九种蟋蟀mtDNA-16S rRNA基因序列及其系统进化(直翅目:蟋蟀科)

蟋蟀科5属9个种的线粒体16S rRNA基因部分序列被测定或从Gen Bank获得,比较其同源性,计算核苷酸使用频率,并构建NJ和MP分子系统树。在获得的449bp的序列中A、T、C和G碱基含量分别为31．8％、36．9％、9．9％和21．4％,A T平均含量为68．7％。研究结果表明：所研究的5属9种蟋蟀聚成3个聚类簇,斗蟋属先与灶蟋属汇合,再与棺头蟋属构成聚类簇Ⅰ;油葫芦属黑脸油葫芦和北京油葫芦与蟋蟀属的家蟋相聚构成聚类簇Ⅱ;蟋蟀属的田蟋单独构成聚类簇Ⅲ。     

诱导子对藏红花悬浮培养细胞生产藏红花色素的影响

考察壳聚糖（chitosan）、壳寡糖（chitosanoligosaccharides,COS）、茉莉酸甲酯（methyljasmonate,MJ）、水杨酸（salicylicacid,SA）和Cu2＋等诱导子对藏红花悬浮培养细胞生长和藏红花色素合成的影响。结果表明：在实验考察浓度范围内,壳寡糖（1～500mg／L）和较低浓度壳聚糖（≤10mrdL）、MJ（≤10μmol／L）、SA（≤10μμmol／L）和Cu2＋（≤1μmoL／L）对细胞生长无显著影响;较高浓度壳聚糖（≥100mg／L）、MJ（≥100μmol／L）、SA（≥100μmoL／L）和cu“（≥10μmoL／L）显著抑制细胞生长。5种诱导子对藏红花色素合成的诱导效果不同,并且与诱导子作用浓度和添加时间有关。MJ诱导效果最好,在细胞培养第0天添加终浓度100仙moL／LMJ,藏红花色素含量（以1克干细胞计）达到28．57mg,比对照提高177．9％。其次是cu“,在细胞培养第4天添加终浓度500μmoL／LCu2＋,色素含量达到19．82mg,比对照提高108．2％。再次是壳聚糖和壳寡糖,在细胞培养第14天分别添加终质量浓度100mg／L壳聚糖和壳寡糖,色素含量分别达到18．33和17．39mg,比对照提高69．1％和69．0％。最后是SA,在细胞培养第14天添加终浓度10μmoL／LSA,色素含量达到14．65mg,比对照提高45．4％。     

甲壳素/壳聚糖在酶固定化中的应用

作为功能性材料,甲壳素与壳聚糖分布广泛,且具有一系列独特的性质:无毒性、凝胶性、生物适应性、降解产物的无毒性、显著的蛋白质亲和性等。正是由于这些特性,虽然甲壳素/壳聚糖材料目前尚未得到充分的开发利用,但是与其它一些酶的固定化载体相比,具有广泛的开发前景。该文综述了近年来甲壳素/壳聚糖在酶的固定化方面的一些研究成果。主要包括:甲壳素/壳聚糖的理化性质、载体不同制备方法的特色和差异、在食品工业、非食品工业、环保、酶的分离纯化以及医疗应用方面的研究进展。     

半干法微波处理制备壳聚糖

本文报导了采用微波处理半干法由甲壳素脱乙酰制备壳聚糖。与传统方法相比,反应时间大大缩短,降低了生产成本。并讨论了影响壳聚糖脱乙酰度和粘度的因素,例如,反应时间,碱浓度,料比。在较适宜的条件下,7分钟内脱乙酰度可大于75％。     

