Bombyx mori L., a primary producer of silk, is the main tool in the sericulture industry and provides the means of livelihood to a large number of people. Silk cocoon crop losses due to bacterial infection pose a major threat to the sericulture industry. Bombyx mori L., a silkworm of the mulberry type, has a sophisticated inherent innate immune mechanism to combat such invasive pathogens. Among all the components in this defense system, antimicrobial peptides (AMPs) are notable due to their specificity towards the invading pathogens without harming the normal host cells. Bombyx mori L. so far has had AMPs identified that belong to six different families, namely cecropin, defensin, moricin, gloverin, attacin and lebocin, which are produced by the Toll and immune deficiency (IMD) pathways. Their diverse modes of action depend on microbial pathogens and are still under investigation. This review examines the recent progress in understanding the immune defense mechanism of Bombyx mori based on AMPs.

X-ray crystallography is a robust and powerful structural biology technique that provides high-resolution atomic structures of biomacromolecules. Scientists use this technique to unravel mechanistic and structural details of biological macromolecules (e.g., proteins, nucleic acids, protein complexes, protein-nucleic acid complexes, or large biological compartments). Since its inception, single-crystal cryocrystallography has never been performed in Türkiye due to the lack of a single-crystal X-ray diffractometer. The X-ray diffraction facility recently established at the University of Health Sciences, İstanbul, Türkiye will enable Turkish and international researchers to easily perform high-resolution structural analysis of biomacromolecules from single crystals. Here, we describe the technical and practical outlook of a state-of-the-art home-source X-ray, using lysozyme as a model protein. The methods and practice described in this article can be applied to any biological sample for structural studies. Therefore, this article will be a valuable practical guide from sample preparation to data analysis.

A Gram-positive, rod-shaped, spore-forming, aerobic bacterium, with biocontrol potential designated as RMG6^T, was isolated from the rhizosphere of the mulberry plant located in the mulberry garden of Raiganj University, West Bengal, India. The strain demonstrated significant antimicrobial activity against Enterococcus faecalis MTCC 439 (1.92 cm inhibition zone) and Escherichia coli MTCC 43 (1.62 cm inhibition zone) in agar-well diffusion assays. Scanning electron microscopy (SEM) confirmed bacterial cell lysis and cytoplasmic leakage. Phylogenetic analysis of the 16S rDNA sequence (1545 bp) revealed that RMG6^T is closely associated to Bacillus siamensis KCTC 13,613 (99.93% similarity). Additionally, multilocus sequence analysis (MLSA) suggested that RMG6^T represents a novel Bacillus species. The morphological characteristics of RMG6^T colonies further distinguished it from closely related Bacillus species. RMG6^T remained unidentified through Vitek-2 analysis. Fatty acid methyl ester (FAME) profiling revealed the predominant cellular fatty acids in RMG6^T were anteiso-C_15:0 (28.13%), iso-C_15:0 (20.72%), C_18:0 (10.72%), iso-C_17:0 (7.00%), iso-C_16:0 (5.88%), and anteiso-C_17:0 (5.87%). MALDI-TOF MS analysis validated that RMG6^T belongs to Bacillus genus. RMG6^T exhibited optimal growth at 35 °C, pH 6, and up to 14% NaCl tolerance. The strain produced indole-3-acetic acid (IAA) through the indole-3-pyruvic acid pathway, with a maximum yield of 73.4 µg/mL at 0.2% L-tryptophan supplementation. The Vigna radiata seed germination assay validated its plant growth-promoting potential, with significantly enhanced radicle growth compared to control treatments, highlighting the potential of RMG6^T for cross-species bioaugmentation. Antibiotic susceptibility profiling revealed that RMG6^T was resistance to beta-lactam antibiotics, aligning with the genomic identification of resistance genes. Whole-genome sequencing (3,818,111 bp; G + C content 46.62%) identified 3723 coding sequences, including biosynthetic gene clusters (BGCs) associated with antimicrobial compound biosynthesis. Moreover, the highest recorded values for average nucleotide identity (ANI) and Genome-to-Genome Distance Calculator 3.0 analysis were 94.44 and 56.80%, respectively, with Bacillus siamensis KCTC 13,613. Comparative genomic and phylogenomic analyses confirmed the novelty of RMG6^T, leading to its proposed designation as Bacillus ayatagriensis sp. nov., with RMG6^T (= MCM-B-1537). We propose Bacillus ayatagriensis RMG6^T as a novel species with significant biocontrol potential and plant growth-promoting capabilities, advocating its expanded use in agriculture and industry.

The aim of this study was to investigate the production of biodegradable bacterial cellulose (BC) composite films from kombucha production residues, provid