Pseudomonas lalkuanensis sp. nov., isolated from a bacterial consortia of contaminated soil enriched for the remediation of e-waste.

A novel e-waste-degrading strain, PE08T, was isolated from contaminated soil collected from a paper mill yard in Lalkuan, Uttarakhand, India. Strain PE08T was Gram-stain-negative, rod-shaped, aerobic, oxidase-positive and catalase-positive. Optimum growth was observed at 30 °C (range, 5-40 °C), with 1-2 % NaCl (range, 0-3 %) and at pH 7 (range 6-11). The phylogeny based on 16S rRNA gene sequences delineated strain PE08T to the genus Pseudomonas and showed highest sequence similarity to Pseudomonas furukawaii KF707T (98.70 %), followed by Pseudomonas aeruginosa DSM 50071T (98.62 %) and Pseudomonas resinovorans DSM 21078T (97.93 %). The genome of strain PE08T was sequenced and had one scaffold of 6056953 bp, 99.84 % completeness and 182× coverage were obtained. The G+C content in the genome was 64.24 mol%. The DNA-DNA hybridization and average nucleotide identity values between strain PE08T and its closely related type strain, P. resinovorans DSM 21078T were below 34.8 % and 87.96 %, respectively. The phylogenetic analysis based on whole-genome sequence and concatenated GyrB and RpoB proteins revealed that strain PE08T forms a district clade in the family Pseudomonadaceae. The predominant fatty acids were summed feature 8 (C18 :  1ω7c and/or C18 :1 ω6c), summed feature 3 (C16 :  1ω7c and/or C16 :  1ω6c), C16 : 0 and C12 : 0. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol and phosphatidylethanolamine. The phenotypic, chemotaxonomic and genetic analysis, including overall genome relatedness index values, indicated that strain PE08T represents a novel species of the genus Pseudomonas, for which the name Pseudomonas lalkuanensis sp. nov. is proposed. The type strain is PE08T (=MCC 3792=KCTC 72454=CCUG 73691).

Towards the development of a biobased economy in Europe and India.

India has emerged as a key player with a high potential to develop a biomass and biobased economy due to its large geographic size and the massive amounts of agricultural and non agricultural biomass produced. India has joined hands with Europe to synchronize its efforts to create and facilitate the development of a biobased economy in this country. This paper aims to examine common research and development actions between the European Union (EU) and India to facilitate the development of these biobased economies. As a base, a thorough study has been performed considering the biomass potential and current status of the bioeconomy in both the EU and India based on the distillation of a series of 80 potential recommendations. The recommendations were grouped into four major categories: (1) biomass production, (2) by-products/waste, (3) biorefineries and (4) policy, market, and value-added products. A questionnaire was designed and distributed to key stakeholders belonging to: academia, industry, and policymakers in both India and the EU. A total of 231 responses were received and analyzed, based on the key recommendations made for the essential research and development topics that are of prime importance to develop biobased economies in both the EU and India. The findings of this study suggest recognizing the value-added contributions made by biobased products such as: food, feed, valuable materials and chemicals in both regions. It is important to reduce the overall process costs and minimize the environmental impacts of such a biobased economy.

Differential proteomic expression of himalayan psychrotrophic diazotroph Pseudomonas palleroniana N26 under low temperature diazotrophic conditions.

BACKGROUND: In low temperature nitrogen-deficient ecosystems, native microorganisms must possess adaptive mechanisms to cope with environmental stress as well as nitrogen (N) starvation-like conditions. However, moderate information is available about the cold adapted diazotrophs and diazotrophy. OBJECTIVE: The aim of this study was to examine the proteomic response(s) of Himalayan psychrotrophic diazotroph under low temperature nitrogen fixing conditions. MATERIALS AND METHODS: Proteomic analysis of Pseudomonas palleroniana N26 was carried out using two dimensional electrophoresis technique. RESULTS: Altogether, fifty three protein spots were found to be differentially expressed revealing several mechanisms thought to be involved in low temperature adaptation and nitrogen fixation, including general stress adaptation, protein synthesis and modifications, and energy metabolism. Expression profiling of the spots revealed the up-regulation of low molecular weight acidic proteins; a majority of which were stress proteins. The largest group of down-regulated proteins were related to biosynthetic processes; thereby, providing the evidence for stress-associated metabolic adaptations. CONCLUSION: The present study, which provides an overview of the cold diazotrophy of a Himalayan psychrotrophic bacterium and its adaptive responses, can facilitate further studies of low temperature nitrogen fixing mechanisms, psychrophilic diazotrophic markers, and transgenic microorganism(s)/crop(s) development.

