98 research outputs found

    Microalgal biomass quantification from the non-invasive technique of image processing through red-green-blue (RGB) analysis

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    Financiado para publicación en acceso aberto: Universidade de Vigo/CISUGContinuous monitoring of biomass concentration in microalgae cultures is essential and one of the most important parameters to measure in this field. This study aims at digital image processing in RGB and greyscale models, being a simple and low-cost method for cell estimation. Images obtained from different photobioreactors with wastewater and at different conditions for the cultivation of Chlorella vulgaris were analyzed. The results suggested that this technique is very effective under controlled lighting conditions, in contrast to photobioreactors placed outdoors and of different design, presenting a lower linearity. The accuracy of the method could be improved with a high-quality charge-coupled device (CCD) camera. The development of efficient methods to assess biomass concentration is an important and necessary step towards large-scale microalgae cultivation. The colour analysis technique has a great potential to meet the needs of monitoring cultures in a cost-effective and automated way using simple and cheap instruments

    On-Line Monitoring of Biological Parameters in Microalgal Bioprocesses Using Optical Methods

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    Microalgae are promising sources of fuels and other chemicals. To operate microalgal cultivations efficiently, process control based on monitoring of process variables is needed. On-line sensing has important advantages over off-line and other analytical and sensing methods in minimizing the measurement delay. Consequently, on-line, in-situ sensors are preferred. In this respect, optical sensors occupy a central position since they are versatile and readily implemented in an on-line format. In biotechnological processes, measurements are performed in three phases (gaseous, liquid and solid (biomass)), and monitored process variables can be classified as physical, chemical and biological. On-line sensing technologies that rely on standard industrial sensors employed in chemical processes are already well-established for monitoring the physical and chemical environment of an algal cultivation. In contrast, on-line sensors for the process variables of the biological phase, whether biomass, intracellular or extracellular products, or the physiological state of living cells, are at an earlier developmental stage and are the focus of this review. On-line monitoring of biological process variables is much more difficult and sometimes impossible and must rely on indirect measurement and extensive data processing. In contrast to other recent reviews, this review concentrates on current methods and technologies for monitoring of biological parameters in microalgal cultivations that are suitable for the on-line and in-situ implementation. These parameters include cell concentration, chlorophyll content, irradiance, and lipid and pigment concentration and are measured using NMR, IR spectrophotometry, dielectric scattering, and multispectral methods. An important part of the review is the computer-aided monitoring of microalgal cultivations in the form of software sensors, the use of multi-parameter measurements in mathematical process models, fuzzy logic and artificial neural networks. In the future, software sensors will play an increasing role in the real-time estimation of biological variables because of their flexibility and extendibility

    A Multi-Channel 3D-Printed Bioreactor for Evaluation of Growth and Production in the Microalga Dunaliella sp

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    We explored the capabilities of additive manufacturing using a photo-cured jetted material 3D printer to manufacture a milli-microfluidic device with direct application in microalgae Dunaliella sp growth and intracellular compounds biosynthesis tests. A continuous microbioreactor for microalgae culture was CAD designed and successfully built in 1 hour and 49 minutes using black photopolymer cured by UV and a support material. The microreactor was made up of 2 parts including the bioreactor itself and a microchannel network for culture media fluids and microalgae. Both parts were assembled to form a single unit. Additional optical and auxiliar components were added. An external photodetection system platform helped to read light information coming from the bioreactor, related to microalgae growth and production of Carotenoids. Several tests were carried out to check manufacturing quality, behavior of microalgae inside microreactor, quality of light based data coming from meauring system and comparison of microalgae culture operation using (flasks) and microbioreactor. Growth of microalgae inside the microreactor was unsuccessful and several hypothesis may explain the lack of cell replication, from low CO₂ content to 3D photopolymer incompatibility with cell environment. Further improvements related to gas exchange, specially CO₂, microalgae retention system, high irradiance for light stressing tests and material biocompatibility need to be addressed in future works. From a mechanical point of view it was demonstrated the 3D fabricated microreactor it is possible and that it has promising advantages compared to other microfabrication processes that involve complexity in the design, longer manufacturing time, more expensive and sophisticated manufacturing techniques as well as specialized operators and designers

