STUDY OF THE CONTAMINATING MICROBIOTA OF OLD PAPER SUPPORTS

Biodeterioration has drawn the attention of different specialists who started to cooperate and to understand the need of joint research to have a picture as comprehensive as possible of the degradation agents and the measures that can be taken to salvage the heritage assets. This paper contains a description of the microbiota identified in two types of old paper supports part of a private collection from North Moldavia (Romania), namely a church book from the end of the 19th century for which the paper was obtained manually from textile fibres, and a book from 1870 with paper from cellulose pulp derived from wood. To the purpose of identifying the types of bacteria and fungi present on the supports examined, several comments were made related to the morphology of the colonies developed on the growth medium, which provided important indications for the determination based on the microscopical examination as well. Bacterial contamination (of the genera Bacillus, Clostridium, Pseudomonas and Micrococcus) was detected in most samples collected. The diversity of the fungi isolated from the paper supports (the genera Penicillium, Alternaria) is the result of the fact that since they are highly hygroscopic materials, they have the capability to retain water more easily, which stimulates fungal growth. The investigations made to determine the presence of microorganisms responsible for degradation and their identification allowed the discovery and acertainment of the real and justified need to find ways to prevent biodeterioration or to inactivate and destroy biodeteriogens by non-invasive, eco-friendly chemical and physical treatments

STUDIES ON THE CARBON CATABOLITE REPRESSION IN LACTIC ACID BACTERIA ISOLATED FROM WINE

In wine, lactic acid bacteria (LAB) are responsible for the bioconversion of malic acid to lactic acid, malolactic fermentation that mainly aims at reducing wine acidity. Two LAB strains isolated from the red wine microbiota (Oenococcus oeni 13-7 and Lactobacillus plantarum R1-1), were tested for their ability to exhibit the carbon catabolite repression (CCR) mechanism, that allows the rapid use of certain carbohydrates, over other carbon sources. Bacterial cells were inoculated in 0.1 M glycine buffer (pH 3.5), incubated at 30°C, with different carbohydrates (45 mM) and malic acid (45 mM). For both strains, the presence of glucose significantly inhibited malic acid metabolization (−60%), a similar effect being observed for galactose, mannose and maltose. The highest rate of malic acid conversion was shown in fructose/malate medium. Obtained results showed that malolactic strains can control the utilization of carbon sources via CCR, further studies being necessary to elucidate the mechanisms underlying this process

The influence of fertilization on the quantitative distribution of denitrifying bacteria in the soil

Highlighting the processes by which the nitrogen compounds are reduced in the soil (i.e. denitrification) and which result in the increase of the ammonium level, is extremely important since denitrification is one of the effective mechanisms that reduce the nitrogen content in the soils rich in nitrites thus preventing soil pollution. The determination of the most probable number of denitrifying bacteria was carried out by the multiple tube technique using Allen’s culture medium, in anaerobic conditions. The test was performed on samples of fertilized and unfertilized soils collected from different depths (i.e. 7-10 cm and 15-25 cm). The denitrification process was found to manifest in all the soil types, with variations depending on the soil sample, fertilizers, type of tillage operations, and the period during which the microbiological determinations were performed. The lowest levels were found in the samples of unfertilized soils from 7-10 cm deep, after ploughing to 20 cm, collected in June 2009 (i.e. 56 x 102 bacteria/g soil), while the highest were found in the samples of fertilized soils tilled using the disk harrow, particularly in the sample collected from 7-10 cm deep (i.e. 31 x 103 bacteria/g soil). The density level, respectively the level of the bacterial metabolic activity, may be considered an indicator of the condition of the ecosystem examined reflected by the availability of the organic matters and the intensity of the processes of organic matter transformation and recirculation

Stabilization of the Penicillium chrysogenum strain with pelletized morphological structure by selection, multiplication, and control of the variability of pure cultures

This study showed that Penicillium chrysogenum exhibits during submerged cultivation two distinct features: a filamentous structure characterized by long, branched, loose hyphae, and a pelletized morphological structure characterized by short, thickened hyphae clustered in a glomerule-like formation called pellet. With a view to maintaining the potential to biosynthesize the pelletized strain penicillin to a maximum, the operations involving the selection, multiplication and variability control of pure culture should be conducted periodically to prevent phenotypic and genotypic deviations to parental forms

IMPACT OF INDUCING CONTROLLED LACTIC FERMENTATION OF CORN EXTRACT ON THE PENICILLIN BIOSYNTHESIS USING THE PELLETIZED FORM OF THE PENICILLIUM CHRYSOGENUM STRAIN

The lactic fermentation of the corn extract used in the process of penicillin biosynthesis is considered essential for a high quality extract. Our investigations showed that the inducing controlled lactic fermentation of the corn extract has a significant impact on the evolution of penicillin biosynthesis because it reduces the protein matter which stimulates growth of the cellular mass over the control limits, assures the preservation of the pelletized structure of the mycelium by the end of biosynthesis and increases the final penicillin biosynthesis titer by 20% at 185 hours of growth to maximum 28% at 226 hour

Plant growth promoting rhizobacteria can inhibit the in vitro germination of Glycine max L. seeds

Utilization of plant growth promoting rhizobacteria (PGPR) in order to increase the productivity may be a viable alternative to organic fertilizers. The main goal is to reduce the pollution and to preserve the environment in the spirit of an ecological agriculture. Because soybean represent a crop of major economic importance, a study was performed to analyze the impact of some rhizobacteria isolated from soybean roots on the on the germination process of Glycine max L. seeds, taking into account the aspartate- and alanin-aminotransferase activities. The results showed that in the early stages, rhizobacteria has an inhibitory effect on the germination process

The effects of inoculum spores content on both Penicillium chrysogenum pf (pelletized form) morphology and penicillin biosynthesis at industrial scale

The present paper is intended to provide a correlation/relationship between the morphological aspect of the mycelia produced by Penicillium chrysogenum strain (pelletized form) and the spores concentration of the inoculum utilized to seed the culture medium for antibiotic biosynthesis. In case of Penicillium chrysogenum strains, the increase of the biosynthesic potential is determined by the close relationship between the genotype features/characteristics and the cultivation conditions

Trichomonas vaginalis a risk factor for cervical cancer

Trichomonas vaginalis is the human parasite most widely spread in the world. The national statistics shows that it occurs in 20 to 25% of the women in Romania. The latest research studies (Carlton, J.M. et al, 2007) have proved that persistent infections with Trichomonas vaginalis increase the risk of HIV infection, cervical cancer, and serious complications in premature births. This study was conducted over a period of five years (2004 - 2008). From the 9117 cases examined, 220 were diagnosed with inflammations caused by Trichomonas vaginalis. Approximately 6.4% of the infected cases exhibited cellular atypia. The purpose of this study was to determine the incidence of atypia associated with trichomoniasis in the cervicovaginal smears examined during the Babes-Papanicolaou tests. Another important objective was to correlate different aspects of the pathogenic mechanism of the parasite with the information of the Trichomonas vaginalis genome, as well as morphopathological characteristics of the cervicovaginal cells