Extraction of chitin and chitosan from larval exuvium and whole body of edible mealworm,Tenebrio molitor

The purpose of this study was to investigate the production of chitin and chitosan from both the exuvium and whole body of mealworm (Tenebrio molitor) larvae. Chitin from the exuvium and whole body of T. molitor larvae was chemically extracted with acid and alkali solutions to achieve demineralization (DM) and deproteinization (DP), respectively. The average DM (%) and DP (%) on a dry weight (DW) basis was 32.56 and 73.16% from larval exuvium, and 41.68 and 91.53% from whole body, respectively. To obtain chitosan, chitin particles from the exuvium and whole body of T. molitor larva were heated at various temperatures in different concentrations of NaOH. Average chitin yields were 18.01% and 4.92% of DW from the exuvium and whole body, respectively. The relative average yield of chitosan from whole body was 3.65% of DW. On average, over 90% of chitosan derived from whole body was deacetylated. The viscosity of chitosan from whole body was ranged from 48.0 cP to 54.0 cP. The chitin content of dry and wet byproducts from whole body were 17.32% and 16.94% respectively, compared to dry weight. The chitosan contents of byproducts on a DW basis were 14.48% in dry and 13.07% in wet byproduct. These results indicate that the exuvium and whole body of T. molitor larva may serve as a source of chitin and chitosan for use in domestic animal feed.     

黄粉虫幼虫小分子量抗茵肽的分离纯化

昆虫抗菌肽具有良好的抑菌效果,有望开发成新一代抗生素。本文以金黄色葡萄球菌和大肠杆菌混合液作为诱导源,采用针刺法使黄粉虫TenebriomolitorL．幼虫感染微生物产生抗菌肽,并对抗菌肽进行了提取、色谱分离纯化及抑菌活性检测。结果显示,诱导组和对照组的三氟乙酸粗提物无抑菌活性;经SephadexG50、SuperdexPeptide凝胶色谱分离后,从诱导组和对照组均可获得对革兰氏阳性菌金黄色葡萄球菌、枯草芽孢杆菌有抑菌作用的组分,而且诱导组活性明显高于对照组;通过Resource15RPC反相色谱分离纯化,从诱导组获得一具有明显抑制革兰氏阳性菌的组分,质谱检测该组分为混合肽,主要由分子量为1876．21u、1904．21u的小肽组成,可能是一种比Thanatin分子量更低的昆虫抗菌肽。     

黄粉虫幼虫体壁硬化过程中酚氧化酶活性的变化

为研究酚氧化酶(PO)在昆虫蜕皮过程中的功能和作用, 采用微量测定法研究了黄粉虫Tenebrio molitor体壁硬化过程中血淋巴和表皮中的PO活性变化。结果表明：初蜕皮幼虫血淋巴中PO活性较高, 但随着体壁的不断黑化与硬化, 其活性呈现下降趋势, 在3～4 h内达到最低点, 而后PO活性逐渐上升, 7 h左右活性上升至最高, 并接近于正常幼虫的水平;在刚蜕完皮后的1 h内, 体壁中 PO活性基本无变化, 但随后即开始下降, 3 h左右降到最低点, 然后开始回升, 6~7 h左右恢复到正常水平, 并趋于稳定;以L-DOPA为底物, 通过双倒数曲线作图法求得黄粉虫血淋巴PO的Km＝1.176 mmol/L, 体壁PO的Km＝0.881 mmol/L, 表明体壁PO与底物L-DOPA的亲和力要高于血淋巴PO。研究表明两种来源的酚氧化酶均参与了黄粉虫幼虫的体壁硬化过程, 但在作用方式及与底物的亲和力方面存在差异。     

