Insight into physico-chemical properties and microbial community structure of biogas slurry from household biogas plants of sub-Himalaya for its implications in improved biogas production.

Numerous metagenomics studies, conducted in both full-scale anaerobic digesters and household biogas plants, have shed light on the composition and activity of microbial flora essential for optimizing the performance of biogas reactors, underscoring the significance of microbial community composition in biogas plant efficiency. Although the efficiency of household biogas plants in the sub-Himalayan region has been reported, there is no literature evidence on the microbial community structure of such household biogas plants in the sub-Himalayan region. The current study evaluated the physico-chemical properties and bacterial community structure from the slurry samples of household biogas plants prevalent in the sub-Himalayan region. The slurry samples were observed to be rich in nutrients; however, their carbon and nitrogen contents were higher than the recommended standard values of liquid-fermented organic manure. The species richness and diversity indices (Chao1, Shannon, and Simpson) of household biogas plants were quite similar to the advanced biogas reactors operating at mesophilic conditions. 16S rRNA gene amplicon sequencing reveals microbial diversity, showing a higher abundance of Firmicutes (70.9%) and Euryarchaeota (9.52%) in advanced biogas reactors compared to household biogas plants. Microbial analysis shows a lack of beneficial microbes for anaerobic digestion, which might be the reason for inefficient biogas production in household biogas plants of the sub-Himalayan region. The lack of efficient bacterial biomass may also be attributed to the digester design, feedstock, and ambient temperatures. This study emphasized the establishment of efficient microbial consortia for enhanced degradation rates that may increase the methane yield in biogas plants.

Red bioactive pigment from Himalayan Janthinobacterium sp. ERMR3:09: optimization, characterization, and potential applications.

Prodigiosin is a red pigment commonly produced as a secondary metabolite by Serratia marcescens. It exhibits inherent bioactivities, including antimicrobial and anticancer, with low to no toxic effects on normal cells. The present study investigates a bioactive prodigiosin production from an atypical, red-pigmented, potentially novel Janthinobacterium sp. ERMR3:09 isolated from a glacial moraine. Statistically optimized culture parameters, i.e., w/v 1.0% glucose and 0.08% peptone as carbon and nitrogen sources, temperature 20 °C, and media pH 7, resulted in a four-fold increase in the pigment yield. The upscaled production in an 8 L volume resulted in higher pigment production within a shorter period of 48 h. The ultra-performance liquid chromatography (UPLC) analysis validated the identity of the purified pigment as prodigiosin that showed thermostability at 75 °C for 3 h. Evaluation of antimicrobial activity showed potent inhibitory effects (> 50%) against the opportunistic pathogenic fungal and Gram-positive bacterial strains. The pigment showed significant cytotoxicity (p < 0.05) towards A549 and HeLa cell lines with IC50 values of 42.2 µM and 36.11 µM, respectively. The study demonstrated that microbial communities from extreme niches can be ideal sources of bioactive pigments with immense pharmaceutical potential vital for the development of non-synthetic therapeutic agents.

Acinetobacter oleivorans IRS14 alleviates cold stress in wheat by regulating physiological and biochemical factors.

AIMS: Climate change is responsible for extreme cold winters, causing a significant loss in crop yield and productivity due to chilling stress. This study aims to investigate the potential of psychrotrophic plant growth-promoting rhizobacteria (PGPR) strain to promote wheat growth under cold stress and explore the adaptive responses of wheat. METHODS AND RESULTS: Wheat seeds and seedlings were inoculated with the psychrotrophic strain IRS14 and the plants were cultivated for five weeks at 6°C ± 2°C. The genetic, biochemical, physiological, and molecular analysis of the bacterium and plant was done to evaluate the effect of the PGPR strain in alleviating chilling stress. IRS14 possesses antioxidant activity and produced multiple phytohormones, which enhanced seed germination (∼50%) and plant growth (∼50%) during chilling stress. CONCLUSIONS: Here, we reported that the application of IRS14 helps to regulate the biochemical and metabolic pathways in wheat plants. It alleviates chilling stress and increases plant growth rate and biomass. Strain IRS14 in wheat effectively increased chlorophyll content, antioxidants, carotenoid, proline, and endogenous phytohormones compared with untreated wheat.

