Identification of a novel quinoline-based UV-protective pigment from a psychrotrophic Arctic bacterium.

AIMS: Psychrotrophs are extremophilic microorganisms that grow optimally in low temperature having many unique bioactive molecules of biotechnological applications. In this study, we characterized a pigment from an arctic bacterium with protective activity towards UV exposure. METHODS AND RESULTS: The present research reports isolation and characterization of a psychrotrophic bacteria, RSAP2, from the soil sample of NyAlesund (78°56"N, 11°54"E), Svalbard, Norway. The strain showed closest 16S rRNA gene sequence similarity (99.9%) with Kocuria indica NIO-1021. RSAP2 is a Gram-positive, coccoid aerobe which produces a yellow pigment. The optimal parameters for pigment production while grown in LB medium were 3% (w/v) NaCl and 4 days of incubation of the culture at 20°C and pH 9 with shaking (180 rpm). The pigment was extracted in methanol and acetone (2:1) and further purified through column chromatography. It was characterized by mass spectrometry, UV-visible, fluorescence, IR, 1 H NMR, 13 C NMR spectroscopy and CHNS/O analysis. The pigment has a molecular weight of about 258 daltons and the molecular formula was determined as C15 H18 N2 O2 and is a quinoline derivative. We show that the pigment can protect Escherichia coli against UV-mediated mutagenesis. We further demonstrate that the pigment displays a significant antimicrobial effect and in sublethal concentrations it impairs biofilm formation ability of the model organism Staphylococcus aureus. CONCLUSIONS: The pigment of a psychrotrophic Arctic bacterium, most likely a strain of K. indica, was purified and its chemical structure was determined. The quinoline-based pigment has the ability to protect live cells from UV induced damage. SIGNIFICANCE AND IMPACT OF STUDY: Analysis and characterization of this newly isolated quinoline-based pigment is a potential candidate for future application in skin care products.

The effect of trust and its antecedents towards determining users' behavioral intention with voice-based consumer electronic devices.

Advances in artificial intelligence (AI) have ushered in a new era of consumer electronic (CE) devices: the voice-based CE devices (VCED's). A striking feature that separates these from other CE devices are their anthropomorphic capabilities. While current CE research has given a strong focus on improving various technical and security aspects of the VCED's, not much efforts have been given to explore their diffusion and acceptance in the society. However, if the CE community is to progress then there is an urgent need to view these systems from a sociotechnical perspective and take the user perceptions into account for further product development. In this work we propose a novel research framework by incorporating Human Computer Interaction (HCI) theories and Para Social Relationship Theory for exploring the effect of trust on the behavioral intention of users towards VCED's, keeping in mind their human-like attributes. Data is analyzed using a Structural Equation Modelling approach from 675 users of VCED devices from two Asian countries. Results show that the functional aspects of performance and effort expectancy, and social aspects of presence and cognition affect the trust factor. Privacy concerns do not affect trust. Overall, the results suggest that users treat VCED's as social objects employing social rules while interaction that indicates a dual nature of anthropomorphic systems. Suitable suggestions are provided for CE researchers for future research.

MEDA Based Biochips: Detection, Prevention and Rectification Techniques for Cyberphysical Attacks.

Recent advances of microelectrode-dot-array (MEDA) based Biochips have revolutionized the application of Lab-on-chip devices. New techniques for MEDA based biochips confide on the concepts on computer-aided design automation and cyberphysical integration to provide ease of use, higher throughput and reliability. One of the major security concerns in MEDA based biochips is actuation tempering attacks targeted to change control sequence daisy chain input resulting in incorrect bioassays. In this paper, we attempted to identify different types of actuation tampering attacks specific to MEDA based biochips. We proposed one technique to detect errors in order to secure the biochips against actuation tempering attacks. This proposed technique is able to monitor such malicious operations and can stall it under any abnormality in operation. Our analysis proves that the proposed method is able to detect errors accurately and proves that this technique is naturally implemented in MEDA.

Production of extracellular lipase from psychrotrophic bacterium Oceanisphaera sp. RSAP17 isolated from arctic soil.

