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A semi-industrial process (800-l fermentor) for lycopene production by mated fermentation ofBlakeslea trisporaplus (+) and minus (-) strains has been developed. The culture medium was designed at the flask scale, using a program based on a genetic algorithm; and a fermentation process by means of this medium was developed. Fermentation involves separate vegetative phases for (+) and (-) strains and inoculation of the production medium with a mix of both together. Feeding with imidazole or pyridine, molecules known to inhibit lycopene cyclase enzymatic activity, enhanced lycopene accumulation. Different raw materials and physical parameters, including dissolved oxygen, stirring speed, air flow rate, temperature, and pH, were checked in the fermentor to get maximum lycopene production. Typical data for the fermentation process are presented and discussed. This technology can be easily scaled-up to an industrial application for the production of this carotenoid nowadays widely in demand. [ABSTRACT FROM AUTHOR]

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. Its mission is to provide O 2 and consume CO 2 while producing edible material. Biological and process characterization of this PBR is performed by analysing the effect of two main variables, dilution rate (D) and PFD (Photon Flux Density) illumination. A maximum oxygen productivity ( r O 2 ) of 1.35 mmol l -1  h -1 is obtained at a D of 0.025 h -1 and PFD of 930 µmol m -2  s -1 . Photoinhibition can occur when a 1 g l -1 cell density culture is exposed to PFD higher than 1700 µmol m -2  s -1 . This process is reversible if the illumination is returned to dim light (150 µmol m -2  s -1 ), proving the cell adaptability and capacity to respond at different illumination conditions. Influence of light intensity in cell composition is also described. Specific photon flux density (qPFD) has a direct effect on phycobiliproteins and chlorophyll content causing a decrease of 62.5% and 47.8%, respectively, when qPFD increases from 6.1 to 19.2 µmol g -1  s -1 . The same trend is observed for proteins and the opposite for carbohydrate content. Morphological and spiral structural features of L. indica are studied by confocal microscopy, and size distribution parameters are quantified. A direct effect between trichome width and CDW/OD ratio is observed. Changes in size distribution are not correlated with environmental factors, further confirms the adaptation capacity of the cells. The systematic analysis performed provides valuable insights to understand the key performance criteria of continuous culture in air-lift PBRs., (© 2021 The Authors. Microbial Biotechnology published by Society for Applied Microbiology and John Wiley & Sons Ltd.)

The MELiSSA Pilot Plant (MPP) is testing in terrestrial conditions regenerative life support technologies for human exploration in Space. One of its components is a controlled Higher Plant Chamber (HPC) accommodating hydroponic plant cultures. It consists of a 9 m 3 single closed growth chamber providing adequate environmental conditions for growing plants, enabling the production of food, water and oxygen for the crew. A critical aspect for a reliable HPC performance is to achieve homogeneous air distribution. The initial experiment carried out in the MPP with lettuce as salad crop, showed uneven plant growth throughout the HPC, which was attributed to inadequate air distribution due to non-homogeneous air velocity profile along the inlet-vents. After a detailed computational fluid dynamics (CFD) analysis, the heating, ventilation, and air conditioning subsystem of the HPC was upgraded and a new experiment was carried out in optimized air flow conditions. Nine-day seedlings of lettuce cultivar "Grand Rapids" were transplanted into the HPC and harvested at the end of the growing cycle, where shoot fresh weight, dry biomass, and shoot mineral composition were analyzed. During the experiment, the environmental control system performed remarkably well based on the biometric measurements as well as the mineral composition leading to a vast homogeneous growth. Overall, the results demonstrated the beneficial effect of an adequate air distribution system in HPCs and the effectiveness of CFD-analysis to design properly the gas distribution. The obtained results are of high relevance for life support systems in space involving plants growth., (Copyright © 2020 Peiro, Pannico, Colleoni, Bucchieri, Rouphael, De Pascale, Paradiso and Gòdia.)

An improved semi-industrial process for astaxanthin production by fermentation of Xanthophyllomyces dendrorhous has been developed. The culture medium was designed at the flask scale, reaching an astaxanthin cellular content of 3.0 mgg(-1) cell weight and a volumetric yield of 119 mgL(-1) broth. Astaxanthin production in flask was significantly improved by white light (4.0 mgg(-1) and 221 mgL(-1)), and by ultraviolet light (4.4 mgg(-1) and 235 mgL(-1)). The scale-up to 10- and 800-L fermentors was developed by feeding with glucose. Representative data for illuminated fermentation processes are presented and discussed at the 10-L scale, where 420 mgL(-1) (4.7 mgg(-1)) astaxanthin were produced, and the 800-L scale, with productivities of 350 mgL(-1) (4.1 mgg(-1)) astaxanthin. The purity of the astaxanthin in the broth was about 84%, with accumulation of the following carotenoids other than astaxanthin: 4% beta-carotene, 4% canthaxanthin, 5% HDCO, 1% zeaxanthin and 2% phoenicoxanthin. This technology can be easily scaled-up to an industrial application for the production of this xanthophyll widely demanded nowadays., (Copyright (c) 2010 Elsevier B.V. All rights reserved.)