CultureLED: A 3D printer-based LED illumination cultivation system for multi-well culture plates.

Microalgae are a source of high value products such as pigments, lipids and carbohydrates. Microalgae cultivation techniques have evolved and improved, but a vast amount of research is still needed to achieve a better understanding of these microorganisms. Due to this, there is a growing need for affordable, flexible, and easy to control research systems and protocols. 3D printing revolutionized design and manufacturing as it became widely available to the mass market, allowing the creation of novel forms, enabling mass customization, and supporting low-volume, distributed production. The emergence of open-source designs combined with 3D printing applications have the potential to replace and outperform standard designs and methods. This protocol describes CultureLED, a well plated cell culture system that can be mounted on an orbital shaker or positioned on a shelf. It is an open hardware design, based on low-cost commercial off-the-shelf components. It was designed for optimized production cost, simplicity, low power consumption, design flexibility, and controllable light conditions. The CultureLED utilizes light-emitting diodes and it can be used for cultivation of small sized organisms or microorganisms with different light requirements and as such, has a wide range of applications.

Shape outline extraction software (DiaOutline) for elliptic Fourier analysis application in morphometric studies.

PREMISE OF THE STUDY: Studies of plant cell and organ outline using shape analysis for taxonomic and morphological research have increased in the past decade. However, there are a limited number of available modern, intuitive, and easy software tools to conduct this work. METHODS: We developed a tool for shape outline extraction using MATLAB accompanied with R scripts to perform elliptic Fourier analysis. To demonstrate the shape tool, we applied the software and scripts for genera and species shape determinations of diatom (single cell) species with x-, y-, and x- + y-shape symmetries. RESULTS: Using the shape analysis tool, we were able to identify and distinguish different diatom taxa based on forms representing size diminutions associated with population changes. DISCUSSION: Independent of symmetry, species were successfully distinguished using supervised and unsupervised analyses. We hope that these shape analysis tools will be used to add another metric to plant science studies.

Methyl chloride emissions from halophyte leaf litter: dependence on temperature and chloride content.

Methyl chloride (CH(3)Cl) is the most abundant natural chlorine containing compound in the atmosphere, and responsible for a significant fraction of stratospheric ozone destruction. Understanding the global CH(3)Cl budget is therefore of great importance. However, the strength of the individual sources and sinks is still uncertain. Leaf litter is a potentially important source of methyl chloride, but factors controlling the emissions are unclear. This study investigated CH(3)Cl emissions from leaf litter of twelve halophyte species. The emissions were not due to biological activity, and emission rates varied between halophyte species up to two orders of magnitude. For all species, the CH(3)Cl emission rates increased with temperature following the Arrhenius relation. Activation energies were similar for all investigated plant species, indicating that even though emissions vary largely between plant species, their response to changing temperatures is similar. The chloride and methoxyl group contents of the leaf litter samples were determined, but those parameters were not significantly correlated to the CH(3)Cl emission rate.

Enhanced formation of methane in plant cell cultures by inhibition of cytochrome c oxidase.

The claim of methane (CH4) formation in plants has caused much controversy and debate within the scientific community over the past 4 years. Here, using both stable isotope and concentration measurements, we demonstrate that CH4 formation occurs in plant cell cultures that were grown in the dark under sterile conditions. Under non-stress conditions the plant cell cultures produced trace amounts [0.3-0.6 ng g⁻¹ dry weight (DW) h⁻¹] of CH4 but these could be increased by one to two orders of magnitude (up to 12 ng g⁻¹ DW h⁻¹) when sodium azide, a compound known to disrupt electron transport flow at the cytochrome c oxidase (complex IV) in plant mitochondria, was added to the cell cultures. The addition of other electron transport chain (ETC) inhibitors did not result in significant CH4 formation indicating that a site-specific disturbance of the ETC at complex IV causes CH4 formation in plant cells. Our study is an important first step in providing more information on non-microbial CH4 formation from living plants particularly under abiotic stress conditions that might affect the electron transport flow at the cytochrome c oxidase in plant mitochondria.

Abiotic methyl bromide formation from vegetation, and its strong dependence on temperature.

Methyl bromide (CH3Br) is the most abundant brominated organic compound in the atmosphere. It is known to originate from natural and anthropogenic sources, although many uncertainties remain regarding strengths of both sources and sinks and the processes leading to its formation. In this study a potential new CH3Br source from vegetation has been examined, analogous to the recently discovered abiotic formation of methyl chloride from plant pectin. Several plant samples with known bromine content, including ash (Fraxinus excelsior), saltwort (Batis maritima), tomato reference material (NIST-1573a), hay reference material (IAEA V-10), and also bromine enriched pectin, were incubated in the temperature range of 25-50 degrees C and analyzed for CH3Br emission using gas chromatography/mass spectrometry. All plant samples inspected showed an exponential increase in CH3Br emission as a function of temperature increase, i.e., emissions were observed to approximately double with every 5 degrees C rise in temperature. Next to temperature, it was found that emissions of CH3Br were also dependent on the bromine content of the plants. The highest CH3Br release rates were found for the saltwort which contained the highest bromine concentration. Arrhenius plots confirmed that the observed emissions were from an abiotic origin. The contribution of abiotic CH3Br formation from vegetation to the global budget will vary geographically as a result of regional differences in both temperature and bromide content of terrestrial plants.