Biomass production of hairy roots of Artemisia annua and Arachis hypogaea in a scaled‐up mist bioreactor

Hairy roots have the potential to produce a variety of valuable small and large molecules. The mist reactor is a gas phase bioreactor that has shown promise for low‐cost culture of hairy roots. Using a newer, disposable culture bag, mist reactor performance was studied with two species, Artemisia annua L. and Arachis hypogaea (peanut), at scales from 1 to 20 L. Both species of hairy roots when grown at 1 L in the mist reactor showed growth rates that surpassed that in shake flasks. From the information gleaned at 1 L, Arachis was scaled further to 4 and then 20 L. Misting duty cycle, culture medium flow rate, and timing of when flow rate was increased were varied. In a mist reactor increasing the misting cycle or increasing the medium flow rate are the two alternatives for increased delivery of liquid nutrients to the root bed. Longer misting cycles beyond 2–3 min were generally deemed detrimental to growth. On the other hand, increasing the medium flow rate to the sonic nozzle especially during the exponential phase of root growth (weeks 2–3) was the most important factor for increasing growth rates and biomass yields in the 20 L reactors. A. hypogaea growth in 1 L reactors was µ = 0.173 day^?1 with biomass yield of 12.75 g DW L^?1. This exceeded that in shake flasks at µ = 0.166 day^?1 and 11.10 g DW L^?1. Best growth rate and biomass yield at 20 L was µ = 0.147 and 7.77 g DW L^?1, which was mainly achieved when medium flow rate delivery was increased. The mist deposition model was further evaluated using this newer reactor design and when the apparent thickness of roots (+hairs) was taken into account, the empirical data correlated with model predictions. Together these results establish the most important conditions to explore for future optimization of the mist bioreactor for culture of hairy roots. Biotechnol. Bioeng. 2010;107: 802–813. © 2010 Wiley Periodicals, Inc.     

叶片和群落尺度净光合速率关系的探讨

叶片净光合速率(P_n)是研究光合作用机理的基本尺度; 而群落净光合速率(P_c)是研究群落光合能力及其与外部环境因子间关系的更好尺度, 特别是区域乃至全球尺度碳循环的研究, 需要将叶片尺度的生理生态模型扩展到冠层尺度。理论上, 群落内所有叶片的累积P_n与实测群落净气体交换速率(NCE)是相等的, 但在野外实际观测中, 两者之间的相互关系目前尚未见报道。该文选取敖汉苜蓿(Medicago sativa ‘Aohan’)人工草地, 采用美国LI-COR公司生产的便携式光合测定系统LI-6400测定P_n, 结合叶面积指数等参数推算P_c, 利用LI-8100连接同化箱测定生态系统净气体交换速率(NEE), 加上土壤呼吸速率, 得到NCE。结果表明: P_c为3.52 μmol CO₂·m^-2·s^-1, 与实测NCE (3.56 μmol CO₂·m^-2·s^-1)基本相等。这表明: 可利用P_n, 结合叶面积指数、群落叶片数目、健康叶片比例和群落可接收有效光照的平均比例等4个关键参数, 准确地换算P_c。然而, 利用同化箱式法测定群落呼吸速率时, 不可避免地会包含土壤呼吸, 所以在观测NCE时, 需要同时测定土壤呼吸。此外, 在冠层模型中, 群落垂直结构和光量子的非线性响应不可忽视。     

固相分离净化技术在进口药品爱维治注射液中的应用

本工作建立了使用ＳＥＰ—ＰＡＫＣ（１８）小柱分离爱维治注射液中对羟基苯甲酸甲酯（ＭＰＢ）、对羟基苯甲酸丙酯（ＰＰＢ）与氨基酸类组分的方法。具有有机溶媒用量少和分离快速的特点,对提高分析结果的准确性和保护色谱柱均具有实际应用价值。     

A combined treatment using ethylmethane sulfonate and ultraviolet light to compare amylase production by three Bacillus sp. isolates