    “Do It Yourself” Microbial Cultivation Techniques for Synthetic and Systems Biology: Cheap, Fun, and Flexible

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    With the emergence of inexpensive 3D printing technology, open-source platforms for electronic prototyping and single-board computers, “Do it Yourself” (DIY) approaches to the cultivation of microbial cultures are becoming more feasible, user-friendly, and thus wider spread. In this perspective, we survey some of these approaches, as well as add-on solutions to commercial instruments for synthetic and system biology applications. We discuss different cultivation designs, including capabilities and limitations. Our intention is to encourage the reader to consider the DIY solutions. Overall, custom cultivation devices offer controlled growth environments with in-line monitoring of, for example, optical density, fluorescence, pH, and dissolved oxygen, all at affordable prices. Moreover, they offer a great degree of flexibility for different applications and requirements and are fun to design and construct. We include several illustrative examples, such as gaining optogenetic control and adaptive laboratory evolution experiments

    Performing calibration of transmittance by single rgb-led within the visible spectrum

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    Spectrophotometry has proven to be an effective non-invasive technique for the characterization of the pollution load of sewer systems, enabling compliance with new environmental protection regulations. This type of equipment has costs and an energy consumption which make it difficult to place it inside a sewer network for real-time and massive monitoring. These shortcomings are mainly due to the use of incandescent lamps to generate the working spectrum as they often require the use of optical elements, such as diffraction gratings, to work. The search for viable alternatives to incandescent lamps is key to the development of portable equipment that is cheaper and with a lower consumption that can be used in different points of the sewer network. This research work achieved the following results in terms of the measured samples: First, the development a calibration procedure that enables the use of RGB-LED technology as a viable alternative to incandescent lamps, within the range of 510 to 645 nm, with high accuracy. Secondly, demonstration of a simple method to model the transmittance value of a specific wavelength without the need for optical elements, achieving a cost-effective equipment. Thirdly, it provides a simple method to obtain the transmittance based on the combination of RGB colors. Finally its viability is demonstrated for the spectral analysis of wastewater.The authors are grateful for the financial support received from the Seneca Foundation of the Región de Murcia (Spain) through the program devoted to training novel researchers in areas of specific interest for the industry and with a high capacity to transfer the results of the research generated, entitled: “Subprograma Regional de Contratos de Formación de Personal Investigador en Universidades y OPIs” (Mod. B, Ref. 20320/FPI/17)

    Technology, Science and Culture

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    From the success of the first and second volume of this series, we are enthusiastic to continue our discussions on research topics related to the fields of Food Science, Intelligent Systems, Molecular Biomedicine, Water Science, and Creation and Theories of Culture. Our aims are to discuss the newest topics, theories, and research methods in each of the mentioned fields, to promote debates among top researchers and graduate students and to generate collaborative works among them

    Marine Resources Application Potential for Biotechnological Purposes

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    Blue biotechnology plays a major role in converting marine biomass into societal value, being a key pillar for many marine economy developmental frameworks and sustainability strategies, such as the Blue Growth Strategy, diverse Sea Basin Strategies (e.g., Atlantic Action Plan Priority 1 and 2 and COM (2017) 183), the Marine Strategy Framework Directive, the Limassol Declaration, or even the UN Sustainable Development 2030 Agenda. However, despite the recognized biotechnological potential of marine biomass, the work is dispersed between multiple areas of applied biotechnology, resulting in few concrete examples of product development.This book highlight the vast potential that marine resources hold, from viruses to seaweeds, and a myriad of applications from antimicrobials and cosmetics to feed and food that contributes to a market-driven and industrially orientated research, which will increase the efficiency of the marine biodiscovery pipeline and ultimately deliver realistic and measurable benefits to society, which is paramount for sustained blue growth and a successful market penetration of targeted biomolecules or enriched extracts for new product development, which are cornerstone issues for the present and the future of a marine biobased economy

