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P. Atthasampunna P. Somchai A. Eur-aree S. Artjariyasripong 《World journal of microbiology & biotechnology》1987,3(2):135-142
Summary Ethanol production from fresh cassava roots using a low-temperature process was evaluated on a pilot-plant scale. The application of low-temperature cooking to cassava starch followed by a dual enzyme action resulted in an ethanol yield comparable to that of a traditional high-temperature cooking process. Pressurized distillation gave a satisfactory recovery efficiency of ethanol but was slightly lower than that obtained from atmospheric pressure distillation. Over 40% of the normal steam consumption was saved by adopting the low-temperature cooking and pressurized distillation systems in the cassava-to-ethanol process. The yield of anhydrous ethanol varied with the starch content in fresh cassava roots and was in the range of 185 to 200 liters per tonne.
Resumen La producción de etanol a partir de raices frescas de cassava como materia prima, empleando un procedimiento a baja temperatura, ha sido evaluada a la escala de planta piloto. El empleo de baja temperatura en el tratamiento del almidón de cassava, sequido de una doble acción enzimática ha resultado en un rendimiento de etanol comparable al obtenido con el procedimiento tradicional de elevada temperatura. La destilación bajo presión ha presentado un rendimiento de etanol satisfactorio, aunque ligeramente inferior al obtenido en la destilación a la presión atmosférica. Se ahorro más de un 40% de consumo de energía en forma de vapor de agua al adoptar el tratamiento del almidón a baja temperatura y el proceso de destilación bajo presión en la producción de etanol a partir de cassava. El rendimiento de etanol anhidro varió según el contenido de almidón de la materia prima, oscilando entre 185 a 200 litros pot tonelada de cassava.
Résumé La production d'éthanol à partir de racines fraîches de cassava comme matière première, à basse température, a été évaluée à l'échelle de plante d'essai. L'utilisation de température basse pour le traitement de l'amidon de cassava, suivi d'une double action enzymatique, a résulté en un rendement d'éthanol comparable a celui obtenu par le procédé traditionel a température élevée.: La destilation sous pression s'est présentée satisfaisante en ce qui concerne le rendement en éthanol. Cependant, celui-ci s'est montré légèrement inférieur à celui obtenu par destilation à la pression atmosphérique. Une économie d'énergie en forme de vapeur d'eau de plus de 40% a été le résultat de l'emploi de basse temperature pour le traitement de l'amidon de cassava et du procédé de destilation sous pression dans la production d'éthanol à partir de racines de cassava. Le rendement en éthanol anhydre a varié selon le contenue en amidon de la matière première, en oscillant entre 185 et 200 litres par tonne de racines de cassava.相似文献
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Paungmoung P Punya J Pongpattanakitshote S Jeamton W Vichisoonthonkul T Bhumiratana S Tanticharoen M Linne U Marahiel MA Cheevadhanarak S 《FEMS microbiology letters》2007,274(2):260-268
Nonribosomal peptides, synthesized by nonribosomal peptide synthetases (NRPS), are an important group of diverse bioactive fungal metabolites. Xylaria sp. BCC1067, which is known to produce a variety of biologically active metabolites, was studied for gene encoding NRPS by two different PCR-based methods and seven different NRPS fragments were obtained. In addition, screening a genomic library with an amplified NRPS fragment as a probe identified a putative NRPS gene named XyNRPSA. The functionality of XyNRPSA for the production of a corresponding metabolite was probed by gene insertion inactivation. Comparing the disrupting metabolite profile with that of the wild type led to the identification of a speculated metabolite. The crude extract of Xylaria sp. BCC1067 also exhibits antifungal activity against the human pathogens Candida albicans and Trichophyton mentagrophytes. However, the evaluation of biological activity of the XyNRPSA product suggests that it is neither a compound with antifungal activity nor a siderophore. In the vicinity of XyNRPSA, a second gene (named XyPtB) was identified. Its localization and homology to orfB of the ergot alkaloid biosynthetic gene cluster suggests that XyPtB may be involved in XyNRPSA product biosynthesis. 相似文献
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Background
The merozoite surface protein-1 (MSP-1) is a candidate target for the development of blood stage vaccines against malaria. Polymorphism in MSP-1 can be useful as a genetic marker for strain differentiation in malarial parasites. Although sequence diversity in the MSP-1 locus has been extensively analyzed in field isolates of Plasmodium falciparum and P. vivax, the extent of variation in its homologues in P. ovale curtisi and P. ovale wallikeri, remains unknown.Methodology/Principal Findings
