Identification and Aggressiveness of Fusarium Species Associated with Onion Bulb (Allium cepa L.) during Storage

Plant pathogens present a major challenge to crop production, leading to decreased yield and quality during growth and storage. During long-term storage, healthy onions can develop diseases from latent pathogen infections. This poses a challenge for onion growers because infected bulbs without visible symptoms can lead to significant crop losses during the growing season. In this study, we aimed to isolate and identify Fusarium species from yellow onion bulbs (Allium cepa L.) that developed disease symptoms during storage. The aggressiveness of these strains against onion bulbs and seedlings was also evaluated. The isolated strains were further subjected to morphological and molecular differentiation. The results revealed that all 16 isolated strains belonged to the Fusarium complex species incarnatum-equiseti and Fusarium fujikuroi, namely, F. proliferatum (98%), F. oxysporum (1%), and Fusarium sp. (1%). Koch's postulate analysis of isolated strains revealed varying aggressiveness on onion bulbs and plants depending on fungal species. Disease symptoms developed more slowly on plants than on onion bulb plants according to Koch's postulates. Moreover, the results revealed that Fusarium strains that can infect onion plants were less pathogenic to onion bulbs and vice versa. In addition, three isolates were found to be non-pathogenic to onions. Furthermore, the in vitro control of Fusarium species through Bacillus velezensis KS04-AU and Streptomyces albidoflavus MGMM6 showed high potential for controlling the growth of these pathogenic fungi. These results may contribute to the development of environmentally friendly approaches for controlling onion spoilage caused by pathogens during storage.

Genomic Insights into the Microbial Agent Streptomyces albidoflavus MGMM6 for Various Biotechnology Applications

Microbial biotechnology plays a crucial role in improving industrial processes, particularly in the production of compounds with diverse applications. In this study, we used bioinformatic approaches to analyze the genomic architecture of Streptomyces albidoflavus MGMM6 and identify genes involved in various metabolic pathways that have significant biotechnological potential. Genome mining revealed that MGMM6 consists of a linear chromosome of 6,932,303 bp, with a high G+C content of 73.5%, lacking any plasmid contigs. Among the annotated genes, several are predicted to encode enzymes such as dye peroxidase, aromatic ring-opening dioxygenase, multicopper oxidase, cytochrome P450 monooxygenase, and aromatic ring hydroxylating dioxygenases which are responsible for the biodegradation of numerous endogenous and xenobiotic pollutants. In addition, we identified genes associated with heavy metal resistance, such as arsenic, cadmium, mercury, chromium, tellurium, antimony, and bismuth, suggesting the potential of MGMM6 for environmental remediation purposes. The analysis of secondary metabolites revealed the presence of multiple biosynthesis gene clusters responsible for producing compounds with potent antimicrobial and metal-chelating activities. Furthermore, laboratory tests conducted under controlled conditions demonstrated the effectiveness of MGMM6 in inhibiting phytopathogenic microbes, decolorizing and degrading aromatic triphenylmethane dyes, particularly Blue Brilliant G250, from wastewater by up to 98 ± 0.15%. Overall, the results of our study highlight the promising biotechnological potential of S. albidoflavus MGMM6.

Gain-switched Fe:ZnSe laser pumped by a coupled-cavity Q-switched Er:ZrF4 fiber laser

We report on a gain-switched operation of single-crystal Fe²⁺:ZnSe pumped by a coupled-cavity Q-switched Er³⁺:ZrF₄ fiber laser. With this approach, we use a continuous wave Er-doped ZrF₄ fiber laser whose cavity is coupled with the Fe:ZnSe laser cavity. A stable Q switching operation of the Er-doped fiber laser was achieved in this case and, as a result, a gain-switched operation of the Fe:ZnSe laser was obtained. The highest repetition rate was 79 kHz, the pulse duration of the pump Er-doped laser was ∼1.6 μs, and the pulse duration of the Fe:ZnSe was 62 ns. The maximum output power achieved from gain-switched Fe:ZnSe was 63 mW.

BLEPHARITIS AND HELICOBACTER-ASSOCIATED GASTRODUODENAL DISEASES (REVIEW)

The aim of the study was to find the relationship between the inflammatory process on the eyelids (blepharitis) and Helicobascter pylori infection. The data of numerous studies are analyzed, which give grounds to suggest a possible pathogenetic or mediated role of H. pylori infection in the development and course of inflammatory eye diseases. Fundamental in these studies are the release of harmful compounds in the exhaled air of patients with H. pylori, such as ammonia, hydrogen nitrate and hydrogen cyanide, the restoration of impression cytology after H. Pylori eradication, the presence of H. pylori in the lacrimal fluid. In this regard, the authors conclude that there are three main possible pathogenetic mechanisms for the association between H. Pylori infection and blepharitis: chronic inflammation, endothelial dysfunction, and oxidative stress.

Spectral dependence of principal axes in anti-resonant hollow-core fibers with different numbers of capillaries

We report on measurements highlighting the spectral dependence of the principal axes' angular orientation that is present within three hollow-core fibers samples of various geometries. Hollow-core anti-resonant fibers (ARFs) with six, five, and four capillaries are investigated in several transmission windows. It is shown that the six-capillary fiber structure demonstrates a much smaller shift in the principal axes' orientation, in comparison with five- and four-capillary structures. The four-capillary structure has a 90° shift of its principal axes' orientation inside even- and odd-numbered transmission windows. These results corroborate the suggestion that the six-capillary ARF structure is a great candidate for polarization-maintaining operation over a wide spectral bandwidth.