Naturally Occurring Ecdysteroids in Triticum aestivum L. and Evaluation of Fenarimol as a Potential Inhibitor of Their Biosynthesis in Plants

Ecdysteroids (ECs) are steroid hormones originally found in the animal kingdom where they function as insect molting hormones. Interestingly, a relatively high number of these substances can also be formed in plant cells. Moreover, ECs have certain regulatory effects on plant physiology, but their role in plants still requires further study. One of the main aims of the present study was to verify a hypothesis that fenarimol, an inhibitor of the biosynthesis of ECs in the animal kingdom, also affects the content of endogenous ECs in plants using winter wheat Triticum aestivum L. as a model plant. The levels of endogenous ECs in winter wheat, including the estimation of their changes during a course of different temperature treatments, have been determined using a sensitive analytical method based on UHPLC-MS/MS. Under our experimental conditions, four substances of EC character were detected in the tissue of interest in amounts ranging from less than 1 to over 200 pg·g⁻¹ FW: 20-hydroxyecdysone, polypodine B, turkesterone, and isovitexirone. Among them, turkesterone was observed to be the most abundant EC and accumulated mainly in the crowns and leaves of wheat. Importantly, the level of ECs was observed to be dependent on the age of the plants, as well as on growth conditions (especially temperature). Fenarimol, an inhibitor of a cytochrome P450 monooxygenase, was shown to significantly decrease the level of naturally occurring ECs in experimental plants, which may indicate its potential use in studies related to the biosynthesis and physiological function of these substances in plants.     

AFB反应器处理啤酒废水中活性污泥的培养与驯化

对活性污泥的培养与驯化条件进行了研究。试验表明,采用一次培养法接种,接种量为30％(V)(反应器容积比)的活性污泥和100mL活性炭,将温度控制在37±2℃,进水的pH控制在7．3～8．0,进水流速控制在使活性炭处于流化状态,不需额外添加营养物质,可在25～30天左右成功地完成驯化。在此控制务件下培养出的活性污泥,对废水COD的去除率可达到85％左右,对减轻生物反应器后续处理单元的负荷具有重要意义。     

厌氧流化床反应器处理啤酒废水中活性污泥的培养与驯化

活性污泥的培养与驯化中,对驯化培养条件进行了研究,试验表明,采用一次培养法接种,接种量为30%体积(按反应器容积比计)的活性污泥和100mL活性炭,将温度控制在37±2℃,进水的pH控制在7.3￣8.0,进水流速控制在使活性炭处于流化状态,不需额外添加营养物质,可在25￣30d左右成功地完成驯化。在此控制的条件下培养出的活性污泥,对废水COD的去除率可达到85%左右,去除效果良好,对减轻生物反应器后续处理单元的负荷具有重要意义。     

造纸漂白废水对生物厌氧过程抑制作用的研究

本文研究了各浓度及经絮凝、超滤处理后漂白废水对厌氧过程甲烷菌的抑制作用,絮凝处理与超滤相比更可有效地降低漂白肇水对厌氧生物过程的毒性,表明漂白废水对厌微生物折抑制不仅来源于废水中低分子量物质,而且与分子量大于１０００的树脂类化合物高分子物质有关。对厌氧甲烷菌在漂白废水驯化过程的研究表明,采用低浓度下起动再逐步提高进水浓度的方式可使漂白废水厌氧污泥的驯化时间明显缩短。     

