Generation of nonlinearity in the electrical response of yeast suspensions

The mechanism through which nonlinearity is generated in the response waveform of the electric current obtained by applying alternating current voltage to yeast suspension has not yet been elucidated. In this paper, we showed that the response waveform depends on the applied voltage and frequency. The results showed that distortion (nonlinearity) in the waveform increases as the applied voltage increases and/or the frequency decreases. We suggest a model for the generation of nonlinearity based on the influx of potassium ions into the cell via potassium ion channels and transporters in the membrane due to the applied voltage. Furthermore, we validated this model by simulating an electrical circuit.

Generation of nonlinearity in the electrical response of yeast suspensions

The mechanism through which nonlinearity is generated in the response waveform of the electric current obtained by applying alternating current voltage to yeast suspension has not yet been elucidated. In this paper, we showed that the response waveform depends on the applied voltage and frequency. The results showed that distortion (nonlinearity) in the waveform increases as the applied voltage increases and/or the frequency decreases. We suggest a model for the generation of nonlinearity based on the influx of potassium ions into the cell via potassium ion channels and transporters in the membrane due to the applied voltage. Furthermore, we validated this model by simulating an electrical circuit.

Effect of Spraying With Bread Yeast Suspension and The Addition of NPK+(TE) on The Chemical Content of The Leaves of Tamarind Young Plants (Tamarindus indica L.)

The experiment was carried out during the spring season from 1/3/2019 to 1/9/2019, to study the effect of foliar spraying with a suspension of bread yeast at concentrations 0.0, 2.5, 5.0 and 7.5 g.L-1, and the addition of the compound chemical fertilizer NPK+Trace Elements(TE)20-20-20 for soil with three levels (0.0, 0.5 and 1.0 g.plant-1 ) and their interactions in the chemical content of the leaves of two years old tamarind young plants. The research was carried out as a factorial experiment (4*3) according to the randomized complete block design (RCBD) with three replications. The indicators of the study showed that the foliar spraying with bread yeast suspension led to an improvement in most of the studied traits of tamarind young plants and the foliar spraying treatment with a concentration of 7.5 g.L-1 excelled in achieving the best results in comparison with the control treatment of nitrogen, phosphorous, potassium and protein content in the tamarind young plants leaves. Total chlorophyll and carotene, yeast did not have any significant effect in any of the concentrations in the experiment. The compound chemical fertilizer NPK+Trace Elements improved all the studied characteristics of tamarind young plants, and the treatment at the level 0.5 g.plant-1. While the concentration of one g.plant-1was superior in recording a significant increase of potassium concentration in the leaves. Whereas, the interaction between foliar spraying with bread yeast suspension and the addition of the neutral chemical fertilizer NPK+Trace Elements showed a significant effect in most of the studied traits, where the treatment was superior to 7.5 g.L-1 yeast and 0.5 g.plant-1 neutral fertilizer in recording the highest content in leaves of element N andprotein in the leaves, while the treatment recorded 7.5 g.L-' yeast and 0g.plant-1 neutral fertilizer was superior in the percentage of phosphorous, while the concentrations7.5 g.L-1 yeast and lg.plant-1. Neutral fertilizer were superior in percentage of Potassium in the leaves of tamarind young plants achieved a concentration of 0.0 g.L-1 yeast and 0.5g.plant-1 neutral fertilizer an outperformance in the leaf content of total chlorophyllwhile the treatment recorded 5 g.L-1 yeast and 0 g.plant-1 neutral fertilizer was superior in the percentage of carotene.

