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This study evaluated the biological characteristics of seaweeds Turbinaria ornata, Ulva lactuca, and Gracilaria crassa. Among the seaweeds tested, ethyl acetate extract of Ulva lactucaexhibited the highest antibacterial activity against Salmonella enterica, Staphylococcus aureus,and Pseudomonas aeruginosa. The phytochemical analysis of ULME and ULEA showed the presence of most of the tested phytochemicals, whereas only amino acids, tannins, glycosides, and carbohydrates were detected by ULHE. The DPPH scavenging property of U. lactucaexerted the maximum antioxidant property of 62.54% (ULME), 75.64% (ULEA), and 39.55% (ULHE), whereas the alpha amylase inhibitory property (µg/mL) of ULME, ULEA, and ULHE was, respectively, 80.99, 51.15, and 49.23. ULME, ULEA, and ULHE exhibited the greatest alpha-glucosidase inhibition, with IC50values (g/mL) of 116.12, 45.59, and 170.10 correspondingly. ULEA also showed potent mosquito-larvicidal effects against Aedes aegyptilarvae with the maximum lethal concentration values with LC50and LC90values (mg/mL) being 11.55 and 65.97, respectively.FTIR analysis of ULME, ULHE, and ULEA were found to have various functional groups, including alkanes, carboxylic acids, alkenes, alkynes, aldehydes, amides and alkanes, ketones, and aromatics, while HPLC revealed a strong peak at 4.760 retention time. In conclusion, Ulva lactuca, particularly its ethyl acetate extract, demonstrates significant antibacterial, antioxidant, and enzyme-inhibitory properties, highlighting its therapeutic and biotechnological potential. Its diverse phytochemicals and effective mosquito-larvicidal activity further support its broad application prospects.

The strain Streptomyces coelicoflavusBC 01 was isolated from mangrove soil and used as inoculum for submerged fermentation. The fermented broth was extracted with ethyl acetate, the crude extract was subjected to silica gel column chromatography and the homogeneity of the isolated fractions was determined by TLC and then subjected to RP-HPLC for their purity. The purification steps led to the isolation of three pure bioactive compounds named as BC 01_C1, BC 01_C2 and BC 01_C3. The chemical structure of these three compounds was established on the basis of their spectroscopic studies like UV, IR, 1H and 13C NMR and GC–MS data by comparison with reference data from literature. The structure of the compound BC 01_C1 was established as 5-amino-2-(6-(2-hydroxyethyl)-3-oxononyl) cyclohex-2-enone. The compound BC 01_C2 was established as8-(aminomethyl)-7-hydroxy-1-(1-hydroxy-4-(hydroxylmethoxy)-2,3-dimethylbutyl)-2-methyl dodecahydro phenanthren-9(1H)-one and the compound BC 01_C3 was established as1-((E)-2-ethylhex-1-en-1-yl)2-((E)-2-ethylidenehexyl)cyclohexane-1,2-dicarboxylate. The MIC values of the three isolated compounds (BC 01_C1, BC 01_C2 and BC 01_C3) were found between 12.5–75 μg/ml for bacteria and 50–125 μg/ml for fungi used in this study. These compounds also possess in vitro antioxidant and anti-inflammatory activities.

Bacterial panicle blight (BPB) caused by Burkholderia glumae(BG) has become significantly more prevalent in the rice-growing regions of North India. Based on virulence screening and in vitro quantification of toxoflavin, the BG strains were classified as hyper- (BG1 and BG3), moderate- (BG2, BG4, BG6, BG8, and BG9), and hypo- (BG5, BG7, and BG10) virulent. Plant inoculation assays with cell-free culture filtrate revealed strains with higher toxoflavin-producing ability had higher virulence. Based on 16S rRNA sequence, 6 isolates from Uttar Pradesh were grouped in clad C1; whereas, clad C2 exhibited 4 isolates, two each from Delhi and Uttar Pradesh. Strain BG1 being the most virulent Indian strain from Uttar Pradesh was further profiled for 11 toxgenes. We found all the 11 toxgenes present in strain BG1. In toxRABCDEcluster, all toxgenes showed high similarity to B. glumaeBGR1 except toxB, whereas in toxFGHIJcluster toxF, toxG, toxHand toxIshared maximum similarity to B. glumae336gr-1. toxgenes of BG1 exhibited homology as well as divergence with B. gladioli. The domain prediction and protein association network analysis indicated the possible involvement of toxgenes in the toxoflavin biosynthesis. As per our knowledge, this is the first report in India on characterization of toxgenes cluster in B. glumae. Altogether, our study unravels a reliable method for identifying and characterizing B. glumaeusing toxgenes and its relationship with disease production.