Abstract

In this study, three Bacillus sp.-producing amylase enzymes were isolated from soil samples and identified using 16S rDNA sequence analysis. Amylase production and total protein productions were spectrophotometrically measured. The following media were tested to increase enzyme production: LB medium and molasses. Three Bacillus sp. were identified as follows: Bacillus subtilis subtilis, Bacillus thuringiensis, and Bacillus cereus. Amylase production levels were in the range of 10?U/mL, whereas total protein production levels were at 15?mg/mL. Higher amylase activity was found in the Bacillus subtilis isolate. Ethylmethane sulfonate (EMS) and ultraviolet (UV) mutagenesis in combination were applied to compare amylase production. Amylase activity was increased to around 58% in the treatment with 0.03?mL of EMS and UV when compared to the control group. A pilot scale bioreactor with a total working volume of 10 liters was used to produce amylase by B. subtilis subtilis. In conclusion, B. subtilis subtilis can be used to produce amylase enzyme for various industrial purposes, and, for the first time, the amylase activities of B. subtilis can be enhanced with EMS and UV treatment.     

Actinomycetes scale‐up for the production of the antibacterial,nocathiacin

An Amycolatopsis fastidiosa culture, which produces the nocathiacin class of antibacterial compounds, was scaled up to the 15,000 L working volume. Lower volume pilot fermentations (600, 900, and 1,500 L scale) were conducted to determine process feasibility at the 15,000 L scale. The effects of inoculum volume, impeller tip speed, volumetric gas flow rate, superficial gas velocity, backpressure, and sterilization heat stress were examined to determine optimal scale‐up operating conditions. Inoculum volume (6 vs. 2 vol %) and medium sterilization (R_o of 68 vs. 92 min^?1) had no effect on productivity or titer, and higher impeller tip speeds (2.1 vs. 2.9 m/s) had a slight effect (20% decrease). In contrast, higher backpressure, incorporating increased head pressure at the 15,000 L scale (1.2 vs. 0.7 kg/cm²) and low gas flow rates (0.25 vs. 0.8 vvm), appeared to be problematic (40–50% decrease). High off‐gas CO₂ levels were likely reasons for observed lower productivity. Consequently, air flow rate for this 25‐fold scale‐up (600–15,000 L) was controlled to match off‐gas CO₂ profiles of acceptable smaller scale batches to maintain levels below 0.5%. The 15,000 L‐scale fermentation achieved an expected nocathiacin I titer of 310 mg/L after 7 days. Other on‐line data (i.e., pH, oxygen uptake rate, and CO₂ evolution rate) and off‐line data (i.e., analog production, glucose utilization, ammonium production, and dry cell weight) at the 15,000 L scale also tracked similarly to the smaller scale, demonstrating successful fermentation scale‐up. © 2009 American Institute of Chemical Engineers Biotechnol. Prog., 2009     

Bacterial community dynamics involved in Reactive Orange M2R dye degradation using a real time quantitative PCR and scale up studies using sequence batch reactor

Bacterial consortium volatile suspended soil (VSS) (Vatva soil sample) with a capability of azo dye Reactive Orange M2R (ROM2R) decolorization and degradation (shown in our earlier studies using Fourier transform infrared spectroscopy (FTIR) and phytotoxicity studies) was isolated from industrial wastewaters by enrichment culture technique. The present study was carried out to study bacterial population dynamics in consortium Vatva soil sample (VSS) during azo dye ROM2R degradation and to identify the consortium members that were actively involved in the degradation process. To achieve this goal, a real-time Polymerase chain reaction (PCR) assay targeting species-specific region of 16S rDNA of each consortial bacteria was developed to provide quantitative information about the bacterial abundance during azo dye degradation. The real-time PCR assay indicated that Pseudomonas aeruginosa (VSS-6) dominated consortium bacterial community during the active continuous bioremediation process. Attempt has been made to scale up from 100 ml volume to 10 L operation volume with intermittent additions (batch fed loadings) in a Sequence batch reactor (SBR). The development of VSS consortium biomass (MLVSS), changes in COD and biochemical oxygen demand, and the dye degradation were studied under conditions simulating the operations of biological effluent treatment in an attempt to develop a commercially applicable dye effluent treatment process unit.     