Cold-active extracellular lipases produced by different psychrotrophs are important for various industrial applications. We have isolated a Gram-negative, rod-shaped, aerobe, non-pigment producing psychrotrophic bacterial strain RSAP17 (MTCC 12991, MCC 4275) from the unexplored Arctic soil sample of NyAlesund, Svalbard, Norway (78° 55″ N, 11° 54″ E). The detailed morphological, biochemical, and molecular characteristics were investigated to characterize the isolate RSAP17. Analyses of the 16S rDNA sequence of strain RSAP17 (Accession no. MK391379) shows the closest match with Oceanisphaera marina YM319T (99.45%) and Oceanisphaera sediminis TW92 JCM 17329T (97.40%). The isolate is capable of producing extracellular lipase but not amylase, cellulase or urease. The optimal parameters for lipase production have been found in tributyrin based (10 mL/L) agar media supplemented with 3% (w/v) NaCl after 2-3 days of incubation at 20-22 °C temperature and pH 9 at shaking condition. We have purified the extracellular lipase from the RSAP17 grown culture supernatant through 75% ammonium sulfate precipitation followed by dialysis and DEAE cellulose column chromatography. The invitro lipolytic activity of the purified lipase enzymes has been done through zymogram analysis. The molecular weight found for the lipase is 103.8 kD. The optimal activity of the purified lipase has been found at 25 °C and pH 9. MALDI-TOF-MS study of the purified lipase showed the highest match with the sequence of prolipoprotein diacylglyceryl transferase with 44% sequence coverage. Further study on large-scale production, substrate utilization and enzymatic kinetics of this lipase could unravel its possibility in future biotechnological applications.

Biotechnological application of endophytic filamentous bipolaris and curvularia: a review on bioeconomy impact.

The filamentous Bipolaris and Curvularia genera consist of species known to cause severe diseases in plants and animals amounting to an estimated annual loss of USD $10 billion worldwide. Despite the harmful effect of Bipolaris and Curvularia species, scarce attention is paid on beneficial areas where the fungi are used in industrial processes to generate biotechnological products. Catalytic potential of Bipolaris and Curvularia species in the production of biodiesel, bioflucculant, biosorbent, and mycoherbicide are promising for the bioeconomy. It is herein demonstrated that knowledge-based application of some endophytic Bipolaris and Curvularia species are indispensable vectors of sustainable economic development. In the twenty-first century, India, China, and the USA have taken progress in the biotechnological application of these fungi to generate wealth. As such, some Bipolaris and Curvularia species significantly impact on global crop improvement, act as catalyst in batch-reactors for biosynthesis of industrial enzymes and medicines, bioengineer of green-nanoparticle, agent of biofertilizer, bioremediation and bio-hydrometallurgy. For the first time, this study discusses the current advances in biotechnological application of Bipolaris and Curvularia species and provide new insights into the prospects of optimizing their bioengineering potential for developing bioeconomy.

Global challenges faced by engineered Bacillus thuringiensis Cry genes in soybean (Glycine max L.) in the twenty-first century.

The most important insect pests causing severe economic damages to soybean (Glycine max L.) production worldwide are Chrysodeixis includens (Walker, Noctuidae), Anticarsia gemmatalis (Hübner, Erebidae), Helicoverpa gelotopoeon (Dyar, Noctuidae), Crocidosema aporema (Walsingham; Tortricidae), Spodoptera albula (Walker, Noctuidae), S. cosmiodes (Walker, Noctuidae), S. eridania (Stoll, Noctuidae), S. frugiperda (Smith; Noctuidae), Helicoverpa armigera (Hübner, Noctuidae), H. zea (Boddie; Noctuidae) and Telenomus podisi (Hymenoptera,Platygastidae). Despite the success of biotech Bacillus thuringiensis (Bt)/herbicide tolerance (HT)-soybean in the past decade in terms of output, unforeseen mitigated performances have been observed due to changes in climatic events that favors the emergence of insect resistance. Thus, there is a need to develop hybrids with elaborated gene stacking to avert the upsurge in insect field tolerance to crystal (Cry) toxins in Bt-soybean. This study covers the performance of important commercial transgenic soybean developed to outwit destructive insects. New gene stacking soybean events such as Cry1Ac-, Cry1AF- and PAT-soybean (DAS-81419-2®, Conkesta™ technology), and MON-87751-7 × MON-87701-2 × MON 87708 × MON 89788 (bearing Cry1A.105 [Cry1Ab, Cry1F, Cry1Ac], Cry2Ab, Cry1Ac) are being approved and deployed in fields. Following this deployment trend, we recommend herein that plant-mediated RNA interference into Bt-soybean, and the application of RNA-based pesticides that is complemented by other best agricultural practices such as refuge compliance, and periodic application of low-level insecticides could maximize trait durability in Bt-soybean production in the twenty-first century.

Global invasive Cochliobolus species: cohort of destroyers with implications in food losses and insecurity in the twenty-first century.

