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101.
Molecular breeding of cellulolytic microbes, plants, and animals for biomass utilization 总被引:1,自引:0,他引:1
Cellulosic materials are the major components of fibrous biomass produced as a result of photosynthesis and are considered as a reservoir of solar energy and organic materials. In order to cope with the problems of food and energy shortages expected in the near future, biotechnologists are encouraged to develop new technologies for the more effective utilization of the world's sustainable resources, i.e., biomass. One way is to engineer microorganisms and animals with the capability of digesting and utilizing cellulosic materials, and plants which can be easily degraded by cellulolytic enzymes. In this article, we summarize recent studies on the molecular breeding of cellulolytic organisms for biomass utilization along with some considerations regarding cellulolytic enzymes. 相似文献
102.
Goto S Takahashi H Kawasaki S Kimura B Fujii T Nakatsuji M Watanabe I 《Shokuhin eiseigaku zasshi. Journal of the Food Hygienic Society of Japan》2004,45(1):25-28
To simplify the labor-intensive conventional routine testing of samples to detect Leuconostoc at a meat processing plant, we developed polymerase chain reaction (PCR) primers specific for Leuconostoc from 16S rRNA gene sequences. These primers did not detect other common lactic acid bacteria such as Lactobacillus plantarum, Lact. sake, Lact. fermentum, Lact. acidophilus and Weissella viridescens. PCR with this primer detected all Leuconostoc species tested (Leu. mesenteroides subsp. mesenteroides, Leu. pseudomesenteroides, Leu. carnosum, Leu. lactic, Leu. citreum, Leu. amelibiosum, Leu. gelidum), except for Leu. fallax, and no other lactic acid bacteria on agarose gel electrophoresis. The method could identify areas contaminated with Leuconostoc in a large-scale industrial meat processing plant. Of 69 samples analyzed, 34 were positive for Leuconostoc according to the conventional culture method (isolation of LAB producing dextran) and PCR, whereas 29 were negative according to both. Six samples were culture-negative but positive by PCR. No false negative results were generated by PCR. The method is rapid and simple, is useful for routinely monitoring areas contaminated with Leuconostoc in meat processing plants, and could help to prevent the spoilage of meat products. 相似文献
103.
The viscoelastic properties of soybean curd (tofu) as affected by soymilk concentration and type of coagulant 总被引:1,自引:0,他引:1
Yongqiang Cheng Naoto Shimizu & Toshinori Kimura 《International Journal of Food Science & Technology》2005,40(4):385-390
The viscoelastic properties of different types of tofu were investigated. Soymilk concentrations were 5, 6, 7, 8 and 9%. Coagulants used were 30 mm CaSO4 or 30 mm glucono‐delta‐lactone (GDL). As the concentration of soymilk was increased viscosity and handling difficulties increased. A high concentration of soymilk in tofu gave a high break stress and produced hard tofu. The four‐element Burgers model fitted the creep behaviour and both viscous and elastic parameters could be acquired from model analysis, reflecting changes in elasticity and viscosity of tofu. The constant viscous parameter in the model increased with increasing soymilk concentration. The viscous parameters of viscoelastic materials like tofu gel, obtained from small deformation tests, seemed to correlate, to some extent, with the break stress obtained from large deformation tests. For hard tofu production increasing the soymilk concentration within a certain range and the partial replacement of calcium sulphate coagulant by GDL could be effective options. 相似文献
104.
The arabinofuranosidase gene was cloned from the cDNA of Aspergillus sojae. It was found to contain an open reading frame composed of 984 base pairs (bp) and to encode 328 amino acid residues (aa). The cDNA sequence suggested that the mature enzyme is preceded by a 26-aa signal sequence and the molecular mass was predicted to be 32,749 Da. The A. sojae arabinofuranosidase consists of a single catalytic domain; it does not have a specific substrate-binding domain such as the xylan-binding domain reported in an arabinofuranosidase from Streptomyces lividans (Vincent, P. et al.: Biochem. J., 322, 845-852, 1997). The deduced amino acid sequence of the catalytic domain of the mature enzyme exhibits extensive identity with the catalytic domains of Streptomyces coelicolor (74%), Aspergillus niger (75%), S. lividans (74%), and Aspergillus tubingensis (75%), which are enzymes that belong to family 62 of the glycosyl hydrolases. The cloned AFdase gene was expressed in Escherichia coli BL21 (DE3) pLysS as a cellulose-binding domain tag fusion protein. The specific activity of the purified recombinant enzyme was 18.6 units/mg protein, which is one-fourth that of the enzyme purified from a solid-state culture of A. sojae. 相似文献
105.
Ken‐Ichiro Ishimori Tsuyoshi Yaita Takaumi Kimura Takashi Yamada Satoshi Shinoda 《溶剂提取与离子交换》2013,31(4):489-500
The extraction equilibria of Am(III) and Eu(III) by using a tripodal ligand, tris(2‐pyridylmethyl)amine (tpa), with various lipophilic anions have been investigated. The extractability of both Am(III) and Eu(III) was increased by the combination of tpa and counteranions due to a synergistic effect. The separation factors between Am(III) and Eu(III) were also increased from 7.6 to 49 by the combination of counteranions and organic solvents. The extraction equilibria of Am(III) and Eu(III) with tpa in 1,2‐dichloroethane were determined by slope analysis. It was found that three anions and one molecule of the ligand coordinated to Am(III) and Eu(III) was extracted regardless of the anions. 相似文献
106.
