT CCG TGT TTCAAG ACG G-3＇） by polymerase chain reaction （PCR）. The nucleotide sequences of D l/D2 domain of 26S rDNA were determined using PCR products. Generated sequences were aligned with related species by using the CLUSTAL W. The result showed that an average dry matter intake of TI was 7.00 kg/d and T2 was 6.99 kg/d. DNA concentrate from TIRI, TIR2, T2RI and T2R2 were 106, 131.5, 84 and 182.5 ng//aL, respectively. The purity of DNA was 1.57, 1.76, 1.78 and 1.86, respectively. The divergent D1/D2 domain of 26S rDNA of treatment could be amplified for T1R1 and T2R1 but could not for T1R2 and T2R2. The sequences of D1/D2 domain of 26S rDNA were compared with nucleotide database by BLAST programs （http：//www.ncbi.nlrn.nih.gov/BLAST）, the T2RI yeast-strain was closest to Yarrowia lipolytica. However, yeast strain in T1R1 could not be specifically identified because D 1/132 domain of 26S rDNA seem to represent variable region with number of nucleotide sequence showing 2-3 substitution from known species. The phylogenetic tree based on the sequences of the DI/D2 domain of 26S rDNA showed that TIR! was related to Pichia and Candida （96%） and T2R1 was related to Yarrowia lypolytica （100%）. This study indicated that ruminal yeast strains could be found varying in different ratio of roughage to concentrate.展开更多
Despite the diversity and ecological importance of cestodes,there is a paucity of studies on their life stages(i.e.,complete lists of intermediate,paratenic,and definitive hosts)and genetic variation.For example,in th...Despite the diversity and ecological importance of cestodes,there is a paucity of studies on their life stages(i.e.,complete lists of intermediate,paratenic,and definitive hosts)and genetic variation.For example,in the Gulf of Mexico(GoM)98 species of cestodes have been reported to date;however,data on their intraspecific genetic variation and population genetic studies are lacking.The trypanorhynch cestode,Oncomegas wageneri,is found(among other places)off the American Western Atlantic Coast,including the GoM,and has been reported as an adult from stingrays and from several teleost species in its larval form(as plerocerci).This study represents the first report of 2 previously unregistered definitive hosts for O.wageneri,namely the Atlantic sharpnose shark Rhizoprionodon terraenovae and the southern stingray Hypanus americanus.In this work,partial sequences of the 28S(region D1-D2)ribosomal DNA were analyzed to include O.wageneri within an eutetrarhynchoid phylogenetic framework.All O.wageneri individuals(which included plerocerci and adults)were recovered as monophyletic and Oncomegas celatus was identified as the sister species of O.wageneri.Furthermore,population genetic analyses of O.wageneri from the southern GoM were carried out using DNA sequences of the mitochondrial cytochrome c oxi-dase subunit 1(COI)gene,which reflected high genetic variation and a lack of genetic structure among the 9 oceanographic sampling sites.Based on these results,O.wageneri is panmictic in the southern GoM.More extensive sampling along the species entire distribution is necessary to make more accurate inferences of population genetics of O.wageneri.展开更多
以甘肃河西走廊葡萄酒产区成熟葡萄浆果自然发酵过程中分离得到的115株酵母菌株为出发菌株,采用对硝基苯基-β-D-吡喃葡萄糖苷为底物的平板初筛,摇瓶复筛,对高产β-葡萄糖苷酶酵母菌株进行WL营养培养基和赖氨酸培养基初步分类以及26S r ...以甘肃河西走廊葡萄酒产区成熟葡萄浆果自然发酵过程中分离得到的115株酵母菌株为出发菌株,采用对硝基苯基-β-D-吡喃葡萄糖苷为底物的平板初筛,摇瓶复筛,对高产β-葡萄糖苷酶酵母菌株进行WL营养培养基和赖氨酸培养基初步分类以及26S r DNA D1/D2区序列分析。结果表明:6株酵母β-葡萄糖苷酶活性与商业酵母ICV-D254酶活性相似,酶活力可达(51.40±4.74)m U/m L,其中菌株QLFE、MQFEH-1、MQFSC-3、MQFEH-2和MQFSM-3为酿酒酵母属,菌株QLFE-4为梅奇酵母属,与分子鉴定结果一致。展开更多