Indirect and direct controls of macroinvertebrates and small fish by abiotic factors and trophic interactions in the Florida Everglades

1. The roles of nutrients, disturbance and predation in regulating consumer densities have long been of interest, but their indirect effects have rarely been quantified in wetland ecosystems. The Florida Everglades contains gradients of hydrological disturbance (marsh drying) and nutrient enrichment (phosphorus), often correlated with densities of macroinvertebrate infauna (macroinvertebrates inhabiting periphyton), small fish and larger invertebrates, such as snails, grass shrimp, insects and crayfish. However, most causal relationships have yet to be quantified. 2. We sampled periphyton (content and community structure) and consumer (small omnivores, carnivores and herbivores, and infaunal macroinvertebrates inhabiting periphyton) density at 28 sites spanning a range of hydrological and nutrient conditions and compared our data to seven a priori structural equation models. 3. The best model included bottom‐up and top‐down effects among trophic groups and supported top‐down control of infauna by omnivores and predators that cascaded to periphyton biomass. The next best model included bottom‐up paths only and allowed direct effects of periphyton on omnivore density. Both models suggested a positive relationship between small herbivores and small omnivores, indicating that predation was unable to limit herbivore numbers. Total effects of time following flooding were negative for all three consumer groups even when both preferred models suggested positive direct effects for some groups. Total effects of nutrient levels (phosphorus) were positive for consumers and generally larger than those of hydrological disturbance and were mediated by changes in periphyton content. 4. Our findings provide quantitative support for indirect effects of nutrient enrichment on consumers, and the importance of both algal community structure and periphyton biomass to Everglades food webs. Evidence for top‐down control of infauna by omnivores was noted, though without substantially greater support than a competing bottom‐up‐only model.     

A mechanistic understanding of ageing revealed by studying the young

A main focus within biomedical research is to understand how adverse environmental conditions experienced during early development affects lifelong health (Barker 1992). Within this context, extensive research in rodent models and humans has shown that intrauterine growth retardation (IUGR) caused by nutrient restriction during early development is often followed by post-natal 'catch-up' growth when access to food resources improves. However, this accelerated growth rate seems to come at a cost, as metabolic and endocrine processes that are programmed during this time cause later-life onset of diseases such as obesity, insulin resistance and cardiovascular disease (reviewed in Crespi & Denver 2005). In this issue Molecular Ecology, Geiger et al. (2012) asked what are the costs of catch-up growth in nutrient-restricted king penguin chicks (Fig. 1) by measuring lengths of telomeres, the protective DNA sequences at the end of chromosomes, before and after catch-up growth, as the amount and rate of telomere sequence loss over time has been associated with reduced lifespan in both model and nonmodel organisms (see reviews of Costantini et al. 2010; Haussmann & Marchetto 2010). Geiger et al. (2011) found that chicks entering the post-winter growth season at a smaller size exhibited increased growth rates (i.e. catch-up growth) at the cost of increased oxidative stress and reduced telomere lengths compared with the chicks entering the growth period at a larger size. Furthermore, chicks that did not survive had drastically shorter telomere lengths and reduced antioxidant capacities at the beginning of the growth period than all other chicks, thereby directly associating telomere length to mortality. These results suggest that while catch-up growth allows smaller chicks to head off into the world on equal footing with chicks that hatched at a larger size, it likely comes at the cost of a shortened lifespan. Thus, this study provides a mechanism that supports the antagonistic pleiotropy theory of senescence (Promislow 2004).     

Biohydrogen production in granular up-flow anaerobic sludge blanket (UASB) reactors with mixed cultures under hyper-thermophilic temperature (70 degrees C)

Hyper-thermophilic hydrogen production without methane was demonstrated for the first time in granular up-flow anaerobic sludge blanket (UASB) system fed with glucose using mixed cultures. The maximum hydrogen yield in this study was 2.47 +/- 0.15 mol H2/mol glucose. This high yield has never been previously reported in mixed culture systems and it was likely due to more favorable thermodynamic conditions at hyper-thermophilic temperatures. Different start-up strategies (bromoethanosulfonate (BES) addition and flow recycle) were evaluated. BES addition during start-up prevented the establishment of methanogenic cultures in granules. Flow recycle was important to achieve higher hydrogen yield through enriching better hydrogen-producing organisms and reduced the start-up period as well. This study indicated UASB system was a promising system for hydrogen production.