Matching the global food demand by 2050 and to ensure the stability of food security in over than 99 countries, it is necessary to scale up the production of food such as sorghum, wheat, rice, maize and sugarcane which are however natural hosts of Cochliobolus species. Cochliobolus species major epidemics such as the Great Bengal famine, Southern corn leaf blight, and Northern leaf spot blight were associated with substantial economic losses in the past decades. Thus, there is an urgent need to establish a specific coordinated global surveillance program for the migration of invasive Cochliobolus species, planning contextual control programs engaging all agricultural stakeholders and information sharing in real time for prevention of disastrous Cochliobolus disease outbreak effects. We discuss pertinent outcome of interactions of cash crops with Cochliobolus species having devastating impact on the livelihood of farmers and food security. While post-genomic era elucidated prominent differences among Cochliobolus heterostrophus, C. carbonum, C. victoriae, C. lunatus and C. miyabeanus, their destructive potentials and implications in food losses remained unearthed. Intriguingly, the annual colossal losses caused by Cochliobolus species in the production perspective of sorghum, wheat, rice, maize, cassava and soybean is estimated over 10 billion USD worldwide. This paper provides a comprehensive analysis of the invasive Cochliobolus species distribution and diversity, evolving pathogenicity, persistent diseases, threats and epidemics, consequences on food crops production and increasing global food insecurity issues.

Invasive Aspergillus terreus morphological transitions and immunoadaptations mediating antifungal resistance.

BACKGROUND AND AIMS: Aspergillus terreus Thom is a pathogen of public health and agricultural importance for its seamless abilities to expand its ecological niche. The aim of this study was holistically to investigate A. terreus morphological and immunoadaptations and their implication in antifungal resistance and proliferation during infection. MATERIALS AND METHODS: In-depth unstructured mining of relevant peer-reviewed literature was performed for A. terreus morphological, immune, resistance, and genetic diversity based on the sequenced calmodulin-like gene. RESULTS: Accessory conidia and phialidic conidia produced by A. terreus confer discrete anti-fungal resistance that ensures survivability during therapies. Interestingly, by producing unique metabolites such as Asp-melanin and terretonin, A. terreus is capable of hijacking macrophages and scavenging iron, respectively. As such, A. terreus has established a rare mechanism to mitigate phagocytosis and swing the interaction dynamics in favor of its proliferation and survival in hosts. CONCLUSION: It is further unraveled that besides A. terreus genetic diversity, morphological, biochemical, and immunologic adaptations associated with conidia germination and discharge of chemical signals during infection enable masking of the host defense as an integral part of its strategy to survive and rapidly colonize hosts.

Cochliobolus lunatus down-regulates proteome at late stage of colonization and transiently alters StNPR1 expression in Solanum tuberosum L.

Cochliobolus lunatus abundantly produces four-celled conidia at high temperatures (>30 °C) and under suitable conditions; the fungus colonizes potato (Solanum tuberosum L.) cultivars by adopting different invasion strategies at the microscopic level. Long-lasting defence during infection requires an upsurge in proteome changes particularly pathogenesis-related proteins chiefly under the control of nonexpresser of pathogenesis-related proteins. In order to gain molecular insights, we profiled the changes in proteome and potato nonexpresser of pathogenesis-related proteins (StNPR1) during the infection process. It is found that C. lunatus significantly (P < 0.05) suppressed the host functional proteome by 96 h after infection (hai), principally, affecting the expression of ribulose bisphosphate carboxylase enzyme, plastidic aldolase enzyme, alcohol dehydrogenase 2 and photosystem II protein prior to the formation of brown-to-black leaf spot disease. Strongest host response was observed at 24 hai hallmarked by 307 differentially expressed peptide spots concurring with the active phase of production of penetrating hyphae. Additionally, C. lunatus differentially down-regulated StNPR1 transcript by 8.19 fold by 24 hai. This study is the first to elucidate that C. lunatus transiently down-regulates the expression of StNPR1 at the onset of infection, and as a whole, infection negatively affects the expression of proteome components involved in photosynthesis, carbon fixation and light assimilation. This study contributes towards better understanding of the mechanism underlining the invasion strategies of C. lunatus.

A cross-sectional study to assess any possible linkage of C/T polymorphism in CYP17A1 gene with insulin resistance in non-obese women with polycystic ovarian syndrome.