Role of psychrotrophic bacteria and cold-active enzymes in composting methods adopted in cold regions.

Temperature-dependent composting is a challenging task but is worthy if it is done in the right manner. Cold composting has been known to be practiced since ancient times but there were not enough advancements to overcome the long mesophilic phase and bring the compost maturation to a short period. The composting processes that have been well practiced are discussed and the role of psychrotrophic bacteria that produce cold tolerant hydrolytic enzymes has been highlighted. In this chapter, the mechanism of substrate degradation has been elaborated to better understand the need of specific bacteria for a specific kind of substrate allowing fast and efficient decomposition. This chapter attempts to pave an appropriate way and suggest the best-suited method of composting for efficient production of compost by the conservation of heat in cold regions.

Rahnella sikkimica sp. nov., a novel cold-tolerant bacterium isolated from the glacier of Sikkim Himalaya with plant growth-promoting properties.

The current study describes a novel species with the strain name ERMR1:05T isolated from the forefield soil of East Rathong Glacier in West Sikkim Himalaya (India). The isolate was facultatively anaerobic, gram-stain negative, non-spore-forming, rod-shaped, and oxidase negative. Whole-genome-based bacterial core gene phylogenetic analysis placed the strain in the genus Rahnella, well separated from Rouxiella spp. The digital DNA-DNA hybridisation and average nucleotide identity values between strain ERMR1:05T and other members of genus Rahnella were below the proposed thresholds for the species delineation. Based on these results, a new species, Rahnella sikkimica sp. nov., is proposed with strain ERMR1:05T (CIP 111636T, MTCC 12598T) as the type strain. The bacterium showed upregulation of cold-stress genes in cold conditions. Additionally, the genome analysis of the bacterium showed the presence of plant growth-promotion factors suggesting its role in crop improvement in cold hilly regions.

Himalayan Microbiomes for Agro-environmental Sustainability: Current Perspectives and Future Challenges.

The Himalayas are one of the most mystical, yet least studied terrains of the world. One of Earth's greatest multifaceted and diverse montane ecosystems is also one of the thirty-four global biodiversity hotspots of the world. These are supposed to have been uplifted about 60-70 million years ago and support, distinct environments, physiography, a variety of orogeny, and great biological diversity (plants, animals, and microbes). Microbes are the pioneer colonizer of the Himalayas that are involved in various bio-geological cycles and play various significant roles. The applications of Himalayan microbiomes inhabiting in lesser to greater Himalayas have been recognized. The researchers explored the applications of indigenous microbiomes in both agricultural and environmental sectors. In agriculture, microbiomes from Himalayan regions have been suggested as better biofertilizers and biopesticides for the crops growing at low temperature and mountainous areas as they help in the alleviation of cold stress and other biotic stresses. Along with alleviation of low temperature, Himalayan microbes also have the capability to enhance plant growth by availing the soluble form of nutrients like nitrogen, phosphorus, potassium, zinc, and iron. These microbes have been recognized for producing plant growth regulators (abscisic acid, auxin, cytokinin, ethylene, and gibberellins). These microbes have been reported for bioremediating the diverse pollutants (pesticides, heavy metals, and xenobiotics) for environmental sustainability. In the current perspectives, present review provides a detailed discussion on the ecology, biodiversity, and adaptive features of the native Himalayan microbiomes in view to achieve agro-environmental sustainability.

Synthesis of Sulfur-Containing Analogues of Hedychenone, a Labdane Diterpenoid from Hedychium spicatum.