从蝉壳制备壳聚糖

以蝉壳为原料制备甲壳素和壳聚糖,研究并提出了适合蝉壳的脱色条件,所得产物为白色片状,脱乙酰度大于９０％。     

基于mtDNA-COⅡ基因部分序列探讨蟋蟀科五属的进化关系（直翅目：蟋蟀科）

采用DNA测序技术并比较了蟋蟀科5个属：斗蟋属Velarifictorus、棺头蟋属Loxoblemmus、油葫芦属Teleogryllus、灶蟋属Gryllodes和蟋蟀属Gryllus以及蛉蟋科针蟋亚科Allonemobiussocius的mtDNA-COⅡ基因部分序列,依据分子数据建立了5个属的系统发育关系。结果显示A、T、C和G碱基含量分别为34．8％、35．3％、19．3％和10．6％,AT含量（70．1％）仅略高于半翅目锥猎蝽和缨尾目。分子系统树显示,油葫芦属黄脸油葫芦与蟋蟀属家蟋亲缘关系较近。显示油葫芦属与斗蟋属的亲缘关系较近。并且,棺头蟋属的多伊棺头蟋和窃棺头蟋先聚合,这与形态学特征的结果相符。     

微波辅助CDA酶法制备烹饪后龙虾壳聚糖及初步表征

本文主要研究开发烹饪后小龙虾壳聚糖的环保酶法制备方法。本研究采用超声辅助EDTA法提取烹饪后小龙虾壳甲壳素,所得甲壳素经乙醇浸泡和微波预处理后,采用CDA酶法制备壳聚糖;通过单因素试验选择最佳的微波功率、微波时间、加酶量、酶解温度、酶解时间,再利用正交试验优化酶法制备小龙虾壳聚糖的最佳工艺。结果表明:酶法制备壳聚糖的最佳条件为:80%乙醇浸泡甲壳素2 h,微波功率550 W,微波时间6 min,加酶量10%,酶解时间3 h,酶解温度45℃,在此条件下制备的壳聚糖脱乙酰度高达93.12%,黏度为96.8 m Pa·s,相对得率87.74%。该制备方法与传统碱法相比,具有无环境污染,产品性质稳定,高D.D的优势,为环境清洁型的小龙虾壳聚糖工业化生产打下基础,也顺应了未来经济发展趋势。     

生物法制备甲壳素/壳聚糖的研究进展

甲壳素是继纤维素之后又一天然生物高分子材料,因其具有重要的物理化学性质及优良的生物相容性、安全性、可生物降解性,使其在农业、医药、食品加工、环境保护及生物技术等领域有着重要的应用。由于其强烈的氢键作用,甲壳素很难溶解,这在很大程度上限制了其应用。甲壳素经脱N-乙酰基得到壳聚糖,由于乙酰基的减少,壳聚糖分子间作用力减弱,溶解性在一定程度上得到改善,同时,由于其存在大量游离的氨基,使其在药物缓释、促进伤口愈合等医药方面有着更重要的经济价值。阐述了甲壳素的传统化学制备方法 -酸碱法,该方法虽技术成熟,却仍存在能耗高、成本高、环境污染严重等诸多局限性和缺点;基于此,重点综述了绿色环保的酶法及微生物发酵法,讨论了酶法和微生物发酵方法各自的优缺点,同时归纳了甲壳素的重要衍生物-壳聚糖的生物制备方法,并分析讨论了在目前生物法制备甲壳素/壳聚糖从实验室研究到工业化过程中存在的限制性问题,进一步展望了甲壳素/壳聚糖生物制备方法的研发方向。     

壳聚糖装载猪胸腺肽微球给药

目的：以猪胸腺肽为芯材、壳聚糖为壁材,采用乳化交联结合单凝聚法制备猪胸腺肽壳聚糖口服微球。方法：以壁材浓度、交联剂含量、油水比值、芯材壁材比值为四因素设计正交实验,确定微球最佳制备条件,并对其体外释放及稳定性进行研究。结果：制备微球最优化条件为壳聚糖浓度1％、25％戊二醛含量7％、油水比值2：1、壳聚糖与胸腺肽比值1：1;微球在pH1．5的HC1溶液中2h释放30％,在pH6．8及7．4的PBS缓冲液中最终释放度约80％,并在24h达到释放终点;微球30rain突释率约为10％,1h释放率约为20％,其后缓慢而持续地释放;猪胸腺肽壳聚糖微球在0℃保存8个月时微球外观及形态没有差异,药物剩余率约为91．8％。结论：采用乳化交联结合单凝聚法制备的猪胸腺肽壳聚糖口服微球为缓释给药系统的临床应用奠定了理论基础,具有重要的实际应用价值和社会意义。     