BACKGROUND & OBJECTIVES: Insulin resistance (IR) is a major confounding factor in polycystic ovarian syndrome (PCOS) irrespective of obesity. Its exact mechanism remains elusive till now. C/T polymorphism in the -34 promoter region of the CYP17 gene is inconsistently attributed to elucidate the mechanism of IR and its link to hyperandrogenemia in obese PCOS patients. In the present study we aimed to evaluate any association of this polymorphism with IR in non-obese women with PCOS. METHODS: Polymorphism study was performed by restriction fragment length polymorphism (RFLP) analysis of the Msp A1 digest of the PCR product of the target gene in 75 PCOS cases against 73 age and BMI matched control women. Serum testosterone, BMI and HOMA-IR (homeostatic model of assessment-insulin resistance) were analyzed by standard techniques. A realistic cut-off value for the HOMA-IR was obtained through receiver operating characteristic (ROC) curve for exploring any possible link between IR and T/C polymorphism in the case group. RESULTS: Significant increases in serum testosterone and HOMA-IR values were observed among the case group (P<0.001) without any significant elevation in BMI and FBG compared to controls. Cut-off value for IR in the PCOS patients was 1.40 against a maximum sensitivity of 0.83 and a minimum false positivity of 0.13. The analysis revealed an inconclusive link between the C/T polymorphic distribution and insulin resistant case subjects. INTERPRETATION & CONCLUSIONS: The results showed that CYP17A1 gene was not conclusively linked to either IR or its associated increased androgen secretion in non-obese women with PCOS. We propose that an increased sensitivity of insulin on the ovarian cells may be the predominant reason for the clinical effects and symptoms of androgen excess observed in non-obese PCOS patients in our region.

Genomic Potential of Stenotrophomonas maltophilia in Bioremediation with an Assessment of Its Multifaceted Role in Our Environment.

The gram negative bacterium Stenotrophomonas is rapidly evolving as a nosocomial pathogen in immuno-compromised patients. Treatment of Stenotrophomonas maltophilia infections is problematic because of their increasing resistance to multiple antibiotics. This article aims to review the multi-disciplinary role of Stenotrophomonas in our environment with special focus on their metabolic and genetic potential in relation to bioremediation and phytoremediation. Current and emerging treatments and diagnosis for patients infected with S. maltophilia are discussed besides their capability of production of novel bioactive compounds. The plant growth promoting characteristics of this bacterium has been considered with special reference to secondary metabolite production. Nano-particle synthesis by Stenotrophomonas has also been reviewed in addition to their applications as effective biocontrol agents in plant and animal pathogenesis.

First proteome study of sporadic flowering in bamboo species (Bambusa vulgaris and Dendrocalamus manipureanus) reveal the boom is associated with stress and mobile genetic elements.

Bamboo species are the fastest-growing plants having a long vegetative cycle. Abrupt switching from the vegetative phase to the reproductive phase via sporadic flowering boom, occasionally leads to death of bamboo clumps, and threatens the existence of many bamboo species. To apprehend the molecular mechanism driving sporadic flowering, proteome changes in the initial and advanced floral buds of two edible bamboo species (Bambusa vulgaris and Dendrocalamus manipureanus) was dissected by two-dimensional gel electrophoresis (2-DE). A total of 39 differentially expressed peptide spots were identified by matrix-assisted laser desorption ionization time-of-flight/time-of-flight mass spectrometry (MALDI-TOF-TOF/MS). In both B. vulgaris and D. manipureanus, identified proteins were categorized as transposon-related, defence and stress-related, cell cycle related, metabolism related, signal transduction related, and some lacked known putative domains. Proteins such as SEPALLATA3, ubiquitin, histone 3, thaumatin-like protein, putative tethering factor, SF-assemblin, polyubiquitin, mitochondrial carrier-like protein and RPT2-like protein were significantly expressed. Differences in D. manipureanus and B. vulgaris suggested that bamboo species have diverse 'drivers' or 'passengers' genes that govern natural sporadic flowering boom. This first floral proteomics analysis of bamboos revealed that sporadic boom is a highly energetic process, associated with stress elements, mobile genetic elements and signal transduction cross-talk elements.

Cochliobolus lunatus colonizes potato by adopting different invasion strategies on cultivars: New insights on temperature dependent-virulence.

