Evaluation and Selection of Potential Biomass Sources of North-East India towards Sustainable Bioethanol Production

Vegetation biomass production in North-East India within Indo-Burma biodiversity hotspot is luxuriant and available from April to October to consider their potential for bioethanol production. Potential of six lignocellulosic biomass (LCB) sources; namely, sugarcane bagasse (BG), cassava aerial parts (CS), ficus fruits (Ficus cunia) (FF), “phumdi” (floating biomass), rice straw (RS), and sawdust were investigated for bioethanol production using standard techniques. Morphological and chemical changes were evaluated by Scanning electron microscopy and Fourier transform infrared spectroscopy and quantity of sugars and inhibitors in LCB were determined by High performance liquid chromatography. Hydrothermally treated BG, CS, and FF released 954.54, 1,354.33, and 1,347.94 mg/L glucose and 779.31, 612.27, and 1,570.11 mg/L of xylose, respectively. Inhibitors produced due to effect of hydrothermal pretreatment ranged from 42.8 to 145.78 mg/L acetic acid, below detection level (BDL) to 17.7 µg/L 5-hydroxymethylfurfural, and BDL to 56.78 µg/L furfural. The saccharification efficiency of hydrothermally treated LCB (1.35–28.64%) was significantly higher compared with their native counterparts (0.81–17.97%). Consolidated bioprocessing of the LCB using MTCC 1755 (Fusarium oxysporum) resulted in maximum ethanol concentration of 0.85 g/L and corresponded to 42 mg ethanol per gram of hydrothermally treated BG in 120 h followed by 0.83 g/L corresponding to 41.5 mg/g of untreated CS in 144 h. These ethanol concentrations corresponded to 23.43 and 21.54% of theoretical ethanol yield, respectively. LCB of CS and FF emerged as a suitable material to be subjected to test for enhanced ethanol production in future experiments through efficient fermentative microbial strains, appropriate enzyme loadings, and standardization of other fermentation parameters

Rhizospheric bacterial community of endemic rhododendron arboreum sm. ssp. delavayi along eastern himalayan slope in tawang

Information on rhizosphere microbiome of endemic plants from high mountain ecosystems against those of cultivated plantations is inadequate. Comparative bacterial profiles of endemic medicinal plant Rhododendron arboreum Sm. subsp. delavayi rhizosphere pertaining to four altitudinal zonation Pankang Thang (PTSO), Nagula, Y-junction and Bum La (Indo-China border; in triplicates each) along cold adapted Eastern slope of Himalayan Tawang region, India is described here. Significant differences in DGGE profile between below ground bulk vs. rhizospheric community profile associated with the plant was identified. Tagged 16S amplicon sequencing from PTSO (3912 m) to Burn La (4509 m), revealed that soil pH, total nitrogen (TN), organic matter (OM) significantly influenced the underlying bacterial community structure at different altitudes. The relative abundance of Acidobacteria was inversely related to pH, as opposed to TN which was positively correlated to Acidobacteria and Proteobacteria abundance. TN was also the significant predictor for less abundant taxonomic groups Chioroflexi, Gemmatimonadetes. and Nitrospirae. Bum La soil harbored less bacterial diversity compared to other sites at lower altitudes. The most abundant phyla at 3% genetic difference were Acidobacteria, Actinobacteria, and Proteobacteria amongst others. Analysis of similarity indicated greater similarity within lower altitudinal than higher altitudinal group (ANOSIM, R = 0.287, p = 0.02). Constraining the ordination with the edaphic factor explained 83.13% of variation. Unique phylotypes of Bradyrhizobium and uncultured Rhizobiales were found in significant proportions at the four regions. With over 1% relative abundance Actinobacteria (42.6%), Acidobacteria (24.02%), Proteobacteria (16.00%), AD3 (9.23%), WPS-2 (5.1%), and Chloroflexi (1.48%) dominated the core microbiome

Rice transcriptome upon infection with Xanthomonas oryzae pv. oryzae relative to its avirulent T3SS-defective strain exposed modulation of many stress responsive genes

Xanthomonas oryzae pv. 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.Supplementary informationThe online version contains supplementary material available at 10.1007/s13205-022-03193-4