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Fungal extracellular enzymes may play a role in biodeterioration of dried materials of medicinal plants and in propagation of toxigenic and pathogenic fungal strains. However, no data on enzymatic activities of xerophilic fungi contaminating these materials have been found in the literature. The objective of the study was to determine extracellular enzyme profiles of slow-growing fungi, i.e. Eurotium amstelodami, E. chevalieri, E. herbariorum and Aspergillus versicolor isolated from dried materials of medicinal plants from herbal shops of Szczecin, Poland. Solid media and API ZYM® test were used to determine enzymatic activities. The highest colony diameters were observed in A. versicolor on gelatin, cellulose, tributyrin, rapeseed oil, biodiesel oil and diesel oil agars, and in E. herbariorum on milk and starch agars. A. versicolor also showed the highest hydrolytic activity on milk, gelatin, starch and tributyrin agars. No hydrolysis zones were formed on cellulose, rapeseed oil and biodiesel oil agars, but the stimulation effect of the oils on fungal growth was clearly observed. The effect was the highest in E. amstelodami, and considerably increased during a 21-day incubation period. In addition, E. amstelodami and A. versicolor showed high catalase, urease and DNA-se activities. A. versicolor had higher pectate lyase activity compared to E. amstelodami. Of the fungi examined, E. amstelodami showed the highest hydrolase activity in the API ZYM® test. A. versicolor and E. amstelodami were found to be the two species with the highest biodeterioration potential for dried materials of medicinal plants. Xerophilic fungi isolated from this environment could also be used in bioremediation.
Extremely halophilic diversity of IncheBroun wetland located in the north of Iran was investigated by using culture-dependent methods. Sampling was carried out in May and September 2014. In each sampling 4 distinct regions of wetland were analyzed by using complex media like MGM, JCM168, MH1 and an alkaliphilic medium containing 23% salts. After incubation at 40˚C, a total of 406 isolates and 2.1 × 106 CFU/ml were obtained in culture media. Among them 361 isolates were obtained from MGM and 39 isolates from JCM 168, 3 isolates from MH1 and 3 isolates from the alkaliphilic media. Initial morphological, biochemical and physiological tests were performed. Production of 4 hydrolytic enzymes by 45 selected strains was assayed qualitatively. A total of 38, 19 and 6 strains were able to produce lipase, DNase and amylase activity. Protease activity was not observed among strains. As total 45 strains were selected randomly and phylogenetic analysis of 16S rRNA was performed for them. Among selected strains 40 isolated strians belonged to Haloarchaea and were belonged to the genera: Haloarcula(30%), Halorubrum(27.5%), Haloferax(17.5%), Halobellus (10%), Halogeometricum(5.2%), Halobacterium(2.6%), Halolamina(2.6%), Halorhabdus (2.6%) and Halostagnicola (2.6%). Haloarcula and Halorubrum were the dominant populations. A total of 5 strains belonged to domain of Bacteria and were similar to members of Rhodovibrio (40%), Pseudomonas (40%) and Salicola (20%).
The paper presents studies on level hydrolytic activity of extracellular enzymes in the surface microlayer and subsurface water in the coastal lake Dołgie Wielkie. The ranking order of the potential enzyme activity rates in the studied water layers was as follows: aminopeptidase > lipase > α-glucosidase > β-glucosidase. The level of activity of all studied hydrolases was higher in the surface microlayer than subsurface water. Activity of extracellular enzymes was influenced by the season.
Continuous cultivation of Trichodcnna reesei M-7 mutant was performed at different temperatures (26, 30 and 34°C) with 1% lactose or glucose alone or a total of 1% mixtures of both sugars at different ratio. The secretion of individual enzymes was affected by the ratio of cellulase inducer (lactose) to the repressor (glucose). The ratio of enzyme secretions was additionally modified by the temperature of cultivations. An insignificant increase of nonspecific activity of cellulases (FPU) and significant increase of aryl-ß-glucosidase activity were observed at 26°C with lactose/glucose ratio of 3:1 and 1:1. However, when cultivated both at 30 or 34°C, the cellulolytic activities (FPU) increased significantly in the presence of 1% glucose alone. The activity of xylanases increased significantly (about 8-fold) with lactose/glucose ratio of 1:1 at 30°C. The increased synthesis of lytic enzymes (proteases, ß-1,3-glucanases) correlated with increased glucose concentration in the feeding medium and this effect potentiated at 34°C of cultivation.
Cultivation has been performed of isolated earlier low-protease mutants and parental strain in the presence of novel inducers of cellulases production - lactulose and lactobionic acid mixed with lactose in the ratio 1:1. Nine among ten tested during batch cultivation low-protease mutants exhibited lower ability for the production of proteases than parental strain M-7. Higher enzymatic activities have been estimated (cellulolytic, xylanolytic and beta - galaktosidase) of culture filtrates during cultivation in the presence of mixtures of lactobionic acid and lactose in comparison to lactulose and lactose. Tested, during continuous cultivation, low-protease mutant T. reesei Mp5 exhibited high resistance for the temperature shifting. FPU activities of culture filtrates were stable in the high range of temperature of cultivation (26-34°C). In addition current knowledge about correlation between protease and other enzymes of culture fluids of selected filamentous fungi has been reviewed. The ways of preventing homologous and heterologous protein produced by fungi and bacteria from enzymatic cleavage by proteases have been also described. This work is an introduction for future studies on correlation between proteases and other enzymes in culture filtrates of Trichoderma reesei.