黄粉甲幼虫抗菌物质的诱导及其抗菌活性

采用饥饿法、紫外线照射法和针刺法处理黄粉甲Tenebriomolitor 6龄幼虫后均能诱导其 产生抗菌物质,收集的血淋巴上清液对真菌有抑制作用,对细菌无抑制作用;经热处理后的血 淋巴上清液则对细菌有抑制作用,而对真菌无抑制作用。SDS-PAGE检测结果发现,与未诱导的 对照相比经诱导的黄粉甲幼虫血淋巴中,原有的一类大分子蛋白质如分子量分别为97kD、44 kD和37 kD左右的蛋白质缺失;而ESI-MS分析结果显示诱导后比诱导前黄粉甲幼虫血淋巴中有 小分子物质产生,推测可能是此类缺失蛋白质分解为小分子量的抗菌肽,从而表现出抗菌活性 。     

黄粉虫幼虫营养成分分析和保健功能的实验研究

对黄粉虫幼虫干粉的营养成分分析显示,其蛋白质和氨基酸含量分别占干重的５９．７０％和５９．５９％;不饱和脂肪酸占总脂肪酸含量的７７．０５％,其中仅亚油酸就占总脂肪酸含量的４１．７０％。有饰物 含量均低于国家标准。有机硒含量高达３４μｇ／１００ｇ。维生素Ａ和Ｅ含量分别为３３７和８９８μｇ／１００ｇ。实验表明,干粉液无毒性。具有较好的抗疲劳,延缓衰老和降低血清胆固醇的功能,并能提高小鼠外周淋巴细胞转化率     

饲养密度对黄粉虫幼虫生长发育的影响

黄粉虫原是一种仓库害虫 ,由于其幼虫、蛹、成虫都含有丰富的蛋白质和多种氨基酸 ,已被作为饲用资源昆虫来开发利用。作为一种群集性的昆虫 ,黄粉虫幼虫的生长受密度影响可分为 2个阶段 ,一是幼虫孵化后 1个月这段时间内 ,高密度处理的幼虫平均体重大于低密度处理的幼虫平均体重 ;二是孵化 1个月后直到化蛹 ,这段时间低密度的幼虫生长要比高密度的幼虫快得多。密度越大 ,历期越长。但密度对化蛹率没有影响。在幼虫生长过程中 ,各处理组中只有 3 2 0头虫密度处理组的幼虫在生长 1个月后显出拥挤效应。     

发酵牛粪对黄粉虫幼虫生长发育的影响

为寻找大型养殖场牛粪资源化与产业化利用途径,本文探讨了杂食性黄粉虫转化与利用牛粪的可行性.将牛粪和黄粉虫常规饲料(65％麦麸、30％玉米面、5％豆粕)按梯度比例混合后,用有益微生物菌群(EM)发酵,筛选出FD1、FD2(牛粪含量分别为60％、80％)两组发酵饲料作为处理,以常规饲料为对照(CK)进行黄粉虫幼虫饲养试验,研究不同发酵料对黄粉虫幼虫生长曲线、死亡率、化蛹率、抗氧化系统等的影响,评价黄粉虫幼虫对发酵牛粪饲料的适应性.结果表明:与CK相比,虽然FD1处理黄粉虫幼虫生长周期延长了20 d,死亡率有所上升,但黄粉虫幼虫单体取食总量增加49％ (P＜0.01),末龄幼虫单体质量增加28％(P＜0.01),粗脂肪含量提高26％(P＜0.05),不饱和与饱和脂肪酸含量的比值比CK高32％(P＜0.05),抗氧化酶活性显著增强,对发酵饲料表现出良好的适应性;而FD2处理各项指标均比CK差,表现出较低的适应性.表明在FD1处理条件下,可利用黄粉虫3龄幼虫对牛粪进行资源化利用,具有较好的应用前景.     

