Production of aromatic amino acids and related compounds from p-hydroxyphenylacetic acid by rumen microorganisms in vitro     

Rokibul Islam KHAN  Sada ANDO  Toshihiro TAKAHASHI  Tetsuo MORITA  Ryoji ONODERA 《Animal Science Journal》2003,74(4):313-319

Suspensions of mixed rumen bacteria (B), protozoa (P), and mixed rumen microorganisms (BP) prepared from rumen contents of fistulated goats were anaerobically incubated with 1 mM p‐hydroxyphenylacetic acid (HPA) at 39°C for 24 h. Tyrosine (Tyr), phenylalanine (Phe), tryptophan (Trp) and other related compounds in both supernatants and hydrolyzates of microbial cells in all incubations were analyzed by HPLC. Large amounts of Tyr (32.1, 42.7 and 36.1% of disappeared HPA in B, P and BP, respectively) were produced from HPA during a 12 h incubation period. The formation of Tyr in P (178.6 µmol/g MN) was 1.5 and 2 times higher than in B and BP, respectively. Phe (7–11% of the disappeared HPA) and Trp (3–6% of the disappeared HPA) were also synthesized from HPA in B, P, and BP. Phe synthesis in P (46.3 µmol/g MN) was 1.7 times higher than in B but, in contrast, Trp synthesis in B, was 1.6 times higher than in P. The metabolites p‐hydroxyphenylpyruvic acid (in the range of 5–14% of disappeared HPA), phenylacetic acid (1–11%), p‐hydroxybenzoic acid (3–7%) and benzoic acid (1–6%) were produced from HPA in B, P and BP. Phenylpropionic acid (6% of the disappeared HPA) was produced only in B and BP.  相似文献   

Analysis of Land use and Land Cover Changes in the Coastal Area of Bangladesh using Landsat Imagery     

M. Rafiqul Islam  M. Giashuddin Miah  Yoshio Inoue 《Land Degradation \u0026amp; Development》2016,27(4):899-909

Coastal land use across the globe has experienced remarkable rapid change over the recent decades because of extraordinary anthropogenic pressure and climate variability and change. Therefore, quantitative information about coastal land use change is imperative for effective management and planning resources for sustainable development. We analysed the quantitative land use and land cover changes during 1989–2000–2010 periods in three important agroecological zones of the most vulnerable coastal region of Bangladesh using Landsat images (Thematic Mapper/Enhanced Thematic Mapper Plus). In the Ganges Tidal Floodplain, the area under shrimp cultivation greatly increased at the rate of 2·05% per annum. The majority of the shrimp area gained from conversion of single cropland. In the Meghna Estuarine Floodplain, decreased mudflat and water bodies were observed, which was predominantly converted into cropland. In Chittagong Coastal Plain, salt pan–shrimp area increased with the expense of single and/or double cropland. In all the study areas, settlement area considerably increased over time. The dynamics of land use change have been attributed to low and unstable food production in the coastal region. The approach adopted in study and the results obtained from the study would likely be useful for policy making and identifying direction for future studies on the coastal land use in Bangladesh. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

Pollen tube growth in crosses between Porteresia coarctata and Oryza sativa   总被引：1，自引：0，他引：1  

R. H. Sarker  M. A. Samad  Zeba I. Seraj  M. I. Hoque  A. S. Islam 《Euphytica》1993,69(1-2):129-134

Summary Comparative study with fluorescence microscopy revealed that the pollen tubes of the self-pollinated rice variety BR-9 reached the ovary within 75 min after pollination. In P. coarctata it took 150 min. In the cross between P. coarctata and BR-9, pollen tubes reached the ovary in 165 min but seed setting was not observed. In the cross between BR-9 and P. coarctata, small and deformed pollen tubes were formed and they failed to grow through the stylodium.  相似文献   

Present status of genetics of rust resistance in flax   总被引：5，自引：0，他引：5  

M. R. Islam  K. W. Shepherd 《Euphytica》1991,55(3):255-267

Summary Present knowledge of host genes conferring resistance to rust in flax and their genetics are reviewed. There are at least 34 genes conferring resistance to rust occurring in seven groups, namely, K, L, M, N, P, D and Q. Expression of these host genes is affected by temperature, genetic background and by the inhibitor gene present in certain rust strains. Recombination analysis indicates that genes within each of the M and N groups are probably closely linked and that of the L group are genetically complex. When testcross progeny between two genes of the L group were screened, susceptible and modified recombinants were recovered. Some of these susceptible recombinants yielded rare resistant revertants in their progeny. Mechanism of such reversion is not defined but appears to follow a definite pattern. It is also indicated that some of the recombinants represent new specificity. A molecular approach of cloning host genes in flax is described.  相似文献   

Identification and characterization of foliar polyphenolic composition in sweetpotato (Ipomoea batatas L.) genotypes   总被引：1，自引：0，他引：1  

Islam MS  Yoshimoto M  Yahara S  Okuno S  Ishiguro K  Yamakawa O 《Journal of agricultural and food chemistry》2002,50(13):3718-3722