    Dynamic interactions in an artificial phototrophic biofilm for biotechnological applications

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    In the present study, a comprehensive investigation of the dynamic processes in an artificial algal biofilm immobilized on a porous substrate has been conducted. Experimental investigations including microsensor measurements were carried out. For this purpose, the microsensor setup used for profiling submerged biofilms was modified to enable measurement on the investigated biofilms. To achieve an accurate evaluation of the data acquired through microsensor measurements, a new mathematical method was developed, and a 20 μm depth resolution has been suggested for future photosynthetic activity measurements. After the establishment of the microsensor methods, a systematic microsenser investigation was carried out: the distribution of dissolved oxygen, pH value and photosynthetic productivity profiles of algal biofilms in a porous substrate biofilm photobioreactor (Twin-Layer photobioreactor) exposed to different surface irradiance and/or exposed to different gas phase CO2 concentrations were measured. The results acquired from these experiments offered important insights into the processes in such biofilms: E.g. light penetration depth, maximal dissolved oxygen concentration and pH distribution. The results show, as expected, photosynthesis in the biofilms occurs only near the biofilms surface (i.e. in the illuminated zones), and dark respiration in the inner part of the biofilm could be the reason of the observed biomass productivity decrease with prolonged cultivation. Also, increases in surface irradiance and/or gas phase CO2 concentrations led to an increase in photosynthetic productivity of the investigated biofilm. No photoinhibition was observed in the studied biofilms, although exceptionally high dissolved oxygen concentrations (12 times of that in normal atmosphere) have been recorded. The model (as described in the 3rd manuscript, Li et al. 2015d) developed in the study has proven to be very effective in predicting experimental observations. The results show clearly the importance of taking into account not only adsorption and scattering, but also the adaptation of the pigment content of the biomass for investigating radiative transfer in PSBR biofilms. Also, through the development of the model, important insights into the dynamic processes in the investigated biofilm were acquired: E.g., it is very likely that the facilitated CO2 transfer plays an important role in inorganic carbon transport in the studied biofilms when the CO2 concentration supplied in the gas phase is low; macronutrients (N and P) do not limit growth even at high surface irradiance and high gas phase CO2 concentrations as long as they are sufficiently supplied in the medium; and the buffering of the medium with a strong buffer will have significant effects on the inorganic carbon availability in the studied biofilm. Through this study, a solid basis has been established for future investigation on PSBR biofilms. The methods and model developed in this study are established specifically for investigating biofilms grown in the Twin-Layer porous substrate biofilm photobioreactor. However, with minor modifications and/or additional experimental measurements, they can be easily applied to other phototrophic biofilm systems or for investigation and/or optimization of commercial scale systems

    Simultaneous visualization of flow fields and oxygen concentrations to unravel transport and metabolic processes in biological systems

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    From individual cells to whole organisms, O2 transport unfolds across micrometer- tomillimeter-length scales and can change within milliseconds in response to fluid flows and organismal behavior. The spatiotemporal complexity of these processes makes the accurate assessment ofO2 dynamics via currently availablemethods difficult or unreliable. Here, we present ‘‘sensPIV,’’ a method to simultaneously measure O2 concentrations and flow fields. By tracking O2-sensitive microparticles in flow using imaging technologies that allow for instantaneous referencing,we measuredO2 transport within (1) microfluidic devices, (2) sinking model aggregates, and (3) complex colony-forming corals. Through the use of sensPIV, we find that corals use ciliary movement to link zones of photosynthetic O2 production to zones of O2 consumption. SensPIV can potentially be extendable to study flow-organism interactions across many life-science and engineering applications
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