Novel Amides Derivative with Antimicrobial Activity of Piper betle var. nigra Leaves from Indonesia

Piper betle var. nigra is a tropical plant closely related to the common piper. P. betle has also been dubbed a promising source of natural antioxidants in herbal health products, antibacterial, antifungal, antimalarial, cytotoxic activity against the cancer cell lines K562 and HL-60, and antileishmanial. The aim of this study to observation Antimicrobial activity and isolation of chemical compound. The antimicrobial activity of P. betle extract was performed by well diffusion method against two oral pathogenic bacteria (Streptococcus mutans and Streptococcus sanguinis) and opportunistic pathogenic yeast (Candida albicans). The inoculum (bacterial and yeast suspension) was prepared from a 24-h culture on NB for bacterial suspension and on TSB for yeast suspension. Extraction and isolation using various method of chromatography. Isolated compounds were characterized by spectroscopic means. Our study showed antimicrobial activity from crude ethanol extract of leaves P. betle L. var. nigra against two oral pathogenic bacteria and opportunistic pathogenic yeast with concentration 0.5% and 1%. The first report of two new amides derivatives, piperenamide A (1) and piperenamide B (2) in P. betle L. var. nigra.

Regenerative ability of grape cuttings under the influence of yeast suspension treatment

The paper presents the growing experiment results on activating the regenerative ability of Moldova table variety grape cuttings by processing pressed baking yeast suspension. The present circumstance became the basis for conducting special studies to check cutting response to the treatment with baking yeast suspension, with the identification of drug optimal concentration. In spring, the two-eyed cuttings were completely soaked for 24 hours in water, and then they were placed with the basal ends in yeast suspension at various concentrations for the same time. Moreover, these yeast suspension concentrations were tested both in pure form and in combination with 3% sucrose. As a result of the conducted studies, it was revealed that pressed baking yeast suspension at certain concentration can have an activating effect on regenerative ability of grape cuttings. The use of yeast suspension together with sucrose solution increases their physiological activity. It was found that cuttings basal end soaking in yeast suspension at concentrations of 10-20 g/l, together with sucrose, contributed to rooting increased by 20-30%, the proportion of cuttings with three roots or more – by 22.5-30.0%, the number of roots by 13.5–16.2%. The best option was with a yeast suspension concentration of 20 g/l.

Effects of Different Incubation Methods on Ethanol Production from SelectedFood Wastes Products

The study describes the potential of producing bioethanol from corn (Zea mays) cobs, collard greens (Brassica oleracea) wasteand banana (Musa acuminate) peels using different methods of incubation. Wastes were pre-treated by grinding into smallerparticles and enzymatic hydrolysis was carried out using commercial cellulase from Aspergillus niger. Anaerobic fermentationwas done using cultured Saccharomyces cerevisiae yeast suspension. Different incubation conditions (incubator, dark roomand under soil) at different temperatures 30oC, 21oC and 19oC respectively were optimised for bioethanol production atdifferent incubation times of 48, 96 and 144 hours. Maximum bioethanol percentages of corn cobs, banana peels and collardgreens were (0.48%), (0.39%) and (0.15%) respectively. The optimum conditions for maximum ethanol concentration in corncobs was the incubator conditions at temperature 30oC and 144 hours; banana peels was under soil conditions at 19oC and48 hours whilst collard greens was dark room conditions at 21oC and 48 hours incubation times. Results obtained show thepotential of producing bioethanol from corn cobs, collard greens and banana peels under different incubation conditions. Useof incubators for fermentation especially in collard greens wastes and banana peels can successfully be replaced with darkroom and soil which are more economically feasible.

Bottle Conditioning: Technology and Mechanisms Applied in Refermented Beers

Bottle conditioning refers to a method of adding fermenting wort or yeast suspension in sugar solution into beer in its final package. Additionally denoted as bottle refermentation, this technique has been originally developed to assure beer carbonation, and has further significance related to formation of distinctive sensory attributes and enhancement of sensory stability, which are the phenomena associated with ongoing yeast metabolic activities in the final package. This review covers historical development of the method, describes metabolic pathways applied during refermentation, and explains practical aspects of the refermentation process management. Furthermore, an overview of the traditional and novel approaches of bottle conditioning with mixed yeast bacterial cultures and its impact on the properties of final beer is provided.