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Magnesium dilactate is increasingly sought after for its applications in the pharmaceutical, food, and dietary supplement industries due to its essential role in various physiological processes. This study explores a sustainable method for synthesizing magnesium dilactate through lactic acid fermentation using tomato juice, coupling the neutralization of lactic acid with hydrated magnesium carbonate hydroxide. Utilizing the lactic acid bacteria Lactobacillus paracasei and Lactobacillus plantarum, fermentation was optimized in a 50% diluted MRS medium supplemented with glucose and tomato juice supplemented with glucose, yielding a maximum lactate concentration of 107 g/L. Notably, fermentation in diluted media proved more effective than in undiluted tomato juice, highlighting the inhibitory effects of certain organic compounds and the physical nature of the original tomato juice. Post-fermentation, magnesium lactate was crystallized, achieving high recovery rates of up to 95.9%. Characterization of the product through X-ray diffraction and scanning electron microscopy confirmed its crystalline purity. This research underscores the viability of tomato juice as a fermentation substrate, promoting the valorization of agricultural by-products while providing an eco-friendly alternative to traditional chemical synthesis methods for magnesium dilactate production. [ABSTRACT FROM AUTHOR]

In this study, the H303A mutant form of the [cbb.sub.3] oxidase (H303A oxidase), which has the H303A mutation in its catalytic subunit (CcoN), was purified from Rhodobacter sphaeroides. The H303A oxidase showed the same catalytic activity as did the wild-type form of the oxidase (WT oxidase). The heme contents of the mutant and WT forms of the [cbb.sub.3] oxidase were also comparable. However, the puf and puc operons, which are under the control of the PrrBA two-component system, were shown to be derepressed aerobically in the R. sphaeroides strain expressing the H303A oxidase. Since the strain harboring the H303A oxidase exhibited the same cytochrome c oxidase activity as the stain harboring the WT oxidase did, the aerobic derepression of photosynthesis gene expression observed in the H303A mutant appears to be the result of a defective signaling function of the H303A oxidase rather than reflecting any redox changes in the ubiquinone/ubiquinol pool. It was also demonstrated that ubiquinone inhibits not only the autokinase activity of full-length PrrB but also that of the truncated form of PrrB lacking its transmembrane domain, including the proposed quinone binding sequence. These results imply that the suggested ubiquinone binding site within the PrrB transmembrane domain is not necessary for the inhibition of PrrB kinase activity by ubiquinone. Instead, it is probable that signaling through H303 of the CcoN subunit of the [cbb.sub.3] oxidase is part of the pathway through which the [cbb.sub.3] oxidase affects the relative kinase/phosphatase activity of the membrane-bound PrrB.

This article describes a new mutagenesis strategy, which incorporates the suicide vector-mediated gene replacement and bacteriophage-mediated transduction. The technique is demonstrated by introducing unmarked mutations into Salmonella enterica serovar Typhimurium via P22HTint-mediated transduction.

Transcriptional analyses of the Bordella chromosomal alc-lacZ operon fusions reveal that under iron stress conditions, alc gene transcription is dependent on the alcaligin siderophore. Mutational and genetic complementation data demonstrate that alcaligin-responsive transcriptional activation of the alcaligin gene system requires a transcriptional regulator AlcR, which uses alcaligin as its inducer.

The control of bacterial pathogens, including Edwardsiella piscicida, in the aquaculture industry has high economic importance. This study aimed to identify a potential live vaccine candidate against E. piscicida infection to minimize the side effects and elicit immunity in the host. This study evaluated the virulence factors of E. piscicida CK108, with a special focus on the flagella. E. piscicida has two important homologous flagellin genes, namely flagellin‐associated protein (fap) and flagellin domain‐containing protein (fdp). CK226 (Δfap), CK247 (Δfdp) and CK248 (Δfap, fdp) mutant strains were constructed. Both CK226 and CK247 displayed decreased length and thickness of flagellar filaments, resulting in reduced bacterial swimming motility, while CK248 was non‐motile as it lacked flagella. The loss of flagella and decreased motility was expected to decrease the pathogenicity of CK248. However, the median lethal dose (LD50) of CK248 against zebrafish was lower than those of the wild‐type, CK226 and CK247 strains. The protective immunity and cytokine gene expression levels in the CK248‐infected zebrafish were lower than those in the wild type‐infected zebrafish. In conclusion, Fap and Fdp are essential for flagella formation and motility, and for stimulating fish immune response, which can be utilized as a potential adjuvants for E. piscicida vaccination. [ABSTRACT FROM AUTHOR]

Research was conducted to isolate and identify a Bordetella bronchiseptica iron transport mutant. In this study, a streptonigrin resistance-based enrichment process was performed and an Escherichia coli expression system was utilized to create the AlcR protein. Results indicate that the protein is necessary for the full expression of B. bronchiseptica and B. pertussis and is needed in the regulation of alcigin biosynthesis.

The Bordetella pertussis alc promoter-operator region deletion mutant and the reporter gene fusion constructs are used to analyze the alc operon of the B. pertussis bacteria. In this study, hybridization and immunoblot tests were conducted. Results show that the bacterial cells have expressed AlcA, AlcB and AlcC hybrid proteins. Alcaligin system genes are observed to have been contranscripted.

Titanium oxide thin film, fabricated with tetraisopropyltitanate and oxygen by electron cyclotron resonance-plasma-enhanced chemical vapor deposition, is investigated as a potential candidate for the antireflective layer in KrF excimer laser (248-nm) lithography. The oxygen flow-rate dependence of the optical properties such as the refractive index (n) and the extinction coefficient (k) of the film at the 248-nm wavelength has been characterized, and the films with the expected combinations of n and k values for the antireflective layer have been deposited. Simulation results indicate that reflectance values of less than 4% and as low as 1.2% can be reached at the interface between the photoresist and the film postulating the structures of the photoresist/300-[Angstrom] Ti[O.sub.x] film/c-Si substrate and the W-Si substrate, respectively, by selected proper combinations of n and k values. Moreover the reflectance can be further reduced to almost zero by changing the film thickness. Thus it is found that titanium oxide thin films can be used as the bottom antireflective layer in KrF excimer laser lithography. Key words: Bottom antirefractive layer, titanium oxide thin film, reflectance, KrF excimer laser lithography.