The labdane diterpene hedychenone, isolated from Hedychium spicatum, is an example of a furan-containing natural product. Herein, a new and efficient method for the synthesis of 19 new thio analogues of hedychenone is reported. The present methodology exhibits a broad substrate scope with good to excellent yields without metal or base under mild reaction conditions. The natural compound 1 and four semisynthetic derivatives (3a, 3b, 3i, and 3j) exhibited strong α-glucosidase inhibition activity with IC50 values of 15.93 ± 0.29, 9.70 ± 0.33, 11.82 ± 0.06, 12.23 ± 0.33, and 12.15 ± 0.14 µg/mL, respectively. In addition, compound 3e (6.0 ± 0.04 mm; zone of inhibition) displayed antibacterial activity against Staphylococcus aureus. This study increases the chemical diversity of bioactive hedychenone derivatives and provides a direction for the development of antidiabetic agents.

Comparative genomics and molecular adaptational analysis of Arthrobacter from Sikkim Himalaya provided insights into its survivability under multiple high-altitude stress.

Arthrobacter is a dominant aerobic bacterium under the class Actinobacteria, known for its nutritionally versatile nature and wide prevalence in stressful environments. In the current study representative two strains of Arthrobacter, ERGS1:01 and ERGS4:06, with efficient survivability under high altitude stress conditions were selected for comparative genomic studies with their mesophilic counterparts. Physiological analysis and genome insights supported the survival of these strains under multiple high-altitude stress conditions. Molecular cold-adaptation and substitution analysis of the studied strains supported the incidence of more cold-adapted proteins for functionality at low temperatures. Studied strains preferred amino acids like serine, asparagine, lysine, tryptophan for favoring increased flexibility supporting their broad temperature survivability. To the best of our knowledge, this is the first molecular cold adaptation analysis performed for the genus Arthrobacter and has revealed that 'aromaticity', one of the cold-adaptor indicators, should be carefully considered while evaluating cold adaptation strategies in psychrotrophic/psychrophilic bacteria.

Physiological and genomic evidence supports the role of Serratia quinivorans PKL:12 as a biopriming agent for the biohardening of micropropagated Picrorhiza kurroa plantlets in cold regions.

The medicinal herb, Picrorhiza kurroa Royle ex Benth has become endangered because of indiscriminate over-harvesting. Although micropropagation has been attempted for mass propagation of the plant, survival of in vitro plantlets under green house/open field poses a major challenge. Biopriming of micropropagated plantlets with plant growth-promoting rhizobacteria (PGPR) are among the successful methods to combat this problem. Serratia quinivorans PKL:12 was the best-characterized PGPR from rhizospheric soil of P. kurroa as it increased the vegetative growth and survival of the micropropagated plantlets most effectively. Complete genome (5.29 Mb) predicted genes encoding proteins for cold adaptation and plant growth-promoting traits in PKL:12. Antibiotic and biosynthetic gene cluster prediction supported PKL:12 as a potential biocontrol agent. Comparative genomics revealed 226 unique genes with few genes associated with plant growth-promoting potential. Physiological and genomic evidence supports S. quinivorans PKL:12 as a potential agent for bio-hardening of micropropagated P. kurroa plantlets in cold regions.

Comparative genomics and physiological investigation supported safety, cold adaptation, efficient hydrolytic and plant growth-promoting potential of psychrotrophic Glutamicibacter arilaitensis LJH19, isolated from night-soil compost.

BACKGROUND: Night-soil compost (NSC) has traditionally been conserving water and a source of organic manure in northwestern Himalaya. Lately, this traditional method is declining due to modernization, its unhygienic conditions, and social apprehensions. Reduction in the age-old traditional practice has led to excessive chemical fertilizers and water shortage in the eco-sensitive region. In the current study, a bacterium has been analyzed for its safety, cold-adaptation, efficient degradation, and plant growth-promoting (PGP) attributes for its possible application as a safe bioinoculant in psychrotrophic bacterial consortia for improved night-soil composting. RESULTS: Glutamicibacter arilaitensis LJH19, a psychrotrophic bacterium, was isolated from the NSC of Lahaul valley in northwestern Himalaya. The strain exhibited amylase (186.76 ± 19.28 U/mg), cellulase (21.85 ± 0.7 U/mg), and xylanase (11.31 ± 0.51 U/mg) activities at 10 °C. Possessing efficient hydrolytic activities at low-temperature garners the capability of efficient composting to LJH19. Additionally, the strain possessed multiple PGP traits such as indole acetic acid production (166.11 ± 5.7 µg/ml), siderophore production (85.72 ± 1.06% psu), and phosphate solubilization (44.76 ± 1.5 µg/ml). Enhanced germination index and germination rate of pea seeds under the LJH19 inoculation further supported the bacterium's PGP potential. Whole-genome sequencing (3,602,821 bps) and genome mining endorsed the cold adaptation, degradation of polysaccharides, and PGP traits of LJH19. Biosynthetic gene clusters for type III polyketide synthase (PKS), terpene, and siderophore supplemented the endorsement of LJH19 as a potential PGP bacterium. Comparative genomics within the genus revealed 217 unique genes specific to hydrolytic and PGP activity. CONCLUSION: The physiological and genomic evidence promotes LJH19 as a potentially safe bio-inoculant to formulate psychrotrophic bacterial consortia for accelerated degradation and improved night-soil compost.

