Degradation of African locust bean oil by Bacillus subtilis and Bacillus pumilus isolated from soumbala,a fermented African locust bean condiment

AIMS: To investigate predominant isolates of Bacillus subtilis and B. pumilus in soumbala, a fermented African locust bean condiment, for their ability to degrade African locust bean oil (ALBO). METHODS AND RESULTS: Agar diffusion test in tributyrin and ALBO agar was used for screening of the isolates for esterase and lipase activity, respectively. The quantity and the profile of free fatty acids (FFA) during 72 h of degradation of ALBO by the Bacillus isolates were studied by titration and gas chromatography. The degradation of tributyrin and ALBO was variable among the isolates. Two strains of B. subtilis and two strains of B. pumilus showed significantly higher esterase and lipolytic activities than the others. The degradation ALBO was most pronounced in enriched nutrient agar except for one isolate of B. pumilus degrading ALBO to the same extent regardless of the enrichment. The quantity of FFA released from ALBO by the most lipolytic strains of Bacillus increased mainly between 0 and 24 h and differed among the isolates. The profile of FFA was similar for the Bacillus isolates with oleic acid (C18:2) occurring as the major FFA in all the samples except in samples incubated with B. subtilis B9 where stearic acid (C18) was dominant. CONCLUSION: Bacillus isolates from soumbala showed high strain dependent lipolytic activity against ALBO. SIGNIFICANCE AND IMPACT OF THE STUDY: This study contributes to the selection of Bacillus strains to be used as starter cultures for controlled production of soumbala.     

西伯利亚蝗辣病毒超微结构和发育及DNA特性

为寻找新的生物治蝗措施 ,采用显微镜和生化方法 ,对 1992年从新疆木垒县西伯利亚蝗上分离的一株痘病毒 (Gomphocerussibiricusentomopoxvirus,GsEPV)的超微结构、发育循环和DNA特性进行了研究 ,结果表明 :该病毒的包含体为球形 ,最大直径约 6 90 μm ,最小直径约 3 95 μm ,平均为 5 33μm。脂肪体超薄切片中的病毒粒子呈椭圆形 ,大小为 2 6 7nm× 10 3nm。病毒粒子髓核折叠成 2～ 3折 ,其横切面呈圆形 ,中间有 3～ 4个电子非致密的圆点。GsEPV主要感染寄主脂肪体。接种后 15～ 2 0天包含体大量形成 ,此时已没有游离病毒粒子存在 ,发育同步 ,并且比其它痘病毒发育周期短。GsEPV -DNA经三种限制性内切酶 HindⅢ、BglⅡ和 EcoRⅠ酶解后分别得到2 0、17和 2 9条片段 ,其分子量分别为 15 5 37× 10 6D ,15 6 45× 10 6D和 15 6 79× 10 6D ,平均为 15 5 37× 10 6D。与已报道的蝗虫痘病毒进行比较 ,这些痘病毒可分为二种类型 :一种包含体为圆形的 ;另一种为椭圆形。形态相似的包含体病毒髓核结构相似 ,分子量也在一个范围内 ,具有椭圆形包含体的痘病毒如OaEPV、CiEPV、MsEPV、AcEPV和PnEPV ,其病毒粒子中DNA链折叠较少 (1～ 2折 ) ,分子量也较小 ,通常在 12 5× 10 6D范围 ;而具有圆形包含体的痘病毒     

杨树刺槐混交林及纯林枯落叶分解

研究了杨树（Ｐｏｐｕｌｕｓｓｐｐ．）、刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ）纯林及混交林枯落叶一年中的分解及养分动态变化规律．结果表明,杨树枯落叶分解速度较慢,刺槐较快,而混交林则较杨树有较大提高．在分解过程中,杨树枯落叶Ｎ、Ｐ释放困难,需经过长达１０个月的养分富积过程;刺槐枯落叶Ｎ、Ｐ元素释放较为容易;混交林枯落叶养分富积时间缩短、幅度下降,分解速度加快,说明杨树和刺槐混交有利于枯落叶分解和Ｎ、Ｐ循环．     

刺槐上分离的花生矮化病毒的研究

刺槐花叶病是我国北方刺槐（Ｒｏｂｉｎｉａｐｓｅｕｄｏａｃａｃｉａ）常见病害。１９８７～１９９５年对河南、河北、山东和北京部分地区刺槐进行调查,刺槐花叶病发病率为４％～８７．５％。该病害主要特征是：叶片出现浅绿与绿色相间带有疱疹的花叶症状,叶缘波状扭...     

Non-target grasshoppers as indicators of the side-effects of chemical locust control in the Karoo, South Africa

In most locust or grasshopper control programmes, the proximate aim is to suppress grasshopper numbers. However, in the semi-arid Karoo, South Africa, only the brown locust (Locustana pardalina) has significant pest status. Non-target grasshoppers form a conspicuous and important part of the Karoo ecosystem, many being endemic. Grasshopper diversity was monitored in treated and untreated plots (0.25 ha) to establish the impact of spraying. Grasshopper abundance was significantly reduced one day after treatment. Vagile species recovered by immigration from the surrounding areas following the breakdown of chemical residues. Endemic apterous bushhoppers with low vagility recovered the following season after rainfall triggered hatching. Grasshopper numbers hatching in treated plots were significantly lower than in untreated plots the following summer season because of a reduction in the number of individuals in the preceding generation. However, species composition was similar to untreated plots and this reduction is unlikely to have significant, long-term biological effects in such small treated areas (0.25 ha being usual for hopper band control). The rate of recovery of grasshoppers, particularly bushhoppers, was linked to rainfall indicating that the timing of control relative to rainfall is important. Grasshopper assemblages are potentially useful indicators of the effect of chemical locust control in the Karoo.     