Differential proteomics in response to low temperature diazotrophy of Himalayan psychrophilic nitrogen fixing Pseudomonas migulae S10724 strain.

Himalayas are considered as a reservoir of diversified and dynamic gene pool. This study describes the response of a Himalayan psychrophilic diazotroph to low temperature diazotrophy. Seven cold adaptive N2 fixing bacteria were isolated and identified as Bacillus sp., Arthrobacter sp., Rhodococcus sp., Pseudomonas sp., etc. In order to examine the physiological response to low temperature diazotrophy, differential proteomic analysis of Pseudomonas migulae S10724 strain was carried out using two dimensional electrophoresis and MALDI-TOF-MS. Functional assessment of 66 differentially expressed proteins revealed several mechanisms thought to be involved in low temperature adaptation and nitrogen fixation, including general stress adaptation, protein and nucleic acid synthesis, energy metabolism, cell growth/maintenance, etc. Major fraction of the upregulated proteins was stress proteins, while majority of the downregulated proteins were related to cell division. Furthermore, MALDI-TOF-MS-based identification of randomly selected peptides encountered two exclusively expressed proteins: NifU family SUF system FeS assembly protein and membrane protein, suppressor for copper-sensitivity B precursor which might have a crucial role at low temperature nitrogen fixation. To the best of our knowledge, this is the first report of the isolation and differential proteomic analysis of psychrophilic diazotroph from Himalayan high altitude rhizospheric soil.

Deciphering the impact of cold-adapted bioinoculants on rhizosphere dynamics, biofortification, and yield of kidney bean across varied altitudinal zones.

Agriculture stands as a thriving enterprise in India, serving as both the bedrock of economy and vital source of nutrition. In response to the escalating demands for high-quality food for swiftly expanding population, agricultural endeavors are extending their reach into the elevated terrains of the Himalayas, tapping into abundant resources for bolstering food production. Nonetheless, these Himalayan agro-ecosystems encounter persistent challenges, leading to crop losses. These challenges stem from a combination of factors including prevailing frigid temperatures, suboptimal farming practices, unpredictable climatic shifts, subdivided land ownership, and limited resources. While the utilization of chemical fertilizers has been embraced to enhance the quality of food output, genuine concerns have arisen due to the potential hazards they pose. Consequently, the present investigation was initiated with the objective of formulating environmentally friendly and cold-tolerant broad ranged bioinoculants tailored to enhance the production of Kidney bean while concurrently enriching its nutrient content across entire hilly regions. The outcomes of this study unveiled noteworthy advancements in kidney bean yield, registering a substantial increase ranging from 12.51 ± 2.39 % to 14.15 ± 0.83 % in regions of lower elevation (Jeolikote) and an even more remarkable surge ranging from 20.60 ± 3.03 % to 29.97 ± 5.02 % in higher elevated areas (Chakrata) compared to the control group. Furthermore, these cold-tolerant bioinoculants exhibited a dual advantage by fostering the enhancement of essential nutrients within the grains and fostering a positive influence on the diversity and abundance of microbial life in the rhizosphere. As a result, to effectively tackle the issues associated with chemical fertilizers and to achieve sustainable improvements in both the yield and nutrient composition of kidney bean across varying elevations, the adoption of cold-tolerant Enterobacter hormaechei CHM16, and Pantoea agglomerans HRM 23, including the consortium, presents a promising avenue. Additionally, this study has contributed significant insights-into the role of organic acids like oxalic acid in the solubilization of nutrients, thereby expanding the existing knowledge in this specialized field.