Genomic insights revealed physiological diversity and industrial potential for Glaciimonas sp. PCH181 isolated from Satrundi glacier in Pangi-Chamba Himalaya.

Himalayan niches provide unprecedented opportunities for finding novel microbes of commercial importance. The present study investigated the genome sequence of Glaciimonas sp. PCH181 isolated from the glacial stream of Indian trans-Himalaya. The draft genome sequence has six contigs with 5.3 Mb size, 51.1% G + C content, and possesses 4876 genes. Phylogenomic analysis revealed PCH181 as a putative novel bacterium in the genus Glaciimonas. Genomic insight showed Glaciimonas sp. PCH181 enriched with genes for diverse physiology, cold/stress adaptation, and industrial potential. The presence of genes for CO2 fixation and hydrogen metabolism suggested for chemolithoautotrophy. However, genes for sugars and organic acids usage showed heterotrophy and validated by physiological experiments. Genes for the metabolism of phenol (up to 500 ppm) and biosynthesis of polyhydroxyalkanoate (25% of dry cell mass) were also verified. Collectively, we present the first whole genome sequencing in the genus Glaciimonas, a taxonomically, physiologically, and industrially noteworthy bacterium.

Genomic and functional insights into the adaptation and survival of Chryseobacterium sp. strain PMSZPI in uranium enriched environment.

Metal enriched areas represent important and dynamic microbiological ecosystems. In this study, the draft genome of a uranium (U) tolerant bacterium, Chryseobacterium sp. strain PMSZPI, isolated from the subsurface soil of Domiasiat uranium ore deposit in Northeast India, was analyzed. The strain revealed a genome size of 3.8 Mb comprising of 3346 predicted protein-coding genes. The analysis indicated high abundance of genes associated with metal resistance and efflux, transporters, phosphatases, antibiotic resistance, polysaccharide synthesis, motility, protein secretion systems, oxidoreductases and DNA repair. Comparative genomics with other closely related Chryseobacterium strains led to the identification of unique inventory of genes which were of adaptive significance in PMSZPI. Consistent with the genome analysis, PMSZPI showed superior tolerance to uranium and other heavy metals. The metal exposed cells exhibited transcriptional induction of metal translocating PIB ATPases suggestive of their involvement in metal resistance. Efficient U binding (~90% of 100 µM U) and U bioprecipitation (~93-94% of 1 mM U at pH 5, 7 and 9) could be attributed as uranium tolerance strategies in PMSZPI. The strain demonstrated resistance to a large number of antibiotics which was in agreement with in silico prediction. Reduced gliding motility in the presence of cadmium and uranium, enhanced biofilm formation on uranium exposure and tolerance to 1.5 kGy of 60Co gamma radiation were perceived as adaptive responses in PMSZPI. Overall, the positive correlation observed between uranium/metal tolerance abilities predicted using genome analysis and the functional characterization reinforced the multifaceted adaptation strategies employed by PMSZPI for its survival in the soil of uranium ore deposit comprising of high concentrations of uranium and other heavy metals.

Complete genome sequence of Pseudomonas frederiksbergensis ERDD5:01 revealed genetic bases for survivability at high altitude ecosystem and bioprospection potential.

