Search results for "Applied Microbiology and Biotechnology"
showing 10 items of 1090 documents
Tryptophan catabolism via kynurenine production in Streptomyces coelicolor: identification of three genes coding for the enzymes of tryptophan to ant…
2011
Most enzymes involved in tryptophan catabolism via kynurenine formation are highly conserved in Prokaryotes and Eukaryotes. In humans, alterations of this pathway have been related to different pathologies mainly involving the central nervous system. In Bacteria, tryptophan and some of its derivates are important antibiotic precursors. Tryptophan degradation via kynurenine formation involves two different pathways: the eukaryotic kynurenine pathway, also recently found in some bacteria, and the tryptophan-to-anthranilate pathway, which is widespread in microorganisms. The latter produces anthranilate using three enzymes also involved in the kynurenine pathway: tryptophan 2,3-dioxygenase (TD…
Acid tolerance inLeuconostoc oenos. Isolation and characterization of an acid-resistant mutant
1996
The acid tolerance ofLeuconostoc oenos was examined in cells surviving at pH 2.6, which is lower than the acid limit of growth (about pH 3.0). Acid-adapted cells survived better than non-adapted cells. Tolerance to acid stress was found to be dependent upon the adaptive pH. Acid resistance was increased by an order of magnitude for cultures adapted to a pH of about 2.9. Inhibiting protein synthesis with chloramphenicol prior to acid shock revealed that acid adaptation may involve two separate systems, one of which appears to be independent of protein synthesis. The acid-resistant mutant LoV8413, isolated during a long-term survival screen at pH 2.6, was found to be able to grow in acidic me…
The yeastWickerhamomyces anomalusAS1 secretes a multifunctional exo-β-1,3-glucanase with implications for winemaking
2014
A multifunctional exo-β-1,3-glucanase (WaExg2) was purified from the culture supernatant of the yeast Wickerhamomyces anomalus AS1. The enzyme was identified by mass spectroscopic analysis of tryptic peptide fragments and the encoding gene WaEXG2 was sequenced. The latter codes for a protein of 427 amino acids, beginning with a probable signal peptide (17 aa) for secretion. The mature protein has a molecular mass of 47 456 Da with a calculated pI of 4.84. The somewhat higher mass of the protein in SDS–PAGE might be due to bound carbohydrates. Presumptive disulphide bridges confer a high compactness to the molecule. This explains the apparent smaller molecular mass (35 kDa) of the native enz…
Identification of monocyte subpopulations and signaling pathways responsible for the immune response to fungal immunomodulatory glycoprotein AMPD
2016
Functional analysis of the cysteine residues and the repetitive sequence ofSaccharomyces cerevisiaePir4/Cis3: the repetitive sequence is needed for b…
2003
Identification of PIR/CIS3 gene was carried out by amino-terminal sequencing of a protein band released by β-mercaptoethanol (β-ME) from S. cerevisiae mnn9 cell walls. The protein was released also by digestion with β-1,3-glucanases (laminarinase or zymolyase) or by mild alkaline solutions. Deletion of the two carboxyterminal Cys residues (Cys214-12aa-Cys227-COOH), reduced but did not eliminate incorporation of Pir4 (protein with internal repeats) by disulphide bridges. Similarly, site-directed mutation of two other cysteine amino acids (Cys130Ser or Cys197Ser) failed to block incorporation of Pir4; the second mutation produced the appearance of Kex2-unprocessed Pir4. Therefore, it seems th…
Lysosome-like particles in Geotrichum candidum : A cytochemical study
1971
Lysosome-like particles were localized in Geotrichum candidum by means of the technique for the detection of acid phosphatase of PEARSE and staining with the vital dyes Brilliant cresyl blue and Neutral red. Pretreatments of the cells with procedures injuring the lysosome membrane resulted in shortening of the incubation time (2 min instead of 30 min). After exposure to 1% Triton X-100 the cells showed uniform strong staining due to the release of the enzyme into the cytoplasm.
Bioavailability of antihypertensive lactoferricin B-derived peptides: Transepithelial transport and resistance to intestinal and plasma peptidases
2013
The transepithelial transport of the angiotensin I-converting enzyme (ACE)-inhibitory and antihypertensive lactoferricin B (LfcinB)-derived hexapeptide LfcinB20-25 (RRWQWR) and of its two main fragments RWQ and WQ were investigated using a human intestinal cell (Caco-2) monolayer. The three peptides were susceptible to the action of brush-border peptidases. Intact LfcinB20-25 was not transported across Caco-2 whereas RWQ and WQ were both absorbed through the cell monolayer. Apparent permeability (Papp) values for absorptive transport across the monolayer were 0.7×10-8cms-1 (RWQ) and 3.9×10-8cms-1 (WQ). The effect of pathway-selective inhibitors on peptide absorption suggested paracellular d…
Plant-growth-regulatingN-(phosphonoacetyl)amines
1994
A series of N‐(phosphonacetyl)amine derivatives were synthesized and screened for plant‐growth regulating activity on Lepidium sativum L. and Cucumis sativus L. Aromatic N‐(phosphonoacetyl)amines. which may be considered as possible analogues of N‐acylaniline herbicides obtained by replacement of their acyl group by the phosphonacetyl moiety, exhibited significant or moderate herbicidal activity. In contrast, N‐(phosphonoacetyl)amino acids and N‐(phosphonoacetyl)aminophosphonic acids promoted the growth of L. sativum and C. sativus roots.
Plant-growth-regulating phosphono peptides
1990
Phosphono peptides exhibited plant‐growth‐regulating activity when tested on Lepidium sativum and Cucumis sativus. The studies have provided evidence that the mechanism of action of these compounds may involve the uptake of the phosphono peptides into the plant, intracellular hydrolysis of the peptide bond and release of the P‐terminal aminoalkylphosphonic acid. This acid or its metabolite is then probably responsible for the observed physiological effect.