This research was aimed to study the effect of Lactobacillus plantarum and Leuconostoc mesenteroides starter cultures application in lower salt concentration fermentation on sauerkraut quality. Fresh cut cabbage was fermented with different starter cultures (L. plantarum, L. mesenteroides or the combination) at different lower salt concentration (0.5% or 1%) at 28oC for 5 days. The obtained sauerkrauts were subjected to evaluation of the quality i.e. total lactic acid bacteria, pH, total acidity, total phenolic content and DPPH scavenging activity analysis. The sulforaphane content analysis was performed by using LC-MS. The starter cultures increased total lactic acid bacteria, total acidity and decreased pH. L. mesenteroides resulted in the highest total phenolic content and the lowest IC50 value. Sauerkraut with the addition of L. mesenteroides contains sulforaphane higher 848.65 ng/g than that of control 776.47 ng/g. The results analysis of LC-MS also detected another compound, namely 2-phenethyl isothiocyanate, an antimicrobial compound. The sauerkraut is potential in functional food development with antiproliferative, antiinflammatory, antioxidant, and anti-cancer activities.

This research was a part of development of functional beverage through fermentation of snake fruit juice with Kombucha consortium. The aim of this research was to study on in vivo evaluation of snake fruit Kombucha as hyperglycemia therapeutic agent. The snake fruit (Salak Suwaru cultivar) juice was fermented for 14 days with the Kombucha consortium. Streptozotocin induced diabetic rats were used in the in vivo evaluation. The snake fruit Kombucha was orally administerred at different level for 28 days. The results revealed the treatment showed a significant fasting plasma glucose reduction in a range of 31-59%, consistent with improving of blood serum superoxide dismutase activity and malondialdehyde level. Immunohistochemical staining of pancreatic tissue proved a regeneration of the pancreatic beta cells in the groups of snake fruit Kombucha treatment compared to control group. Snake fruit Kombucha was proven as a hyperglycemia therapeutic agent in diabetic rats model. (c) All Rights Reserved

This paper describes two different semiconductor gas sensors devoted to the detection of oxidizing pollutants in the atmosphere. The first sensor consists of thin films of phthalocyanines as sensing layers (CuPc, ZnF/sub 16/Pc, and LuPc/sub 2/) evaporated onto alumina substrate fitted with interdigitated electrodes. The second sensor is realized with a mineral monocrystalline semiconductor: n-doped epitaxial layer grown on a semi-insulating substrate of indium phosphide. Each sensor has been submitted to low-controlled concentrations of ozone and nitrogen dioxide, and their detection characteristics, such as response time, stability, and sensitivity, are described. Comparison of these two sensors shows their complementary sensing characteristics, and NO/sub 2/ and O/sub 3/ act in the same way. Measurements under noncontrolled atmosphere (urban air) have been realized and have demonstrated the potentialities of these structures to be used as oxidizing pollutant detectors. Proposed methods to improve the detection of oxidizing species in urban air are discussed.

After a brief summary on environmental pollution and commonly used materials for NO2 and O3 sensing, simple InP-based resistive sensors are studied. The gas sensitive device is a thin n-type InP epitaxial layer grown on a semi-insulating InP substrate. The electrical resistance of the layer, measured between ohmic contacts, increases in the presence of oxidising gases, the most important variations occurring in NO2 and ozone-containing atmospheres. A complete study performed in laboratory at a moderate operating temperature of 80°C on the sensor exposed to nitrogen dioxide enabled to obtain a precise NO2 calibration curve. In an outdoor application, only NO2, ozone and humidity seem to act on the sensor resistance, confirming laboratory experiments. One of these devices was used to monitor air pollution in an urban atmosphere. The resistance changes were compared with the readings of a commercial analysing equipment. The results clearly show that the sensor resistance variation follow the total O3 and NO2 concentrations variation in air. Different operating methods are discussed for these type of sensors, depending on what of these two pollutants has to be measured.

Investigations were carried out on concrete walls stained by biological growth. Pieces of this material were removed down and observed using optical microscopy, low-vacuum scanning electron microscopy (LVSEM) and normal SEM. The results show that biological stains are due to two different kinds of microscopic algae, Chlorophyceae and Cyanophyceae, whose presence depends on the amount of moisture on the concrete wall. Accelerated laboratory tests of biological growth on mortar samples that were performed show that algal developments increase with the porosity of the underlying material. Thus, it seems that the use of dense, high-performance mortars can slow down or even inhibit microorganism growth.