Expression of CspE by a psychrotrophic bacterium Enterobacter ludwigii PAS1, isolated from Indian Himalayan soil and in silico protein modelling, prediction of conserved residues and active sites.

Proteome analysis of Enterobacter ludwigii PAS1 provide a powerful set of tool to study the cold shock proteins along with that combination of bioinformatics is useful for interpretation of comparative results from many species. There is a considerable interest in the use of psychrotrophic bacteria for nitrogen fixation, especially at hilly regions, thus better understanding of cold adaptation mechanisms too. The psychrotrophic E. ludwigii PAS1 grown at 30 and 4 °C, isolated from Himalaya soil was undertaken for proteomic responses during optimal and cold shock conditions. Comparative proteomic analyses using two-dimensional gel electrophoresis (2-DE) and MALDI-TOF/TOF MS revealed the presence of Cold shock protein E (CspE). Three-dimensional structure of CspE of E. ludwigii PAS1 divulge the presence of five antiparallel ß-sheets forming a ß-barrel structure with surface exposed aromatic and basic residues that were responsible for nucleic acid binding and also reveals the presence of highly conserved nucleic acid-binding motifs RNP1 and RNP2 in Csp family.

Comparative e-waste plastics biodegradation efficacy of monoculture Pseudomonas aeruginosa strain PE10 and bacterial consortium under in situ condition.

A significant amount of electronic obsoletes or electronic waste (e-waste) is being generated globally each year; of these, ~20% of obsolete electronic items have plastic components. Current remediation practices for e-waste have several setbacks due to its negative impact on the environment, agro-ecosystem, and human health. Therefore, comparative biodegradation studies of e-waste plastics by monoculture Pseudomonas aeruginosa strain PE10 and bacterial consortium consisting of Achromobacter insolitus strain PE2 (MF943156), Acinetobacter nosocomialis strain PE5 (MF943157), Pseudomonas lalkuanensis PE8 (CP043311), and Stenotrophomonas pavanii strain PE15 (MF943160) were carried out in situ. Biological treatment of e-waste with these candidates in soil ecosystems has been analyzed through diversified analytical techniques such as Fourier transform infrared spectroscopy (FTIR), thermogravimetric-derivative thermogravimetry-differential thermal analysis (TG-DTG-DTA), and scanning electron microscopy (SEM). Both P. aeruginosa strain PE10 and the bacterial consortium have a tremendous ability to accelerate the biodegradation process in the natural environment. However, FTIR analysis implied that the monoculture had better efficacy than the consortium, and it was consistent until the incubation period used for the study. Some polymeric bonds such as ν C=C and δ C-H were completely removed, and ν C=C ring stretching, νasym C-O-C, νsym C-H, etc. were introduced by strain PE10. Furthermore, thermal analysis results validated the structural deterioration of e-waste as the treated samples showed nearly two-fold weight loss (WL; 6.8%) than the untreated control (3.1%) at comparatively lower temperatures. SEM images provided the details of surface disintegrations. Conclusively, individual monoculture P. aeruginosa strain PE10 could be explored for e-waste bio-recycling in agricultural soil ecosystems thereby reducing the cost, time, and management of bioformulation in addition to hazardous pollutant reduction.

Credibility assessment of cold adaptive Pseudomonas jesenni MP1 and P. palleroniana N26 on growth, rhizosphere dynamics, nutrient status, and yield of the kidney bean cultivated in Indian Central Himalaya.

