排序方式: 共有46条查询结果,搜索用时 917 毫秒
31.
Naoko Yamano Norioki Kawasaki Sahori Takeda Atsuyoshi Nakayama 《Journal of Polymers and the Environment》2013,21(2):528-533
We have developed a simple and highly efficient process for the production of 2-pyrrolidone (2-PRN) from biobased l-glutamic acid (Glu). First, we produced γ-aminobutyric acid (GABA) from Glu obtained by fermentation of biomass using Escherichia coli, which is known to possess GABA producing activity. The reaction solution contained only the substrate Glu, bacterial cells, and water, and did not require buffers or coenzymes, pyridoxal-5′-phosphate (PLP). Every 24 h, cells were removed by centrifugation, and GABA containing supernatant was obtained. This reaction can be repeated 14 times by adding water and Glu, without any decrease in activity. Finally, 303.7 g of GABA was produced from 560 g (40 g × 14 times) of Glu with a yield of 77.4 %. The concentration of this solution was almost 40 %. The GABA was then converted to biobased 2-PRN by heating and distillation under reduced pressure without pretreatment. The yield obtained with this chemical process was 95.8 %. These results showed that biobased 2-PRN could be produced from biomass-derived Glu. Biobased 2-PRN has great potential as a raw material to change other petroleum-based materials to biobased materials. 相似文献
32.
Naoko Yamano Atsuyoshi Nakayama Norioki Kawasaki Noboru Yamamoto Seiichi Aiba 《Journal of Polymers and the Environment》2008,16(2):141-146
We identified a biodegrading microorganism of polyamide (nylon) 4, a linear polymer of γ-aminobutyric acid (GABA). From activated
sludge, the biodegrading bacteria strains of Pseudomonas sp. were isolated and identified by their taxonomic characteristics and nucleotide sequences of 16S rDNA. One strain, ND-11,
was grown on a minimal medium containing polyamide 4 (PA4) as the sole carbon source. The strain produced GABA as a degradation
intermediate, as identified by analyzing the NMR spectra of degraded products. The culture supernatant of strain ND-11 degraded
the emulsified PA4 completely within one day. These results suggest that the ND-11 strain degraded PA4 using its extracellular
enzymes to hydrolyze amide bonds. 相似文献
33.
Miyuki Nishiyama Akihiko Sekizawa Kohei Ogawa Hideaki Sawai Hiroaki Nakamura Osamu Samura Nobuhiro Suzumori Setsuko Nakayama Takahiro Yamada Masaki Ogawa Yukiko Katagiri Jun Murotsuki Yoko Okamoto Akira Namba Haruka Hamanoue Masanobu Ogawa Kiyonori Miura Shunichiro Izumi Yoshimasa Kamei Haruhiko Sago 《黑龙江环境通报》2016,36(12):1121-1126
34.
Chai Xiaoli Lou Ziyang Takayuki Shimaoka Hirofumi Nakayama Zhu Ying Cao Xiaoyan Teppei Komiya Toshio Ishizaki Zhao Youcai 《Waste management (New York, N.Y.)》2010,30(3):446-451
To elucidate the influence of landfill gas (LFG) emission on environmental factors, an ecological investigation that was primarily concerned with the characteristics of vegetation, cover soil, and solid waste in the landfill was carried out. Temporal and spatial variations in vegetation diversity and coverage and their effects on reducing the emission of methane in the landfill were investigated. The results showed that both vegetation coverage and diversity increased with elapsed landfill closure time. The transition trend of the vegetation species was from perennial plant (Phragmites australis) to annual plants. Perennial vegetation was the dominant type of vegetation during the early closure period, and annual vegetation coverage increased with closure time. Vegetation preferentially appeared in areas of comparatively high depth of cover soil, which was characterized by high moisture retentiveness that enabled vegetation growth. The concentrations of methane and carbon dioxide in the cover soil significantly decreased with increasing closure time. The concentrations of methane and carbon dioxide from bare cover soil were higher than those from vegetated cover soil whereas the CO2 flux of bare cover soil was less than that of vegetated cover soil. 相似文献
35.
Summary. In the natural habitat of Papilio polytes, a
Rutaceae feeder utilizing Toddalia asiatica as a major host plant, some other rutaceous plants such as
Murraya paniculata
(abundant) and Glycosmis citrifolia (relatively rare)
occur sympatrically as potential hosts. Whereas
G. citrifolia
is occasionally infested in the field, M. paniculata
remains entirely unexploited by the butterfly. We thus examined the
phytochemical mechanisms that can explain the differential
acceptance of the two plants by ovipositing females of
P. polytes. The foliage of
G. citrifolia was found to readily
induce oviposition and females deposited eggs in response
to a methanolic extract of the plant. Stimulatory activity-directed
fractionation of the extract revealed the presence of
two characteristic compounds, trans-4-hydroxy-N-methylproline
and 2-C-methylerythronic acid, known to serve as
oviposition stimulants for the butterfly. In addition, larvae
performed as well or better onG. citrifolia
as on T. asiatica.