Xanthomonas oryzaepv. oryzae(Xoo) is a pathogen of concern for rice growers as it limits the production potential of rice varieties worldwide. Due to their high genomic plasticity, the pathogen continues to evolve, nullifying the deployed resistance mechanisms. It is pertinent to monitor the evolving Xoo population for the virulent novel stains, and the affordable sequencing technologies made the task feasible with an in-depth understanding of their pathogenesis arsenals. We present the complete genome of a highly virulent Indian Xoo strain IXOBB0003, predominantly found in northwestern parts of India, by employing next-generation sequencing and single-molecule sequencing in real-time technologies. The final genome assembly comprises 4,962,427 bp and has 63.96% GC content. The pan genome analysis reveals that strain IXOBB0003 houses total of 3655 core genes, 1276 accessory genes and 595 unique genes. Comparative analysis of the predicted gene clusters of coding sequences and protein count of strain IXOBB0003 depicts 3687 of almost 90% gene clusters shared by other Asian strains, 17 unique to IXOBB0003 and 139 CDSs of IXOBB0003 are shared with PXO99A. AnnoTALE-based studies revealed 16 TALEs conferred from the whole genome sequence. Prominent TALEs of our strain are found orthologous to TALEs of the Philippines strain PXO99A. The genomic features of Indian Xoo strain IXOBB0003 and in comparison with other Asian strains would certainly contribute significantly while formulating novel strategies for BB management.

Biosurfactants have gained a renewed interest in the recent years for their commercial application in diverse research areas. Recent evidences suggest that the antimicrobial activities exhibited by biosurfactants make them promising molecules for the application in the field of therapeutics. Marine microbes are well known for their unique metabolic and functional properties; however, few reports are available till date regarding their biosurfactant production and antimicrobial potential. In an ongoing survey for bioactive microbial metabolites from microbes isolated from diverse ecological niches, a marine Staphylococcus saprophyticusSBPS 15 isolated from the petroleum hydrocarbon contaminated coastal site, Puducherry, India, was identified as a promising biosurfactant producer based on multiple screening methods. This bacterium exhibited growth-dependent biosurfactant production and the recorded yield was 1.345 ± 0.056 g/L (on dry weight basis). The biosurfactant was purified and chemically characterized as a glycolipid with a molecular mass of 606.7 Da, based on TLC, biochemical estimation methods, FT-IR spectrum and MALDI-TOF–MS analysis. Further, the estimated molecular mass was different from the earlier reports on biosurfactants. This new glycolipid biosurfactant exhibited a board range of pH and temperature stability. Furthermore, it revealed a promising antimicrobial activity against many tested human pathogenic bacterial and fungal clinical isolates. Based on these observations, the isolated biosurfactant from the marine S.saprophyticusrevealed board physicochemical stabilities and possess excellent antimicrobial activities which proves its significance for possible use in various therapeutic and biomedical applications. To the best of our knowledge, this is the first report of a biosurfactant from the bacterium, S. saprophyticus.

Xanthomonas oryzaepv. oryzae(Xoo) is a destructive pathogen that causes bacterial blight disease of rice worldwide. Xoo uses T3SS (type III secretion system) effectors to subvert rice innate immunity. However, the comprehensive knowledge of rice genes involved in T3SS effectors-mediated interaction remains unclear. In this study, the transcriptome profiles of rice infected with a virulent Xoo strain from North-eastern region of India relatives to its avirulent strain (that lacks functional T3SS) were analyzed at early (2–6 hpi) and late (16–24 hpi) hours of infection. Out of total 255 differentially expressed genes (DEGs), during early infection, 62 and 70 genes were upregulated and downregulated, respectively. At late infection, 70 and 53 genes were upregulated and downregulated, respectively. The transcriptomic data identified many differentially expressed resistant genes, transposons, transcription factors, serine/threonine protein kinase, cytochrome P450 and peroxidase genes that are involved in plant defense. Pathway analysis revealed that these DEGs are involved in hormone signaling, plant defense, cellular metabolism, growth and development processes. DEGs associated with plant defense were also validated through quantitative real-time PCR. Our study brings a comprehensive picture of the rice genes that are being differentially expressed during bacterial blight infection. Nevertheless, the DEG-associated pathways would provide sensible targets for developing resistance to bacterial blight.

4‐Coumarate: coenzyme A ligase (4CL) is a key enzyme involved in the early steps of the monolignol biosynthetic pathway. It is hypothesized to modulate S and G monolignol content in the plant. Lignin removal is imperative to the paper industry and higher S/G ratio governs better extractability of lignin and economics of the pulping process. This background prompted us to predict 3D structure of two isoforms of 4CLin Leucaena leucocephalaand evaluate their substrate preferences. The 3D structure of Ll4CL1and Ll4CL2protein were created by homology modeling and further refined by loop refinement. Molecular docking studies suggested differential substrate preferences of both the isoforms. Ll4CL1preferred sinapic acid (− 4.91 kcal/mole), ferulic acid (− 4.84 kcal/mole), hydroxyferulic acid (− 4.72 kcal/mole), and caffeic acid (− 4.71 kcal/mole), in their decreasing order. Similarly, Ll4CL2preferred caffeic acid (− 6.56 kcal/mole, 4 H bonds), hydroxyferulic acid (− 6.56 kcal/mole, 3 H bonds), and ferulic acid (− 6.32 kcal/mole) and sinapic acid (− 5.00 kcal/mole) in their decreasing order. Further, active site residues were identified in both the isoforms and in silico mutation and docking analysis was performed. Our analysis suggested that ASP228, TYR262, and PRO326 for Ll4CL1and SER165, LYS247 and PRO315 for Ll4CL2were important for their functional activity. Based on differential substrate preferences of the two isoforms, as a first step towards genetically modified Leuaenahaving the desired phenotype, it can be proposed that over-expression of Ll4CL1gene and/or down-regulation of Ll4CL2gene could yield higher S/G ratio leading to better extractability of lignin.