Microorganisms for fermentation of lignocellulosic hydrolyzates

Velika količina lignoceluloznog otpada, kojeg čine uglavnom celuloza, hemiceluloza i lignin, nastaju u šumarstvu, poljoprivredi i prehrambenoj industriji. Lignoceluloza je jeftina, ali i kompleksna obnovljiva sirovina koja se može prevesti u razne visokovrijedne biotehnološke proizvode. Da bi se iskoristio potencijal lignoceluloze potrebno je primijeniti prikladne metode predobrade. Lignocelulozni hidrolizati su složene smjese heksoza i pentoza te drugih spojeva od kojih neki mogu djelovati kao inhibitori fermentacije. Optimalni radni mikroorganizam trebao bi fermentirati pentoze i heksoze pri čemu se preferira da ih troši istodobno. Također bi trebao imati visoku toleranciju prema inhibitorima i produktima fermentacije, biti otporan na mikrobiološke kontaminacije te postizati visoku produktivnost i prinos proizvoda. Uz to, trebao bi tolerirati visoke temperature i niske pH-vrijednosti kako bi se smanjio rizik od kontaminacije. Poželjno je da radni mikroorganizam posjeduje i izlučuje celulolitičke i hemicelulolitičke enzime. Ova svojstva mogu biti prirodno prisutna u mikroorganizmu ili se mogu postići primjenom metoda genetičkog inženjerstva. U ovom radu dan je pregled prokariotskih i eukariotskih mikroorganizama koji su istraživani za dobivanje etanola, ali i nekih drugih ekonomski važnih proizvoda koji se mogu dobiti biotehnološkom preradom lignoceluloznih sirovina.Huge amounts of lignocellulosic waste, consisting mainly of cellulose, hemicellulose and lignin, are generated through forestry, agriculture and food industry. Lignocellulose is a cheap but complex renewable raw material that can potentially be converted into various value-added biotechnological products. In order to exploit lignocellulose potential, it is necessary to implement appropriate pretreatment methods. Lignocellulosic hydrolysates are complex mixtures of hexoses, pentoses and other compounds, some of which may act as inhibitors of fermentation. Optimal working microorganism should ferment pentoses and hexoses, which should be preferentially simultaneously consumed. It should also have a high tolerance to inhibitors and fermentation products, to be resistant to microbiological contamination as well as to achieve a high productivity and high product yields. In addition, it should tolerate high temperatures and low pH-values in order to reduce the risk of contamination. It is also desirable for working microorganism to produce and secrete cellulolytic and hemicellulolytic enzymes. These properties can be naturally present in the microorganism or can be achieved by using genetic engineering methods. This paper gives an overview of prokaryotic and eukaryotic microorganisms which have been investigated for production of ethanol as well as other economically important products which can be obtained by biotechnological processing of lignocellulosic raw materials

Determination of peanut allergens in samples of cookies and tea biscuits by immunoenzymatic method

Tijekom ovog istraživanja, imunoenzimskom ELISA (engl. Enzyme-Linked Immunosorbent Assay) metodom analizirani su udjeli potencijalnih alergena kikirikija u 28 uzoraka keksa i čajnih peciva iz trgovačkih lanaca, pekarnica i slastičarnica te su prikupljeni stavovi i mišljenja potrošača o kikirikiju i proizvodima od kikirikija kao tvarima ili proizvodima koji uzrokuju alergije. U svih deset analiziranih uzoraka keksa i čajnih peciva iz trgovačkih lanaca detektirani su alergeni kikirikija, a prosječni udio iznosio je 0,37 mgkg-1. Alergeni kikirikija detektirani su u devet od deset uzoraka keksa i čajnih peciva iz pekarnica, a njihov udio iznosio je prosječno 0,38 mgkg-1. Prosječni udio alergena kikirikija, detektiranih u osam analiziranih uzoraka keksa i čajnih peciva iz slastičarnica, iznosio je 0,28 mgkg-1. Rezultati ispitivanja stavova i mišljenja potrošača pokazali su da je 84,8 % ispitanika upoznato sa pojmom alergije te također 39,2 % ispitanika smatra kako se kikiriki ubraja u orašaste plodove. Od dvadeset i osam analiziranih uzoraka keksa i čajnih peciva, ELISA metodom detektirani su alergeni kikirikija u dvadeset sedam uzoraka pri čemu su samo dva uzorka iz trgovačkog lanca sadržavala navod o mogućoj prisutnosti alergena kikirikija.During this study, the content of potential peanut allergens in 28 samples of cookies and tea biscuits from supermarkets, bakeries and pastry shops was analysed by ELISA (Enzyme-Linked Immunosorbent Assay) method, and also the consumers opinion on peanut and peanut products as substances or products that cause allergies was examined. The presence of peanut allergens was detected in ten analysed samples of cookies and tea biscuits from supermarkets, with an average value of 0,37 mgkg-1. Peanut allergens were detected in nine of ten samples of cookies and tea biscuits from bakeries, with an average value of 0,38 mgkg-1. The average content of peanut allergens, detected in eight analysed samples of cookies and tea biscuits from pastry shops, was 0,28 mgkg-1. The results of consumers attitudes and opinions showed that 84,8 % of respondents are familiar with the term of allergy and also 39,2 % of respondents consider peanuts as tree nuts. Among twenty eight analysed samples of cookies and tea biscuits by ELISA method, peanut allergens were detected in twenty seven samples of which only two from supermarkets had advisory label related to the presence of peanut allergens