Similar examination of the inhibitory chemical constituents
of M. paniculata led to the isolation of an oviposition deterrent. The compound, identified as trigonelline
(N-methylpyridine-
3-carboxylic acid), exhibited moderate
oviposition deterrency to females. These results combined
with our previous data are in agreement with the observed
differential utilization of the two plants by
P. polytes in the field. 相似文献
36.
37.
Perfluorinated compounds in common carp (Cyprinus carpio) fillets from the Upper Mississippi River 总被引:1,自引:0,他引:1
Ye X Schoenfuss HL Jahns ND Delinsky AD Strynar MJ Varns J Nakayama SF Helfant L Lindstrom AB 《Environment international》2008,34(7):932-938
Ten different perfluoroalkyl acids (PFAAs), including perfluooctane sulfonate (PFOS), were measured in 30 common carp (Cyprinus carpio) fillets collected from three sites on the Upper Mississippi River in Minnesota in an effort to evaluate the potential impact of PFAA emissions in this area. Samples upstream of the city of St. Cloud (reference site) had median PFOS concentrations of 8.1 ng/g wet weight (ng/g wet wt), but median levels increased significantly downstream in the Minneapolis-St. Paul urban area, with concentrations from the Pig's Eye Lake site at 26 ng/g wet wt (p=0.0015) and the Spring Lake site at 40 ng/g wet wt (p=0.0004). This latter PFOS concentration is within the advisory range for limiting fish consumption to one meal a week according to the Minnesota Department of Health. Other PFAAs were also found to increase significantly between the reference site and the Minneapolis-St. Paul area, but maximal concentrations remained below 2.0 ng/g wet wt. This study demonstrates the bioaccumulation of PFAAs in a ubiquitous fish species in a major urban area known to have historical inputs of various PFAA compounds. The full extent of this contamination and the potential for accumulation in other species remain to be evaluated. 相似文献
38.
River basin management in China has focused on large rivers, such as the Yangtze and Yellow Rivers. However, there are also about 20,000 small river basins that deserve attention. The Biliu River basin in Liaoning Province, northeast China, which is 156 km in length, has many features common to small river basins, including divided jurisdiction among governments leading to vertical and horizontal fragmentation. In the Biliu basin, the key municipalities are Dalian with a population of almost 6 million people and Yingkou with about 2.28 million people. Each has different interests and needs, making coordination and collaboration difficult. The literature and practice suggest that effective integrated water resource management (IWRM) requires at least six features: (1) vision, policy and strategy; (2) a legislative or statutory basis to provide credibility and authority; (3) a river basin organization to coordinate development and management; (4) specification of functions and authority of the river basin organization; (5) public participation and community involvement; and (6) an IRWM strategy and plan. Water management in the Biliu River basin is assessed relative to these features of IWRM, with recommendations offered regarding changes to have water management in the Biliu River basin to reflect what is expected in an IWRM approach. 相似文献
39.
Yohannes Yared Beyene Ikenaka Yoshinori Ito Gengo Nakayama Shouta M. M. Mizukawa Hazuki Wepener Victor Smit Nico J. Van Vuren Johan H. J. Ishizuka Mayumi 《Environmental science and pollution research international》2017,24(30):23763-23770
Environmental Science and Pollution Research - Ethiopia and South Africa are among the few countries to still implement indoor residual spraying with dichloro-diphenyl-trichloroethane (DDT) for... 相似文献
40.
M Kawaguchi Y Sugahara T Watanabe K Irie M Ishida D Kurokawa S Kitamura H Takata IC Handoh K Nakayama Y Murakami 《Environmental science and pollution research international》2011,19(7):2488-2497
BACKGROUND AND OBJECTIVE: Spills of heavy oil (HO) over the oceans have been proven to have an adverse effect on marine life. It has been hypothesized that exposure of early larvae of sinking eggs to HO leads largely to normal morphology, whereas abnormal organization of the developing neural scaffold is likely to be found. HO-induced disruption of the nervous system, which controls animal behavior, may in turn cause abnormalities in the swimming behavior of hatched larvae. To clarify the toxicological effects of HO, we performed exposure experiments and morphological and behavioral analyses in pufferfish (Takifugu rubripes) larvae. EXPERIMENTAL PROCEDURE: Fertilized eggs of pufferfish were exposed to 50?mg/L of HO for 8?days and transferred to fresh seawater before hatching. The hatched larvae were observed for their swimming behavior, morphological appearance, and construction of muscles and nervous system. RESULTS AND DISCUSSION: In HO-exposed larvae, we did not detect any anomaly of body morphology. However, they showed an abnormal swimming pattern and disorganized midbrain, a higher center controlling movement. Our results suggest that HO-exposed fishes suffer developmental disorder of the brain that triggers an abnormal swimming behavior and that HO may be selectively toxic to the brain and cause physical disability throughout the life span of these fishes. 相似文献