Cultivation of Chlorella vulgaris in microfluid segments and microtoxicological determination of their sensitivity against CuCl₂ in the nanoliter range

Abstract

International audienceThe cultivation of the monocellular green alga Chlorella vulgaris was implemented into microfluid segments to demonstrate the possibility of an automated screening of toxic effects of the common algaecide CuCl2. Therefore, the nutritional as well as light and carbon dioxide requirements of the algae had to be adapted to the microfluidic device. Generally, sequences of about 350 fluid segments with single volumes of about 500nL were applied for the doseresponse experiments. The growth of algae cultures inside microfluidic segments was non-invasively measured by microflow through techniques using two different optical channels. A multi-endpoint detection was realized by the photometric characterization of cell density by transmission measurements and the measurement of density of autofluorescent cells. The different methods revealed comparable half maximal effective concentrations (EC50) in the range between 34.6 and 39.9 mu g/mL for the toxicity of CuCl2 to the green algae C. vulgaris. By reference experiments in microtiter plates lower EC50 were achieved presumably caused by increased alkalinity of the growth medium due to higher photosynthesis. The results show that the microsegmented flow technique is well suited for the automated determination of dose/response functions for microorganisms like C. vulgaris and for the application of multi-endpoint procedures at the nanoliter scale

Droplet‐based microfluidics for microtoxicological studies

“…Life Sci. 2015, 00, 1-12 www.biotecvisions.com salts [64,82,83,88] as well as antibiotics [53,67,68,89,90] and other drugs [84,[91][92][93], and food components [80]. The obtained highly resolved dose/response functions from microfluidic investigations reflect roughly the same EC 50 values as observed in conventional screenings.…”

“…The spectrum of the analyzed organisms spans from bacteria as E. coli [53,57,67,74,[79][80][81] and Streptomyces [82], to eukaryotic microorganisms as Chlorella vulgaris [83], to multicellular organisms [64,65,84], animal cell lines [85], and human cells cultures such as human embryonic kidney (HEK) [86] and Jurkat cells [86,87]. The test substances involve heavy metal www.els-journal.com Eng.…”

A Millifluidic Study of Cell-to-Cell Heterogeneity in Growth-Rate and Cell-Division Capability in Populations of Isogenic Cells of Chlamydomonas reinhardtii

“…One of the challenges in droplet-based screening tests is the recovery of viable cells of interest, belonging to a particular drop, for further studies. To our knowledge, this feat was not achieved in previous studies on microalgae, using either milli- or microfluidic technologies [35,50,76,77,83]. We therefore developed a droplet-sorter, which can collect individual algal drops and either deliver them to a 96-well plate or discard them.…”

Why is Micro Segmented Flow Particularly Promising for the Synthesis of Nanomaterials?

“…The ordered transport of liquid compartments in micro segmented flow is of high interest for the realization of well-controlled, homogeneous, and reproducible conditions in a large spectrum of chemical applications [10,11], reaching from chemical analytics [12][13][14][15] over chemical synthesis [16] to biochemistry [17,18], cell cultivation [19][20][21], and biological screenings [22][23][24][25]. It is particularly in the focus of the synthesis of microparticles and nanomaterials.…”