Development and implementation of a simulated microgravity setup for edible cyanobacteria.

Regenerative life support systems for space crews recycle waste into water, food, and oxygen using different organisms. The European Space Agency's MELiSSA program uses the cyanobacterium Limnospira indica PCC8005 for air revitalization and food production. Before space use, components' compatibility with reduced gravity was tested.

Plant and microbial science and technology as cornerstones to Bioregenerative Life Support Systems in space.

Long-term human space exploration missions require environmental control and closed Life Support Systems (LSS) capable of producing and recycling resources, thus fulfilling all the essential metabolic needs for human survival in harsh space environments, both during travel and on orbital/planetary stations. This will become increasingly necessary as missions reach farther away from Earth, thereby limiting the technical and economic feasibility of resupplying resources from Earth. Further incorporation of biological elements into state-of-the-art (mostly abiotic) LSS, leading to bioregenerative LSS (BLSS), is needed for additional resource recovery, food production, and waste treatment solutions, and to enable more self-sustainable missions to the Moon and Mars.

gen. nov., sp. nov., a thermophilic chain-elongating bacterium, producing -caproate from polymeric carbohydrates.

Strain MDTJ8 is a chain-elongating thermophilic bacterium isolated from a thermophilic acidogenic anaerobic digestor treating human waste while producing the high commodity chemical -caproate. The strain grows and produces formate, acetate, -butyrate, -caproate and lactate from mono-, di- and polymeric saccharides at 37-60 °C (optimum, 50-55 °C) and at pH 5.0-7.

Isolation and characterization of a thermophilic chain elongating bacterium that produces the high commodity chemical n-caproate from polymeric carbohydrates.

A thermophilic chain elongating bacterium, strain MDTJ8, was isolated from a thermophilic acidogenic anaerobic digestor producing n-caproate from human waste, growing optimally at 50-55 °C and pH 6.5. 16S rRNA gene analysis suggests that MDTJ8 represents a new species/genus within a group currently composed of mesophilic chain elongators of the Oscillospiraceae family.

Dynamics of long-term continuous culture of Limnospira indica in an air-lift photobioreactor.

MELiSSA (Microecological Life Support System Alternative) is a developing technology for regenerative life support to enable long-term human missions in Space and has developed a demonstration Pilot Plant. One of the components of the MELiSSA Pilot Plant system is an 83L external loop air-lift photobioreactor (PBR) where Limnospira indica (previously named Arthrospira sp. PC8005) is axenically cultivated in a continuous operation mode for long-periods.

Online analysis of D-glucose and D-mannose aqueous mixtures using Raman spectroscopy: an in silico and experimental approach.

Raman spectroscopy was applied to an aqueous solution containing D-mannose and D-glucose at a fixed dry matter content. The Raman measurement apparatus was adapted online at the industrial scale to monitor a bioprocess including an epimerization reaction. Online Raman spectroscopy and deconvolution techniques were successfully applied to monitor in real time the D-mannose and D-glucose concentrations using the Raman shifts at 960 cm and 974 cm respectively.

Use of Photobioreactors in Regenerative Life Support Systems for Human Space Exploration.

There are still many challenges to overcome for human space exploration beyond low Earth orbit (LEO) (e.g., to the Moon) and for long-term missions (e.

Assessing the impact of industrial waste on environment and mitigation strategies: A comprehensive review.

The increasing demand of rising population leads to the escalation of industrial sectors such as agro-, food-, paper and pulp industries. These industries generated hazardous waste which is primarily organic in nature thus is being dumped or processed in the environment. These waste leads to increasing contamination leading to increased mortality, physical and morphological changes in the organisms/animals in contact.

Comprehensive assessment of 2G bioethanol production.

The advancements in second-generation bioethanol produced from lignocellulosic biomass, such as crops residues, woody crops or energy grasses are gaining momentum. Though, they are still representing less than 3% of total bioethanol production, the GHG reduction potential is higher than for 1G-bioethanol. The environmental impacts of bioethanol production are totally dependent on feedstock availability and conversion technology.

Limnospira indica PCC8005 growth in photobioreactor: model and simulation of the ISS and ground experiments.

The Arthrospira-B experiment is the first experiment in space ever allowing the online measurements of both oxygen production rate and growth rate of Limnospira indica PCC8005 in batch photobioreactors running on-board ISS. Four bioreactors were integrated in the ISS Biolab facility. Each reactor was composed of two chambers (gas and liquid) separated by a PTFE membrane and was run in batch conditions.

A Physical Modeling Approach for Higher Plant Growth in Reduced Gravity Environments.

Including plants in bioregenerative life-support systems enables simultaneous food production and water and air recycling, while closing cycles for water, oxygen, nitrogen, and carbon. To understand and predict higher plant behavior for a wide range of environmental conditions, including reduced gravity levels, a mechanistic physical model is being developed. The emphasis is set on the influence of gravity levels and forced convection on higher plant leaf gas exchanges, which are altered by reduction of free convection in lower gravity environments, such as microgravity or martian and lunar gravities.

Assessment of transient effects of alternative nitrogen sources in continuous cultures of Arthrospira sp. using proteomic, modeling and biochemical tools.

The ability of cyanobacterium Arthrospira sp. to assimilate waste nitrogen sources (ammonium and urea) makes it an important candidate for wastewater management. The aim of this work was to evaluate a cultivation approach based on continuous-transitional-feeding regime (nitrate-ammonium-nitrate) in a photobioreactor to assess the effects of ammonium salts on Arthrospira sp.

