WEAVE J4-4561

Abstract

Increased demands for olive oil production result in more than 30mio m3 of lignocellulosic wastes per year in the Mediterranean basin, calling for sustainable management of olive pomace (OP) waste. The phytotoxic nature of fresh OP, caused by the high concentrations of polyphenols, lipids and organic acids, can be reduced by two distinctive approaches: either by burning the waste or by valorising it to meet the objectives of sustainability and circularity. Valorization can be achieved at two technical levels: (i) by composting aiming to produce organic fertilizers or (ii) by biotransformation aiming to produce added value compounds that can be used in polymer, food and pharmaceutical industries. Preparation of artificial consortia will be incorporated into carriers or attached on insoluble plant material to: (i) achieve a faster composting process, i.e. reducing OP quantity and transforming it into organic fertilizer and (ii) demonstrate the production of various added-value products out of the compounds present in OP material (e.g. polyhydroxyalkanoates and aromatic substances). To achieve these objectives we will select, construct and characterize the most efficient consortia using different molecular biology methodologies as well as chemical analytic approaches. We will mainly try to assess the activity of these consortia by determining the various metabolic side products of the decomposition process as well as by molecular tools such as transcriptomics and metagenomics to determine community dynamics and their stability to efficiently optimize processes. The prepared immobilized consortia will be then also used in the pilot-scale composting reactors, while the mature compost will be tested with bioassays to determine phytotoxic and plant growth-promoting activity.

Abstract

Posledica povečanega povpraševanja po proizvodnji oljčnega olja je več kot 30 milijonov m3 lignoceluloznih odpadkov na leto v sredozemlju, kar zahteva trajnostno ravnanje z odpadnimi oljčnimi tropinami (OP). Fitotoksično naravo svežih OP, ki jo povzročajo visoke koncentracije polifenolov, lipidov in organskih kislin, je mogoče zmanjšati z dvema različnima pristopoma: bodisi s sežiganjem odpadkov, bodisi z njihovo valorizacijo, da se dosežejo cilji trajnosti in krožnosti. Valorizacijo je mogoče doseči na dveh tehničnih ravneh: (i) s kompostiranjem za proizvodnjo organskih gnojil ali (ii) z biotransformacijo za proizvodnjo spojin z dodano vrednostjo, ki se lahko uporabljajo v polimerni, prehrambeni in farmacevtski industriji. Pripravek umetnih konzorcijev bakterij bo vgrajen v nosilce ali pritrjen na netopni rastlinski material za: (i) doseganje hitrejšega procesa kompostiranja, tj. zmanjšanje količine OP in njegovo pretvorbo v organsko gnojilo ter (ii) prikaz proizvodnje različnih produktov z dodano vrednostjo iz spojin, prisotnih v materialu OP (npr. polihidroksialkanoati in aromatične snovi). Za dosego teh ciljev bomo izbrali, zgradili in karakterizirali najučinkovitejše konzorcije z uporabo različnih metodologij molekularne biologije in kemijskih analitičnih pristopov. V glavnem bomo poskušali oceniti aktivnost teh konzorcijev z določanjem različnih presnovnih stranskih produktov procesa razgradnje kot tudi z molekularnimi orodji, kot sta transkriptomika in metagenomika, da bi določili dinamiko skupnosti in njihovo stabilnost za učinkovito optimizacijo procesov. Pripravljene imobilizirane konzorcije bomo nato uporabili tudi v pilotnih reaktorjih za kompostiranje, medtem ko bomo zrel kompost testirali z biološkimi testi za ugotavljanje fitotoksičnosti in aktivnosti za spodbujanje rasti rastlin.

Slovenian project leader: Jožef Stefan Institute (dr. Aleš Lapanje)

Slovenian research group collaborators: National Institute of Chemistry 

Croatian project leader: Institute of Agriculture and Tourism (dr. Marko Černe)

Croatian research group collaborators: University of Zagreb Faculty of Agriculture; National School of Agriculture, Meknes, Morocco