Trials over two years were conducted using 1389 sweetpotato (Ipomoea batatas L.) genotypes collected from all over the world to characterize the polyphenolic composition in sweetpotato leaves. Wide variation was observed in relation to their total and individual leaf polyphenolic constituents. In all genotypes studied, the total polyphenol contents of sweetpotato leaf ranged from 1.42 to 17.1 g/100 g dry weight. The six different polyphenolic compounds were identified and quantified by NMR, FABMS, and RPHPLC analysis procedures. This is the first report of polyphenolic compositions in sweetpotato leaves. The relative levels of polyphenolic acids in sweetpotato leaves were as follows: 3,5-di-O-caffeoylquinic acid > 4,5-di-O-caffeoylquinic acid > chlorogenic acid (3-O-caffeoylquinic acid) > 3,4-di-O-caffeoylquinic acid > 3,4,5-tri-O-caffeoylquinic acid > caffeic acid. The highest 3,4,5-tri-O-caffeoylquinic acid and 4,5-di-O-caffeoylquinic acid occurred at 221 and 1183.30 mg/100 g dry weight, respectively.  相似文献   

Genetic variability in cultivated common bean beyond the two major gene pools   总被引：7，自引：0，他引：7  

F.M.A. Islam  K.E. Basford  R.J. Redden  A.V. Gonzalez  P.M. Kroonenberg  S. Beebe 《Genetic Resources and Crop Evolution》2002,49(3):271-283

It is generally accepted that two major gene pools exist in cultivatedcommon bean (Phaseolus vulgaris L.), a MiddleAmerican and an Andean one. Some evidence, based on unique phaseolin morphotypesand AFLP analysis, suggests that at least one more gene pool exists incultivated common bean. To investigate this hypothesis, 1072 accessions from acommon bean core collection from the primary centres of origin, held at CIAT,were investigated. Various agronomic and morphological attributes (14categorical and 11 quantitative) were measured. Multivariate analyses,consisting of homogeneity analysis and clustering for categorical data,clustering and ordination techniques for quantitative data and nonlinearprincipal component analysis for mixed data, were undertaken. The results ofmost analyses supported the existence of the two major gene pools. However, theanalysis of categorical data of protein types showed an additional minor genepool. The minor gene pool is designated North Andean and includes phaseolintypes CH, S and T; lectin types 312, Pr, B and K; and mostly A5, A6 and A4 types-amylase inhibitor. Analysis of the combined categorical data ofprotein types and some plant categorical data also suggested that some othergermplasm with C type phaseolin are distinguished from the major gene pools.  相似文献   

Premelting at defects within bulk colloidal crystals     

Alsayed AM  Islam MF  Zhang J  Collings PJ  Yodh AG 《Science (New York, N.Y.)》2005,309(5738):1207-1210

Premelting is the localized loss of crystalline order at surfaces and defects at temperatures below the bulk melting transition. It can be thought of as the nucleation of the melting process. Premelting has been observed at the surfaces of crystals but not within. We report observations of premelting at grain boundaries and dislocations within bulk colloidal crystals using real-time video microscopy. The crystals are equilibrium close-packed, three-dimensional colloidal structures made from thermally responsive microgel spheres. Particle tracking reveals increased disorder in crystalline regions bordering defects, the amount of which depends on the type of defect, distance from the defect, and particle volume fraction. Our observations suggest that interfacial free energy is the crucial parameter for premelting in colloidal and atomic-scale crystals.  相似文献   

Aeromonas hydrophila-associated septicemia in captive crocodiles (Crocodylus johnstoni and Crocodylus porosus)     

Roh YS  Park H  Cho HU  Cho A  Islam MR  Cho HS  Lim CW  Kim B 《Journal of zoo and wildlife medicine》2011,42(4):738-742

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Canning and pH stability of epichlorohydrin-treated parboiled rice     

J E Rutledge  M N Islam 《Journal of agricultural and food chemistry》1973,21(3):458-460

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Sequence Analysis of the Full‐Length Cloned DNA of a Chicken Anaemia Virus (CAV) Strain from Bangladesh: Evidence for Genetic Grouping of CAV Strains Based on the Deduced VP1 Amino Acid Sequences     

M. R. Islam  R. Johne  R. Raue  D. Todd  H. Müller 《Zoonoses and public health》2002,49(7):332-337

Chicken anaemia virus (CAV) was detected in the bursa of Fabricius of a 4‐week‐old chicken obtained from an outbreak of acute infectious bursal disease in Bangladesh. Repeated attempts to grow this virus in MDCC‐MSB1 cells were not successful. A full‐length PCR amplicon of the genome of this strain, designated as BD‐3 CAV, was cloned and sequenced. The complete nucleotide sequence and the deduced amino acid sequence were compared with those of 12 other CAV strains. The genetic analysis of the amino acid sequences of VP1 indicated the possible existence of genetic groups among CAV strains, as BD‐3 CAV along with four other strains (CIA‐1, L‐028, Isolate 704 and TR‐20) formed a distinct lineage. These strains have four signatory amino acids in VP1, such as ⁷⁵I/T, ⁹⁷L, ¹³⁹Q and ¹⁴⁴Q, out of which the latter two are located in a small hydrophilic peak.  相似文献