Perspektywy zastosowania biotechnologii w produkcji lotnych zwiazkow smakowo-zapachowych

Praca prezentuje obecny stan badań nad mikrobiologiczną produkcją naturalnych związków smakowo-zapachowych, zwłaszcza laktonów, związków aromatycznych (waniliny i aldehydu benzoesowego) oraz terpenów. Szczególny nacisk położono na przedstawienie zalet, ograniczeń oraz perspektyw wykorzystania w tym celu procesów biotransformacji.This rewiev presents the current state of the art of microbiological production of natural flavours, particulary lactones, aromatic compounds (vanillin, benzaldehyde) and terpenes. Special emphasis is placed on advantages, disadvantages and prospects for application to this end biotransformation processes

Optimization of mutanase production by Trichoderma harzianum

The present paper describes optimization of fermentation conditions in shaken flasks and scale-up of fermentor production up to 115 L. The response surface methodology (RSM) has been successfully applied in standardization of mutanase production by Trichoderma harzianum CCM F-340. The model was very well fitted to the experimental data and explained more than 96% of the whole variation of the response (adjusted R2 = 0.962). In order to confirm the adequacy of the regression model based on the experimental data, validation cultures were grown in conditions created through optimization. The highest enzyme activity (0.747 U/mL) was reached in shaken flask cultures on Mandels’ medium in a volume of 140 mL modified in terms of carbon (cell wall preparation from the polypore fungus Laetiporus sulphureus 8.08 g/L) and nitrogen (soybean peptone 1.38 g/L) sources, under culture conditions 30°C, pH 5.3, agitation 270 rpm. The scale-up of the culture in the bioreactors with a working volume of 5 and 115 L resulted in a slight decrease in the mutanase activity (0.734 and 0.682 U/mL, respectively). The validation experiment showed a 70.6% increase in the production of mutanase compared with the culture before optimization. The results proved that the cultures could be scaled-up successfully from shaken flasks to the bioreactor scale. Our results indicate that in optimal conditions, T. harzianum could be a highly effective extracellular mutanase source. This report is the first to deal with optimization of mutanase biosynthesis using a mathematical model and scale-up of enzyme production in controlled fermentors with a view to facilitate application thereof in industry.Keywords: Mutanase, Trichoderma harzianum, response surface methodology (RSM), bioreactors, submerged culture.African Journal of Biotechnology, Vol 13(25) 2538-254

Assessing biological activity of carboxymethylated derivatives of alpha-(1→3)-glucans isolated from fruiting bodies of cultivated pleurotus species

α-(1→3)-Glukany stanowią najmniej poznaną grupę polisacharydów budujących ścianę komórkową grzybów. Celem pracy była ocena aktywności biologicznej karboksymetylowanych pochodnych α-(1→3)-glukanów uzyskanych z owocników uprawnych gatunków rodzaju Pleurotus (P. citrinopileatus, P. djamor, P. erynii i P. precoce). Polisacharydy wyizolowane z owocników poddano analizom strukturalnym (FT-IR i ¹H NMR), w wyniku czego wykazano, że są one liniowymi α-(1→3)-glukanami. Po zastosowaniu metody karboksymetylacji nierozpuszczalne w wodzie α-(1→3)-glukany przeprowadzono w formy rozpuszczalne, tj. karboksymetyl-α-(1→3)-glukany (KM-α-(1→3)-glukany). Następnie analizowano ich wpływ na żywotność komórek prawidłowych CCD 841 CoTr (ludzkie komórki nabłonka jelita grubego) i CCD-18Co (miofibroblasty jelitowe) oraz komórek nowotworowych HeLa (ludzki rak szyjki macicy). Wykonano analizy aktywności metabolicznej i toksyczności (MTT i NR) oraz zdolności do redukcji wolnych rodników (DPPH). Wykazano, że żywotność komórek nowotworowych była najsilniej redukowana przez KM-α-(1→3)-glukan otrzymany z owocników P. citrinopileatus. Z kolei metodą NR wykazano, że wszystkie badane KM-α-glukany w całym zakresie stężeń powodowały statystycznie istotny wzrost żywotności komórek prawidłowych (CCD 841 CoTr i CCD-18Co). Badane KM-α-glukany nie wykazywały aktywności zmierzającej do redukcji wolnych rodników tlenowych. Na podstawie analizy wyników różnicowego barwienia fluorescencyjnego stwierdzono, że KM-α-glukan z owocników P. citrinopileatus zaburza integralność błony komórek nowotworowych. Z kolei barwienie fluorescencyjne filamentów F-aktynowych (F-aktyny) wykazało, że nie wpływał on destrukcyjnie na cytoszkielet badanych komórek.α-(1→3)-Glucans constitute the least known group of polysaccharides that make up the fungal cell wall. The objective of the study was to assess the biological activity of carboxymethylated derivatives of α-(1→3)-glucans extracted from fruiting bodies of the cultivated species of Pleurotus (P. citrinopileatus, P. djamor, P. erynii, and P. precoce) genus. The polysaccharides extracted from the fruiting bodies were structurally analyzed (using FT-IR and ¹H NMR) and, based on the analysis results, it was proved that they were linear α-(1→3)-glucans. With the use of a carboxymethylation method, the water-insoluble α-(1→3)-glucans were converted into soluble forms, i.e. carboxymethyl-α-(1→3)-glucans (KM-α-(1→3)-glucans). Next, their effect was investigated on the viability of normal CCD 841 CoTr cells (normal human colonic epithelial cells), CCD-18Co (intestinal myofibroblasts), and HeLa tumour cells (human cervical cancer). The metabolic activity, toxicity (MTT and NR), and free radical scavenging ability (DPPH) were analyzed. It was shown that the effect of KM-α-(1→3)-glucan derived from the P. citrinopileatus fruiting bodies was the strongest as regards the reduction of the cancer cell viability. Then, the NR method used showed that all the tested KM-α-(1→3)-glucans within the entire concentration range caused the viability of normal cells (CCD 841 CoTr and CCD-18Co) to increase statistically significantly. The KM-α-glucans analyzed did not exhibit any free oxygen radical reduction activity. Based on the results of the differential fluorescent staining analysis, it was confirmed that the KM-α-glucan from fruiting bodies of P. citrinopileatus disturbed the membrane integrity of tumour cells. On the other hand, the fluorescent staining of the F-actin filaments proved that this KM-α-glucan did not have any destructive effect on the cytoskeleton of the cells studied

Targeting microbial biofilms: current and prospective therapeutic strategies

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Biofilm formation is now recognized as a key virulence factor for a wide range of chronic microbial infections. While it has been well known for decades that bacteria and fungi in biofilms become highly tolerant of antibiotics, the development of effective therapeutics has lagged behind our growing understanding of biofilm biology. The multifactorial nature of biofilm development and drug tolerance imposes significant challenges to conventional antimicrobials, and indicates the need for multi-targeted or combinatorial therapies. In light of the discrepancy between the explosion of papers presenting multitude of methods to control biofilms and the sparsity of biofilm specific treatments available to the clinician, in this review, we focus on current therapeutic strategies and those in development for the treatment of biofilm infections, which target vital structure-function traits and drug tolerance mechanisms, including the extracellular matrix and dormant cells. We emphasize strategies that are supported by in vivo or ex vivo studies, highlight emerging anti-biofilm technologies, and provide a rationale for multi-targeted therapies aimed at disrupting the complex biofilm microenvironment