Cell disruption for microalgae biorefineries
Günerken, E. ; Hondt, E. d'; Eppink, M.H.M. ; Garcia-Gonzalez, L. ; Elst, K. ; Wijffels, R.H. - \ 2015
Biotechnology Advances 33 (2015)2. - ISSN 0734-9750 - p. 243 - 260.
microwave-assisted extraction - fluidized-bed adsorption - electric-field treatment - synechocystis pcc 6803 - life-cycle assessment - chlorella-vulgaris - lipid extraction - microbial-cells - saccharomyces-cerevisiae - biodiesel production
Microalgae are a potential source for various valuable chemicals for commercial applications ranging from nutraceuticals to fuels. Objective in a biorefinery is to utilize biomass ingredients efficiently similarly to petroleum refineries in which oil is fractionated in fuels and a variety of products with higher value. Downstream processes in microalgae biorefineries consist of different steps whereof cell disruption is the most crucial part. To maintain the functionality of algae biochemicals during cell disruption while obtaining high disruption yields is an important challenge. Despite this need, studies on mild disruption of microalgae cells are limited. This review article focuses on the evaluation of conventional and emerging cell disruption technologies, and a comparison thereof with respect to their potential for the future microalgae biorefineries. The discussed techniques are bead milling, high pressure homogenization, high speed homogenization, ultrasonication, microwave treatment, pulsed electric field treatment, non-mechanical cell disruption and some emerging technologies.
The potential effect of greenwater technology on water quality in the pond culture of Penaeus monodon Fabricius
Tendencia, E.A. ; Bosma, R.H. ; Verdegem, M.C.J. ; Verreth, J.A.J. - \ 2015
Aquaculture Research 46 (2015)1. - ISSN 1355-557X - p. 1 - 13.
white-spot-syndrome - syndrome virus - shrimp ponds - litopenaeus-vannamei - chlorella-vulgaris - vibrio-harveyi - salinity - temperature - susceptibility - mortalities
Whitespot syndrome virus (WSSV) has caused severe production drops in the shrimp industry. Numerous scientific manuscripts deal with WSSV epidemiology, but reports on minimizing disease outbreaks through ecological means are rare. Industry stakeholders resorted to various innovative techniques to recover from heavy economic losses. Some shrimp farmers in the Philippines claimed that 'greenwater' (GW) technology could prevent disease outbreaks due to WSSV. The efficiency of the GW technology was evaluated by comparing three ponds using the GW culture technique with three ponds not using it. WSSV was detected only in one of the GW ponds and not in the non-GW ponds. No WSSV disease outbreak occurred, and no conclusion could be reached. In GW ponds, available soil sulphur content was lower; and in water, the observed counts of luminous bacteria were lower and counts of Chlorophyceae were higher. Chlorophyceae, i.e. algae, enhanced nutrient uptake in effluent streams resulting in improved water quality in Penaeus monodon Fabricius culture ponds. This suggests that the use of the GW technique to culture P. monodon improved water quality.
Functional ingredients from microalgae
Buono, S. ; Langellotti, A.L. ; Martello, A. ; Rinna, F. ; Fogliano, V. - \ 2014
Food & Function 5 (2014)8. - ISSN 2042-6496 - p. 1669 - 1685.
polyunsaturated fatty-acids - induced oxidative stress - chlorella-vulgaris - dunaliella-salina - spirulina-fusiformis - beta-carotene - eicosapentaenoic acid - in-vivo - haematococcus-pluvialis - antioxidant activity
A wide variety of natural sources are under investigation to evaluate their possible use for new functional ingredient formulation. Some records attested the traditional and ancient use of wild harvested microalgae as human food but their cultivation for different purposes started about 40 years ago. The most popular species are Arthrospira (traditional name, Spirulina), Chlorella spp., Dunaliella spp. and Haematococcus spp. Microalgae provide a bewildering array of opportunities to develop healthier food products using innovative approaches and a number of different strategies. Compared to other natural sources of bioactive ingredients, microalgae have many advantages such as their huge biodiversity, the possibility to grow in arid land and with limited fresh water consumption and the flexibility of their metabolism, which could be adapted to produce specific molecules. All these factors led to very sustainable production making microalgae eligible as one of the most promising foods for the future, particularly as source of proteins, lipids and phytochemicals. In this work, a revision of the knowledge about the use of microalgae as food and as a source of functional ingredients has been performed. The most interesting results in the field are presented and commented upon, focusing on the different species of microalgae and the activity of the nutritionally relevant compounds. A summary of the health effects obtained together with pros and cons in the adoption of this natural source as functional food ingredients is also proposed.