The contamination of dried medicinal plants with microscopic fungi has been the subject of many studies. However, no data on extracellular enzyme activities of xerophilic fungi contaminating the plants have been found in the literature. Therefore, the objective of our study was to determine extracellular enzyme profiles of fast-growing xerophilic fungi, i.e. Aspergillus flavus, A. fumigatus, A. melleus, A. nidulans, A. niger, A. parasiticus and Trichothecium roseum isolated from dried medicinal plants from herbal shops in Szczecin, Poland. Solid media and the API ZYM® test were used for measuring enzyme activities. Among the fungi, A. melleus had the highest hydrolytic activity on milk, gelatin, starch, tributyrin, rapeseed oil and biodiesel oil agars, while A. fumigatus showed extremely high stimulation index values on rapeseed oil and biodiesel oil agars. The stimulation index increased during a 5-day incubation period. In the API ZYM® test A. nidulans showed the highest hydrolase activity. Among the hydrolases, ß-glucosidase activity was the highest, followed by acid phosphatase, N-acetyl-ß-glucosaminidase and naphthol-AS-BI-phosphohydrolase activities. The fungi contaminating dried medicinal plants are able to utilize a number of substrates and, therefore, possess high biodeterioration potential. Due to the ability to degrade hydrocarbons, fungal isolates from dried medicinal plants can be used for biotechnological purposes, e.g. in air biofiltration and waste or soil bioremediation.
Extracellular enzymes occurring in aquatic environment are heterogeneous in respect to their origin and function, place, where they are located and their activity. They can be divided into mainly ‘bacterial-origin’ enzymes produced by heterotrophic organisms in order to obtain organic carbon, and mostly ‘phytoplankton-bacterial-origin’ enzymes, which are produced by autotrophic and heterotrophic organisms, and are responsible mainly for obtaining inorganic compounds. Enzymes activity provides information about microorganisms present in given environment and about their physiological state. We hypothesize that the patterns (‘fingerprints’) calculated on the basis of activity of several enzymes both mainly ‘bacterial-origin’ and mainly ‘phytoplankton-bacterial-origin’ may be used to characterise lake ecosystems in terms of the physiological structure of aquatic microorganisms present in these lakes. For the study we selected four lakes from Mazurian Lakes District in north-eastern Poland. Three of them were clear-water (lakes: Kuc, Mikołajskie, Tałtowisko) and ranged from oligotrophy to eutrophy, the fourth (Lake Smolak Duży) was slightly acidic (pH 5.2), highly productive and polyhumic. Activity of phosphatase (PA), L-leucine-aminopeptidase (AMP), β-glucosidase (B-Glu), esterase (EST), glucosaminidase (Glu-ami), glucuronidase (Glu-uro) and cellobiohydrolase (Cellob) were measured fluorometrically. The results were normalised and analysis of agglomerative clustering was performed to create an enzyme activity patterns characteristic for lakes. We found out that the enzymatic pattern reflected trophic differences between studied lakes. The patterns (‘fingerprints’) of enzymes were similar for three clear-water lakes, with urease (U–ase), AMP and EST dominating the overall enzymatic activity, but differed substantially for polyhumic lake, in which considerably high PA and saccharolytic enzyme activities were observed. We conclude that the analysis of enzymatic ‘fingerprints’ can be a useful tool to characterise lakes with respect to their trophic status and physiological diversity of microbial assemblages associated with each particular lake.
Praca miała na celu określenie zmian aktywności lipaz w poszczególnych fazach wzrostu drożdży Yarrowia lipolytica oraz dokonanie porównania i zestawienia ak­tywności lipaz zewnątrz- i wewnątrzkomórkowych. Podczas hodowli szczepu Yarrowia lipolytica KKP 379 w bioreaktorze dokonywano pomiaru gęstości optycznej komórek drożdży oraz określano aktywność lipolityczną frakcji supernatantu. Porównania aktyw­ności lipaz zewnątrzkomórkowych (w supernatancie po hodowli) z lipazami znajdującymi się we wnętrzu komórek dokonywano, mierząc aktywność lipolityczną supernatantu po­wstałego po procesie częściowego uszkodzenia ściany komórkowej. Aktywność poszcze­gólnych frakcji szacowano na podstawie stopnia hydrolizy oleinianu etylu. Uzyskane wyniki pozwoliły stwierdzić, iż szczep drożdży Yarrowia lipolytica KKP 379 jest zdolny do produkcji zarówno lipaz zewnątrz-, jak i wewnątrzkomórkowych. Ilość li­paz wydzielanych do podłoża wzrasta w trakcie prowadzenia hodowli.
ProductiomnftFamylase under solid state fermentation by Streptomyces erumpens MTCC 7317 has been investigated using different agro-industrial residues, i.e. cassava bagasse, sugarcane bagasse and wheat bran; wheat bran was found to be the best substrate. Among different nitrogen source supplemented to wheat bran, beef extract or peptone (1 %) showed maximum enzyme production. Response surface methodology was used to evaluate the effect of main process parameters as incubation period (48 h), moisture holding capacity (70%), pH (7.0) and temperature (50°C) on enzyme production by applying a full factorial central composite design. The maximum hydrolysis of soluble starch (90%) and cassava starch (75%) was obtained with the application of 4 ml (~12096 U) of S. erumpens crude enzyme after 5 h of incubation.
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