Effects of the venom of the solitary wasp Philanthus triangulum F. on glutamate uptake in the nerve endings of locust muscles—A high resolution autoradiographic study

Using electron microscope autoradiography it was shown that the glutamate uptake in both glia cells and axon in the synaptic region of locust muscles was reduced to ca. 50% under the influence of the venom of the solitary wasp Philanthus triangulum F. However, the ratio of the glutamate accumulation in the glia and the nerves remained identical. Implications are discussed in relation to known postsynaptic effects of the venom of Philanthus triangulum F.     

The locust foraging gene

Our knowledge of how genes act on the nervous system in response to the environment to generate behavioral plasticity is limited. A number of recent advancements in this area concern food‐related behaviors and a specific gene family called foraging (for), which encodes a cGMP‐dependent protein kinase (PKG). The desert locust (Schistocerca gregaria) is notorious for its destructive feeding and long‐term migratory behavior. Locust phase polyphenism is an extreme example of environmentally induced behavioral plasticity. In response to changes in population density, locusts dramatically alter their behavior, from solitary and relatively sedentary behavior to active aggregation and swarming. Very little is known about the molecular and genetic basis of this striking behavioral phenomenon. Here we initiated studies into the locust for gene by identifying, cloning, and studying expression of the gene in the locust brain. We determined the phylogenetic relationships between the locust PKG and other known PKG proteins in insects. FOR expression was found to be confined to neurons of the anterior midline of the brain, the pars intercerebralis. Our results suggest that differences in PKG enzyme activity are correlated to well‐established phase‐related behavioral differences. These results lay the groundwork for functional studies of the locust for gene and its possible relations to locust phase polyphenism. © 2010 Wiley Periodicals, Inc.     

The glycosaminoglycans of the thoracic ganglia of the nymphal stages of the cockroach, Periplaneta americana, and the locust, Locusta migratoria: A histochemical study

The glycosaminoglycans of the connective tissue matrices of the developing meso- and metathoracic ganglia of locusts and cockroach nymphs have been characterized. The neural lamella contains only chondroitin sulphate in the early nymphs, but gradually keratan sulphate accumulates in the later nymphs. The glial lacunar system cannot be detected histochemically in first instar locust nymphs, but it can be seen in the youngest cockroach nymphs; it is clearly visible in the older nymphs of both species. It contains only hyaluronate.A stereological analysis of the developing meso- and meta-thoracic ganglia of the cockroach shows that the relative volumes occupied by the neurones, neuropile, glial cells and glial lacunar system change during post-embryonic development.The physiological functions of the glycosaminoglycans in the neural lamella and glial system are discussed.     

新疆典型蝗虫适生区分布预测

新疆草原面积广阔,农牧业地位突出,蝗灾对当地经济、生态威胁很大,近年新疆极端天气日渐频发,蝗灾监测与防治任务艰巨。以意大利蝗、西伯利亚蝗和亚洲飞蝗为代表的蝗虫数据为基础,综合考虑对蝗虫各生命周期有重要影响的环境因素,运用BIOCLIM模型、领域模型（DOMAIN）、马氏距离模型（MAHAL）、广义线性模型（GLM）、随机森林模型（RF）、提升回归树模型（BRT）、支持向量机模型（SVM）、最大熵模型（MaxEnt）等八种经典物种分布模型及集成模型对新疆典型蝗虫适生区展开了预测。结果表明：（1）不同模型对新疆典型蝗虫适生区预测存在差异,其中DOMAIN最差（曲线下面积（AUC）=0.688,真实技巧统计（TSS）=0.301）,而提升回归树（BRT）最佳（AUC=0.920,TSS=0.910）,基于BRT、SVM和MaxEnt 3个集成模型预测的新疆蝗虫适生区可靠性更高;（2）新疆典型蝗虫不同等级适生区面积约56.844万km²,占新疆总面积的36%,其中高适生区面积16.568万km²;（3）新疆典型蝗虫适生区主要集中于北疆阿勒泰、塔城地区,此外东部哈密地区及南疆绿洲边缘地带亦有分布。研究可为新疆草原工作部门推进蝗虫监测防治工作提供支持。     

The circadian clock genes affect reproductive capacity in the desert locust Schistocerca gregaria

The circadian clocks govern many metabolic and behavioral processes in an organism. In insects, these clocks and their molecular machinery have been found to influence reproduction in many different ways. Reproductive behavior including courtship, copulation and egg deposition, is under strong influence of the daily rhythm. At the molecular level, the individual clock components also have their role in normal progress of oogenesis and spermatogenesis. In this study on the desert locust Schistocerca gregaria, three circadian clock genes were identified and their expression profiles were determined. High expression was predominantly found in reproductive tissues. Similar daily expression profiles were found for period (per) and timeless (tim), while the clock (clk) mRNA level is higher 12 h before the first per and tim peak. A knockdown of either per or tim resulted in a significant decrease in the progeny produced by dsRNA treated females confirming the role of clock genes in reproduction and providing evidence that both PER and TIM are needed in the ovaries for egg development. Since the knockdown of clk is lethal for the desert locust, its function remains yet to be elucidated.