温度对黄粉虫幼虫生长发育及体液免疫防御能力的影响

【目的】探究饲养温度对黄粉虫Tenebrio molitor幼虫生长发育和体液免疫防御的影响。【方法】测定了不同温度（18, 22, 26和30℃）下饲养的黄粉虫幼虫的发育历期、蛹重、化蛹率;采用抑制区分析法测定了不同温度下饲养的免疫（用生理盐水将大肠杆菌Escherichia coli配制成1×104个菌体/μL悬浮液,用微量注射器将其注入虫体腹部的背面,每头幼虫注射1 μL）和非免疫(注射生理盐水)黄粉虫幼虫血淋巴的抑菌和溶菌酶活性,通过分光光度法测定了其酚氧化酶活性。【结果】结果显示,黄粉虫幼虫发育历期随饲养温度的上升而明显缩短（P<0.0001）,而不同温度下蛹重（P=0.067）与化蛹率（P=0.869）差异不显著。免疫组黄粉虫幼虫血淋巴的抑菌、酚氧化酶和溶菌酶活性随饲养温度上升而降低：抑菌和酚氧化酶活性随温度变化差异极显著（P<0.0001）,溶菌酶活性差异显著（P=0.013）。【结论】本研究结果表明,温度对黄粉虫的生长发育和免疫防御具有较大的影响,低温下黄粉虫幼虫的发育历期延长,但其体液免疫防御能力明显增强。     

基于啮食泡沫塑料黄粉虫肠道菌群中聚苯乙烯生物降解的探究

【背景】石油基塑料垃圾污染具有高度的化学惰性而不易分解,严重威胁着生态和海洋环境,筛选其高效降解菌并利用生物法治理塑料污染具有重要意义。【目的】聚苯乙烯是其中一种不能降解且用途广泛的塑料。近期有研究报道黄粉虫幼虫可啮食聚苯乙烯泡沫塑料。本文以啮食聚苯乙烯白色泡沫塑料的黄粉虫幼虫为研究材料,以期从肠道菌群中分离聚苯乙烯降解菌。【方法】分别以聚苯乙烯泡沫塑料与麦麸(对照组)为唯一食物来源饲喂黄粉虫幼虫,经过60 d的驯化,采用多种培养基对幼虫肠道提取液及虫体粪便排泄物进行分离、培养;通过形态学特征观察、扫描电镜与16S rRNA基因、ITS序列分析扩增、测定,根据序列信息构建系统进化树确定菌株的分类地位;将真菌菌种分别接种于加有PS膜片与颗粒的液体培养基中振荡培养,对膜片的力学性能变化进行测定,并对聚苯乙烯颗粒失重率进行计算。【结果】从幼虫粪便中分离的2株好氧菌分别被鉴定为Bacillus anthracis Ames PSI-1和Enterobacter cloacae PSI-2,从肠道中分离的真菌被鉴定为Aspergillus niger KHJ-1;电镜检测PS膜片表面出现大量孔洞,并且膜片疏水性减弱而亲水性增强,膜片的断裂伸长率与拉伸强度等力学性能也显著下降;真菌KHJ-1对PS颗粒的60 d降解测定中,发现PS颗粒由5 g原始重量减少了214.8 mg,失重率为4.29%。【结论】黄粉虫肠道中存在可以降解聚苯乙烯塑料的菌株,具有开发为新型降解聚苯乙烯高分子塑料的潜力。     

Effects of fumonisin B1 on growth and metabolism of larvae of the yellow mealworm, Tenebrio molitor

The chronic and acute toxicity of fumonisin B₁ (FB₁), a mycotoxin from Fusarium moniliforme, to the larvae of the yellow mealworm, Tenebrio molitor, was assessed. The toxin was administered via the diet or injected directly into the larvae. Young T. molitor larvae fed on a diet containing 450 µg FB₁ per g diet exhibited reduced growth performance but only after consuming the fumonisin-contaminated diet for several weeks. FB₁-contaminated diet also reduced the rate of carbon dioxide production, food consumption and protein metabolism. The concentrations of FB₁ in the diet did not increase mortality, even when tested at the highest dose of 450 µg FB₁ per g of diet. Injection of 25 ng FB₁ per larva decreased the CO₂ production, but became significant only 11 days after the injection and was reversible with time. A parallel analysis of the retention of FB₁ by the larvae indicated that about 40% of the ingested FB₁ was excreted in the faeces.     

