Search the digital library catalog

Abstract: Our goal for these lab instructions is to provide insight into common techniques used in microbiology and to link them to the basic principles of microbiological hazards and risks in food safety. The study material was created for foreign exchange students, who choose the Biological Risk Factors course from the Master Food Safety curriculum.
Keywords: Biological risk factors, Master Food Safety curriculum, Erasmus
Published in DKUM: 30.07.2025; Views: 0; Downloads: 8
Full text (4,62 MB)

Abstract: The interaction of microorganisms and their enzyme activity is one of the key indicators for a comprehensive measurement of soil health. The aim of this study was to determine significant correlations between different soil microorganisms and enzyme activities of β-glucosidase, N-acetyl-glucosaminidase, urease, arylamidase, phosphatase, acid phosphatase, alkaline phosphatase, and arylsulfatase after supplementation with standard fertilizer, spent mushroom substrate and composed fertilizer in soils from conventional–integrated, organic and biodynamic farming. Samples were grouped according to the farming system and fertilization for all seasons. The biodynamic farm was the least affected by the different fertilizations, except for standard fertilization. Standard fertilizer caused negative correlations between the actinomycetes and the arylsulfatase in organic and biodynamic farms. The same fertilization affected the actinomycetes/phosphatase relationship differently, regardless of the basic soil structure. Actinomycetes correlated positively with acid phosphatase and urease in conventional–integrated and biodynamic farms after spent mushroom substrate, respectively. Arylamidase activity in relation to total microorganisms responded to fertilization with standard fertilizer and spent mushroom substrate independently of the basic soil structure. Fertilization can influence the soil microbe/enzyme relationships in different soils. Regardless of the basic soil structure, some of these relationships could be important indicators for further studies.
Keywords: agriculture, conventional-integrated, organic, biodynamic, fertilization, soil microorganisms, soil enzyme activity
Published in DKUM: 17.04.2025; Views: 0; Downloads: 4
Link to file

Abstract: Izrabljen substrat za gobe (IGS) je stranski proizvod gojenja gob, ki sestoji iz raznovrstnih organskih materialov. Po nekaj sezonah rabe se substrat izčrpa in praviloma velja za odpadek, vendar sodobne raziskave nakazujejo številne koristne možnosti uporabe izrabljenega gobjega substrata. V projektni raziskavi se je IGS uporabljal kot organsko gnojilo na treh različnih lokacijah v ekološki, integrirani in biodinamični pridelavi paradižnika v rastlinjakih. V vsaki od pridelav se je v triplikatih testiralo gnojenje z SMS, standardno gnojenje (S), SMS+S in kontrola brez gnojenja. V sklopu magistrskega dela smo na obravnavanih lokacijah jemali vzorce zemlje v vseh letnih časih, v vzorcih pa smo analizirali aktivnost encimov N-acetil-glukozaminidaza (NAG), fosfataza (PHOS), beta-glukozidaza (β0GLU), arilsulfataza (ARS), ureaza (URE), arilamidaza (ARN), alkalna fosfataza (PAK) in kisla fosfataza (PAC) po standardu ISO 20130:2018- Kakovost tal - Merjenje encimske aktivnosti v vzorcih tal s kolorimetričnimi substrati na mikrotitrski plošči. Primerjali smo razlike v encimski aktivnosti med posameznimi letnimi časi ter med različnimi načini gnojenja. Rezultati so pokazali, da različni letni časi vplivajo na aktivnost encimov v tleh, medtem ko dodatek gobjega substrata kot gnojila ne povzroči nujno povišanja encimske aktivnosti.
Keywords: talni encimi, izrabljen gobji substrat, aktivnost, gnojenje, kmetijstvo
Published in DKUM: 03.09.2024; Views: 52; Downloads: 94
Full text (3,58 MB)

Abstract: The maintenance of a healthy status depends on the coexistence between the host organism and the microbiota. Early studies have already focused on the nutritional properties of probiotics, which may also contribute to the structural changes in the gut microbiota, thereby affecting host metabolism and homeostasis. Maintaining homeostasis in the body is therefore crucial and is reflected at all levels, including that of glucose, a simple sugar molecule that is an essential fuel for normal cellular function. Despite numerous clinical studies that have shown the effect of various probiotics on glucose and its homeostasis, knowledge about the exact function of their mechanism is still scarce. The aim of our review was to select in vivo and in vitro studies in English published in the last eleven years dealing with the effects of probiotics on glucose metabolism and its homeostasis. In this context, diverse probiotic effects at different organ levels were highlighted, summarizing their potential mechanisms to influence glucose metabolism and its homeostasis. Variations in results due to different methodological approaches were discussed, as well as limitations, especially in in vivo studies. Further studies on the interactions between probiotics, host microorganisms and their immunity are needed.
Keywords: probiotic, mechanism, glucose, metabolism, homeostasis
Published in DKUM: 28.06.2024; Views: 415; Downloads: 19
Full text (2,58 MB)
This document has many files! More...

Abstract: The antioxidant activity (AA) of hop extracts obtained from different hop genotypes (n = 14) was studied. For comparison, the purified β-acids-rich fraction and α-acids-with-β-acids-rich fraction were also used to test the antioxidative potential. The AA of purified hydroacetonic hop extracts was investigated using the Ferric Reducing Ability of Plasma (FRAP), Oxygen Radical Absorption Capacity (ORAC) and Intracellular Antioxidant (IA) methods. The FRAP values in different hop genotypes ranged between 63.5 and 101.6 μmol Trolox equivalent (TE)/g dry weight (DW), the ORAC values ranged between 1069 and 1910 μmol TE/g DW and IA potential values ranged between 52.7 and 118.0 mmol TE/g DW. Significant differences in AA between hop genotypes were observed with all three methods. AAs were determined using three different methods, which did not highly correlate with each other. We also did not find significant correlations between AA and different chemical components, which applies both to AA determined using individual methods as well as the total AA. Based on this fact, we assume that the synergistic or antagonistic effects between hop compounds have a more pronounced effect on AA than the presence and quantity of individual hop compounds.
Keywords: hop, antioxidant activity, FRAP, ORAC, intracellular antioxidative potential, genotypes
Published in DKUM: 20.03.2024; Views: 271; Downloads: 32
Full text (1,23 MB)
This document has many files! More...