Narayan Chandra Talukdar

Introduction: Intracellular colonization by endophytic bacteria (EB) is a relatively new and less explored aspect of plant microbiome research. In this study, we investigated the presence and localization of EB in Nicotiana tabacum var. Podali and Vigna radiata var. Pratap using SYTO9 (S9) and Propidium Iodide (PI) staining.Methodology: Confocal Laser Scanning Microscopy (CLSM) was used to visualized bacterial localization, MitoTracker Deep Red (MDR) was used to confirm non- overlapping mitochondrial staining. Time-lapse imaging was employed to observe bacterial motility. For microbial community profiling next-generation sequencing (NGS) of the 16S rRNA gene was conducted to analyze bacterial diversity and composition.Results: Confocal laser scanning microscopy (CLSM) revealed S9-labelled live bacteria located close to the nucleus in Podali tissues and suspension cultures, while PI selectively stained dead cells. MitoTracker Deep Red (MDR) confirmed that there was no overlap with mitochondrial staining. Interestingly, time-lapse imaging captured the movement of bacteria within the cells, indicating possible bacterial motility. EB were observed in both in vitro and field-grown Podali plants, whereas they were detected only in field-grown Pratap plants. Next-generation sequencing revealed that Podali harbored a much higher bacterial diversity, with 37 bacterial families identified mainly from Burkholderiaceae and Enterobacteriaceae. In contrast, Pratap plants showed lower diversity, with only 10 bacterial families, dominated by Rhizobiaceae.Conclusion: This study is among the first to report intracellular EB localization in these plant varieties and demonstrates how environmental conditions and growth methods can influence the composition of plant-associated microbiomes.

Endophytes colonize interior regions of oilseeds depending on water, nutrient, space availability and microbial competition. Oilseeds are filled with oil globules making it difficult for microbes to obtain direct uptake of water and nutrient for growing into colonies. Recent research shows very less areas explored in endophytic study in oilseeds and as endophytes play a vital part in managing diseases in plants by releasing genes encoding jasmonate and salicylic acid which induces defense against pathogens and modify plant regions structurally adding to their fitness and increased productivity, their study is indispensable. This review focuses on the bacterial endophytes in oilseeds, the challenges faced in their isolation, their colonization and interactions with host and pathogens and their applications. Oilseed endophytic study is essential for understanding the benefits of oilseeds consumed as vegetable oil or used as fuel by people all over the world.

The present study evaluated the therapeutic potential of the medicinal plant Lysimachia candida Lindl. against metabolic syndrome in male SD rats fed with a high-fat high-fructose (HFHF) diet. Methanolic extract of Lysimachia candida Lindl. (250 mg kg⁻¹ body weight p.o.) was administrated to the HFHF-fed rats daily for 20 weeks. Blood samples were collected, and blood glucose levels and relevant biochemical parameters were analysed and used for the assessment of metabolic disease phenotypes. In this study, Lysimachia candida decreased HFHF diet-induced phenotypes of metabolic syndrome, i.e., obesity, blood glucose level, hepatic triglycerides, free fatty acids, and insulin resistance. Liquid chromatography-mass spectrometry-based metabolomics was done to study the dynamics of metabolic changes in the serum during disease progression in the presence and absence of the treatment. Furthermore, multivariate data analysis approaches have been employed to identify metabolites responsible for disease progression. Lysimachia candida Lindl. plant extract restored the metabolites that are involved in the biosynthesis and degradation of amino acids, fatty acid metabolism and vitamin metabolism. Interestingly, the results depicted that the treatment with the plant extract restored the levels of acetylated amino acids and their derivatives, which are involved in the regulation of beta cell function, glucose homeostasis, insulin secretion, and metabolic syndrome phenotypes. Furthermore, we observed restoration in the levels of indole derivatives and N-acetylgalactosamine with the treatment, which indicates a cross-talk between the gut microbiome and the metabolic syndrome. Therefore, the present study revealed the potential mechanism of Lysimachia candida Lindl. extract to prevent metabolic syndrome in rats.

It is known that alcoholic beverages alter the human gut microbiome. This study focused on the potential impact of non-ethanolic ingredients in whisky on the gut bacteriome. A pilot study was carried out on 15 whisky drinkers, 5 rice beer drinkers, and 9 non-drinkers to determine the effect of alcoholic beverages on the host microbiome and metabolome. Additionally, a mouse model was used to assess the differential impact of three whisky brands (each with an equal ethanol concentration). The results indicate that the non-ethanolic components have an impact on the gut microbiome, as well as on the metabolites in blood and feces. The amount of Prevotella copri, a typical core Indian gut bacterium, decreased in both the human and mouse groups of whisky type 1, but an increase in abundance of Helicobacteriaceae (p = 0.01) was noticed in both groups. Additionally, the alcohol-treated cohorts had lower levels of short-chain fatty acids (SCFAs), specifically butyric acid, and higher amounts of lipids and stress marker IL1-ß than the untreated groups (p = 0.04–0.01). Furthermore, two compounds, ethanal/acetaldehyde (found in all the whisky samples) and arabitol (unique to whisky type 1), were tested in the mice. Similar to the human subjects, the whisky type 1 treated mouse cohort and the arabitol-treated group showed decreased levels of Prevotella copri (p = 0.01) in their gut. The results showed that non-ethanolic compounds have a significant impact on host gut bacterial diversity and metabolite composition, which has a further vital impact on host health. Our work further emphasizes the need to study the impact of non-ethanolic ingredients of alcoholic beverages on host health.

