Inhibitors formed by lignocellulose hydrolysis

Pojam lignocelulozne sirovine odnosi se na ostatke iz drvne i prehrambene industrije te različite poljoprivredne ostatke. Ove sirovine sastoje se od celuloze, hemiceluloze i lignina, a u novije vrijeme sve se više radi na njihovoj primjeni za dobivanje različitih biotehnoloških proizvoda (npr. organskih kiselina, enzima, biogoriva, antibiotika, mikrobne biomase i biopesticida). Prije početka biotehnološkog procesa potrebno je razmotriti pojedine metode predobrade različitih vrsta lignoceluloznih sirovina radi razgradnje njihove složene strukture. Metode predobrade dijele se na fizikalne, fizikalno-kemijske te kemijske i biološke. Razgradnjom lignoceluloznih sirovina kemijskim metodama, nastaje veliki broj nusprodukata, odnosno inhibitora koji štetno djeluju na radne mikroorganizme kao npr. furfural, vanilin, octena kiselina, mravlja kiselina i 5-hidroksimetil furfural. Kako bi se smanjila inhibicija, razvijene su mnoge metode detoksikacije kojima se inhibitori uklanjaju ili prevode u manje štetne spojeve. Potrebno je poznavati sastav sirovina te strukturu inhibitora kako bi odabrali odgovarajuće metode detoksikacije.Lignocellulosic materials are residues from wood and food industry as well as different agricultural residues. These materials consist of cellulose, hemicellulose and lignin. Recently, the use of lignocellulosic materials have became actual in production of biotechnological products (such as organic acids, enzymes, biofuels, antibiotics, microbial biomass and biopesticides). Because of their complex structure, lignocellulosic materials require the appropriate methods of pretreatment before starting biotechnological process. Preatreatments methods are divided in physical, physical-chemical, chemical and biological methods. Chemical lignocellulose degradation causes release of various byproducts, i.e. inhibitors that negatively affect to fermentative microorganisms. Some of these inhibitors are furfural, vanilin, acetic acid, formic acid and HMF. To avoid inhibition, many detoxification methods are developed that degrade inhibitors in less adverse compounds or decrease inhibitor concentrations. Knowledge of the composition of lignocellulosic raw materials and inhibitors formed during their pretreatment are important for selection of the appropriate detoxication method