The coronaviruses (CoVs) are enveloped viruses of animals and humans associated mostly with enteric and respiratory diseases, such as the severe acute respiratory syndrome and 10–20% of all common colds. A subset of CoVs uses the cell surface aminopeptidase N (APN), a membrane-bound metalloprotease, as a cell entry receptor. In these viruses, the envelope spike glycoprotein (S) mediates the attachment of the virus particles to APN and subsequent cell entry, which can be blocked by neutralizing antibodies. Here we describe the crystal structures of the receptor-binding domains (RBDs) of two closely related CoV strains, transmissible gastroenteritis virus (TGEV) and porcine respiratory CoV (PRCV), in complex with their receptor, porcine APN (pAPN), or with a neutralizing antibody. The data provide detailed information on the architecture of the dimeric pAPN ectodomain and its interaction with the CoV S. We show that a protruding receptor-binding edge in the S determines virus-binding specificity for recessed glycan-containing surfaces in the membrane-distal region of the pAPN ectodomain. Comparison of the RBDs of TGEV and PRCV to those of other related CoVs, suggests that the conformation of the S receptor-binding region determines cell entry receptor specificity. Moreover, the receptor-binding edge is a major antigenic determinant in the TGEV envelope S that is targeted by neutralizing antibodies. Our results provide a compelling view on CoV cell entry and immune neutralization, and may aid the design of antivirals or CoV vaccines. APN is also considered a target for cancer therapy and its structure, reported here, could facilitate the development of anti-cancer drugs. The cell surface aminopeptidase N (APN), a membranebound metalloprotease target for cancer therapy, is a major cell entry receptor for coronaviruses (CoVs), agents that cause important respiratory and enteric diseases. In some CoVs, the virus envelope spike glycoprotein (S) mediates attachment of the virus particles to the host APN protein and cell entry, which is blocked by antibodies that prevent CoV infections. The crystal structures of the S proteins of two porcine CoV in complex with the pig APN (pAPN) or with a neutralizing antibody shown here, reveal how some CoV bind to its cell surface APN receptor and how antibodies prevent receptor binding and infection. The report uncovers a unique virus-receptor recognition mode that engages a glycan N-linked to the pAPN ectodomain, revealing structural determinants of the receptor-binding specificity in CoVs. Neutralizing antibodies target viral residues used for binding to the APN receptor and entry into host cells, showing that efficient CoV neutralization requires immune responses focused toward key receptor binding motifs in the virus envelope. These structural insights, together with the structure of the APN ectodomain, provide a compelling view of relevant cell membrane processes related to infectious diseases and cancer.

A peculiar bacterial growth was very often noticed in leaf-initiated tissue cultures of Sansevieriatrifasciata, a succulent belonging to the Asparagaceae family. The isolate left trails of some highly viscous material on the walls of the suspension vessels or developed a thick overlay on semisolid media without adversities in plant growth. FTIR identified this substance to be an extracellular polysaccharide. Various morphological, biochemical tests, and molecular analyses using 16S rRNA, atpD, and recA genes characterized this isolate JAS1 as a novel strain of Agrobacteriumpusense. Its mucoidal growth over Murashige and Skoog media yielded enormous exopolysaccharide (7252 mg l⁻¹), while in nutrient agar it only developed fast-growing swarms. As a qualifying plant growth-promoting bacteria, it produces significant indole-3-acetic acid (86.95 mg l⁻¹), gibberellic acid (172.98 mg l⁻¹), ammonia (42.66 µmol ml⁻¹). Besides, it produces siderophores, 1-aminocyclopropane-1-carboxylicaciddeaminase, fixes nitrogen, forms biofilms, and productively solubilizes soil inorganic phosphates, and zinc. Under various treatments with JAS1, wheat and chickpea resulted in significantly enhanced shoot and root growth parameters. PGP effects of JAS1 positively enhanced plants’ physiological growth parameters reflecting significant increments in overall chlorophyll, carotenoids, proline, phenols, flavonoids, and sugar contents. In addition, the isolated strain maintained both plant and soil health under an intermittent soil drying regime, probably by both its PGP and EPS production attributes, respectively.

The commercial processing of various biomaterials extensively uses azo dyes (including reactive, direct, acidic, and basic dyes). These industrial applications produce wastewater containing a large volume of solubilized azo dye and hydrolyzed by-products. The treatment of such wastewater is primarily carried out by chemical and, to an extent, physical methods, which lack selectivity and efficiency. Notably, the chemical methods employ free radicals and oxidizing agents that further increase the chemical waste and produce non-biodegradable side-products. Therefore, there is an increasing trend of using microbial-assisted methods. The current study identified a specific Agrobacterium strain (JAS1) that degraded the three structurally distinct azo dyes (Reactive Black 5, Methyl Orange, Congo Red). JAS1 can tolerate high concentrations and be used to perform the in-solution degradation of azo dyes, respectively: Methyl Orange (5.5 g/L and 5.0 g/L), Congo Red (0.50 g/L and 0.40 g/L), and Reactive Black 5 (0.45 g/L and 0.40 g/L). Our study elucidated the molecular mechanisms (primarily enzymatic degradation and adsorption) responsible for the JAS-1-assisted decoloration of azo dyes. The JAS-1-assisted degraded products from these azo dyes were found biodegradable as the germination and seedling growth of wheat seeds were observed. To enhance the scope of the study, JAS1-assisted decolorization was studied for cellulosic materials, indicating a potential application in de-inking and de-dyeing process in recycling industries.

Soil salinity is a major environmental stressor impacting global food production. Staple crops like wheat experience significant yield losses in saline environments. Bioprospecting for beneficial microbes associated with stress-resistant plants offers a promising strategy for sustainable agriculture. We isolated two novel endophytic bacteria, Bacillus cereus (ADJ1) and Priestia aryabhattai (ADJ6), from Agave desmettiana Jacobi. Both strains displayed potent plant growth-promoting (PGP) traits, such as producing high amounts of indole-3-acetic acid (9.46, 10.00 µgml⁻¹), ammonia (64.67, 108.97 µmol ml⁻¹), zinc solubilization (Index of 3.33, 4.22, respectively), ACC deaminase production and biofilm formation. ADJ6 additionally showed inorganic phosphate solubilization (PSI of 2.77), atmospheric nitrogen fixation, and hydrogen cyanide production. Wheat seeds primed with these endophytes exhibited enhanced germination, improved growth profiles, and significantly increased yields in field trials. Notably, both ADJ1 and ADJ6 tolerated high salinity (up to 1.03 M) and significantly improved wheat germination and seedling growth under saline stress, acting both independently and synergistically. This study reveals promising stress-tolerance traits within endophytic bacteria from A. desmettiana. Exploiting such under-explored plant microbiomes offers a sustainable approach to developing salt-tolerant crops, mitigating the impact of climate change-induced salinization on global food security.