Potential of bacteria for bioethanol production from lignocellulosic raw materials

Poljoprivreda, šumarstvo i prehrambena industrija izvori su velike količine lignocelulozne biomase, koja može poslužiti kao lako dostupna i jeftina obnovljiva sirovina za dobivanje različitih bioproizvoda. Jedan od takvih proizvoda je i bioetanol. Ovaj rad daje pregled bakterija koje se koriste i/ili istražuju za proizvodnju bioetanola iz lignoceluloznih sirovina. U navedenim istraživanjima proizvodnje bioetanola pomoću bakterija primijenjuju se različiti pristupi kako bi se povećala ekološka i ekonomska efikasnost procesa. Pored uobičajenih bioprocesa, koji se provode u više faza i uz pomoć monokulture, razvijaju se i visokointegrirani (konsolidirani) bioprocesi uz primjenu mikrobnih kokultura.Agriculture, forestry and food industry are sources of large quantities of lignocellulosic biomass, which can be used as an easily accessible and cheap renewable raw material for production of different bioproducts. One of these bioproducts is also bioethanol. This paper provides an overview of bacteria used and/or investigated for bioethanol production from lignocellulose-containing feedstocks. In the research of bioethanol production using bacteria, various approaches are applied in order to increase ecological and economic efficiency of bioprocess. In addition to conventional multi-stage bioprocesses that are carried out using monoculture, highly integrated (consolidated) bioprocesses and applications of microbial cocultures are also in developing stage

Yeasts for bioethanol production from lignocellulose hydrolyzates

Velika količina lignoceluloznog otpada, kojeg čine uglavnom celuloza, hemiceluloza i lignin, nastaje u šumarstvu, poljoprivredi i prehrambenoj industriji. Obzirom na dostupne količine ovih jeftinih i obnovljivih sirovina u Republici Hrvatskoj, važno je razmotriti mogućnosti njihove primjene u proizvodnji bioetanola i raznih drugih biotehnoloških proizvoda. Lignocelulozni hidrolizati su složene smjese heksoza i pentoza te drugih spojeva od kojih neki mogu djelovati kao inhibitori fermentacije. U ovom radu dan je pregled kvasaca koji se koriste i/ili istražuju za proizvodnju etanola iz lignoceluloznih hidrolizata.Huge amounts of lignocellulosic waste, consisting mainly of cellulose, hemicellulose and lignin, are ge- nerated through forestry, agriculture and food industry. Given the available amount of these cheap and renewable raw materials in the Republic of Croatia, it is important to consider the possibility of their conversion into ethanol and other biotechnological products. Lignocellulosic hydrolysates are complex mixtures of hexoses, pentoses and other compounds, some of which may act as fermentation inhibitors. This paper reviews yeast strains that are used and/or studied for ethanol production by fermentation of lignocellulosic hydrolyzates

