苹果类胡萝卜素研究进展

类胡萝卜素是苹果果实色泽形成的一个重要影响因子,其种类和含量决定果实是否具有良好的外观和丰富的营养。本文综述了近年来有关苹果果实类胡萝卜素方面的研究进展,并对苹果类胡萝卜素的种类和含量,苹果发育和贮藏过程中类胡萝卜素含量的变化规律,生物合成途径中相关基因的表达,以及环境因子对类胡萝卜素积累的影响等方面进行了阐述。     

茶类胡萝卜素研究进展

类胡萝卜素是茶(Camellia sinensis (L.) O. Ktze.)中一类重要的光合色素,具有光保护、抗氧化等众多生理功能,同时也是脱落酸、独脚金内酯和胡萝卜内脂等植物激素的合成前体,在茶生长发育过程中起极其重要的作用。类胡萝卜素还是构成茶叶外形、叶底色泽的重要成分,也是茶叶重要致香物质的前体物,其种类、含量对茶叶品质起着至关重要的作用。本文对茶中类胡萝卜素种类、代谢途径及其对制茶品质的影响等方面的研究进展进行了综述,同时对茶类胡萝卜素下一步的研究方向进行了展望。     

高等植物类胡萝卜素代谢工程研究进展

类胡萝卜素是自然界中种类繁多的天然化合物。植物类胡萝卜素由类异戊二烯碳骨架组成,并含有或没有环氧的、羟基或酮基基团。类胡萝卜素是人类饮食结构中不可缺少的重要成分,具有多种重要的保健功能,并且是安全的食品、饲料和化妆品着色剂。类胡萝卜素植物代谢基因工程的应用旨在增加特殊植物的营养价值、利用植物来生产特殊的类胡萝卜素、提高植物对光氧化的抵抗力及对植物的花色进行修饰等。     

红酵母生物合成类胡萝卜素研究进展

类胡萝卜素(carotenoid)是一类呈黄色、橙红色或红色的多烯类化合物,具有预防血管硬化和抑制肿瘤发生,增加宿主免疫力,抗氧化能力和抑制自由基等功能.目前类胡萝卜素已被FAO和WHO等国际组织定为A类营养色素,并在50多个国家获准为营养、色素双重功用的食品添加剂,被广泛应用于保健食品及医药和化妆品工业[1].生产类胡萝卜素可采用提取法、化学合成法和微生物发酵法,其中最有发展前景的是微生物发酵法.目前国内外微生物发酵技术生产天然类胡萝卜素的研究,主要集中在三孢布腊拉霉菌和红酵母等菌种上.利用红酵母生产类胡萝卜素具有营养要求简单,培养周期短,可综合利用等优点,具有很好的应用价值和开发前景.本文主要对红酵母生物合成类胡萝卜素的菌种选育、培养条件及类胡萝卜素的提取检测方法进行了综述.     

红辣椒中类胡萝卜素的研究进展

红辣椒中含有丰富的类胡萝卜素,不但具有一定的营养价值,而且是应用广泛的食品着色剂.本文主要阐述了红辣椒中类胡萝卜素的分离鉴定方法、种类、结构,及在对红辣椒的加工、贮存过程中影响类胡萝卜素稳定性因素的研究情况,为红辣椒的开发应用研究提供参考.     

水产动物体色色素组分及着色剂研究进展

综述了近几年来水产动物着色剂的研究成果,指出了水产动物着色的关键是选择合理的养殖条件和优良的增色饵料,增色饵料的研究和开发急待解决的问题是真正弄清水产动物体内色素的代谢途径,明确代谢过程中的调控因子和调控点,本文将为水产动物增色饵料的开发和利用提供理论依据。     

类胡萝卜素的生物合成途径及生物学功能研究进展

类胡萝卜素具有重要的生物学功能,一直是研究的热点。综述近十年来对植物类胡萝卜素的生物合成途径,并对其生物学功能参与光系统的组装、非光化学猝灭、基因表达、抗氧化性和维持膜的稳定性等五个方面的研究进展作一介绍。     

类胡萝卜素裂解双加氧酶及其生理功能

类胡萝卜素是一大类结构相似的化合物,其裂解途径主要有羟化酶途径、双加氧酶裂解途径和氧化酶途径。类胡萝卜素经羟化酶途径可最终转化成脱落酸,经氧化酶途径则最终转化成维生素A;而在裂解双加氧酶(carotenoid cleavage dioxygenases,CCDs)催化下,类胡萝卜素氧化成脱辅基类胡萝卜素。AtCCDs是包括9个成员的小基因家族,CCD1影响果实的色泽和风味;CCD7和CCD8分别编码一个质体区域化蛋白,并参与侧根、侧芽的萌发。9-顺式-环氧类胡萝卜素双氧合酶(NCED)催化的裂解是ABA合成的关键步骤。本文对类胡萝卜素裂解途径及相关酶类的生理功能进行了综述。     

类胡萝卜素代谢工程

类胡萝卜素能预防癌症和慢性病,并有很强的肿瘤抑制活性,对人体健康有着重要作用,其药用潜力引起人们极大关注。迄今已发现600多种天然类胡萝卜素,但绝大部分都是痕量中间产物,很难用化学法生产。大量类胡萝卜素生物合成基因的克隆为在细菌、酵母和植物中异源生产结构多样类胡萝卜素提供了基础。     