Kidney bean (Phaseolus vulgaris) productivity and nutritional quality are declining due to less nutrient accessibility, poor soil health, and indigent agronomic practices in hilly regions, which collectively led to a fall in farmer's income, and to malnutrition in consumers. Addressing such issues, the present investigation was designed to assess the impact of Pseudomonas jesenii MP1 and Pseudomonas palleroniana N26 treatment on soil health, microbial shift, yield, and nutrient status of the kidney bean in the Harsil and Chakrata locations of Indian Central Himalaya. P. jesenii MP1 and P. palleroniana N26 were characterized as cold adaptive PGPR as they possessed remarkable in vitro plant growth promoting traits. Further, field trial study with PGPR treatments demonstrated remarkable and prolific influence of both strains on yield, kidney bean nutrient status, and soil health at both geographical locations, which was indicated with improved grain yield (11.61%-23.78%), protein (6.13%-24.46%), and zinc content (21.86%-61.17%) over control. The metagenomic study revealed that use of bioinoculants also concentrated the nutrient mobilizing and plant beneficial microorganisms in the rhizosphere of the kidney bean. Moreover, correlation analysis also confirmed that the plant growth-promoting traits of P. jesenii MP1 and P. palleroniana N26 are the basis for improved yield and nutrient status of the kidney bean. Further, cluster and principal component analysis revealed that both P. jesenii MP1 and P. palleroniana N26 exhibited pronounced influence on yield attributes of the kidney bean at both the locations. At the Harsil location, the P. jesenii MP1-treated seed demonstrated highest grain yield over other treatments, whereas at Chakarata, P. jesenii MP1, and P. palleroniana N26 treatment showed almost equal enhancement (~23%) in grain yield over control. The above results revealed that these bioinoculants are efficient plant growth promoters and nutrient mobilizers; they could be used as green technology to improve human health and farmer's income by enhancing soil health, yield, and nutrient status of the kidney bean at hilly regions.

Microbial bioformulation: a microbial assisted biostimulating fertilization technique for sustainable agriculture.

Addressing the pressing issues of increased food demand, declining crop productivity under varying agroclimatic conditions, and the deteriorating soil health resulting from the overuse of agricultural chemicals, requires innovative and effective strategies for the present era. Microbial bioformulation technology is a revolutionary, and eco-friendly alternative to agrochemicals that paves the way for sustainable agriculture. This technology harnesses the power of potential microbial strains and their cell-free filtrate possessing specific properties, such as phosphorus, potassium, and zinc solubilization, nitrogen fixation, siderophore production, and pathogen protection. The application of microbial bioformulations offers several remarkable advantages, including its sustainable nature, plant probiotic properties, and long-term viability, positioning it as a promising technology for the future of agriculture. To maintain the survival and viability of microbial strains, diverse carrier materials are employed to provide essential nourishment and support. Various carrier materials with their unique pros and cons are available, and choosing the most appropriate one is a key consideration, as it substantially extends the shelf life of microbial cells and maintains the overall quality of the bioinoculants. An exemplary modern bioformulation technology involves immobilizing microbial cells and utilizing cell-free filters to preserve the efficacy of bioinoculants, showcasing cutting-edge progress in this field. Moreover, the effective delivery of bioformulations in agricultural fields is another critical aspect to improve their overall efficiency. Proper and suitable application of microbial formulations is essential to boost soil fertility, preserve the soil's microbial ecology, enhance soil nutrition, and support crop physiological and biochemical processes, leading to increased yields in a sustainable manner while reducing reliance on expensive and toxic agrochemicals. This manuscript centers on exploring microbial bioformulations and their carrier materials, providing insights into the selection criteria, the development process of bioformulations, precautions, and best practices for various agricultural lands. The potential of bioformulations in promoting plant growth and defense against pathogens and diseases, while addressing biosafety concerns, is also a focal point of this study.

Leveraging arsenic resistant plant growth-promoting rhizobacteria for arsenic abatement in crops.

Arsenic is a toxic metalloid categorized under class 1 carcinogen and is detrimental to both plants and animals. Agricultural land in several countries is contaminated with arsenic, resulting in its accumulation in food grains. Increasing global food demand has made it essential to explore neglected lands like arsenic-contaminated lands for crop production. This has posed a severe threat to both food safety and security. Exploration of arsenic-resistant plant growth-promoting rhizobacteria (PGPR) is an environment-friendly approach that holds promise for both plant growth promotion and arsenic amelioration in food grains. However, their real-time performance is dependent upon several biotic and abiotic factors. Therefore, a detailed analysis of associated mechanisms and constraints becomes inevitable to explore the full potential of available arsenic-resistant PGPR germplasm. Authors in this review have highlighted the role and constraints of arsenic-resistant PGPR in reducing the arsenic toxicity in food crops, besides providing the details of arsenic transport in food grains.

