Starmerella bombicola and Saccharomyces cerevisiae in Wine Sequential Fermentation in Aeration Condition: Evaluation of Ethanol Reduction and Analytical Profile

In the last few decades, the increase of ethanol in wine, due to global climate change and consumers’ choice is one of the main concerns in winemaking. One of the most promising approaches in reducing the ethanol content in wine is the use of non-Saccharomyces yeasts in co-fermentation or sequential fermentation with Saccharomyces cerevisiae. In this work, we evaluate the use of Starmerella bombicola and S. cerevisiae in sequential fermentation under aeration condition with the aim of reducing the ethanol content with valuable analytical profile. After a preliminary screening in synthetic grape juice, bench-top fermentation trials were conducted in natural grape juice by evaluating the aeration condition (20 mL/L/min during the first 72 h) on ethanol reduction and on the analytical profile of wines. The results showed that S. bombicola/S. cerevisiae sequential fermentation under aeration condition determined an ethanol reduction of 1.46% (v/v) compared with S. cerevisiae pure fermentation. Aeration condition did not negatively affect the analytical profile of sequential fermentation S. bombicola/S. cerevisiae particularly an overproduction of volatile acidity and ethyl acetate. On the other hand, these conditions strongly improved the production of glycerol and succinic acid that positively affect the structure and body of wine.

An Evaluation of the Water Quality Characteristics of Shipboard Sewage Disposal and Usability Based on Water Quality Enhancement

International Maritime Organization recognizes vessel-induced pollution as a global issue. The designation of the Baltic Sea as the special uncontaminated area was the beginning of the regulations for preventing marine pollution. In this regard, a process is needed which meets the provisions of MEPC. 227(64) for the specificity and constrained conditions of vessels, removes both nitrogen and phosphorus, requires convenient operation and low construction cost and is little affected by the load variation of inflow. This study used an SBR(sequencing batch reactor) and MBR(membrane bioreactor) combined process to iterate the stirring and aeration process and maintained the ratio of raw wastewater parameters (C:N:P) to be 10:3:1 in order to assess the quality and future availability of ultimate outflow in each time period of the stirring and aeration process. The removal efficiencies of COD and T-N exceeded 90% and 93% respectively. However, a detailed mechanism will be identified by a further study on nitrogen removal issues like DO aeration condition, stirring duration, ORP and NO3. As the removal efficiency of T-P exceeded 95%, the SBR and MBR process formed anaerobic and aerobic conditions without a separate coagulation process for removing phosphorus, thereby enabling easy phosphorus release and uptake. The optimal stirring and aeration condition seems to be 70–50 min. A further study will be efficiently conducted by focusing on the water quality criteria of the Maritime Environment Protect Committee. 227 (64) for E. coli and chlorine and a detailed mechanism.

OPTIMIZATION OF ASPERGILLUS ORYZAE FERMENTATION CONDITIONS FOR KOJIC ACID PRODUCTION

Objective: The objective of this study is to obtain the optimal fermentation conditions for Aspergillus oryzae by gradually optimizing the medium andfermentation conditions.Methods: Fermentation condition were optimized by varying carbon and nitrogen sources, pH medium, temperature, and aeration condition. Levelsof kojic acid were determined using thin-layer chromatography-densitometry with an ultraviolet detector at a wavelength of 318 nm.Results: A combination of sucrose and yeast extract was chosen as the best source of carbon and nitrogen, respectively, from nine medium variations,producing 1.5425 g/L kojic acid. The optimum acidity of the medium was at pH 4.5, producing 1.7127 g/L of kojic acid, compared with pH 3.5 and5.5. Compared with fermentation at room temperature, fermentation at 35°C yielded greater kojic acid production. The best aeration condition was100 mL medium in 250 mL flask that produced the most kojic acid (1.6472 g/L).Conclusion: The optimal medium for fermentation of kojic acid using A. oryzae uses sucrose and yeast extract as carbon and nitrogen sources,respectively, at pH 4.5. The optimal aeration and incubation conditions were used, a volume of 100 mL in a 250 mL conical flask, incubated at 35°C,obtaining the highest yield value of 0.0370 g/g.

Aeration condition of a clayey oxisol under long-term no-tillage

The hypothesis of this study was that the absence of soil tillage in long-term no-tillage (NT) systems can be detrimental to soil aeration. The objective was to assess the aeration condition of an Oxisol (Rhodic Ferrasol), very clayey texture (750 g kg-1 of clay; 200 g kg-1 of sand), after 30 years of cultivation under NT. The physical property soil air permeability (Ka) is sensitive to changes in the soil pore system. Aside from Ka, the air-filled porosity (ε a) and indices of pore continuity (K1 and N), derived from the relationship between Ka and εa, were used as indices of soil aeration. From the soil layers 0.0-0.1 and 0.1-0.2 m, 240 undisturbed samples were collected along a transect perpendicular to the crop rows, at three sampling positions: corn plant row (CR); center of the interrow (INT); and the equidistant point between CR and INT (PE). The properties Ka and εa were determined at soil matric potentials (Ψm) of -2, -4, -6, -10, -30, and -50 kPa. Soil bulk density (BD) was also determined. The results confirmed the hypothesis. In the 0.0-0.1 m layer, Ka, K1, N and Ψa were significantly greater and BD significantly lower in CR than at the other sampling positions. At a Ψm of -10 kPa, the Ka of CR was 6.9 and 8.4 times higher than in PE and INT, respectively, in the 0.0-0.1 m layer. The properties Ka, K1 and N were sensitive enough to detect changes in the pore system and their differences between the sampling positions demonstrated the importance of the spatial location for soil sampling. Tilling the crop rows provides better soil aeration under NT.