5 research outputs found
Diversity of lactic acid bacteria on organic flours and application of isolates in sourdough fermentation
Organic farming preserves biodiversity and organic products can be the source of many microbial species. The species diversity in organically grown wheat, spelt and rye was investigated in order to find strains suitable for sourdough fermentation. Colonies representing various morphological appearances were isolated and catalase-negative colonies were identified by mass spectrometer Microflex LT ā¢ MALDI-TOF. The fermentation products (lactic, acetic, formic and phenyllactic acid) were determined by high performance liquid chromatography, while the antifungal activity was determined using an overlay agar method. Wheat flours showed less microbial biodiversity than the rye and spelt flours. The most common genera in the tested flour were Lactobacillus, Pediococcus and Enterococcus. Isolated Lactobacillus farciminis, Pediococcus pentosaceus, Leuconostoc citreum and Lactobacillus brevis showed the best acidification activity. Lactobacillus brevis, Pediococcus pentosaceus, Weissella cibaria and Lactobacillus farciminis showed significant antifungal activity against A. niger 357 and Penicillium sp. 505. The prefermented medium of Lactobacillus farciminis were characterized by high content of lactic and phenyllactic acid
The Position of the Croatian Society of Hypertension on the Observed Increase in Risk of Non-melanoma Skin Cancer Associated with Hydrochlorothiazide Treatment
Upravni odbor Hrvatskoga druÅ”tva za hipertenziju na svojoj elektroniÄkoj sjednici održanoj 12. prosinca 2018. raspravljao je o opaženom poveÄanom riziku za nastanak nemelanomskih karcinoma kože povezanom s lijeÄenjem hidroklorotiazidom i pripremio sljedeÄe miÅ”ljenje. ZakljuÄci 1. Rizik od nemelanomskoga karcinoma kože i usnica veÄi je u bolesnika lijeÄenih hidroklorotiazidom nego Å”to je u osoba koje nisu lijeÄene ovim lijekom. Rizik se poveÄava s duljinom trajanja lijeÄenja, tj. s kumulativnom dozom. 2. Mehanizam karcinogenosti hidroklorotiazida temelji se na fotosenzitivnosti. UV zraÄenje dovodi do disocijacije kloridnoga dijela molekule lijeka, Äime se stvara pretpostavka za sintezu slobodnih radikala kisika i posljediÄno oÅ”teÄenje molekule DNK. 3. Korist od primjene hidroklorotiazida veÄa je od rizika. 4. Omjer koristi i rizika napose je veÄi u starijih i teže bolesnih osoba. 5. Bolesnik mora biti informiran o postojeÄem riziku. 6. Bolesnik mora biti informiran o postojeÄoj alternativnoj terapiji koja je na raspolaganju u Hrvatskoj. 7. Svaki lijeÄnik mora u svakoga pojedinog bolesnika procijeniti omjer koristi i rizika te nakon razgovora s bolesnikom odluÄiti nastavlja li terapiju hidroklorotiazidom ili se odluÄuje za postojeÄu alternativu. 8. Svim bolesnicima, a napose bolesnicima koji su lijeÄeni hidroklorotiazidom, treba preporuÄiti uporabu adekvatne fotoprotekcije i redovito provjeravanja pojave ili promjena na koži
Effect of growth medium composition on the growth and activity of lactic acid bacteria
Primjena bakterija mlijeÄne kiseline ima dugu tradiciju u biotehnoloÅ”koj industrijskoj proizvodnji fermentiranih proizvoda. Sastav podloga u kojima se ove bakterije uzgajaju i aktivne su podržava specifiÄne zahtjeve ovih kutura za hranjivim tvarima. Takve podloge obiÄno sadrže jedan ili viÅ”e izvora ugljika, vodika, duÅ”ika, fosfora, sumpora kao i odreÄene sastojke koji podržavaju fermentativni metabolizam ovih bakterija. Neke vrste bakterija mlijeÄne kiseline imaju genetiÄki potencijal koji podržava aerobni (respiratorni) metabolizam. U podloge u kojima se u stanicama ovih bakterija uspostavlja respiratorni metabolizam potrebno je dodati izvore hema ili, u nekim sluÄajevima, menakinona. Tijekom respiratornog metabolizma pridobiva se viÅ”e metaboliÄke energije, smanjuje se koncentracija otopljenog kisika i proizvedene mlijeÄne kiseline, dok se koncentracija bakterijske biomase poveÄava kao i preživljavanje stanica u odabranim uvjetima bioprocesa. Odvijanje aerobnog metabolizma u stanicama bakterija mlijeÄne kiseline ima industrijsku primjenu u proizvodnji starter kultura.Lactic acid bacteria have been traditionally