Dietary inclusion of mealworm (Tenebrio molitor) meal as an alternative protein source in practical diets for juvenile rockfish (Sebastes schlegeli)

An 8‐week feeding trial was designed to evaluate the potential of yellow mealworm (Tenebrio molitor) as a locally available nutrient‐rich feedstuff for juvenile rockfish (Sebastes schlegeli). Experimental diets containing elevated levels of mealworm meal (WM) supplemented with synthetic methionine were formulated to be isonitrogenous, isolipidic and isoenergetic to a WM‐free fishmeal (FM) based control diet (designated as WM0, WM8, WM16, WM24 and WM32, respectively). To determine the necessity of dietary methionine supplementation at the highest inclusion of WM, a diet was prepared to contain 32% WM without methionine supplementation (WM32‐AA). Triplicate groups of rockfish juveniles (Mean ± S.E.; 3.11 ± 0.01 g) were fed one of the experimental diets to apparent satiation twice daily for 8 weeks. Fish growth performance in terms of weight gain and specific growth rate increased with increasing dietary inclusion of WM from 0 to 16% and then tended to decrease with further increase in dietary WM levels to 32%. Protein retention (PR) values followed the same trend as growth rates with the highest values found in fish offered WM16 diet. Although fish fed WM32‐AA diet showed significantly lower growth rate and PR values compared to those fed WM16 diet, their performance was still comparable to that of the WM‐free control group. Plasma triglyceride level was negatively affected by dietary WM inclusion and the lowest values were observed in the WM32‐AA group. Whole‐body and fillet proximate and essential amino acid compositions were not altered by dietary treatment and these values were comparable to those of the WM0 group. These findings suggested that WM might prove to be a promising alternative to FM in practical diets for juvenile rockfish and could be used at an inclusion level of up to 32% without having any adverse consequences for the health and performance of the fish. Although the diet containing 32% WM seemed to support a performance similar to that of the control diet, the recommended dietary inclusion level was no more than 16% of the diet dry matter.     

基于转录组数据高通量发掘黄粉甲微卫星引物（英文）

黄粉虫Tenebrio molitor作为理想的模式研究生物, 虽然已围绕该昆虫在多个研究领域开展了诸多研究, 但是有关其分子和遗传方面的研究仍知之甚少。为此, 本研究基于前期构建的黄粉甲转录组数据库, 成功发掘获得1 249个微卫星序列。其中, 单碱基或三碱基序重复列最多, 分别占44.44%和41.15%; A/T型重复序列出现频率最高, 占42.70%。除单核苷酸重复序列外, 重复单元的重复次数以5次最多, 占30.90%。基于鉴定获得的微卫星序列, 共设计获得1 004对微卫星引物, 而且每对引物还设计了5对替代引物。研究获得的微卫星引物将有助于今后开展黄粉甲功能和比较基因组学方面的研究。     

黄粉虫防卫物质苯醌的测定及其去除

采用分光光度法测定了黄粉虫的防卫毒素苯醌的含量。结果表明 :各虫态各性别的黄粉虫在不同发育阶段其苯醌含量均有不同 ,各虫态的苯醌含量随日龄而增大 ,雌蛹和雌成虫的苯醌含量均高于同一日龄的雄蛹和雄成虫。经刺激后各虫态的苯醌含量升高 2 0 72 %～ 41 64%,刺激后用水清洗的虫体其体内苯醌含量下降 88 2 7%～ 92 60 %;烘烤也可使苯醌大量挥发和分解 ,采用刺激 -水洗 -研磨 -烘烤工艺处理幼虫可清除 94 3 0 %苯醌 ,此法可为保障黄粉虫作为饲用昆虫的安全性提供依据     