Pseudomonas frederiksbergensis ERDD5:01 is a psychrotrophic bacteria isolated from the glacial stream flowing from East Rathong glacier in Sikkim Himalaya. The strain showed survivability at high altitude stress conditions like freezing, frequent freeze-thaw cycles, and UV-C radiations. The complete genome of 5,746,824 bp circular chromosome and a plasmid of 371,027 bp was sequenced to understand the genetic basis of its survival strategy. Multiple copies of cold-associated genes encoding cold active chaperons, general stress response, osmotic stress, oxidative stress, membrane/cell wall alteration, carbon storage/starvation and, DNA repair mechanisms supported its survivability at extreme cold and radiations corroborating with the bacterial physiological findings. The molecular cold adaptation analysis in comparison with the genome of 15 mesophilic Pseudomonas species revealed functional insight into the strategies of cold adaptation. The genomic data also revealed the presence of industrially important enzymes.

Chemical Composition, Cytotoxic and Antibacterial Activities of Essential Oils of Cultivated Clones of Juniperus communis and Wild Juniperus Species.

Needles of seven cultivated clones (C1 - C7) of Juniperus communis at lower altitude and three wild Juniperus species (J. communis, J. recurva and J. indica) at higher altitudes were investigated comparatively for their essential oils (EOs) yields, chemical composition, cytotoxic and antibacterial activities. The EOs yields varied from 0.26 to 0.56% (v/w) among samples. Sixty-one volatile components were identified by gas chromatography-mass spectrometry (GC/MS) and quantified using gas chromatography GC (FID) representing 82.5 - 95.7% of the total oil. Monoterpene hydrocarbons (49.1 - 82.8%) dominated in all samples (α-pinene, limonene and sabinene as major components). Principal component analysis (PCA) of GC data revealed that wild and cultivated Juniperus species are highly distinct due to variation in chemical composition. J. communis (wild species) displayed cytotoxicity against SiHa (human cervical cancer), A549 (human lung carcinoma) and A431 (human skin carcinoma) cells (66.4 ± 2.2%, 74.4 ± 1.4% and 57.4 ± 4.0%), respectively, at 200 µg/ml. EOs exhibited better antibacterial activity against Gram-positive bacteria than against Gram-negative bacteria with the highest zone of inhibition against Staphylococcus aureus MTCC 96 (19.2 ± 0.7) by clone-7. As per the conclusion of the findings, EOs of clone-2, clone-5 and clone-7 can be suggested to the growers of lower altitude, as there is more possibility of uses of these EOs in food and medicinal preparations.

Bacterial community distribution and functional potentials provide key insights into their role in the ecosystem functioning of a retreating Eastern Himalayan glacier.

Himalayan glaciers are receding at an exceptional rate, perturbing the local biome and ecosystem processes. Understanding the microbial ecology of an exclusively microbe-driven biome provides insights into their contributions to the ecosystem functioning through biogeochemical fluxes. Here, we investigated the bacterial communities and their functional potential in the retreating East Rathong Glacier (ERG) of Sikkim Himalaya. Amplicon-based taxonomic classification revealed the dominance of the phyla Proteobacteria, Bacteroidota, and candidate Patescibacteria in the glacial sites. Further, eight good-quality metagenome-assembled genomes (MAGs) of Proteobacteria, Patescibacteria, Acidobacteriota, and Choloflexota retrieved from the metagenomes elucidated the microbial contributions to nutrient cycling. The ERG MAGs showed aerobic respiration as a primary metabolic feature, accompanied by carbon fixation and complex carbon degradation potentials. Pathways for nitrogen metabolism, chiefly dissimilatory nitrate reduction and denitrification, and a complete sulphur oxidation enzyme complex for sulphur metabolism were identified in the MAGs. We observed that DNA repair and oxidative stress response genes complemented with osmotic and periplasmic stress and protein chaperones were vital for adaptation against the intense radiation and stress conditions of the extreme Himalayan niche. Current findings elucidate the microbiome and associated functional potentials of a vulnerable glacier, emphasizing their significant ecological roles in a changing glacial ecosystem.