applied in biotechnological industrial production of fermented products. The bacteria are usually cultivated in media which composition supports specific requirements of those cultures for nutrients. Such media usually contain one or more carbon sources as well as sources of hydrogen, nitrogen, phosphorus, sulphur, and specific ingredients which maintain fermentative metabolism of the bacteria. Some species of lactic acid bacteria have genetic potential which supports aerobic (respiration) metabolism. Respiration metabolism can be established in cells in media with exogenous source of heme and, in some cases, menaquinones. During respiration metabolism more metabolic energy can be yielded, concentration of dissolved oxygen and produced lactic acid is reduced while concentration of bacterial biomass and survival of the cells in bioprocess conditions are enhanced. Aerobic metabolism in the cells of lactic acid bacteria has found its industrial implemetation for the production of starter cultures
Identification and characterization of lactic acid bacteria isolated from organic flours
Izolirane, identificirane i okarakterizirane su bakterije mlijeÄne kiseline (BMK) prirodno prisutne u braÅ”nu ekoloÅ”ki uzgojenih žitarica. Identifikacija je provedena na osnovu spektrometrije masa pomoÄu Microflex LTā¢ MALDI-TOF instrumenta. Identificiranim vrstama odreÄena je fermentativna i antimikrobna aktivnost. Produkti fermentacije odreÄeni su visoko uÄinkovitom tekuÄinskom kromatografijom dok je antimikrobna aktivnost odreÄivana metodom s dvostrukim slojem agara te turbidimetrijski. Rezultati su pokazali da su koriÅ”teni uzorci braÅ”na imali bogatu mikrofloru. Izolirano je ukupno 16 BMK i 1 kvasac pri Äemu nije uoÄena znaÄajna razlika u broju i vrstama kultura izoliranih iz ekoloÅ”kih i konvencionalnih uzoraka braÅ”na. Kod pÅ”eniÄnog braÅ”na uoÄena je manja bioloÅ”ka raznolikost u odnosu na raženo braÅ”no i braÅ”no pira. Rodovi Lactobacillus i Enterococcus bili su najzastupljeniji rodovi u ispitivanim uzorcima braÅ”na. Od izoliranih bakterijskih vrsta, vrste Lactobacillus farciminis, Pediococcus pentosaceus, Leuconostoc citreum i Lactobacillus brevis pokazale su veÄu fermentativnu aktivnost. Vrste Lactobacillus brevis, Pediococcus pentosaceus, Weissella cibaria i Lactobacillus farciminis izolirane iz ekoloÅ”ki uzgojenih žitarica pokazale su znaÄajnu antimikrobnu aktivnost prema A. niger i Penicillium sp. MeÄutim, inhibicija nije bila znaÄajnija u odnosu na sojeve bakterija uzetih iz zbirke Laboratorija za tehnologiju vrenja i kvasca.In this thesis naturally occurring lactic acid bacteria (LAB) in organic flour were isolated. Identification was based on mass spectrometry using a Microflex LT ā¢ MALDI-TOF instrument. Fermetative and antimicrobial activity of indentified spieces was determined. Fermentation products were determined by high pressure liquid chromatography while the antimicrobial activity was determined using a overlay agar method and turbitimer. The results showed that the used samples of flour had a rich flora. There were total of 16 LAB and 1 yeast isolated with no significant difference in the number and types of cultures isolated from organic and conventional flour.Wheat flour showed less bidiversity than the rye and spelled flour. The most common genera in the tested flour were Lactobacillus and Enterococcus. Isolated Lactobacillus farciminis, Pediococcus pentosaceus, Leuconostoc citreum and Lactobacillus brevis showed the best fermentation activity. Lactobacillus brevis, Pediococcus pentosaceus, Weissella cibaria and Lactobacillus farciminis isolated from organic grains showed significant antimicrobial activity against A. niger and Penicillium sp. However, the inhibition was not significant compared to laboratory strains of these bacterial species
Flour - Bread '19 : Proceedings of the 10th International Congress Flour - Bread '19 and 12th Croatian Congress of Cereal Technologists BraŔno - Kruh '19
Proceedings contains 3 Reviews, 8 Original research articles and 3 Professional articles presented at 10th International Congress Flour ā Bread ā19 and 12th Croatian Congress of Cereal Technologists BraÅ”no ā Kruh ā1