A 100-Year Review: Stress physiology including heat stress

Stress is an external event or condition that places a strain on a biological system. The animal response to a stress involves the expenditure of energy to remove or reduce the impact of the stress. This increases maintenance requirements of the animal and results in loss of production. The biological response to stress is divided into acute and chronic phases, with the acute phase lasting hours to a few days and the chronic phase lasting several days to weeks. The acute response is driven by homeostatic regulators of the nervous and endocrine systems and the chronic phase by homeorhetic regulators of the endocrine system. Both responses involve alterations in energy balance and metabolism. Thermal environment affects all animals and therefore represents the largest single stressor in animal production. Other types of stressors include housing conditions, overcrowding, social rank, disease, and toxic compounds. “Acclimation” to a stress is a phenotypic response developed by the animal to an individual stressor within the environment. However, under natural conditions, it is rare for only one environmental variable to change over time. “Acclimatization” is the process by which an animal adapts to several stressors within its natural environment. Acclimation is a homeorhetic process that takes several weeks to occur and occurs via homeorhetic, not homeostatic, mechanisms. It is a phenotypic change that disappears when the stress is removed. When the stress is severe and not relieved by acclimatization or management changes, the animal is considered chronically stressed and is susceptible to increased incidence of disease and poor health. Milk yield and reproduction are extremely sensitive to stress because of the high energy and protein demands of lactation and the complexity of the reproductive process and multiple organs that are involved. Improvements in protection of animals against stress require improved education of producers to recognize stress and methods for estimating degree of stress on animals.     

The Influence of Light Quality,Circadian Rhythm,and Photoperiod on the CBF-Mediated Freezing Tolerance

Low temperature adversely affects crop yields by restraining plant growth and productivity. Most temperate plants have the potential to increase their freezing tolerance upon exposure to low but nonfreezing temperatures, a process known as cold acclimation. Various physiological, molecular, and metabolic changes occur during cold acclimation, which suggests that the plant cold stress response is a complex, vital phenomenon that involves more than one pathway. The C-Repeat Binding Factor (CBF) pathway is the most important and well-studied cold regulatory pathway that imparts freezing tolerance to plants. The regulation of freezing tolerance involves the action of phytochromes, which play an important role in light-mediated signalling to activate cold-induced gene expression through the CBF pathway. Under normal temperature conditions, CBF expression is regulated by the circadian clock through the action of a central oscillator and also day length (photoperiod). The phytochrome and phytochrome interacting factor are involved in the repression of the CBF expression under long day (LD) conditions. Apart from the CBF regulon, a novel pathway involving the Z-box element also mediates the cold acclimation response in a light-dependent manner. This review provides insights into the progress of cold acclimation in relation to light quality, circadian regulation, and photoperiodic regulation and also explains the underlying molecular mechanisms of cold acclimation for introducing the engineering of economically important, cold-tolerant plants.     

窖池微生态调控对窖泥驯化及酒质影响的研究

为更好地解析窖泥,为窖泥质量提升提供更多的技术储备,采用化学法和物理法对窖泥进行驯化。化学法利用高通量测序技术解析老熟窖泥中原核微生物多样性,针对其中的主要菌群梭菌及甲烷菌设计一种无机盐培养基进行窖泥核心菌群的驯化;物理法利用窖池不同层次生酸情况的差异,采用置换法进行窖泥驯化。结果表明,窖池微生态经化学法调控后酒样中的己酸乙酯含量提高了44.67%,乳酸乙酯含量降低了37.25%;经物理法调控后酒样中的己酸乙酯含量提高了12.22%,乳酸乙酯含量先升后降,杂醇油中正丙醇含量降低了20.8%。两种方法均达到了窖泥驯化的目的,综合酒质得到提高。     

低C/N比工业园区废水微生物驯化实验研究

以安徽省某工业园区的低C/N比废水为研究对象,采用连续曝气、定期换水的方式对微生物进行培养驯化.结果表明,当COD∶N∶P为100∶5∶1,相当于COD,N,P浓度分别为600mg·L-1,30mg·L-1和6mg·L-1时,COD的最高去除率为95.4%,出水COD为27.5mg·L-1,出水氨氮稳定在5mg·L-1...     

脂肪酶产生菌的筛选及其耐甲醇驯化的研究

从土样中分离出34株脂肪酶产生菌,在维多利亚蓝培养基上初筛出透明圈与菌落直径比值较大的6株菌,复筛出产脂肪酶活性较高的菌株FM-1,其所产脂肪酶主要为胞内酶,产脂肪酶活力为132 U/g cell。通过反复的驯化培养方式将菌株FM-1驯化成耐甲醇的优良菌株。在甲醇质量浓度为11 mg/L的培养基中驯化后的脂肪酶相对活力为35%,而出发菌株在此环境中不能生长。