After a brief introduction about: the different gaseous pollutants present in the atmosphere; the cause of their concentration rise; their consequences on human health; and the different devices used to monitor each gas, two types of semiconductor gas sensors are presented. The first of them is a simple InP-based resistive sensor. The sensitive layer is a thin n-type InP epitaxial layer grown on a semi-insulating InP substrate. The electrical resistance, increasing in the presence of oxidising gases, is measured between two ohmic contacts. The second sensor is a thin film of copper phthalocyanine deposited by sublimation on an alumina substrate. The conductivity of the phthalocyanine layer increases in the presence of oxidising gases. Influence of NO2 and O3, especially at low concentration, is investigated. Influence of other parameters like operating temperature or interfering gases is also studied. In conclusion, optimisation of sensor characteristics to improve the evaluation of oxidising air pollutants concentrations is discussed.

ABSTRACT During submerged culture in the presence of glucose and glutamate, the filamentous fungus Monascus ruber produces water-soluble red pigments together with citrinin, a mycotoxin with nephrotoxic and hepatoxic effects on animals. Analysis of the13C-pigment molecules from mycelia cultivated with [1-13C]-, [2-13C]-, or [1,2-13C]acetate by 13C nuclear magnetic resonance indicated that the biosynthesis of the red pigments used both the polyketide pathway, to generate the chromophore structure, and the fatty acid synthesis pathway, to produce a medium-chain fatty acid (octanoic acid) which was then bound to the chromophore by atrans-esterification reaction. Hence, to enhance pigment production, we tried to short-circuit the de novo synthesis of medium-chain fatty acids by adding them to the culture broth. Of fatty acids with carbon chains ranging from 6 to 18 carbon atoms, only octanoic acid showed a 30 to 50% stimulation of red pigment production, by a mechanism which, in contrast to expectation, did not involve its direct trans-esterification on the chromophore backbone. However, the medium- and long-chain fatty acids tested were readily assimilated by the fungus, and in the case of fatty acids ranging from 8 to 12 carbon atoms, 30 to 40% of their initial amount transiently accumulated in the growth medium in the form of the corresponding methylketone 1 carbon unit shorter. Very interestingly, these fatty acids or their corresponding methylketones caused a strong reduction in, or even a complete inhibition of, citrinin production byM. ruber when they were added to the medium. Several data indicated that this effect could be due to the degradation of the newly synthesized citrinin (or an intermediate in the citrinin pathway) by hydrogen peroxide resulting from peroxisome proliferation induced by medium-chain fatty acids or methylketones.

Slow cooling rate and pre-freezing stress brings about a high increase in the cell resistance and preservation of their physiological characteristics. A brutal decrease in temperature (from 37°C to −80°C) causes a considerable loss of cell viability, in contrast a slow one preserves a survival rate of 75%. Pre-incubation of cells at low temperature (22°C) during 6 h led to the development of cryotolerance indicated by an enhanced capacity to survive after a freezing treatment of 24 h at −80°C. Exposure of the cells to low pH (5.5) caused a large decrease in cell resistance but did not lead to any significant decrease of survival rate after freezing treatment. However, an increase of 15±3% in protein level compared to cells cultivated at regulated pH was observed.

This paper deals with a new type of NO2 sensor using n-type InP epitaxial layers as sensing material. The gas action makes the conductance of the device, measured parallel to the surface between ohmic contacts, decrease. It is shown how the thickness and the doping level of these layers affect the sensor sensitivity. A simple model is proposed to describe the gas action, based on ionization of chemisorbed NO2 molecules inducing field-effect mechanism. Calculations lead to thickness, doping level and gas concentration dependence in agreement with experimental results. The ability for environmental applications is also discussed and it is concluded that even if such devices can detect low NO2 concentrations, they suffer from limitations due to a parasitic effect of moisture.

n-InP epitaxial thin layers are exposed to concentrations of a diluted oxidizing gas: NO2. In the presence of this gas, the resistance measured parallel to the surface of the InP layer, between ohmic contacts, increases. The magnitude of its variations depends on several parameters: the operating temperature, the thickness and the doping concentration level of the InP layer, and the gas concentration. A theoretical model of the action of the gas is proposed, mixing chemisorption equilibrium and surface field effect. The experimental results are in agreement with the theoretical predictions.

