Raman spectroscopy has a broad range of applications across numerous scientific fields, including microbiology. Our work here monitors the influence of culture media on the Raman spectra of clinically important microorganisms (Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis and Candida albicans). Choosing an adequate medium may enhance the reproducibility of the method as well as simplifying the data processing and the evaluation. We tested four different media per organism depending on the nutritional requirements and clinical usage directly on a Petri dish. Some of the media have a significant influence on the microbial fingerprint (Roosvelt-Park Institute Medium, CHROMagar) and should not be used for the acquisition of Raman spectra. It was found that the most suitable medium for microbiological experiments regarding these organisms was Mueller-Hinton agar.
In this work, capability of Fusarium solani F-552 of producing lignocellulose-degrading enzymes in submerged fermentation was investigated. The enzyme cocktail includes hydrolases (cellulases, xylanases, and proteinases) as well as ligninolytic enzymes: manganese-dependent peroxidase (MnP), lignin peroxidase (LiP), and laccase (Lac). To our knowledge, this is the first report on production of MnP, LiP, and Lac together by one F. solani strain. The enzyme productions were significantly influenced by application of either lignocellulosic material or chemical inducers into the fermentation medium. Among them, corn bran significantly enhanced especially productions of cellulases and xylanases (248 and 170 U/mL, respectively) as compared to control culture (11.7 and 29.2 U/mL, respectively). High MnP activity (9.43 U/mL, control 0.45 U/mL) was observed when (+)-catechin was applied into the medium, the yield of LiP was maximal (33.06 U/mL, control 2.69 U/mL) in gallic acid, and Lac was efficiently induced by, 2,2'-azino-bis-[3-ethyltiazoline-6-sulfonate] (6.74 U/mL, not detected in control). Finally, in order to maximize the ligninolytic enzymes yields, a novel strategy of introduction of mild oxidative stress conditions caused by hydrogen peroxide into the fermentation broth was tested. Hydrogen peroxide significantly increased activities of MnP, LiP, and Lac which may indicate that these enzymes could be partially involved in stress response against H(2)O(2). The concentration of H(2)O(2) and the time of the stress application were optimized; hence, when 10 mmol/L H(2)O(2) was applied at the second and sixth day of cultivation, the MnP, LiP, and Lac yields reached 21.67, 77.42, and 12.04 U/mL, respectively.
- MeSH
- enzymy metabolismus sekrece MeSH
- Fusarium enzymologie metabolismus MeSH
- kukuřice setá metabolismus MeSH
- kultivační média chemie MeSH
- lignin metabolismus MeSH
- peroxid vodíku metabolismus MeSH
- regulace genové exprese enzymů MeSH
- regulace genové exprese u hub MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