基因工程菌产类胡萝卜素的研究进展

从类胡萝卜素的合成机理,类胡萝卜素代谢酶的基因,类胡萝卜素分子育种及微生物类胡萝卜素代谢等方面概述了用基因工程菌产类胡萝卜素的研究进展。     

APPLICABILITY OF RAPID METHODS FOR DETECTION OF SALMONELLA SPP. IN POULTRY FEEDS: A REVIEW

The rapid detection of pathogenic microbial species in feed is of paramount importance considering its implications for animal production and food safety. More sensitive and rapid detection of contaminated feedstuffs may lead to more selective and therefore less expensive treatment of feeds, reduced rates of transmission to a poultry host and reduced carcass contamination. In order to interrupt the cycle of Salmonella spp. transmission from feed to poultry to the consumer, more rapid detection methods to monitor these sources are needed that provide conclusive results within the time frame of feed mixing or broiler processing. Within the last decade, new variations of selective media have been investigated to increase selectivity without reducing Salmonella spp. recovery. Immunological assay methods may also decrease assay time from 96 h to within 24–30 h. But all commercially available methods still require 16 to 57 h for preenrichment, enrichment, and in some cases, postenrichment to recover sublethally injured cells before the assay can be performed. Among the molecular methods that are currently available, the polymerase chain reaction (PCR) represents a tremendous potential for the detection of low levels of pathogenic bacteria. Once optimized, rapid methods may be used to quickly, reliably and inexpensively screen a variety of feedstuffs and feed components for the presence of Salmonella spp., with the goal of minimizing both the cost of feed treatment and the horizontal transmission of Salmonella spp. from feed to poultry.     

EVOLUTION OF CAROTENOID PIGMENTATION IN CACIQUES AND MEADOWLARKS (ICTERIDAE): REPEATED GAINS OF RED PLUMAGE COLORATION BY CAROTENOID C4‐OXYGENATION

Many animals use carotenoid pigments to produce yellow, orange, and red coloration. In birds, at least 10 carotenoid compounds have been documented in red feathers; most of these are produced through metabolic modification of dietary precursor compounds. However, it is poorly understood how lineages have evolved the biochemical mechanisms for producing red coloration. We used high‐performance liquid chromatography to identify the carotenoid compounds present in feathers from 15 species across two clades of blackbirds (the meadowlarks and allies, and the caciques and oropendolas; Icteridae), and mapped their presence or absence on a phylogeny. We found that the red plumage found in meadowlarks includes different carotenoid compounds than the red plumage found in caciques, indicating that these gains of red color are convergent. In contrast, we found that red coloration in two closely related lineages of caciques evolved twice by what appear to be similar biochemical mechanisms. The C4‐oxygenation of dietary carotenoids was responsible for each observed transition from yellow to red plumage coloration, and has been commonly reported by other researchers. This suggests that the C4‐oxygenation pathway may be a readily evolvable means to gain red coloration using carotenoids.     

台湾海峡鱼类物种多样性研究回顾

台湾海峡位于中国福建和台湾岛之间, 其特殊的海洋环境使得其鱼类物种多样性水平较高并独具特色。本文综述了台湾海峡鱼类物种多样性研究的历程和成果。20世纪以来, 台湾海峡鱼类物种多样性的研究可以划分为早期研究时期、研究起步时期、系统调查时期和综合研究时期4个阶段, 从最初以新种描述为主的零星报道, 到大规模系统性的综合调查和研究; 目前为止, 大陆文献共记录台湾海峡鱼类1390种, 台湾地区文献共记录鱼类1525种, 总计台湾海峡鱼类1697种。这些种类多数为暖水性广布种, 鱼类区系以印度-西太平洋暖水区的印度-马来亚区和中-日亚区过渡海区种为主; 今后台湾海峡鱼类物种多样性的研究应加强两岸合作, 并充分发挥数据库应用的优势地位。     

A REVIEW OF MESOZOIC OSTEOGLOSSOMORPH FISH LYCOPTERA LONGICEPHALUS

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微囊藻毒素对鱼类毒性影响的研究进展

微囊藻毒素 (Microcystins,简称MC)是一些有毒蓝藻,如微囊藻、颤藻和鱼腥藻等,产生的一种具有肝毒性的环状七肽。       

POTENTIAL FOR MEASUREMENT OF LYSINE BIO AVAILABILITY IN POULTRY FEEDS BY RAPID MICROBIOLOGICAL ASSAYS — A REVIEW

Optimizing economic utilization of feed protein sources for poultry nutritional requiremens is difficult to achieve given the varied protein quality of the respective sources. Although there are several limiting amino acids in feeds that would benefit from development of rapid and more reliable bioavailability assays, lysine is of key importance since this amino acid is usually the first or second limiting amino acid in poultry feeds and is susceptible to processing treatments. However, to incorporate incoming sources in the most cost-effective manner, accurate and timely prediction of lysine bioavailability prior to use is desired to achieve a consistent nutritional value. Animal bioassays involving chicks are one of the standard accepted practices for evaluating protein quality and amino acid bioavailability, but such assays have several limitations. Alternative in vitro tests that accurately predict lysine bioavailability for feed proteins would solve many of the problems associated with currently used animal bioassays. The expected focus should be on the development of more rapid in vitro lysine bioavailability assays that could be easily used for evaluation of poultry feed protein sources.     

铜对鱼类慢性毒性研究进展

重金属铜既是生物体自身所必需的元素,也可造成污染。       

鱼类免疫组织和细胞的研究概况

近几十年来,随着世界人口的增长和消费水平的提高,世界渔业也得到了长足的发展。但与此同时,高密度养殖模式也引起水产动物病害的频繁发生,并造成一定的环境污染。作为主要水产养殖对象的鱼类,在其与病原和环境之间相互作用的过程中,主要是靠其免疫系统来抵御外来病原生物的侵害,通过非特异性和特异性的免疫防御机制来维持机体内环境的稳定。因此,对鱼类免疫系统的研究,不仅可以认识鱼体同病原间的作用方式,反映鱼类赖以生存的水环境的质量,还可用以研究脊椎动物免疫系统的进化规律。