Erwinia carotovora subsp. carotovora與Erwinia chrysanthemi引起籮蔔細菌性軟腐病

Bacterial soft rot of radish frequently occurs in Taiwan and was reported to be caused by Erwinia carotovora subsp. carotovora (Ecc). In 1988, a total of fifty strains of soft-rotting Erwinia was isolated from diseased radish tissues collected from several fields in the central and southern parts of Taiwan, among them, forty-six strains were identified as Ecc, while the other four strains were Erwinia chrysantherni (Ech) with phenotypic characteristics similar to the strains in subdivision II according to Dickey’s classification. Strains of both Ecc and Ech induced soft rot extensively on a wide variety of vegetable tissues. However, Ech strains were more virulent to bulb scales of onion than most Ecc strains. The rotting ability of Ech on radish taproot tissues was also stronger than that of Ecc especially at higher temperature (32℃). In addition1, when radish taproot tissues were inoculated with cell suspensions of both Ecc and Ech in a 1:1 ratio, Ecc was dominant in the rotted tissues at 28℃ or below, but Ech became dominant at higher1temperature (32℃). 蘿蔔細菌性軟腐病於台灣田間經常可見，然對其病原細菌之特性，未曾有較深入之探討。民國77年間筆者等自台灣中南部不同地區之蘿蔔田，採回罹軟腐病之蘿蔔塊根與葉柄組織，共分離了50個Erwinia屬軟腐細菌菌株，經生理生化特性測定結果，其中46個菌株為Erwinia carotouora subsp. carotouora (Ecc)，另4個菌株為Erwinia chrysanthemi (Ech)，此4個Ech菌株皆屬於Dickey分類體系之第II型。Ecc與Ech菌株對許多蔬菜組織常具有強之致腐能力，然而Ecc與Ech菌株在洋蔥鱗片上之致腐能力，則有很大差異，許多Ecc菌株對洋蔥鱗片之致腐能力很弱，而Ech菌株則很強。又溫度可影饗此兩種軟腐細菌之致腐能力，於蘿蔔塊根組織上，Ech菌株常較Ecc菌株之致腐能為強，尤其於較高的溫度下(32℃)。以等量之Ecc與Ech細菌同時接種於蘿蔔塊根組織，在較高的溫度下(32℃)，於軟腐組織中Ech之族軍較Ecc為優勢

(48(4):64-70)Effects of Peat Moss Amendment on Propagation of Arbuscular Mycorrhizal Fungi

叢枝菌根菌Glomus mosseae 的繁殖一般採用河砂為栽培介質，是因河砂具有高透氣性與低肥份的特性，但缺點是保水性差及不具緩衝性，泥炭苔則具有高保水性的優點，因此本試驗目的是探討河砂中添加泥炭苔，提高叢枝菌根菌在宿主根系的繁殖效果。試驗首先將泥炭苔（10%）添加方式分成混合或覆蓋兩種處理，供試宿主植物有百喜草、營多藤、玉米及甘藷等四種，結果除甘藷外，菌根形成率與孢子濃度都以混合處理者高於覆蓋處理者。將河砂混合1/5, 1/3, 1/2（體積／體積）的泥炭苔，或單獨使用河砂，探討對G. mosseae 在百喜草根圈土繁殖之影響，結果顯示盆缽中完全為河砂者，菌根形成率與厚膜孢子數最高，隨著泥炭苔混合比例增加，菌根形成率與厚膜孢子數逐漸減低。泥炭苔採用覆蓋方式，定期調查 G. mosseae 在玉米根圈土的繁殖，顯示隨接種時間增加，菌根形成率與孢子數逐漸提高，至接種後第11週達到高峰，而後逐漸降低。由以上結果，顯示單獨以河砂為介質，所生產的孢子數最高，添加泥炭苔反而不利於菌根形成與孢子的產生，其可能的原因有待進一步探討。Sand is a good medium for inoculum production of vesicular-arbuscular mycorrhizal fungi, because of its high aeration and lower fertility, but it has poor water-conserved and buffering ability. In contrast, peat moss has high water-conserved ability, so we try to amend sand with peat moss to improve initial growth of host plants, and to increase colonization and spore of VAM fungi. Effect of 10% peat moss mulched or mixed with sand on colonization and spore production of G. mosseae are tested in four host plants of bahiagrass, intortum, corn, and sweet potato. Results indicated sand mixed with peat moss is better than those mulched with peat moss. Then, the effects of sand mixed with peat moss in ratio of 1/5, 1/3, 1/2 on propagation of G. mosseae in rhizospheric soil of bahiagrass were conducted. Results indicated that the amendment of peat moss in sand could improve initial growth of host plants, but colonization or spore production was the highest in treatment without peat moss amendment. When amended volume of peat moss was over 1/4, there was no spore in rhizospheric soil at 14 weeks after inoculation. Periodic investigation were conducted to monitor propagation of G. mosseae in the rhizosphere of corn, and results indicated that root colonization and spore production in soil gradually increased, and reached the highest at 11 weeks after inoculation, and then decreased. The results showed that spore production was the highest in sand without any amendment. Peat moss was not beneficial to colonization and spore production, if amended with sand