Effect of three innovative culture systems on water quality and whitespot syndrome virus (WSSV) viral load in WSSV-fed Penaeus monodon cultured in indoor tanks
Alapide-Tendencia, E.V. ; Bosma, R.H. ; Rose Sorio, L. - \ 2012
Aquaculture 350-353 (2012). - ISSN 0044-8486 - p. 169 - 174.
vibrio-harveyi - litopenaeus-vannamei - chlorella-vulgaris - shrimp ponds - bacteria - mortalities - microalgae - juveniles - tilapia - growth
White spot syndrome virus is the most important among the shrimp diseases. It has been devastating the shrimp industry for more than 3 decades. Previous studies reported that greater percentage of yellow colonies on thiosulfate citrate bile salt sucrose agar (yellow vibrios) in the rearing water, abundant supply of natural food such as Chlorella, and the use of the greenwater technology (GW) are some ecological ways of preventing WSSV outbreak. The aim of this study was to investigate the efficiency of the 3 systems against WSSV. Shrimp, experimentally infected with WSSV by feeding with WSSV positive shrimp carcass, was cultured in tanks using three treatments: with tilapia to simulate the GW, seeded with Chlorella, and with molasses added to enhance growth of yellow vibrios. Shrimp cultured in seawater served as the control. Survival was recorded and shrimp were analyzed for WSSV quantification using qPCR upon termination. Analysis showed no significant differences in shrimp survival at 120 h post infection in all treatments and the control. However, from the original viral load of 1.40 × 101 WSSV/mg sample, WSSV decreased and was significantly lowest in shrimp cultured using GW (7.0 × 100), compared to the control (4.82 × 105) and the other treatments (3.66 × 105 for molasses added and 4.64 × 105 for Chlorella seeded) in which viral load increased 4–5 times. Shrimp survival was highest in Chlorella seeded treatment and lowest in GW. Nitrogenous waste concentrations were lowest in molasses added water and highest in GW. Results suggest that the GW culture technology provides protection against WSSV while addition of molasses lowers nitrogenous waste concentration. The use of GW in combination with the addition of molasses for shrimp culture is suggested.
Scenario Analysis of Nutrient Removal from Municipal Wastewater by Microalgal Biofilms
Boelee, N.C. ; Temmink, H. ; Janssen, M. ; Buisman, C.J.N. ; Wijffels, R.H. - \ 2012
Water 4 (2012)2. - ISSN 2073-4441 - p. 460 - 473.
afvalwaterbehandeling - biofilms - algen - biologische waterzuiveringsinstallaties - vergelijkend onderzoek - volgorden - haalbaarheidsstudies - heterotrofe micro-organismen - stikstof - fosfor - verwijdering - biomassa productie - biobased economy - waste water treatment - biofilms - algae - biological water treatment plants - comparative research - sequences - feasibility studies - heterotrophic microorganisms - nitrogen - phosphorus - removal - biomass production - biobased economy - marine-phytoplankton - chemical-composition - chlorella-vulgaris - nitrate uptake - algal biofilm - growth - photobioreactor - photosynthesis
Microalgae can be used for the treatment of municipal wastewater. The application of microalgal biofilms in wastewater treatment systems seems attractive, being able to remove nitrogen, phosphorus and COD from wastewater at a short hydraulic retention time. This study therefore investigates the area requirement, achieved effluent concentrations and biomass production of a hypothetical large-scale microalgal biofilm system treating municipal wastewater. Three scenarios were defined: using microalgal biofilms: (1) as a post-treatment; (2) as a second stage of wastewater treatment, after a first stage in which COD is removed by activated sludge; and (3) in a symbiotic microalgal/heterotrophic system. The analysis showed that in the Netherlands, the area requirements for these three scenarios range from 0.32 to 2.1 m2 per person equivalent. Moreover, it was found that it was not possible to simultaneously remove all nitrogen and phosphorus from the wastewater, because of the nitrogen:phosphorus ratio in the wastewater. Phosphorus was limiting in the post-treatment scenario, while nitrogen was limiting in the two other scenarios. Furthermore, a substantial amount of microalgal biomass was produced, ranging from 13 to 59 g per person equivalent per day. These findings show that microalgal biofilm systems hold large potential as seasonal wastewater treatment systems and that it is worthwhile to investigate these systems further
Towards increased microalgal productivity in photobioreactors
Bosma, R. ; Vermuë, M.H. ; Tramper, J. ; Wijffels, R.H. - \ 2010
International Sugar Journal 112 (2010)1334. - ISSN 0020-8841 - p. 74 - 85.