Analysis of the mitochondrial cytochrome b sequences of 10 P. ovale isolates from symptomatic malaria patients from diverse endemic areas of Thailand revealed co-existence of P. ovale curtisi (n = 5) and P. ovale wallikeri (n = 5). Direct sequencing of the PCR-amplified products encompassing the entire coding region of MSP-1 of P. ovale curtisi (PocMSP-1) and P. ovale wallikeri (PowMSP-1) has identified 3 imperfect repeated segments in the former and one in the latter. Most amino acid differences between these proteins were located in the interspecies variable domains of malarial MSP-1. Synonymous nucleotide diversity (πS) exceeded nonsynonymous nucleotide diversity (πN) for both PocMSP-1 and PowMSP-1, albeit at a non-significant level. However, when MSP-1 of both these species was considered together, πS was significantly greater than πN (p<0.0001), suggesting that purifying selection has shaped diversity at this locus prior to speciation. Phylogenetic analysis based on conserved domains has placed PocMSP-1 and PowMSP-1 in a distinct bifurcating branch that probably diverged from each other around 4.5 million years ago.Conclusion/Significance
The MSP-1 sequences support that P. ovale curtisi and P. ovale wallikeri are distinct species. Both species are sympatric in Thailand. The low level of sequence diversity in PocMSP-1 and PowMSP-1 among Thai isolates could stem from persistent low prevalence of these species, limiting the chance of outcrossing at this locus. 相似文献6.
Ratchadawan Aukkanimart Thidarut Boonmars Somchai Pinlaor Smarn Tesana Surasit Aunpromma Chantana Booyarat Pranee Sriraj Porntip Laummaunwai Wiyada Punjaruk 《The Korean journal of parasitology》2013,51(5):537-544
The present study was performed to observe histopathological changes in tissues of Bithynia siamensis goniomphalos (Gastropoda, Bithyniidae) incubated in crude extract solutions of camellia (Camellia oleifera) seed and mangosteen (Garcinia mangostana) pericarp, and furthermore to estimate the molluscicidal effects of 2 plant substances. Substantial numbers of bithyniid snails were incubated in various concentrations of 2 plant solution for 24 hr. As the positive control, snails incubated in various concentrations of niclosamide, a chemical molluscicide, were used. The histopathological findings were observed in sectioned snail specimens of each experimental and control groups. The results showed that both camellia and mangosteen extracts had molluscicidal effects at 24 hr with 50% lethal concentration (LC50) at concentrations of 0.003 and 0.002 g/ml, respectively, while niclosamide had LC50 at concentrations 0.599 ppm. B. siamensis goniomphalos snail tissues (foot, gill, and digestive system) showed disruption of columnar muscle fibers of the foot, reduction of the length and number of gill cilia, numerous mucous vacuoles, and irregularly shaped of epithelial cells. Irregular apical and calciferous cells, dilatation of the digestive gland tubule, and large hemolymphatic spaces, and irregular apical surfaces, detachment of cilia, and enlargement of lysosomal vacuoles of epidermis were also shown in all groups. By the present study, it is confirmed that 2 plants, camellia and mangosteen, are keeping some substance having molluscicidal effects, and histopathological findings obtained in this study will provide some clues in further studies on their action mechanisms to use them as natural molluscicides. 相似文献
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Prapaporn Jattujan Somchai Pinlaor Lakhanawan Charoensuk Channarong Arunyanart Jariya Umka Welbat Wunnee Chaijaroonkhanarak 《The Korean journal of parasitology》2013,51(6):695-701
Opisthorchis viverrini infection causes inflammation and liver injury leading to periductal fibrosis. Little is known about the pathological alterations in bile canaliculi in opisthorchiasis. This study aimed to investigate bile canalicular alterations in O. viverrini-infected hamsters and to examine the chemopreventive effects of curcumin on such changes. Hamsters were infected with O. viverrini and one group of animals was fed with 1% dietary curcumin supplement. Animals were examined during the acute infection phase, days 21 and 30 post-infection (PI) and chronic infection phase (day 90 PI). Scanning electron microscopy revealed that in the infected group fed with a normal diet, bile canaliculi became slightly tortuous by 30 day PI and more tortuous at day 90 PI. Transmission electron microscopy showed a reduction in microvilli density of canaliculi starting at day 30 PI, with a marked loss of microvilli at day 90 PI. These ultrastructral changes were slightly seen at day 21 PI, which was similar to that found in infected animals fed with 1% curcumin-supplemented diet. Notably, curcumin treatment prevented the reduction of microvilli density, reduced the dilation of bile canaliculi, and decreased the tortuosity of the bile canaliculi relative to non-infected animals on a normal diet at days 30 and 90 PI. These results suggest that curcumin reduces alteration of bile canaliculi and may be a promising agent to prevent the onset of bile duct abnormalities induced by O. viverrini infection. 相似文献
