A novel integrated approach employing Desertifilum tharense BERC-3 for efficient wastewater valorization and recycling for developing peri-urban algae farming system.

Peri-urban environments are significant reservoirs of wastewater, and releasing this untreated wastewater from these resources poses severe environmental and ecological threats. Wastewater mitigation through sustainable approaches is an emerging area of interest. Algae offers a promising strategy for carbon-neutral valorization and recycling of urban wastewater. Aiming to provide a proof-of-concept for complete valorization and recycling of urban wastewater in a peri-urban environment in a closed loop system, a newly isolated biocrust-forming cyanobacterium Desertifilum tharense BERC-3 was evaluated. Here, the highest growth and lipids productivity were achieved in urban wastewater compared to BG11 and synthetic wastewater. D. tharense BERC-3 showed 60-95% resource recovery efficiency and decreased total dissolved solids, chemical oxygen demand, biological oxygen demand, nitrate nitrogen, ammonia nitrogen and total phosphorus contents of the water by 60.37%, 81.11%, 82.75%, 87.91%, 85.13%, 85.41%, 95.87%, respectively, making it fit for agriculture as per WHO's safety limits. Soil supplementation with 2% wastewater-cultivated algae as a soil amender, along with its irrigation with post-treated wastewater, improved the nitrogen content and microbial activity of the soil by 0.3-2.0-fold and 0.5-fold, respectively. Besides, the availability of phosphorus was also improved by 1.66-fold. The complete bioprocessing pipeline offered a complete biomass utilization. This study demonstrated the first proof-of-concept of integrating resource recovery and resource recycling using cyanobacteria to develop a peri-urban algae farming system. This can lead to establishing wastewater-driven algae cultivation systems as novel enterprises for rural migrants moving to urban areas.

"Noah's Ark" Project: Interim Results and Outlook for Classic Collection Development.

The "Noah's Ark" project, afoot at M.V. Lomonosov Moscow State University since 2015 and aimed at studying biodiversity, is the largest ongoing Russian project in life sciences. During its implementation, several hundred new species have been described; a comprehensive genetic and biochemical characterization of these species, as well as that of the pre-existing specimens in Moscow University's collections, has been performed. A consolidated IT system intended to house the knowledge generated by the project has been developed. Here, we summarize the investigations around the Moscow University classical biocollections which have taken place within the framework of the project and discuss future promise and the outlook for these collections.

Analysis of Photoprotection and Apparent Non-photochemical Quenching of Chlorophyll Fluorescence in Tradescantia Leaves Based on the Rate of Irradiance-Induced Changes in Optical Transparence.

The kinetics of irradiation-induced changes in leaf optical transparence (ΔT) and non-photochemical quenching (NPQ) of chlorophyll fluorescence in Tradescantia fluminensis and T. sillamontana leaves adapted to different irradiance in nature was analyzed. Characteristic times of a photoinduced increase and a dark decline of ΔT in these species were 12 and 20 min, respectively. The ΔT was not confirmed to be the main contributor to the observed middle phase of NPQ relaxation kinetics (τ = 10-28 min). Comparison of rate of photoinduced increase in ΔT and photosystem II quantum yield recovery showed that the former did not affect the tolerance of the photosynthetic apparatus (PSA) to irradiances up to 150 µmol PAR·m-2·s-1. Irradiance tolerance correlated with the rate of "apparent NPQ" induction. Considering that the induction of apparent NPQ involves processes significantly faster than ΔT, we suggest that the photoprotective mechanism induction rate is crucial for tolerance of the PSA to moderate irradiance during the initial stage of light acclimation (first several minutes upon the onset of illumination).

Tolerance of the Photosynthetic Apparatus to Acidification of the Growth Medium as a Possible Determinant of CO2-Tolerance of the Symbiotic Microalga Desmodesmus sp. IPPAS-2014.

The symbiotic unicellular chlorophyte Desmodesmus sp. IPPAS-2014 capable of growth at extremely high CO2 levels prohibitive for most other microalgae is an interesting model for studies of CO2 tolerance mechanisms and a promising organism for CO2 biocapture. We studied the initial (0-60 min) phase of acclimation of this microalga to an abrupt decrease in pH of the medium sparged with air/20% CO2 mixture. Acclimation of the culture to these conditions was accompanied by a sharp decrease in photochemical activity of the chloroplast followed by its recovery with a characteristic time of 10-50 min. We hypothesize that acidification of the cultivation medium by dissolving CO2 plays a key role in the observed decrease in the photochemical activity. The possible role of photosynthetic apparatus tolerance to abrupt acidification in overall high tolerance of symbiotic microalgae to extremely high CO2 levels is discussed.

Induction of Secondary Carotenogenesis in New Halophile Microalgae from the Genus Dunaliella (Chlorophyceae).

We report on the effects of high light irradiance (480 µmol quanta/(m(2)·s)) and salinity (160 and 200 g/liter NaCl) on culture growth as well as on cell lipid pigment and fatty acid (FA) composition in three novel strains of halophile microalga from the genus Dunaliella. Based on the ITS1-5.8S rRNA-ITS2 sequence and on the capability of accumulation of secondary (uncoupled from the photosynthetic apparatus) ß-carotene, the strains Dunaliella sp. BS1 and BS2 were identified as D. salina and Dunaliella sp. R5 as D. viridis. Under conditions optimal for growth, chlorophylls and primary carotenoids (mainly lutein) dominated the pigment profile of all investigated strains. The main FA were represented by unsaturated C18 FA typical of thylakoid membrane structural lipids. In all studied cells, stressors caused a decline in chlorophylls and an increase in unsaturated C16 and C18 FA associated with reserve lipids. The carotenogenic species D. salina demonstrated 10-fold increase in carotenoids accompanied by a decline in lutein and a drastic increase in ß-carotene (up to 75% of total carotenoids). In D. viridis, only 1.5-fold increase in carotenoid content took place, the ratio of major carotenoids remaining essentially unchanged. The role of the carotenogenic response in mechanisms of protection against photooxidative damage is discussed in view of halophile microalgae stress tolerance and application of the new Dunaliella strains for biotechnological production of ß-carotene.