high photosynthetic productivity - outdoor mass cultivation - genetic algorithm - medium optimization - chlorella-vulgaris - growth-inhibition - strain selection - algal cultures - fatty-acids - light
Currently there is much interest to cultivate microalgae for the production of bulk products like lipids for biodiesel or as feedstock for industrial chemical processes. To make the production economically feasible, it is essential to develop cultivation systems in which algae convert the light with a high photosynthetic efficiency, to obtain microalgae with specific production characteristics, to optimize the culture medium, to develop cheap harvesting methods and finally professionals to implement and develop the technology. For the development of better algal cultivation systems, insight is needed on the efficiency of light conversion by these algae. Two concepts of light dilution in photobioreactor design are presented to reflect how potentially higher photosynthetic efficiencies can be achieved. Also, fast screening methods for microalgae are discussed, which can be applied to select strains with better production characteristics, to optimize the medium, to compare cultivation conditions and to investigate the toxic effects of chemicals. Apart from obtaining enhanced algal productivities a low-cost harvesting process is required. For harvesting of bulk products, as preconcentration step, controlled auto-flocculation is worthwhile investigating. Beside these research lines, more and better education for biochemical engineers should be developed to push microalgal biotechnology ahead.
Application of bench-scale biocalorimetry to photoautotrophic cultures
Janssen, M. ; Patino, R. ; Stockar, U. von - \ 2005
Thermochimica Acta 435 (2005)1. - ISSN 0040-6031 - p. 18 - 27.
light-emitting-diodes - chlamydomonas-reinhardtii - saccharomyces-cerevisiae - chlorella-vulgaris - growth - photosynthesis - calorimetry - photobioreactor - identification - incident
Bench-scale biocalorimetry (=1 L) allows for the determination of the metabolic heat flow during bioprocesses under complete control of all process conditions for extended periods of time. It can be combined with a number of on-line and off-line measurement techniques. This combination can significantly improve insight into the metabolism of microorganisms and the optimization of bioprocesses. In this study it is demonstrated that bench-scale biocalorimetry can also be applied to phototrophic microorganisms. The green microalga Chlorella vulgaris CCAP 211/11B was cultivated in a Mettler-Toledo RC1 calorimeter adapted for high-sensitivity biological calorimetry (BioRC1). Heat production was monitored in 1.5 L batch cultures. In the linear phase of growth, inhibitors of photosynthetic electron transport (DCMU, 3-(3,4-dichlorophenyl)-1,1-dimethylurea, and DBMIB, 2,5-dibromo-3-methyl-6-isopropyl-p-benzoquinone), were used to stop photosynthesis and to monitor the resulting increase in the energy dissipating heat flux. This resulted in a calculated storage of light energy as chemical energy, i.e. biomass, of 141 ± 12.2 mW L-1 (±S.D.). In addition, it was demonstrated that calorimetric determination of the total amount of light energy absorbed within the reactor was accurate by comparing two different calorimetric techniques. Using both the value of the total light input and the quantity stored as chemical energy, the photosynthetic efficiency could be calculated as 10.5% in this example.
In vivo uniform 15N-isotope labelling of plants: Using the greenhouse for structural proteomics
Ippel, J.H. ; Pouvreau, L.A.M. ; Kroef, T. ; Gruppen, H. ; Versteeg, G. ; Putten, P.E.L. van der; Struik, P.C. ; Mierlo, C.P.M. van - \ 2004
Proteomics 4 (2004)1. - ISSN 1615-9853 - p. 226 - 234.
chlorella-vulgaris - growth - c-13
Isotope labelling of proteins is important for progress in the field of structural proteomics. It enables the utilisation of the power of nuclear magnetic resonance spectroscopy (NMR) for the characterisation of the three-dimensional structures and corresponding dynamical features of proteins. The usual approach to obtain isotopically labelled protein molecules is by expressing the corresponding gene in bacterial or yeast host organisms, which grow on isotope-enriched media. This method has several drawbacks. Here, we demonstrate that it is possible to fully label a plant with N-15-isotopes. The advantage of in vivo labelling of higher organisms is that all constituting proteins are labelled and become available as functional, post-translationally modified, correctly folded proteins. A hydroponics set-up was used to create the first example of a uniformly N-15-labelled (>98%) plant species, the potato plant (Solanum tuberosum L., cv. Elkana). Two plants were grown at low costs using potassium[N-15]-nitrate as the sole nitrogen source. At harvest time, a total of 3.6 kg of potato tubers and 1.6 kg of foliage, stolons and roots were collected, all of which were fully N-15-labelled. Gram quantities of soluble N-15-labelled proteins (composed mainly of the glycoprotein patatin and Kunitz-type protease inhibitors) were isolated from the tubers. NMR results on the complete proteome of potato sap and on an isolated protease inhibitor illustrate the success of the labelling procedure. The presented method of isotope labelling is easily modified to label other plants. Its envisioned impact in the field of structural proteomics of plants is discussed.