Comparative protein modeling, prediction of conserved residue and active sites in cold resistant protein isolated from CRPF(1), a cold tolerant mutant of Pseudomonas fluorescens.

Proteins interacting with the biological information molecules DNA and RNA play important cellular roles in all organisms. One widespread super family of proteins implicated in such function(s) is cold shock protein (CSP) that contains the cold shock domain (CSD). This work is planned to study the three-dimensional structure, conserved residues, and different active sites in the structure of cold resistant protein (CRP) from CRPF(1), cold tolerant mutant of Pseudomonas fluorescence by comparative homology modeling. Here we tried to identify crucial residues that are involved in active sites or functional sites of the protein. The study reveals that CRP represent the prototype of the CSD and share a highly similar overall fold consisting of five antiparallel beta-sheets forming a beta-barrel structure with surface exposed aromatic and basic residues that were responsible for nucleic acid binding properties of variable binding affinities and sequence selectivity and harbors the nucleic acid binding motifs RNP1 and RNP2 that is highly conserved in CSP family.

Implications of SPION and NBT nanoparticles upon in-vitro and in-situ biodegradation of LDPE film.

Comparative influence of two nanoparticles viz. superparamagnetic iron oxide nanoparticles (SPION) and nanobarium titanate (NBT) was studied upon the in-vitro and in-situ low-density polyethylene (LDPE) biodegradation efficiency of a potential polymer-degrading microbial consortium. Supplementation of 0.01% concentration (w/v) of the nanoparticles in minimal broth significantly increased the bacterial growth, along with early onset of the exponential phase. Under in-vitro conditions, lambda-max shifts were quicker with nanoparticles and Fourier transform infrared spectroscopy (FTIR) illustrated significant changes in CH/CH2 vibrations, along with introduction of hydroxyl residues in the polymer backbone. Further, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) reported multiple-step decomposition of LDPE degraded in the presence of nanoparticles. These findings were supported by scanning electron micrographs (SEM) which revealed greater dissolution of film surface in the presence of nanoparticles. Furthermore, progressive degradation of the film was greatly enhanced when it was incubated under soil conditions for 3 months with the nanoparticles. The study highlights the significance of bacteria-nanoparticle interactions which can dramatically influence key metabolic processes like biodegradation. The authors also propose the exploration of nanoparticles to influence various other microbial processes for commercial viabilities.

Implications of fullerene-60 upon in-vitro LDPE biodegradation.

Fullerene-60 nanoparticles were used for studying their influence upon the LDPE biodegradation efficiency of two potential polymer-degrading consortia comprising of three bacterial strains each. At a concentration of 0.01% (w/v) in minimal broth lacking dextrose, fullerene did not have any negative influence upon the consortial growth. However, fullerene was found to be detrimental for bacterial growth at higher concentrations (viz. 0.25%, 0.5% and 1%). Although, addition of 0.01% fullerene into the biodegradation assays containing 5 mg/ml LDPE subsided growth-curves significantly, but subsequent analysis of degraded products revealed enhanced biodegradation. Fourier transform infrared spectroscopy (FT-IR) revealed breakage and formation of chemical bonds along with introduction of nu C-O frequencies into hydrocarbon backbone of LDPE. Further, simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis (TG-DTG-DTA) revealed higher number of decomposition steps along with a 1,000-fold decrease in the heat of reactions (DeltaH) in fullerene-assisted biodegraded LDPE suggesting probable formation of multiple, macromolecular by-products. This is the first report whereby fullerene-60, which is otherwise considered toxic, has helped to alleviate polymer biodegradation process of bacterial consortia.

Diversification of nitrogen fixing bacterial community using nifH gene as a biomarker in different geographical soils of Western Indian Himalayas.