Matsubara Y Kawada R Iwasaki K Kimura Y Oda T Muramatsu T 《Journal of Bioscience and Bioengineering》2000,89(2):199-202
The aly PG gene, coding for a poly alpha-l-guluronate lyase (PG lyase) of Corynebacterium strain ALY-1, was cloned and sequenced. The gene consists of 768 bp encoding a signal peptide of 32 amino acids and a mature protein of 224 amino acids. Two disulfide bond cross-linkages were found to be formed between Cys-4 and Cys-51 and between Cys-200 and Cys-206 in the native PG lyase molecule. The deduced amino acid sequence of the Corynebacterium sp. aly PG gene exhibited 29% homology toward that of the Klebsiella pneumoniae, subsp. aerogenes aly A gene, with two conserved regions (the amino acid sequences from Y-102 to M-110 and from Y-221 to Q-229). 相似文献
107.
R. Subramanian M. Nakajima A. Yasui H. Nabetani T. Kimura T. Maekawa 《Journal of the American Oil Chemists' Society》1999,76(10):1247-1253
The first step in the process of vegetable oil refining is degumming, in which phospholipids and mucilaginous gums are removed
that otherwise result in a low-grade oil. A membrane process is remarkably simple yet potentially offers many advantages in
degumming. Studies were conducted on surfactant-aided membrane degumming with soybean and rapeseed oils in a magnetically
stirred flat membrane batch cell with different types of microfiltration membranes. The reduction of phospholipids in soybean
oil was in the range of 85.8–92.8% during the membrane process. The phosphorus content of membrane permeates of soybean oil
was in the range of 20–58 mg/kg. Crude rapeseed oil contained higher amount of nonhydratable phospholipids and hence resulted
in lower reduction in phospholipids, in the range of 66.4–83.2%. Addition of hydratable phospholipids could improve the efficiency
of degumming in the membrane process without using any electrolyte, resulting in improvement of quality as well as quantity
of the phospholipids. 相似文献
108.
The effect of chitosan feeding (for 21 days) on intestinal bile acids was studied in male rats. Serum cholesterol levels in
rats fed a commercial diet low in cholesterol were decreased by chitosan supplementation. Chitosan inhibited the transformation
of cholesterol to coprostanol without causing a qualitative change in fecal excretion of these neutral sterols. Increased
fiber consumption did not increase fecal excretion of bile acids, but caused a marked change in fecal bile acid composition.
Litcholic acid increased sigificantly, deoxycholic acid increased to a leasser extent, whereas hyodeoxycholic acid and the
6β-isomer and 5-epimeric 3α-hydroxy-6-keto-cholanoic acid(s) decreased. The pH in the cecum and colon became elevated by chitosan
feeding which affected the conversion of primary bile acids to secondary bile acids in the large intestine. In the cecum,
chitosan feeding increased the concentration of α-,β-, and ω-muricholic acids, and lithocholic acid. However, the levels of
hyodeoxycholic acid and its 6β-isomer, of monohydroxy-monoketo-cholanoic acids, and of 3α, 6ξ, 7ξ-trihydroxy-cholanoic acid
decreased. The data suggest that chitosan feeding affects the metabolism of intestinal bile acids in rats. 相似文献
109.
The yield and quality of tofu made from blends of soybeans and raw peanuts, partially defatted peanut flour, and defatted
peanut flour were investigated. Defatted peanut flour appears to be the most compatible with soybeans for tofu making, followed
by partially defatted peanut flour and raw peanuts. Raw peanuts could be incorporated at levels of 10% while partially defatted
or defatted peanut flour could be incorporated at a level of 20%: higher levels produced tofu with either poor texture or
low yield.
SEM images of tofu made from 100% soybeans showed a uniform, continuous, three-dimensional honeycomb-like protein network
structure. When 10% of the soybeans was replaced by either raw peanuts; partially defatted peanut flour; or defatted peanut
flour, the protein strands that make up the network structure were thicker than those of 100% soybean tofu. When soybeans
were replaced with either of the three peanut products at a 30% level, the protein strands of the network structure were either
less continuous or appeared perforated. 相似文献
110.
Hideto Tsuji Yoshito Ikada Suong-Hyu Hyon Yoshiharu Kimura Toshio Kitao 《应用聚合物科学杂志》1994,51(2):337-344
To obtain poly(lactic acid) (PLA) complex fibers, spinning was performed by wet and dry methods from 5–10 g/dL chloroform solutions of poly(D-lactic acid) (PDLA) and poly(L-lactic), both with a viscosity-average molecular weight of 3 × 105. The dope was extruded from a monohole nozzle into coagulation baths from ethanol and chloroform for wet spinning and into a drying column kept at 60°C for dry spinning. Scanning electron microscopic observation of the as-spun fibers showed that the surface of the wet-spun fiber had large basins with diameters of 50–100 μm and many pores with diameters from sub μm to 10 μm, whereas the surface of dry-spun fiber had a microporous structure with the pore diameter of 1–3 μm. The tensile strength of the wet-spun complex fiber was very low and could not be drawn at high temperatures, in contrast to the dry-spun fiber. The tensile strength of dry-spun complex fiber increased upon hot drawing and showed the tensile strength of 94 kg/mm2 by drawing at 160°C to the draw ratio of 13. Differential scanning calorimetry revealed that the complex fibers contained both the stereocomplex crystallites (racemic crystallites) and the crystallites of the single polymers, PDLA and PLLA, regardless of the spinning methods. The ratio of the racemic crystallites to the single-polymer crystallites increased with the draw ratio of the complex fiber. © 1994 John Wiley & Sons, Inc. 相似文献