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Biotechnology for cultivation of the source of antioxidants – cyanobacterium Nostoc linckia

Author: Valuța Ana
Degree:doctor of biology
Speciality: 03.00.23 - Biotechnology
Scientific adviser: Liliana Cepoi
doctor, associate professor (docent), Institute of Microbiology and Biotechnology of the ASM
Institution: Institute of Microbiology and Biotechnology of the ASM


The thesis was presented on the 23 October, 2015
Approved by NCAA on the 22 December, 2015


Adobe PDF document1.59 Mb / in romanian


CZU 573.6.086.83 : 663.1

Adobe PDF document 3.85 Mb / in romanian
160 pages


Technology of cultivation, cyanobacteria, Nostoc linckia, aqueous and ethanolic extracts, antioxidant preparation, biosorbent, and bionanosynthesis


The thesis consists of an introduction, four chapters, conclusions and recommendations, bibliography list with 292 references. It comprises 131 pages of the main text, 49 figures, 10 tables and 3 annexes. The results were published in 24 scientific papers.

Field of study: 167.01 – Biotechnology, Bionanotechnology.

Aim: To develop cultivation technologies of cyanobacteria Nostoc linckia, obtaining the antioxidant preparations and valorization of the biomass residue. Objectives: Monitoring the biochemical changes and antioxidant activity of biomass and extracts during static culture of Nostoc linckia development; Highlighting the biotechnology indicators with tangency to vital cycle, useful for antioxidant preparations obtaining from biomass of Nostoc linckia; Determining the optimal biotechnological parameters for extraction and long term storage of antioxidant components from Nostoc biomass; Elucidation of the peculiarities for modification of antioxidant content in the biomass of cyanobacteria Nostoc linckia under oxidative stress induced by Fe(III) compounds; Study the possibility of recovery of biomass residue after extraction of Nostoc linckia antioxidant components; Development of complex technology of Nostoc linckia cultivation, antioxidant preparations obtaining; use of biomass residue as an effective biosorbent in the environmental purification technologies and for silver nanoparticles biosynthesis.

Scientific novelty of research. For the first time the problem of developing the cultivation technology of cyanobacteria Nostoc linckia as a source for obtaining the antioxidant complex preparations was stated.

Important scientific problem, solved in this research work, is to identify the key-elements of the biotechnology process of Nostoc linckia cultivation in order to use biomass for production of antioxidant preparations.

Theoretical signification. There were collected and exposed new results about the importance of monitoring the changes in biochemical and antioxidant status of Nostoc linckia biomass during static culture cycle. It was revealed high sensitivity threshold of the culture of Nostoc linckia to chemical compounds with metals in terms of modifying the antioxidant status of biomass. It was demonstrated effectiveness of Nostoc biomass as biosorbent in polluted multimetallic systems and as matrix for bionanosynthesis.

Practical value. In this paper were making the parts of complex technology of Nostoc linckia cultivation and efficient use of biomass, which can be applied as a whole and as autonomous units: procedures for Nostoc biomass with high antioxidant activity; efficient extraction procedures of antioxidant components from Nostoc biomass; procedures for obtaining the biomass with silver nanoparticles; procedures for the use of biomass residue after obtaining the antioxidant preparations as effective biosorbent.

Implementation of scientific results. Technology of obtaining the antioxidant preparation AON was implemented at LTD "Ficotehfarm" (Implementation Act Nr. 03/11 from 20.11.2014).