Six soil samples (Pantnagar, Chamoli, Almora, Ranichauri, Pithoragarh and Badrinath) belonging to different geographical locations of Western Himalayas in India, were analyzed to diversify the nitrogen fixing bacterial community using nifH gene biomarker DNA from soil samples were isolated and amplified using nifH gene specific primers. Genomic DNA and PCR amplified products were then individually subjected to restriction digestion with tetra to octacutter enzymes (AluI, MspI, BgIII, XbaI, HindIII, HaeIII, AluI, MspI and PasI. Further restriction pattern was studied by preparing dendograms on the basis of similarity matrix and compared for the nifH community. It was observed that temperate region soils (Ranichauri and Pithoragarh) were negative for nifH marker while subalpine region (Badrinath) and tarai region soils (Pantnagar) documented similar nifH community. Moreover; the direct genomic DNA restriction analysis indicated that subalpine region soil (Badrinath) was most diversified.

Psychrophilic Pseudomonas helmanticensis proteome under simulated cold stress.

Himalayan mountains are distinctly characterized for their unique climatic and topographic variations; therefore, unraveling the cold-adaptive mechanisms and processes of native life forms is always being a matter of concern for scientific community. In this perspective, the proteomic response of psychrophilic diazotroph Pseudomonas helmanticensis was studied towards low-temperature conditions. LC-MS-based analysis revealed that most of the differentially expressed proteins providing cold stress resistance were molecular chaperons and cold shock proteins. Enzymes involved in proline, polyamines, unsaturated fatty acid biosynthesis, ROS-neutralizing pathways, and arginine degradation were upregulated. However, proteins involved in the oxidative pathways of energy generation were severalfold downregulated. Besides these, the upregulation of uncharacterized proteins at low temperature suggests the expression of novel proteins by P. helmanticensis for cold adaptation. Protein interaction network of P. helmanticensis under cold revealed that Tif, Tig, DnaK, and Adk were crucial proteins involved in cold adaptation. Conclusively, this study documents the proteome and protein-protein interaction network of the Himalayan psychrophilic P. helmanticensis under cold stress.

Exploration of Csp genes from temperate and glacier soils of the Indian Himalayas and in silico analysis of encoding proteins.

The metagenomic Csp library was constructed from the temperate and glacier soils of central Himalaya, India followed by polymerase chain reaction (PCR) amplification. The library was further screened for low-temperature adaptation, and the positive recombinants were sorted out by determining changes in the melting temperature (Tm). A homology search of cloned sequence showed their identity with the Csp genes of Pseudomonas fluorescens, Psychrobacter cryohalolentis K5, and Shewanella spp MR-4. Amino acid sequence analysis annotated the presence of conserved aromatic and basic amino acids as well as RNA binding motifs from the cold shock domain. Furthermore, a PROSITE scan showed a moderate identity of less than 60% with the known cold shock-inducible proteins (ribosomal proteins, rbfA, DEAD-box helicases), cold acclimation protein, and temperature-induced protein (SRP1/TIP1). This study highlighted the prevalence of Csp genes from cold Himalayan environments that can be explored for tailor-made crop constructions in future.

Microbial diversity and soil physiochemical characteristic of higher altitude.