Microorganisms for fermentation of lignocellulosic hydrolyzates

Velika količina lignoceluloznog otpada, kojeg čine uglavnom celuloza, hemiceluloza i lignin, nastaju u šumarstvu, poljoprivredi i prehrambenoj industriji. Lignoceluloza je jeftina, ali i kompleksna obnovljiva sirovina koja se može prevesti u razne visokovrijedne biotehnološke proizvode. Da bi se iskoristio potencijal lignoceluloze potrebno je primijeniti prikladne metode predobrade. Lignocelulozni hidrolizati su složene smjese heksoza i pentoza te drugih spojeva od kojih neki mogu djelovati kao inhibitori fermentacije. Optimalni radni mikroorganizam trebao bi fermentirati pentoze i heksoze pri čemu se preferira da ih troši istodobno. Također bi trebao imati visoku toleranciju prema inhibitorima i produktima fermentacije, biti otporan na mikrobiološke kontaminacije te postizati visoku produktivnost i prinos proizvoda. Uz to, trebao bi tolerirati visoke temperature i niske pH-vrijednosti kako bi se smanjio rizik od kontaminacije. Poželjno je da radni mikroorganizam posjeduje i izlučuje celulolitičke i hemicelulolitičke enzime. Ova svojstva mogu biti prirodno prisutna u mikroorganizmu ili se mogu postići primjenom metoda genetičkog inženjerstva. U ovom radu dan je pregled prokariotskih i eukariotskih mikroorganizama koji su istraživani za dobivanje etanola, ali i nekih drugih ekonomski važnih proizvoda koji se mogu dobiti biotehnološkom preradom lignoceluloznih sirovina.Huge amounts of lignocellulosic waste, consisting mainly of cellulose, hemicellulose and lignin, are generated through forestry, agriculture and food industry. Lignocellulose is a cheap but complex renewable raw material that can potentially be converted into various value-added biotechnological products. In order to exploit lignocellulose potential, it is necessary to implement appropriate pretreatment methods. Lignocellulosic hydrolysates are complex mixtures of hexoses, pentoses and other compounds, some of which may act as inhibitors of fermentation. Optimal working microorganism should ferment pentoses and hexoses, which should be preferentially simultaneously consumed. It should also have a high tolerance to inhibitors and fermentation products, to be resistant to microbiological contamination as well as to achieve a high productivity and high product yields. In addition, it should tolerate high temperatures and low pH-values in order to reduce the risk of contamination. It is also desirable for working microorganism to produce and secrete cellulolytic and hemicellulolytic enzymes. These properties can be naturally present in the microorganism or can be achieved by using genetic engineering methods. This paper gives an overview of prokaryotic and eukaryotic microorganisms which have been investigated for production of ethanol as well as other economically important products which can be obtained by biotechnological processing of lignocellulosic raw materials

Determination of peanut allergens in samples of cookies and tea biscuits by immunoenzymatic method

Tijekom ovog istraživanja, imunoenzimskom ELISA (engl. Enzyme-Linked Immunosorbent Assay) metodom analizirani su udjeli potencijalnih alergena kikirikija u 28 uzoraka keksa i čajnih peciva iz trgovačkih lanaca, pekarnica i slastičarnica te su prikupljeni stavovi i mišljenja potrošača o kikirikiju i proizvodima od kikirikija kao tvarima ili proizvodima koji uzrokuju alergije. U svih deset analiziranih uzoraka keksa i čajnih peciva iz trgovačkih lanaca detektirani su alergeni kikirikija, a prosječni udio iznosio je 0,37 mgkg-1. Alergeni kikirikija detektirani su u devet od deset uzoraka keksa i čajnih peciva iz pekarnica, a njihov udio iznosio je prosječno 0,38 mgkg-1. Prosječni udio alergena kikirikija, detektiranih u osam analiziranih uzoraka keksa i čajnih peciva iz slastičarnica, iznosio je 0,28 mgkg-1. Rezultati ispitivanja stavova i mišljenja potrošača pokazali su da je 84,8 % ispitanika upoznato sa pojmom alergije te također 39,2 % ispitanika smatra kako se kikiriki ubraja u orašaste plodove. Od dvadeset i osam analiziranih uzoraka keksa i čajnih peciva, ELISA metodom detektirani su alergeni kikirikija u dvadeset sedam uzoraka pri čemu su samo dva uzorka iz trgovačkog lanca sadržavala navod o mogućoj prisutnosti alergena kikirikija.During this study, the content of potential peanut allergens in 28 samples of cookies and tea biscuits from supermarkets, bakeries and pastry shops was analysed by ELISA (Enzyme-Linked Immunosorbent Assay) method, and also the consumers opinion on peanut and peanut products as substances or products that cause allergies was examined. The presence of peanut allergens was detected in ten analysed samples of cookies and tea biscuits from supermarkets, with an average value of 0,37 mgkg-1. Peanut allergens were detected in nine of ten samples of cookies and tea biscuits from bakeries, with an average value of 0,38 mgkg-1. The average content of peanut allergens, detected in eight analysed samples of cookies and tea biscuits from pastry shops, was 0,28 mgkg-1. The results of consumers attitudes and opinions showed that 84,8 % of respondents are familiar with the term of allergy and also 39,2 % of respondents consider peanuts as tree nuts. Among twenty eight analysed samples of cookies and tea biscuits by ELISA method, peanut allergens were detected in twenty seven samples of which only two from supermarkets had advisory label related to the presence of peanut allergens