壳聚糖辐照降解产物涂膜保鲜草莓研究

壳聚糖具有抑菌性与成膜性。将壳聚糖辐照降解得到的一系列不同粘均分子量产物进行涂膜草莓保鲜,研究涂膜液中壳聚糖粘均分子量、浓度、pH值、有机酸、明胶含量对草莓保鲜效果的影响;并设计四因素三水平正交试验。实验结果表明：1％（w／v）7．0×10^4Da壳聚糖、1％（v／v）醋酸、pH5、添加明胶0．5％的涂膜配方具有最好的保鲜效果;在常温（20℃、湿度80％～90％）下可以延长贮藏期2d;低温（3℃-4℃、湿度80％-90％）下可以延长贮藏期3d。     

NUTRITIONAL VALUE OF THE FIELD CRICKET (GRYLLUS TESTACEUS WALKER)

Abstract The chemical composition and the nutritional quality of protein, fatty acids and chitin of adult field cricket Gryllus testaceus Walker were investigated. The adult insect contained: crude protein 58.3 %; fat 10.3 %, chitin 8.7 % and ash 2.96 % on dry matter basis respectively. The essential amino acid profile compared well with FAO/WHO recommended pattern except for cysteine and methionine. The fatty acid analysis showed unsaturated acid of the field cricket to be present in high quantities, and the total percentage of oleic acid, linolic acid and linolenic acid was 77.51%. The chitin content of the insect was 8.7% with a better quality than the commercial chitin that was prepared from shells of shrimp and crab. Therefore the chemical composition of the field cricket indicates the insect to be a good supplement to nutrition for food and feed, even a raw material for medicine.     

Cuticular lipids of adults and puparia of the Australian sheep blowfly Lucilia cuprina (Wied.)

The presence of a strong contact component in the sex and ovipositing behavior of the sheep blowfly Lucilia cuprina Wied. prompted an investigation into the chemical composition of the cuticular wax of the adult male and female flies as well as that of the blowfly puparia. Thin-layer chromatography indicated that the lipids in all the waxes examined comprise hydrocarbons, nonglyceryl esters, triglycerides, free fatty acids, and hydroxy compounds, probably diglycerides and monoglycerides. Phospholipids were not detected. Straight-and branched-chain saturated compounds, the latter often pre-dominating, are present in the hydrocarbon, free fatty acid, and ester fractions. Unsaturated molecules were absent. The hydrocarbons resemble those of the cricket to some extent, but the absence of unsaturated compounds is in striking contrast to both the cricket and the cockroach. Pheromones may be present in the low molecular weight fatty acids obtained on brief extraction of the insects.     

Complete Nutrient Content of Four Species of Feeder Insects

A variety of insects are commonly fed to captive insectivores but detailed nutritional analyses are only available for the most commonly fed species. Soldier fly larvae, Turkestan cockroach nymphs, tebo worms, and adult house flies were analyzed for moisture, protein, fat, ash, acid detergent fiber, neutral detergent fiber, minerals, amino acids, fatty acids, vitamins, and selected carotenoids. The acid detergent fiber was analyzed for amino acids to estimate chitin content. Nutrient content varied widely between the four insect species. Ranges for the macronutrients were as follows: moisture (60.2–74.8%), crude protein (15.5–19.7%), crude fat (1.9%–29.4%), acid detergent fiber (1.4–3.0%), neutral detergent fiber (2.6–3.8%), and ash (0.8–3.5%). Energy content ranged from a low of 918 kcal/kg for house flies to 2,977 kcal/kg for tebo worms. The chitin content of these four species ranged from 6.7 to 21.0 mg/kg. The nutrients most likely to be deficient when these species of insects are used as food for insectivores are vitamin A, vitamin D, calcium, vitamin E, thiamine, iodine, and vitamin B₁₂. The number of nutrients deficient vs. the NRC requirements for rats on an energy basis by insect species was as follows: soldier fly larvae (3), tebo worms (15), Turkestan cockroach nymphs (5), and adult house flies (6). These data are valuable in helping assess the nutrient intake of captive insectivores and in developing gut‐loading diets to improve the nutrient intake of captive insectivores. Zoo Biol. 32:27‐36, 2013. © 2012 Wiley Periodicals, Inc.     

Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products

Insects receive increasing attention as an alternative protein-rich food source for humans. Producing edible insects on diets composed of organic by-products could increase sustainability. In addition, insect growth rate and body composition, and hence nutritional quality, can be altered by diet.Three edible mealworm species Tenebrio molitor L., Zophobas atratus Fab. and Alphitobius diaperinus Panzer were grown on diets composed of organic by-products originating from beer brewing, bread/cookie baking, potato processing and bioethanol production. Experimental diets differed with respect to protein and starch content. Larval growth and survival was monitored. Moreover, effects of dietary composition on feed conversion efficiency and mealworm crude protein and fatty acid profile were assessed. Diet affected mealworm development and feed conversion efficiency such that diets high in yeast-derived protein appear favourable, compared to diets used by commercial breeders, with respect to shortening larval development time, reducing mortality and increasing weight gain. Diet also affected the chemical composition of mealworms. Larval protein content was stable on diets that differed 2–3-fold in protein content, whereas dietary fat did have an effect on larval fat content and fatty acid profile. However, larval fatty acid profile did not necessarily follow the same trend as dietary fatty acid composition. Diets that allowed for fast larval growth and low mortality in this study led to a comparable or less favourable n6/n3 fatty acid ratio compared to control diets used by commercial breeders. In conclusion, the mealworm species used in this study can be grown successfully on diets composed of organic by-products. Diet composition did not influence larval protein content, but did alter larval fat composition to a certain extent.     

沙蟋飞行肌中保幼激素滴度的昼夜节律

沙蟋Gryllus firmus是一种翅多型性的昆虫, 是研究种内迁飞和生殖调控的模式生物。本研究应用高效液相色谱仪（HPLC）、 气相色谱-质谱联用仪(GC-MS)对沙蟋长翅（有飞行能力）和短翅（无飞行能力）雌虫飞行肌内保幼激素（juvenile hormone, JH）和脂肪酸进行了定性定量分析。结果表明： 在温度28℃, 光周期16L∶8D条件下, 第5和第7日龄的沙蟋长翅雌虫飞行肌中JH的滴度具有明显的昼夜节律, 在飞行前（即关灯前）4 h, JH的滴度分别由386.52±68.40 ng/g和630.36±37.26 ng/g增加至1 327.53±277.98 ng/g和1 685.77±143.95 ng/g, 与短翅型SW相比分别增加了约3.4倍与2.7倍 (P＜0.05)。而相同日龄的短翅雌虫及第1日龄的两型雌虫均无明显的节律变化。进一步在第5和7日龄的长翅雌虫中发现了一个16C的脂肪酸--14-甲基十五烷酸, 也具有节律变化且与JH节律出现的时间相吻合, 而在无飞行能力的沙蟋中没有发现这种现象。实验还证明JH滴度的增加和节律不是由飞行肌的重量或者飞行肌重量比的变化所致。这些发现有助于探讨和了解保幼激素对飞行调控的内在机理。     

Changes in the biochemical composition of fat body stores during adult development of female crickets, Gryllus bimaculatus

Age-dependent changes in the fat body composition and aspects of lipogenesis in the free abdominal fat body of female crickets, Gryllus bimaculatus, were studied. Lipid, protein, glycogen, and free carbohydrate content of the fat body, and fat body wet weight increased simultaneously and sharply from day 0 onwards and were doubled/almost doubled by day 2 after adult emergence. Lipogenic activity of the fat body, fat body weight, and the energy stores in the fat body peaked on day 2, except for free carbohydrate, which peaked on day 3. On day 2, the fat body was mainly comprised of lipid (53.8%) and protein (6.6%), while glycogen and free carbohydrate together contributed less than 1% of the fat body wet weight. After peaking, both lipogenesis and energy stores decreased in a synchronous manner. The depletion of the fat body energy stores and the consequent decrease in the fat body weight were concomitant with a fast and massive gain in ovary weight (day 2: 19.5 +/- 1.5 mg; day 4: 332.8 +/- 31.5 mg) due to the vitellogenic oocyte growth that started on day 2. Our data clearly underline the importance of the free abdominal fat body as a source of energy for reproduction in the cricket. Fat body fatty acid synthase activity coincided with lipogenic activity. Adipokinetic hormone inhibits lipid synthesis in the fat body, but treatment of the fat body with adipokinetic hormone in vitro showed no consistent effect on fatty acid synthase activity.     

