3D tailored design as a bioremediation strategy for a lagoon in Matanza-Riachuelo Basin

TRENTINI A.; NADRA C.; MARCONI P.; ZAWOZNIK M.S.; GROPPA M.D.

Congreso; 5th World Congress on New Technologies (NewTech'19); 2019

3D Tailored Design as a Bioremediation Strategy for a Lagoon inMatanza-Riachuelo BasinPatricia Laura Marconi1, Andrea Trentini1, María Daniela Groppa2, Myriam Zawoznik3, Carlos Nadra41CONICET, CEBBAD , Univ. Maimónides,Hidalgo 775, Buenos Aires, Argentina ;marconi.patricialaura@maimonides.edu; trentini.andrea@maimonides.edu2CONICET, FFyB, Universidad de Buenos Aires,Junin 954, Buenos Aires, Argentinadanielagroppa@gmail.com3FFyB, Universidad de Buenos Aires,Junin 954, Buenos Aires, Argentina;myriamz@ffyb.uba.ar4ACUMAREsmeralda 225, Buenos Aires, Argentinacnadra@acumar.gov.arExtended AbstractA native strain of the microalgae Chlorella vugaris was shown to be effective for the reduction of several chemical andmicrobial contaminants present in polluted streams from the Matanza-Riachuelo Basin (M-R, 1). The microalgaeimmobilization in calcium alginate beads protects the cells from the toxic effects of numerous substances and from extremepH and temperatures, allowing better survival and greater efficiency in the production of biomass [2, 3]. However, cellstrapped in the matrix are easy to be devoured by the fauna existent. Saladita Norte lagoon is part of M-R, this watercourseexhibits a wide range of contaminants levels along the year, mainly depending on the seasonal regime. At certain periods ofthe year, these levels usually exceed the limits established in international standards of water quality [4-6]. Similarly to thatobserved in other streams of M-R, several nitrogenated compounds, phosphorus, metals, and saprophytic and pathogenicbacteria are the main contaminants of Saladita Norte. In order to protect the alginate beadsfrom the birds and fishes predation,a 3D-printed PLA (polylactic acid) device was designed. PLA is a biocompatible and biodegradable material that has beendescribed as suitable for biotechnological applications. [7]. Bioprocesses carried out with this material must be checked formechanical stability and optimal pore size to allow an effective bioremediation process. For this purpose, we used a stirredtank bioreactor supplied with a marine propeller and aeration during 6 days. Growth index and biomass production werecompared between algae immobilized in alginate beads versus immobilized in alginate beads placed into a complex 3Dprinted PLA device.As previously observed, our native isolate of C. vulgaris could grow inside the alginate beads based on the consumptionof several of the above-mentioned contaminants, such as phosphorus and nitrogenated ions[1]. The results obtained in controltreatments with immobilized cells in alginate beads were: A- MS synthetic culture media supplemented with sucrose (3%w/v) and indolacetic acid (1 mg/L) as growth regulator [1] (=0.737, dt= 24 h) and B- as A- but growing in Saladita Nortewater (=0.668, dt= 24 h). Also, treatments using 3D-device were: C- like B, but Chlorella cultures immobilized in alginatebeads growing into a PLA3D scaffold coloured red (=0.341, dt= 2 d); D- like C, but coloured white (=0.206, dt= 3 d);and E- like C, but uncoloured (=0.342, dt= 2 d) were effective and successful to bioremediation in vitro. All cultures werekept at 24±2ºC, with a photoperiod of 16 h under PAR (above 400 μmol photon m-2 s-1). The data obtained werecomplemented with standardized cytotoxicity tests using Allium cepa and Lactuca sativa seeds. Germination rate and mitoticindex of onion seeds and germination rate and length of lettuce seeds using polluted water or bioremediated water werecompared. The results obtained demonstrate the potential of this technology to be used in integrated processes thatseek removal of xenobiotics.ICEPR 121-2References[1] M. D. Groppa, A. Trentini, M. Zawoznik, R