槲皮素对黄粉虫血淋巴酚氧化酶的生理效应

用酶标仪法测定了槲皮素对黄粉虫Tenebrio molitor酚氧化酶（phenoloxidase, PO）的生物活性。结果表明：在离体条件下,对黄粉虫血淋巴PO的IC₅₀为0.625 mmol/L。在活体情况下,当槲皮素-DMSO溶液或槲皮素水悬浮液（5 μL）注入虫体后,在浓度低于1.0 mmol/L时对黄粉虫血淋巴PO具有激活作用,当浓度高于2.0 mmol/L时则对PO具有明显的抑制作用;单独注射5 μL DMSO溶液对PO活性亦有一定的激活作用。试虫被注射槲皮素后,PO活性在2～4 h内迅速下降,然后缓慢上升,处理8 h左右达到最高点,其后低浓度处理PO活性保持不变,而高浓度处理则逐渐下降,提示低浓度槲皮素可以引起试虫的免疫反应。在PO测活体系中加入0.5％的BSA后对PO活性无影响,并能使槲皮素在测活体系中保持稳定。     

黄粉虫有效物质的综合提取及提取方法的比较

比较了用石油醚和用环己烷抽提黄粉虫TenebriomolitorL .虫粉中脂肪的提取率 ,以及用碱法和用酶法提取去脂虫渣中蛋白质的提取率。并从 2种去脂、去蛋白质虫渣中和虫蜕中提取壳聚糖。用环己烷和酶法提取为最佳组合 ,可综合提取出占幼虫干重 5 0 .5 %的有效物质。同时 ,讨论了碱法和酶法提取率出现差异的原因。     

Effect of pretreatment with paste and sauce extract made using Tenebrio molitor larvae on ethanol‐damaged HepG2 cells

In this study, we made koji using protein‐rich Tenebrio molitor larvae (TML) inoculated with Aspergillus oryzae, and then used the koji to prepare a paste and a sauce. The TML koji showed the highest amino nitrogen, protease activity, and free amino acids content when it was fermented for 72 h after inoculation with 0.8% A. oryzae. The koji was aged in 20% saltwater for 50 days, and then the paste and sauce were separated. To evaluate the effect of TML paste and sauce on ethanol (EtOH)‐damaged hepatocytes, aspartate aminotransferase (AST) and alanine aminotransaminase (ALT) were measured in EtOH‐treated HepG2 cells after pretreatment with TML paste and sauce extract. As a result, we confirmed that TML paste and sauce extracts lowered the AST and ALT content in the medium, compared to soybean sauce and paste extracts. TML paste and sauce extract significantly reduced the expression of tumor necrosis factor (TNF)‐α and interleukin (IL)‐6, a biomarker of inflammation, and significantly increased the activity of the antioxidants superoxide dismutase (SOD) and reduced glutathione (GSH) in proportion to the amount of TML added to the paste and sauce. These results suggest that the intake of TML paste and sauce, a new type of fermented food made from insects, may provide effective protection to the liver against hepatocyte injury by EtOH via anti‐inflammatory and antioxidative effects.     

Periodic muscular activity and its possible functions in pupae of Tenebrio molitor

Abstract. During pupal development, Tenebrio molitor L. show regular periods of rhythmic muscular contractions and associated body movements. These periods of activity last 2.5-5.8 min and are more frequent in newly ecdysed pupae ( c. 3h^-1). They become less frequent ( c. 1.5 h^-1) when the basal metabolism reaches its lowest level. In the pharate adult stage the clear pattern of muscular activity disappears.
Muscular activity is temperature-dependent and is commonly absent below 20C. Muscular activity did not disturb the cyclic output of CO₂, which is characteristic of metamorphosis. The heart shows characteristic periods (1–3 min) of activity during pupal development. The frequency of these heart pulsation periods depends on metabolic rate. Heart pumping was correlated mostly with muscular contractions. Therefore we suggest that the main physiological function of muscular activity is to support circulation.     

我国黄粉虫的营养价值和饲养方法

对我国黄粉虫Tenebriomolitor (L .)的人工饲养、营养价值现状以及当前开发利用研究的热点问题等方面进行了较全面的概括 ,并针对今后的研究工作和规模化生产提出了一些建议。