Carbon isotope distribution of [13C]citrinin from Monascus ruber incubated with [13C]acetate revealed that the biosynthesis of the toxin originated from a tetraketide, instead of a pentaketide as has been shown for Penicillium and Aspergillus species. The production of polyketide red pigments and citrinin by M. ruber may therefore be regulated at the level of the tetraketide branch point.

The action of the oxidizing gases O2 and NO2 on the electrical conductivity of thin layers of ZnF16Pc and ZnPc is investigated. Differences in the behavior of the two phthalocyanines are interpreted on the basis of electrochemical data and compared to previous results obtained with NH3 and H2. The metallo phthalocyanine gas responses vary as a function of the presence of substituents on the macrocycle. Gas sensor application is considered.

Two methods for rapid sampling and three procedures for extraction of metabolites from the filamentous fungus Monascus ruber were compared. It is shown that arrest of metabolism by either dropping the mycelial cultures in liquid nitrogen or by spraying them on a 60% solution of methanol kept at −40°C followed by rapid centrifugation at −10°C were equally effective. Metabolites were extracted from mycelia using different procedures including acid and alkaline treatments, permeabilization by cold chloroform and extraction by boiling buffered ethanol, to demonstrate that the latter method gave the best results both in terms of recovery and stability of metabolites. In addition, this method is very simple to handle and allows the use of very low amounts (i.e. 10–20 mg dry mass) of cellular material since the removal of ethanol by evaporation after extraction results in a concentration step of metabolites.

Thin layers of zinc hexadecafluorophthalocyanine ZnF16Pc and of zinc phthalocyanine ZnPc were prepared by vapor deposition. Their conductivity was measured during exposures to the reducing gases NH3 and H2 diluted in N2. The conductivity of ZnF16Pc increases in the presence of NH3 whereas ZnPc exhibits no sensitivity to this gas. Correlatively, the sensitivity to H2 is higher for ZnF16Pc than for ZnPc. This behavior is related to redox potentials of the two phthalocyanines. Gas sensing applications are considered.

Formation of red pigment by Monascus purpureus via diauxic growth on glucose and ethanol in submerged culture was optimized based on inoculum preparation and culture medium. A vegetative inoculum was prepared from spores grown on ethanol. The optimized culture medium was low in phosphates, and had an initial pH of 5.5. The characteristics of Monascus purpureus grown on glucose and on ethanol were compared: the specific consumption rate of glucose (q(G)) was higher than the specific consumption rate of ethanol (q(E)), whereas the specific growth rate was greatest with ethanol. The specific production rate of red pigment (p(OD)) and pigment yield (Y-OD/s) with glucose was twice that with ethanol. A novel fermentation process was developed with M. purpureus initially grown with controlled ethanol formation, and consumption of the latter during pigment formation.

As a part of the investigations on red pigment production by Monascus species, an antibacterial compound was isolated from the supernatant fungal cultures and identified as the nephrotoxic agent, citrinin. It was produced both by Monascus purpureus as well as M. ruber and was synthesized the pigments, through the polyketides pathway. As Monascus red pigments are commonly used in Asia as food additives, where these are produced on rice, the commercial preparations obtained by SSF were analyzed. These contained no citrinin at all, while our preparations obtained by submerged cultures contained a non-negligible fraction of citrinin. In the liquid medium, M. purpureus and M. ruber produced citrinin at concentrations of 240 and 370 mg/l, respectively, while in SSF on rice, the production was 100 and 300 mg/kg of dried fermented rice powder, respectively.

The resistance of n-InP epitaxial layers is shown to increase or decrease in the presence of oxidizing (O2, NO2) or reducing (NH3) gases, respectively. The magnitude of resistance variations depends on gas concentration, on InP layer thickness and on temperature. Interpretation is based on field effect mechanisms resulting from ionization of surface-chemisorbed gas molecules. Gas sensing devices are considered.