Influence of phenol, p-cresol and indole on growth and survival of intestinal lactic acid bacteria

Some intestinal bacteria can produce many genotoxic, mutagenic and carcinogenic substances. The major products of the bacterial aromatic amino acids fermentation-phenolic and indolic compounds which are responsible for colon cancer development are accumulated in the colon. The effect of phenol, p-cresol and indole (2, 20 and 100 microg/ml doses) on growth and survival of four strains of intestinal lactic acid bacteria was studied. Growth of bacteria was not affected by any of the concentrations of phenol and p-cresol tested. The growth of 2 strains was slightly inhibited by 100 microg/ml of indole. There was no influence of phenol and p-cresol on survival of lactic bacteria until 120 h and specific reaction to carcinogens depending on strain was observed after that incubation time. Indole concentrations 20 and 100 microg/ml appeared to be toxic for all tested strains but just after 24, 48 or 72 h of incubation depending on the strain. In total, 2 microg/ml of indole had a very little effect.     

Electrophoretic seed albumin patterns inVicia species of sectt.Hypechusa andPeregrinae (Fabaceae)

This work is a continuation of electrophoretic investigations aimed at revealing a wild relative ofVicia faba. Electrophoretic analysis (PAGE) of seed albumins covered 52 accessions representing eightVicia species of sect.Hypechusa and two species of sect.Peregrinae. Most of the examined species showed an intraspecific variation due to differences between accessions and/or individual variation within accessions. In spite of the intraspecific variation, marked interspecific differences were recorded. However, none of the investigated species displayed electrophoretic seed albumin patterns similar to those reported earlier forV. faba. Contribution of the obtained results to characterization of the examined taxa is discussed.     

Frequently asked questions about in vivo chlorophyll fluorescence: practical issues

The aim of this educational review is to provide practical information on the hardware, methodology, and the hands on application of chlorophyll (Chl) a fluorescence technology. We present the paper in a question and answer format like frequently asked questions. Although nearly all information on the application of Chl a fluorescence can be found in the literature, it is not always easily accessible. This paper is primarily aimed at scientists who have some experience with the application of Chl a fluorescence but are still in the process of discovering what it all means and how it can be used. Topics discussed are (among other things) the kind of information that can be obtained using different fluorescence techniques, the interpretation of Chl a fluorescence signals, specific applications of these techniques, and practical advice on different subjects, such as on the length of dark adaptation before measurement of the Chl a fluorescence transient. The paper also provides the physiological background for some of the applied procedures. It also serves as a source of reference for experienced scientists.     

Revision of the Indo-Australian genus Cnematoplatys Schmidt with description of a new species from Queensland (Coleoptera: Scarabaeidae: Aphodiinae: Eupariini)

Abstract  The euparine genus Cnematoplatys Schmidt, with seven species, is reviewed, including one species, C. yorkensis described as new. The generic diagnosis is revised, a lectotype of the type species, C. benardi Schmidt, is designated, a key to the species is provided and pertinent morphological details are illustrated. All data on taxonomy and available data on distribution are given, and a cladistic analysis is included to test the monophyly of the genus.     

Potential of Chlorella vulgaris culture for waste treatment from anaerobic biomass biodigestion at the Piaszczyna (Poland) integrated facility

Many strains of microalgae are potentially useful for industrial purposes. Microalgal biomass and microalgae‐derived substances are becoming valuable products with a widening range of applications including biofuels and human food. In this study, the possibility of using the methane waste from biomass biodigestion in the cultivation of Chlorella vulgaris biomass with simultaneous waste treatment was investigated. The methane waste from biomass biodigestion was obtained from a multifunctional facility (Piaszczyna, Poland) producing bioethanol from plant biomass with several steps to reuse the wastes, heat, and carbon dioxide. The growth and biomass yield, as well as photosynthetic performance of C. vulgaris on diluted waste, were similar to the results obtained on the standard mineral medium. The cultivation of C. vulgaris was the waste, treatment step that significantly reduced chemical oxygen demand. The results indicated that the waste contained micro‐ and macronutrients sufficient to sustain the growth of C. vulgaris cell culture up to 2 g of dry biomass per liter of culture. The results contributed to the development of the waste treatment step in the Piaszczyna facility that allowed for a further decrease in emissions and may lead to development of microalgae biomass‐based products in the facility portfolio.     

Structural characteristics of a major seed albumin ofPisum sativum

The major pea seed albumin fromPisum sativurn was carboxymethylated, cleaved with CNBr, and submitted to sequence analysis of the fragments in order to characterize the structural organization of the protein chains. Four major pools of largely homogeneous CNBr fragments were obtainede and likely N-and C-terminal fragments were identified. StruCtural analysis suggested the presence of single positions with microheterogeneities. It also revealed structures with long segments of distinct homology (52% structural identity), indicating the presence of different but related protein chains, or less likely, of repetitive structural elements within a chain. However, preparations appear largely homogeneous in protein class, and contain similar polypeptide chains of about 200 residues in mainly hydrophilic structures, with few methionine and cysteine/half-cystine residues.     

Ability of intestinal lactic bacteria to bind or/and metabolise phenol and p-cresol

Intestinal microflora can contribute to colon cancer by the production of substances playing a role in carcinogenesis. Metabolites of protein fermentation in the colon, such as ammonia, H₂S, indole, phenol, skatole are toxic. Lactic bacteria existing in the colon may exert an anti-carcinogenic action, but the mechanism is poorly understood. In the present study the ability of intestin|al lactobacilli to bind or metabolise phenol and p-cresolin vitro was determined.Lactobacillus strains were cultivated in MRS and in a modified MRS broth with reduced concentrations of carbon source. Phenol and p-cresol content in the media were from 2 to 10 μg/ml. In MRS medium lactobacilli could decrease the concentration of phenol and p-cresol and it was 0.2-5.8 μg/ml for phenol and 0.2-1.4 μg/ml for p-cresol. After cultivation in a modified MRS broth, the decrease was 0.5-2.0 μg/ml for phenol and 0.5-2.4 μg/ml for p-cresol. The binding capacity of bacterial cells was rather low. After incubation of non-growing bacteria the decrease of phenol concentration was 0.1-0.5 μg/ml and p-cresol 0.1-2.8 μg/ml. But the ability of growing lactobacilli to metabolise the compounds cannot be excluded. After interaction of lactobacilli with 10 μg/ml of phenol they displayed a lower genotoxicity, as evaluated by the alkaline comet assay. The phenomenon not always depended on the decrease of phenol concentration, but on the medium, the strain of bacteria and for phenol it ranged from 32 to 48%.Lactobacillus strains tested did not lower the genotoxicity of p-cresol.