High-frequency, high-intensity electromagnetic field effects on Saccharomyces cerevisiae conversion yields and growth rates in a reverberant environment.

Studies of the effects of electromagnetic waves on Saccharomyces cerevisiae emphasize the need to develop instrumented experimental systems ensuring a characterization of the exposition level to enable unambiguous assessment of their potential effects on living organisms. A bioreactor constituted with two separate compartments has been designed. The main element (75% of total volume) supporting all measurement and control systems (temperature, pH, agitation, and aeration) is placed outside the exposure room whereas the secondary element is exposed to irradiation.

Determination of Gibbs energies of formation in aqueous solution using chemical engineering tools.

Standard Gibbs energies of formation are of primary importance in the field of biothermodynamics. In the absence of any directly measured values, thermodynamic calculations are required to determine the missing data. For several biochemical species, this study shows that the knowledge of the standard Gibbs energy of formation of the pure compounds (in the gaseous, solid or liquid states) enables to determine the corresponding standard Gibbs energies of formation in aqueous solutions.

Test of an anaerobic prototype reactor coupled with a filtration unit for production of VFAs.

The artificial ecosystem MELiSSA, supported by the European Space Agency is a closed loop system consisting of 5 compartments in which food, water and oxygen are produced out of organic waste. The first compartment is conceived as a thermophilic anaerobic membrane bioreactor liquefying organic waste into VFAs, ammonium and CO2 without methane. A 20 L reactor was assembled to demonstrate the selected design and process at prototype scale.

A model-based method for investigating bioenergetic processes in autotrophically growing eukaryotic microalgae: application to the green algae Chlamydomonas reinhardtii.

A constraint-based modeling approach was developed to investigate the metabolic response of the eukaryotic microalgae Chlamydomonas reinhardtii under photoautotrophic conditions. The model explicitly includes thermodynamic and energetic constraints on the functioning metabolism. A mixed integer linear programming method was used to determine the optimal flux distributions with regard to this set of constraints.

A simple and reliable formula for assessment of maximum volumetric productivities in photobioreactors.

This article establishes and discusses the consistency and the range of applicability of a simple but general and predictive analytical formula, enabling to easily assess the maximum volumetric biomass growth rates (the productivities) in several kinds of photobioreactors with more or less 15% of deviation. Experimental validations are performed on photobioreactors of very different conceptions and designs, cultivating the cyanobacterium Arthrospira platensis, on a wide range of volumes and hemispherical incident light fluxes. The practical usefulness of the proposed formula is demonstrated by the fact that it appears completely independent of the characteristics of the material phase (as the type of reactor, the kind of mixing, the biomass concentration.

Spectral kinetic modeling and long-term behavior assessment of Arthrospira platensis growth in photobioreactor under red (620 nm) light illumination.

The ability to cultivate the cyanobacterium Arhtrospira platensis in artificially lightened photobioreactors using high energetic efficiency (quasi-monochromatic) red LED was investigated. To reach the same maximal productivities as with the polychromatic lightening control conditions (red + blue, P/2e(-) = 1.275), the need to work with an optimal range of wavelength around 620 nm was first established on batch and continuous cultures.

Dynamic aspects and controllability of the MELiSSA project: a bioregenerative system to provide life support in space.

Manmade ecosystems differ from their prototype biosphere by the principle of control. The Earth Biosphere is sustainable by stochastic control and very large time constants. By contrast, in a closed ecosystem such as the micro-ecological life support system alternative (MELiSSA system) developed by the European Space Agency for space exploration, a deterministic control is a prerequisite of sustainable existence.

Application of a data reconciliation method to the stoichiometric analysis of Fibrobacter succinogenes growth.

Fibrobacter succinogenes S85, a strictly anaerobic Gram-negative bacterium, was grown in continuous culture in a bioreactor at different dilution rates (0.02 to 0.092 h(-1)) on a fully synthetic culture medium with glucose as carbon source.

Chemical and conformational study of the interactions involved in mycotoxin complexation with beta-D-glucans.

In a previous paper we reported that beta-D-glucans isolated from Saccharomyces cerevisiae could adsorb zearalenone, reduce its bioavailability in the digestive tract, and protect animals against its adverse effects. We have now investigated, in vitro, the kinetics of the interaction between other mycotoxins and beta-D-glucans from several sources at three pH values found along the digestive tract (3.0, 6.

Alkali extraction of beta-d-glucans from Saccharomyces cerevisiae cell wall and study of their adsorptive properties toward zearalenone.

The isolated cell wall of Saccharomyces cerevisiae has some capacity to adsorb zearalenone (affinity near 30%) and reduce the bioavailability of toxins in the digestive tract. The adsorption process was quantified in vitro, and the data obtained when plotted with Hill's equation indicated a cooperative process. The model showed that the adsorption capacity was related to the yeast cell wall composition.

Modeling stability of photoheterotrophic continuous cultures in photobioreactors.

Continuous cultures of the purple non-sulfur bacterium Rhodospirillum rubrum were grown in a cylindrical photobioreactor in photoheterotrophic conditions, using acetate as carbon source. A new kinetic and stoichiometric knowledge model was developed, and its ability to simulate experimental results obtained under varying incident light fluxes and residence times is discussed. The model accurately predicts the stable, unstable, or oscillating behavior observed for the reactor productivity.