Metagenomic assembled genomes indicated the potential application of hypersaline microbiome for plant growth promotion and stress alleviation in salinized soils.

Climate change is causing unpredictable seasonal variations globally. Due to the continuously increasing earth's surface temperature, the rate of water evaporation is enhanced, conceiving a problem of soil salinization, especially in arid and semi-arid regions. The accumulation of salt degrades soil quality, impairs plant growth, and reduces agricultural yields. Salt-tolerant, plant-growth-promoting microorganisms may offer a solution, enhancing crop productivity and soil fertility in salinized areas. In the current study, genome-resolved metagenomic analysis has been performed to investigate the salt-tolerating and plant growth-promoting potential of two hypersaline ecosystems, Sambhar Lake and Drang Mine. The samples were co-assembled independently by Megahit, MetaSpades, and IDBA-UD tools. A total of 67 metagenomic assembled genomes (MAGs) were reconstructed following the binning process, including 15 from Megahit, 26 from MetaSpades, and 26 from IDBA_UD assembly tools. As compared to other assemblers, the MAGs obtained by MetaSpades were of superior quality, with a completeness range of 12.95%-96.56% and a contamination range of 0%-8.65%. The medium and high-quality MAGs from MetaSpades, upon functional annotation, revealed properties such as salt tolerance (91.3%), heavy metal tolerance (95.6%), exopolysaccharide (95.6%), and antioxidant (60.86%) biosynthesis. Several plant growth-promoting attributes, including phosphate solubilization and indole-3-acetic acid (IAA) production, were consistently identified across all obtained MAGs. Conversely, characteristics such as iron acquisition and potassium solubilization were observed in a substantial majority, specifically 91.3%, of the MAGs. The present study indicates that hypersaline microflora can be used as bio-fertilizing agents for agricultural practices in salinized areas by alleviating prevalent stresses. IMPORTANCE: The strategic implementation of metagenomic assembled genomes (MAGs) in exploring the properties and harnessing microorganisms from ecosystems like hypersaline niches has transformative potential in agriculture. This approach promises to redefine our comprehension of microbial diversity and its ecosystem roles. Recovery and decoding of MAGs unlock genetic resources, enabling the development of new solutions for agricultural challenges. Enhanced understanding of these microbial communities can lead to more efficient nutrient cycling, pest control, and soil health maintenance. Consequently, traditional agricultural practices can be improved, resulting in increased yields, reduced environmental impacts, and heightened sustainability. MAGs offer a promising avenue for sustainable agriculture, bridging the gap between cutting-edge genomics and practical field applications.

Cold-adapted Exiguobacterium sibiricum K1 as a potential bioinoculant in cold regions: Physiological and genomic elucidation of biocontrol and plant growth promotion.

The scarcity of soil nutrient availability under cold conditions of Himalayan regions needs a sustainable approach for better crop yields. The cold-adapted bacteria, Exiguobacterium sibiricum K1, with the potential to produce several plant growth-promoting (PGP) attributes, nitrogen fixation, indole acetic acid production, phosphate and potassium solubilization at 10 °C can provide an opportunity to promote crop yield improvement in an eco-friendly way under cold conditions. The bacterium also exhibited biocontrol activity against two phytopathogens and produced siderophore (53.0 ± 0.5 % psu). The strain's PGP properties were investigated using a spinach-based bioassay under controlled conditions. The bacterized seeds showed a notable increase in germination rate (23.2 %), shoot length (65.3 %), root length (56.6 %), leaf area (73.7 %), number of leaflets (65.2 %), and dry matter (65.2 %). Additionally, the leaf analysis indicated elevated chlorophyll pigments, i.e., chlorophyll a (55.5 %), chlorophyll b (42.8 %), carotenoids (35.2 %), percentage radical scavenging activity (47.4 %), and leaf nutrient uptake such as nitrogen (23.4 %), calcium (60.8 %), potassium (62.3 %), and magnesium (28.9 %). Moreover, the whole-genome sequencing and genome mining endorsed various biofertilisation-related genes, including genes for potassium and phosphate solubilization, iron and nitrogen acquisition, carbon dioxide fixation, and biocontrol ability of Exiguobacterium sibiricum K1. Overall, this study highlights the role of Exiguobacterium sibiricum K1 as a potential bioinoculant for improving crop yield under cold environments.