Multimode D-type Optical Fiber Sensor Based on ATR Effect in Temperature Detection

An application of a multimode D-type optical fiber sensor (OFS) in temperature measurement is proposed. The sensor is based on the attenuated total reflection (ATR) effect and acts as a probe to sense a liquid or gas temperature in real-time. We use the optical spectrum method combined with the minimum value of relative power ratio technique to analyze and record the temperature. The temperature resolution is 0.01 °C in the measurement range of 24~75 °C. The proposed system offers the advantages of simplicity, sensitivity, and remote testing

A review in the current developments of genus Dehalococcoides, its consortia and kinetics for bioremediation options of contaminated groundwater

This article reviews the current developments in genus Dehalococcoides as key dechlorinating bacteria in chlorinated ethene contaminated sites. The presence of chlorinated ethenes in environment had been a concern for more than five decades as it represents significant threat to human and ecological health due to its extreme toxicity. This review elucidates the kinetics of Dehalococcoides spp. growth and compound utilization in dechlorination of chlorinated ethenes compounds. The metabolic pathways in physiology of Dehalococcoides spp. are important in the transformation of chlorinated species. The potential of isolates and its reductive dehalogenase genes are seen to infer activities of Dehalococcoides spp. that would be used to the development of engineered systems. This system is helpful in making decision on bioremediation option to treat the contaminated groundwater. Hence, the role of Dehalococcoides spp. in chlorinated ethene biodegradation is controlled by kinetics in complex ways. Therefore, intensive in-situ characterization and understanding the microbial growth on dechlorination evaluation are essential to develop a consistent and rational engineered system. This is to achieve a successful bioremediation strategies for sites contaminated with chlorinated ethenes

Reclaimed water in Taiwan: current status and future prospects

Abstract According to the Taiwan Water Resources Agency, Ministry of Economic Affairs, the average water demand shortage is 530.6 million m3 yr−1 during the period of 2011 to 2019, and the situation will worsen in the near future due to global climate change. Therefore, reclaimed water has been an important new water source in Taiwan, particularly for industrial consumers such as high-tech industries in Science Parks. In order to meet the targeted reclaimed water supply of 1.32 million m3 d−1 (CMD) in 2031, Taiwan is focusing on two major reclaimed water sources, including reclaimed water from high water-consuming industries and municipal wastewater treatment plants. This report reviews current technologies used for reclaimed water including units for pretreatment, desalting, polishing, and reclamation. Case studies in Taiwan including reclaimed water from high water-consuming industries such as thin film transistor-liquid crystal display (TFT-LCD) and semiconductor industries, as well as from municipal wastewater treatment plants are presented. The TFT-LCD company Innolux and semiconductor company Advaned Semiconductor Engineering have implemented total recycled water system to recycle and reclaim wastewater from manufacturing processes, achieving a total recycled water of 290 million m3 yr−1 with about 97% recovery and 3.5 million m3 yr−1 with 80% recovery, respectively. The Fengshan reclaimed water treatment plant produces 40,436 CMD reclaimed water from municipal wastewater for the China Steel Cooperation’s steel-making processes, at an overall operation and maintenance cost of 11.5 NT dollars m−3. Meanwhile the Yongkang plant produces 15,500 CMD of reclaimed water for semiconductor and TFT-LCD manufacturing processes at an overall operation and maintenance costs of 25.8 NT dollars m−3, which is due to low urea and boron limits requested by the user. Finally, challenges and future prospects for promoting the use of reclaimed water to meet the targeted supply in 2031 will be discussed

A contemporary study into the application of neural network techniques employed to automate CAD/CAM integration for die manufacture

In recent years, collaborative research between academia and industry has intensified in finding a successful approach to take the information from a computer generated drawings of products such as casting dies, and produce optimal manufacturing process plans. Core to this process is feature recognition. Artificial neural networks have a proven track record in pattern recognition and there ability to learn seems to offer an approach to aid both feature recognition and process planning tasks. This paper presents an up-to-date critical study of the implementation of artificial neural networks (ANN) applied to feature recognition and computer aided process planning. In providing this comprehensive survey, the authors consider the factors which define the function of a neural network specifically: the net topology, the input node characteristic, the learning rules and the output node characteristics. In additions the authors have considered ANN hybrid approaches to computer aided process planning, where the specific capabilities of ANN's have been used to enhance the employed approaches. © 2009 Elsevier Ltd. All rights reserved