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8-nitroguanine formation in the liver of hamsters infected with Opisthorchis viverrini 总被引:4,自引:0,他引:4
Pinlaor S Yongvanit P Hiraku Y Ma N Semba R Oikawa S Murata M Sripa B Sithithaworn P Kawanishi S 《Biochemical and biophysical research communications》2003,309(3):567-571
Nucleic acid damage by reactive nitrogen and oxygen species may contribute to the carcinogenesis associated with chronic infection and inflammation. We examined 8-nitroguanine and 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodG) formation and nitric oxide (NO) production in hamsters infected with Opisthorchis viverrini (OV). Formation of 8-nitroguanine was assessed immunohistochemically with an antibody specific for 8-nitroguanine. 8-nitroguanine formation was found mainly in the cytoplasm and slightly in the nucleus of inflammatory cells and epithelial lining of bile duct at inflammatory areas in the liver. 8-nitroguanine immunoreactivity reached the highest intensity on day 30. A time profile of 8-nitroguanine formation was closely associated with that of plasma nitrate/nitrite. HPLC with an electrochemical detector revealed that the amount of 8-oxodG in the liver reached the maximal level on day 21. The mechanisms of 8-oxodG and 8-nitroguanine formation via O2*- and NO production triggered by OV infection were discussed in relation to cholangiocarcinoma development. 相似文献
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Leelakusolvong S Sarr MG Miller SM Phillips SF Bharucha AE 《American journal of physiology. Gastrointestinal and liver physiology》2002,283(1):G230-G239
The human colon can dilate, often to life-threatening proportions. Our aim was to explore nitrergic mechanisms underlying colonic dilation in conscious dogs with enterically isolated ileocolonic loops either extrinsically innervated (n = 4) or extrinsically denervated (n = 4). We recorded phasic pressures in ileum and ileocolonic sphincter (ICS), colonic tone, compliance, and relaxation during ileal distension. By NADPH-diaphorase histochemistry, we assessed effects of extrinsic denervation and enteric isolation on nitrergic fibers. Extrinsic denervation increased phasic pressures in ileum, ICS, and colon and abolished ICS and colonic relaxation in response to ileal distension. The nitric oxide synthase (NOS) inhibitor N(omega)-nitro-L-arginine (L-NNA) increased phasic pressures at all sites and ICS tone but did not abolish colonic relaxation during ileal distension in innervated loops. L-NNA reduced compliance and induced colonic high-amplitude propagated contractions in denervated loops. The NOS substrate donor L-arginine reversed effects of L-NNA. The number of NADPH-diaphorase fibers increased in both enterically isolated preparations. Nonnitrergic extrinsic nerve pathways mediate reflex colonic relaxation during ileal distension. Enteric isolation augments the number of NOS fibers, an effect not modified by extrinsic denervation. 相似文献
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Kho WG Chung JY Sim EJ Kim MY Kim DW Jongwutiwes S Tanabe K 《Parasitology international》2003,52(3):229-236
A multiplex PCR was designed for the differential diagnosis of the two parasite species by targeting the 18S rRNA gene with a set of primer combinations, amplifying DNA fragments of 1451-bp and 833-bp for P. falciparum and P. vivax, respectively. The sensitivity of this PCR test was high, as minimal as 0.1 parasite per one microliter of blood sample and a minimum of four copies of the target gene could be detected. For the diagnosis of mixed infection of two Plasmodium spp., there were no apparent competition or cross-reaction between the majority and minority Plasmodium species. The multiplex PCR was evaluated on 210 clinical samples and 60 normal controls. The PCR test yielded highly concordant results with microscopic examination, with the only one exception of a mixed (P. falciparum plus P. vivax) infection case, which was diagnosed as a single infection of P. falciparum by microscopy. We propose that the multiplex PCR is a sensitive, specific, and rapid tool that can serve as a useful differential diagnostic tool for detecting P. falciparum and P. vivax. 相似文献