Physiological and genomic insights into a psychrotrophic drought-tolerant bacterial consortium for crop improvement in cold, semiarid regions.

The agricultural land in the Indian Himalayan region (IHR) is susceptible to various spells of snowfall, which can cause nutrient leaching, low temperatures, and drought conditions. The current study, therefore, sought an indigenous psychrotrophic plant growth-promoting (PGP) bacterial inoculant with the potential to alleviate crop productivity under cold and drought stress. Psychrotrophic bacteria preisolated from the night-soil compost of the Lahaul Valley of northwestern Himalaya were screened for phosphate (P) and potash (K) solubilization, nitrogen fixation, indole acetic acid (IAA) production, siderophore and HCN production) in addition to their tolerance to drought conditions for consortia development. Furthermore, the effects of the selected consortium on the growth and development of wheat (Triticum aestivum L.) and maize (Zea mays L.) were assessed in pot experiments under cold semiarid conditions (50 % field capacity). Among 57 bacteria with P and K solubilization, nitrogen fixation, IAA production, siderophore and HCN production, Pseudomonas protegens LPH60, Pseudomonas atacamensis LSH24, Psychrobacter faecalis LUR13, Serratia proteamaculans LUR44, Pseudomonas mucidolens LUR70, and Glutamicibacter bergerei LUR77 exhibited tolerance to drought stress (-0.73 MPa). The colonization of wheat and maize seeds with these drought-tolerant PGP strains resulted in a germination index >150, indicating no phytotoxicity under drought stress. Remarkably, a particular strain, Pseudomonas sp. LPH60 demonstrated antagonistic activity against three phytopathogens Ustilago maydis, Fusarium oxysporum, and Fusarium graminearum. Treatment with the consortium significantly increased the foliage (100 % and 160 %) and root (200 % and 133 %) biomasses of the wheat and maize plants, respectively. Furthermore, whole-genome sequence comparisons of LPH60 and LUR13 with closely related strains revealed genes associated with plant nutrient uptake, phytohormone synthesis, siderophore production, hydrogen cyanide (HCN) synthesis, volatile organic compound production, trehalose and glycine betaine transport, cold shock response, superoxide dismutase activity, and gene clusters for nonribosomal peptide synthases and polyketide synthetases. With their PGP qualities, biocontrol activity, and ability to withstand environmental challenges, the developed consortium represents a promising cold- and drought-active PGP bioinoculant for cereal crops grown in cold semiarid regions.

Antioxidant prodigiosin-producing cold-adapted Janthinobacterium sp. ERMR3:09 from a glacier moraine: Genomic elucidation of cold adaptation and pigment biosynthesis.

Janthinobacterium from cold niches has been studied broadly for bioactive violacein production. However, reports on the atypical red-pigmented Janthinobacterium strains are shallow. The bioactive red prodigiosin pigment has immense pharmacological significance, including antioxidant, antimicrobial and anticancer potential. Here, we report the first complete genome of a prodigiosin-producing Janthinobacterium sp. ERMR3:09 from Sikkim Himalaya in an attempt to elucidate its cold adaptation and prodigiosin biosynthesis. Nanopore sequencing and Flye assembly of the ERMR3:09 genome resulted in a single contig of 6,262,330 bp size and 62.26% GC content. Phylogenomic analysis and genome indices indicate that ERMR3:09 is a potentially novel species of the genus Janthinobacterium. The multicopy cold-responsive genes and gene upregulation under cold stress denoted its cold adaptation mechanisms. Genome analysis identified the unique genes, gene cluster and pathway for prodigiosin biosynthesis in ERMR3:09. Considering the notable antioxidant activity, it can be the next powerhouse of bioactive prodigiosin production.