Altitude is the major factor affecting both biodiversity and soil physiochemical properties of soil ecosystems. In order to understand the effect of altitude on soil physiochemical properties and bacterial diversity across the Himalayan cold desert, high altitude Gangotri soil ecosystem was studied and compared with the moderate altitude Kandakhal soil. Soil physiochemical analysis showed that altitude was positively correlated with soil pH, organic matter and total nitrogen content. However soil mineral nutrients and soil phosphorus were negatively correlated to the altitude. RT-PCR based analysis revealed the decreased bacterial and diazotrophic abundance at high altitude. Metagenomic study showed that Proteobacteria, Acidobacteria and Actinobacteria were dominant bacteria phyla at high altitude soil while Bacteroidetes and Fermicutes were found dominant at low altitude. High ratio of Gram-negative to Gram positive bacteria at Gangotri suggests the selective proliferation of Gram negative bacteria at high altitude with decrease in Gram positive bacteria. Moreover, Alphaproteobacteria was found more abundant at high altitude while the opposite was true for Betaproteobacteria. Abundance of Cytophaga, Flavobacterium and Bacteroides (CFB) were also found comparatively high at high altitude. Presence of many taxonomically unclassified sequences in Gangotri soil indicates the presence of novel bacterial diversity at high altitude. Further, isolation of bacteria through indigenously designed diffusion chamber revealed the existence of bacteria which has been documented in unculturable study of WIH (Western Indian Himalaya) but never been cultivated from WIH. Nevertheless, diverse functional free-living psychrotrophic diazotrophs were isolated only from the high altitude Gangotri soil. Molecular characterization revealed them as Arthrobacter humicola, Brevibacillus invocatus, Pseudomonas mandelii and Pseudomonas helmanticensis. Thus, this study documented the bacterial and psychrophilic diazotrophic diversity at high altitude and is an effort for exploration of low temperature bacteria in agricultural productivity with the target for sustainable hill agriculture.

Differential protein profiling of soil diazotroph Rhodococcus qingshengii S10107 towards low-temperature and nitrogen deficiency.

Protein-based biomarkers can be a promising approach for identification and real-time monitoring of the bio-inoculants employed under sustainable agricultural plans. In this perspective, differential proteomics of psychrophilic diazotroph Rhodococcus qingshengii S10107 (JX173283) was performed to unravel its adaptive responses towards low-temperature nitrogen deficiency and identification of a biomarker for respective physiological conditions. LC-MS/MS-based proteome analysis mapped more than 4830 proteins including 77 up-regulated and 47 down-regulated proteins (p ≤ 0.05). Differential expression of the structural genes of nif regulon viz. nifH, nifD, and nifK along with their response regulators i.e. nifA, nifL, and nifB indicated that the nitrogenase complex was activated successfully. Besides up-regulating the biosynthesis of certain amino acids viz. Leucine, Lysine, and Alanine; the expression of the peptidoglycan synthesis proteins were also increased; while, the enzymes involved in Lipid biosynthesis were found to decrease. Furthermore, two important enzymes of the pentose phosphate pathway viz. Transketolase and Transaldolase along with Ribose import ATP-binding protein RbsA were also found to induce significantly under low temperature a nitrogen deficient condition, which suggests the cellular need for ample ribose sugar instantly. Additionally, comparative protein profiling of S10107 strain with our previous studies revealed that CowN protein was significantly up-regulated in all the cases under low-temperature nitrogen deficient conditions and therefore, can be developed as a biomarker. Conclusively, present study for the first time provides an in-depth proteome profiling of R. qingshengii S10107 and proclaims CowN as a potential protein biomarker for monitoring BNF under cold niches.

Comparative biodegradation of HDPE and LDPE using an indigenously developed microbial consortium.

A variety of bacterial strains were isolated from waste disposal sites of Uttaranchal, India, and some from artificially developed soil beds containing maleic anhydride, glucose, and small pieces of polyethylene. Primary screening of isolates was done based on their ability to utilize high- and low-density polyethylenes (HDPE/LDPE) as a primary carbon source. Thereafter, a consortium was developed using potential strains. Furthermore, a biodegradation assay was carried out in 500-ml flasks containing minimal broth (250 ml) and HDPE/ LDPE at 5 mg/ml concentration. After incubation for two weeks, degraded samples were recovered through filtration and subsequent evaporation. Fourier transform infrared spectroscopy (FTIR) and simultaneous thermogravimetric-differential thermogravimetry-differential thermal analysis TG-DTG-DTA) were used to analyze these samples. Results showed that consortium-treated HDPE (considered to be more inert relative to LDPE) was degraded to a greater extent 22.41% weight loss) in comparison with LDPE (21.70% weight loss), whereas, in the case of untreated samples, weight loss was more for LDPE than HDPE (4.5% and 2.5%, respectively) at 400 degrees . Therefore, this study suggests that polyethylene could be degraded by utilizing microbial consortia in an eco-friendly manner.