The fungus Ustilaginoidea virens, the causative agent of false smut in rice (Oryza sativa L.), is responsible for one of the severe grain diseases that lead to significant losses worldwide. In this research, microscopic and proteomic analyses were performed by comparing U. virens infected and non-infected grains of the susceptible and resistant rice varieties to provide insights into the molecular and ultrastructural factors involved in false smut formation. Prominent differentially expressed peptide bands and spots were detected due to false smut formation as revealed by sodium dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional gel electrophoresis (2-DE) SDS-PAGE profiles and were identified using liquid chromatography-mass spectrometry (LC-MS/MS). The proteins identified from the resistant grains were involved in diverse biological processes such as cell redox homeostasis, energy, stress tolerance, enzymatic activities, and metabolic pathways. It was found that U. virens produces diverse degrading enzymes such as β-1, 3-endoglucanase, subtilisin-like protease, putative nuclease S1, transaldolase, putative palmitoyl-protein thioesterase, adenosine kinase, and DNase 1 that could discretely alter the host morphophysiology resulting in false smut. The fungus also produced superoxide dismutase, small secreted proteins, and peroxidases during the smut formation. This study revealed that the dimension of rice grain spikes, their elemental composition, moisture content, and the specific peptides produced by the grains and the fungi U. virens play a vital role in the formation of false smut.

North East (NE) India is one of the ‘biodiversity hotspots’ of the world supporting about 50% of India’s biodiversity. In the sparse to dense forests across alpine to tropical climatic conditions, the NE region has a vast distribution of medicinal plants. The present study has compiled and enlisted the wide range of medicinal plants used by different ethnic communities along with the highly traded medicinal and endemic plant species of superior quality attributes in the region. The results are derived from an extensive review of information published in different research papers including those in books, journals, public domain documents of government agencies, NGOs and business and trade databases. The number of important species used in traditional healthcare systems of the different sister states of NE India ranges from 400 to 952 and out of these, the number of different commercially promising species ranges from 7 to 14 species. Thirty-seven species of medicinal plants in NE India are identified to have importance in the national and international trade of medicinal plants and products and most of these are harvested from the wild. Despite of rich heritage and large plant diversity, the herbal drugs market of NE India has not grown at the pace observed the mainland India’s herbal drug trade. Poor infrastructure in terms of quality control and quality assurance, GLP-compliant laboratories for herbal drugs, constraints of accessibility to the region, widespread collection of the medicinal herbs from the wild coupled with lack of sustainable harvesting and package of practices for domestic cultivation of medicinal herbs are issues need to be addressed in future for exploring maximum benefit to the economy of the region from medicinal plant resources.

Fusarium oxysporum is among the few filamentous fungi capable of fermenting ethanol directly from lignocellulose biomass (LCB). It has the essential enzymatic toolbox to disintegrate LCB to its monosaccharides, which subsequently fermented to ethanol under anaerobic and micro-aerobic conditions. However, the structural complexity of LCB and modest performances of wild fungi are major limitations for application in local biorefineries. This study assessed the potential of the locally isolated Fusarium oxysporum for the production of bioethanol from Ficus fruits (Ficus cunia) using Consolidated Bioprocessing (CBP). The maximum ethanol concentration achieved was at 5% substrate loadings with pH 6 irrespective of temperature variance, attaining a concentration of 3.54 g/L and 3.88 g/L at 28 °C and 32 °C, respectively. The monitoring of analytes (glucose, arabinose, cellobiose, xylose, acetic acid, ethanol, furfural, and HMF) in this study suggests the utilization of an array of sugars released from Ficus fruits, irrespective of the difference in the process parameters. This study also shows that CBP of freshly grounded Ficus fruits was feasible employing a mild hydrothermal pretreatment (autoclaved at 121 °C for 30 min in 1:10 w/v) and without supplementing any extraneous enzymes.

Metabolic disturbances in different tissue cells and obesity are caused by excessive calorie intake, and medicinal plants are potential sources of phytochemicals for combating these health problems. This study investigated the role of methanolic extract of the folklore medicinal plant Lysimachia candida (LCM) and its phytochemical, astragalin, in managing obesity in vivo and in vitro. Administration of LCM (200 mg/kg/body weight) daily for 140 days significantly decreased both the body weight gain (15.66%) and blood triglyceride and free fatty acid levels in high-fat-diet-fed male Wistar rats but caused no substantial change in leptin and adiponectin levels. The protein expression of adipogenic transcription factors in visceral adipose tissue was significantly reduced. Further, the 3T3-L1 cell-based assay revealed that the butanol fraction of LCM and its isolated compound, astragalin, exhibited antiadipogenic activity through downregulating adipogenic transcription factors and regulatory proteins. Molecular docking studies were performed to depict the possible binding patterns of astragalin to adipogenesis proteins. Overall, we show the potential antiobesity effects of L. candida and its bioactive compound, astragalin, and suggest clinical studies with LCM and astragalin.