Search results for "BETA-GLUCOSIDASE"
showing 7 items of 17 documents
Contrasting Effects of Environmental Concentrations of Sulfonamides on Microbial Heterotrophic Activities in Freshwater Sediments
2021
The sulfonamide antibiotics sulfamethoxazole (SMX) and sulfamethazine (SMZ) are regularly detected in surface sediments of contaminated hydrosystems, with maximum concentrations that can reach tens of μg kg–1 in stream and river sediments. Little is known about the resulting effects on the exposed benthic organisms. Here we investigated the functional response of stream sediment microbial communities exposed for 4 weeks to two levels of environmentally relevant concentrations of SMX and SMZ, tested individually. To this end, we developed a laboratory channel experiment where natural stream sediments were immersed in water contaminated with nominal environmental concentrations of 500 and 5,0…
Transcriptome comparison of murine wild-type and synaptophysin-deficient retina reveals complete identity
2005
Loss of synaptophysin, one of the major synaptic vesicle membrane proteins, is surprisingly well tolerated in knockout mice. To test whether compensatory gene transcription accounts for the apparent lack of functional deficiencies, comparative transcriptome analyses were carried out. The retina was selected as the most suitable tissue since morphological alterations were observed in mutant photoreceptors, most notably a reduction of synaptic vesicles and concomitant increase in clathrin-coated vesicles. Labeled cRNA was prepared in triplicate from retinae of age- and sex-matched wild-type and mutant litter mates and hybridized to high-density microarray chips. Only three differentially expr…
Differentiation of Penicillium griseofulvum Dierckx isolates by enzyme assays and by patulin and griseofulvin analyses
1990
The production of patulin and griseofulvin by 49 different isolates of Penicillium griseofulvum Dierckx was analyzed by high-performance liquid chromatography. Eleven isolates were obtained from pistachio nuts, 37 were obtained from wheat seeds, and 1 was obtained from the American Type Culture Collection. Activities of 19 enzymes were also assayed by the API ZYM system. From these results it may be deduced that there are two different groups among the strains tested which cannot be distinguished by morphological and cultural characteristics. One group of isolates did not produce detectable amounts of patulin and griseofulvin when grown in sucrose-yeast extract and Wickerham media, while en…
Metabolism of phenol in the terrestrial snail Cepaea nemoralis L
1992
1. The metabolism of phenol in the terrestrial snail Cepaea nemoralis was studied after injection into the haemocoel of the dorsolateral foot region. 2. Excreted metabolites, and metabolites extracted from the body, were analysed by h.p.l.c. In addition to phenyl beta-D-glucoside, arbutine (quinol beta-D-glucoside), a new conjugate of phenol, was detected.
Soil enzyme assays using p-nitrophenyl derivatives: an inter-laboratory comparison
2011
Reproducibility and reliability of soil enzyme assays need to be validated by comparing results among different labs. The Italian Group of Enzymology organized a ring test among five labs. Beta-glucosidase, acid- and alkaline phosphatase activities were chosen as they are all measurable by using substrates with wide applicability, i.e. p-nitrophenyl derivatives. The five labs preliminarily agreed and standardised the specific methodological procedure for each enzymatic activity, also taking into account factors such as practicability and equipment availability. Nine soils with contrasting physico- chemical and biological properties were adequately sampled, pre-treated and sieved, in order t…
Localized versus systemic effect of arbuscular mycorrhizal fungi on defence responses to Phytophthora infection in tomato plants
2002
Development of biological control for plant diseases is accepted as a durable and environmentally friendly alternative for agrochemicals. Arbuscular mycorrhizal fungi (AMF), which form symbiotic associations with root systems of most agricultural, horticultural and hardwood crop species, have been suggested as widespread potential bioprotective agents. In the present study the ability of two AMF (Glomus mosseae and Glomus intraradices) to induce local or systemic resistance to Phytophthora parasitica in tomato roots have been compared using a split root experimental system. Glomus mosseae was effective in reducing disease symptoms produced by P. parasitica infection, and evidence points to …
Increase of trans-resveratrol in typical Sicilian wine using β-Glucosidase from various sources
2008
β-Glucosidase (EC 3.2.1.21) (β-G) from different sources were tested to increase the trans-resveratrol in some Sicilian wines by hydrolysing resveratrol glucoside. β-G from Aspergillus niger mould was tested as a crude and purified enzyme, and compared with the same enzyme from Saccharomyces cerevisiae yeast. Specific purification served to eliminate collateral enzyme activities so that β-G could be used simply and economically. Aspergillus niger β-G produced trans-resveratrol increases of up to 75%, with no change in physico-chemical properties and bouquet, and an increase in health and nutritional properties. S. cerevisiae β-G raised free-terpenol levels, but impaired wine colour due to a…