Diet Composition and Lipids of In Vitro-Produced Heterorhabditis bacteriophora

Several entomopathogenic nematode species are currently under evaluation for mass production and field efficacy for biological control of insect pests. However, quality and quantity of in vitro-produced entomopathogenic nematodes vary considerably, depending on media, temperature, and production method. In addition, nematode production should be cost effective. We investigated nematode yield, production time, total lipid content, and fatty acid composition of Heterorhabditis bacteriophora produced in artificial media supplemented with different lipid sources. Lipid source significantly affected lipid quantity and quality in H. bacteriophora. Media supplemented with extractable insect lipids produced yields 1.9 times higher than did beef fat- or lard-supplemented media. Moreover, the developmental rate in media supplemented with host lipids was 1.7 times faster than that in media supplemented with beef fat or lard. Nematodes grown in media supplemented with insect lipids accumulated significantly higher lipid proportion per dry biomass than those grown in media supplemented with other lipid sources. H. bacteriophora produced in media supplemented with insect lipids, olive oil, or canola oil had similar fatty acid patterns, with oleic (18:1) acid as the major lipid fatty acid. Media supplemented with other lipid sources produced nematodes with fatty acid patterns different from those of media supplemented with insect lipids. We recommend addition of fatty acid mixtures that resemble natural host lipids for mass-producing entomopathogenic nematodes. This could provide nematode quality similar to in vivo-produced nematodes and could improve yield.     

Estimate of chitin in raw whole insects

Insects contain significant amounts of fiber as measured by crude fiber, acid detergent fiber (ADF) or neutral detergent fiber (NDF). It has always been assumed that the fiber in insects represents chitin based on the structural similarity between cellulose and chitin and the fact that the ADF fraction from insects contains nitrogen. In this study, a number of insect species that are raised commercially as food for insectivores were analyzed for moisture, crude protein (nitrogen × 6.25), fat, ash, NDF, ADF, and amino acids. Additionally, the ADF fraction was analyzed for nitrogen and amino acids to determine if proteins might be present in the ADF fraction. The ADF fraction contained a significant amount of amino acids accounting for 9.3–32.7% of the ADF (by weight). The presence of amino acids in the ADF fraction means that using ADF to estimate insect chitin results in an overestimation of insect chitin content. Using ADF adjusted for its amino acid content, the estimated chitin content of these insect species ranged from 2.7–49.8 mg/kg (as is) and 11.6–137.2 mg/kg (dry matter basis). Additionally, these data suggest that for the species measured here the amount of chitin nitrogen is quite small (as a % of total nitrogen) and that crude protein (nitrogen × 6.25) provides a reasonable estimate of the true protein for most species of insects. Zoo Biol 0:1–11, 2007. © 2007 Wiley‐Liss, Inc.     

Calcofluor disrupts the midgut defense system in insects

The insect midgut is generally lined with a unique protective chitin/protein structure, the peritrophic membrane (PM). We demonstrated that in Trichoplusia ni larvae, the majority of PM proteins were assembled with chitin as a consequence of their chitin binding properties. These proteins could be dissociated from the PM in vitro by Calcofluor, a well-known chemical with chitin binding properties. The chitin binding characteristics of PM proteins were confirmed by their high affinity binding in vitro to regenerated chitin. In vivo assays demonstrated that Calcofluor could inhibit PM formation in five lepidopteran insects tested. The inhibition of T. ni PM formation by Calcofluor, was accompanied by increased larval susceptibility to baculovirus infection. Continuous inhibition of PM formation by Calcofluor resulted in retarded larval development and mortality. The destructive effect of Calcofluor on PM formation was demonstrated to be transient and reversible depending on the presence of Calcofluor within the midgut. In addition, degradation of the insect intestinal mucin was observed concurrently with the inhibition of PM formation by Calcofluor. Our studies revealed a potential novel approach to develop strategies for insect control by utilizing chitin binding molecules to specifically target PM formation in a broad range of insect pest species.