文摘The objective of these studies were to identify ruminal yeast in varying ratios of roughage to concentrate in TMR diets in order to explore yeast diversity by using molecular technique with similarity of rDNA sequence. The experiment was assigned to four 98.6% of cross bred Holstein Friesian heifers with 2 levels and two replicates of roughage to concentrate ratios as： 10：90 （T1） and 50：50 （T2）. The experimental period was 14 days. Rumen fluid sample was collected by stomach tube for total DNA extraction by using silica gel method, and analysis of quantity and quality of DNA by Nanovue and agarose gel electrophoresis. The divergent DI/D2 domain of 26S rDNA was amplified by primers NL-1（5＇-GCA TAT CAA TAA GCG GAG GAA AAG-Y） and NL4 （5＇-GGT CCG TGT TTCAAG ACG G-3＇） by polymerase chain reaction （PCR）. The nucleotide sequences of D l/D2 domain of 26S rDNA were determined using PCR products. Generated sequences were aligned with related species by using the CLUSTAL W. The result showed that an average dry matter intake of TI was 7.00 kg/d and T2 was 6.99 kg/d. DNA concentrate from TIRI, TIR2, T2RI and T2R2 were 106, 131.5, 84 and 182.5 ng//aL, respectively. The purity of DNA was 1.57, 1.76, 1.78 and 1.86, respectively. The divergent D1/D2 domain of 26S rDNA of treatment could be amplified for T1R1 and T2R1 but could not for T1R2 and T2R2. The sequences of D1/D2 domain of 26S rDNA were compared with nucleotide database by BLAST programs （http：//www.ncbi.nlrn.nih.gov/BLAST）, the T2RI yeast-strain was closest to Yarrowia lipolytica. However, yeast strain in T1R1 could not be specifically identified because D 1/132 domain of 26S rDNA seem to represent variable region with number of nucleotide sequence showing 2-3 substitution from known species. The phylogenetic tree based on the sequences of the DI/D2 domain of 26S rDNA showed that TIR! was related to Pichia and Candida （96%） and T2R1 was related to Yarrowia lypolytica （100%）. This study indicated that ruminal yeast strains could be found varying in different ratio of roughage to concentrate.
基金Grant No.Al-S-15134 by the Conscjo National de Ciencia y Tecnologia(CONACyT)(to F.S.C.)Research funded by the CONACyT(Mexican Ministry of Energy)Hydrocarbon Trust,project 201441.
文摘Despite the diversity and ecological importance of cestodes,there is a paucity of studies on their life stages(i.e.,complete lists of intermediate,paratenic,and definitive hosts)and genetic variation.For example,in the Gulf of Mexico(GoM)98 species of cestodes have been reported to date;however,data on their intraspecific genetic variation and population genetic studies are lacking.The trypanorhynch cestode,Oncomegas wageneri,is found(among other places)off the American Western Atlantic Coast,including the GoM,and has been reported as an adult from stingrays and from several teleost species in its larval form(as plerocerci).This study represents the first report of 2 previously unregistered definitive hosts for O.wageneri,namely the Atlantic sharpnose shark Rhizoprionodon terraenovae and the southern stingray Hypanus americanus.In this work,partial sequences of the 28S(region D1-D2)ribosomal DNA were analyzed to include O.wageneri within an eutetrarhynchoid phylogenetic framework.All O.wageneri individuals(which included plerocerci and adults)were recovered as monophyletic and Oncomegas celatus was identified as the sister species of O.wageneri.Furthermore,population genetic analyses of O.wageneri from the southern GoM were carried out using DNA sequences of the mitochondrial cytochrome c oxi-dase subunit 1(COI)gene,which reflected high genetic variation and a lack of genetic structure among the 9 oceanographic sampling sites.Based on these results,O.wageneri is panmictic in the southern GoM.More extensive sampling along the species entire distribution is necessary to make more accurate inferences of population genetics of O.wageneri.
文摘以甘肃河西走廊葡萄酒产区成熟葡萄浆果自然发酵过程中分离得到的115株酵母菌株为出发菌株,采用对硝基苯基-β-D-吡喃葡萄糖苷为底物的平板初筛,摇瓶复筛,对高产β-葡萄糖苷酶酵母菌株进行WL营养培养基和赖氨酸培养基初步分类以及26S r DNA D1/D2区序列分析。结果表明:6株酵母β-葡萄糖苷酶活性与商业酵母ICV-D254酶活性相似,酶活力可达(51.40±4.74)m U/m L,其中菌株QLFE、MQFEH-1、MQFSC-3、MQFEH-2和MQFSM-3为酿酒酵母属,菌株QLFE-4为梅奇酵母属,与分子鉴定结果一致。