Extreme temperature fluctuations affect the interaction dynamics of Cochliobolus lunatus through temperature-dependent virulence, virulence differentiation and induced-virulence which poses a major threat to global food security. The relationship between higher temperature and pathogenicity of C. lunatus on reported hosts are poorly understood. In this study, temperature stress was applied on C. lunatus to investigate the correlation among the different types of conidia. Additionally, a comparative dissection of the invasion process, infection structures and conidial germination pattern on four different Solanum tuberosum L. (potato) cultivars were performed. Based on microscopic examination, it was found that C. lunatus adopts different hyphae morphology and septation pattern at different temperature regimes and produce different types of conidia. The study showed that four-celled conidia are overproduced at elevated temperature (>30 °C) than one, two, three and five-celled conidia. Our finding revealed that C. lunatus conidia exhibit bipolar germination (>14.67%, P<0.05), unipolar germination (>35.33%, P<0.05), penetrate subcutaneously via epidermal anticlinal cell wall (>0.33%, P < 0.05) and differentially form appressoria-like structures during colonization of four different potato cultivars. Importantly, it is shown that unipolar germination and bipolar germination in C. lunatus are independently occurring phenomenon irrespective of the host. It is confirmed that C. lunatus adopt different but highly successful strategies on four different potato cultivars to incite brown-to-black leaf spot disease. Altogether, our data showed that increase in temperature enhances C. lunatus virulence on different potato cultivars irrespective of their inherent thermotolerant traits.

Host-range dynamics of Cochliobolus lunatus: from a biocontrol agent to a severe environmental threat.

We undertook an investigation to advance understanding of the host-range dynamics and biocontrol implications of Cochliobolus lunatus in the past decade. Potato (Solanum tuberosum L) farms were routinely surveyed for brown-to-black leaf spot disease caused by C. lunatus. A biphasic gene data set was assembled and databases were mined for reported hosts of C. lunatus in the last decade. The placement of five virulent strains of C. lunatus causing foliar necrosis of potato was studied with microscopic and phylogenetic tools. Analysis of morphology showed intraspecific variations in stromatic tissues among the virulent strains causing foliar necrosis of potato. A maximum likelihood inference based on GPDH locus separated C. lunatus strains into subclusters and revealed the emergence of unclustered strains. The evolving nutritional requirement of C. lunatus in the last decade is exhibited by the invasion of vertebrates, invertebrates, dicots, and monocots. Our results contribute towards a better understanding of the host-range dynamics of C. lunatus and provide useful implications on the threat posed to the environment when C. lunatus is used as a mycoherbicide.

Invasion of Solanum tuberosum L. by Aspergillus terreus: a microscopic and proteomics insight on pathogenicity.

BACKGROUND: Aspergillus terreus is one of the most harmful filamentous fungal pathogen of humans, animals and plants. Recently, researchers have discovered that A. terreus can cause foliar blight disease in potato (Solanum tuberosum L.). We used light and scanning electron microscopy, and performed proteomics analysis in an attempt to dissect the invasion process of A. terreus in this important crop. RESULTS: Microscopic study revealed that invasion of leaf tissue is marked by rapid germination of A. terreus phialidic conidia (PC) by 4 h after inoculation. By 8 h after inoculation, primary germ tubes from PC differentiated into irregular protuberance, often displayed stomata atropism, and failed to penetrate via the epidermal cells. Colonization of leaf tissues was associated with high rate of production of accessory conidia (AC). These analyses showed the occurrence of a unique opposing pattern of AC, tissue-specific and produced on melanized colonizing hyphae during the infection of leaf tissue. A significant proteome change hallmarked by differential expression of class I patatin, lipoxygenase, catalase-peroxidase complex, and cysteine proteinase inhibitor were observed during tuber colonization. These proteins are often involved in signal transduction pathways and crosstalk in pathogenic responses. CONCLUSION: A. terreus abundantly produced AC and multipolar germinating PC to invade potato leaf tissue. Additionally, A. terreus differentially induced enzymes in potato tuber during colonization which facilitates rapid disease development.

Secretome weaponries of Cochliobolus lunatus interacting with potato leaf at different temperature regimes reveal a CL[xxxx]LHM - motif.

BACKGROUND: Plant and animal pathogenic fungus Cochliobolus lunatus cause great economic damages worldwide every year. C. lunatus displays an increased temperature dependent-virulence to a wide range of hosts. Nonetheless, this phenomenon is poorly understood due to lack of insights on the coordinated secretome weaponries produced by C. lunatus under heat-stress conditions on putative hosts. To understand the mechanism better, we dissected the secretome of C. lunatus interacting with potato (Solanum tuberosum L.) leaf at different temperature regimes. RESULTS: C. lunatus produced melanized colonizing hyphae in and on potato leaf, finely modulated the ambient pH as a function of temperature and secreted diverse set of proteins. Using two dimensional gel electrophoresis (2-D) and mass spectrometry (MS) technology, we observed discrete secretomes at 20°C, 28°C and 38°C. A total of 21 differentially expressed peptide spots and 10 unique peptide spots (that did not align on the gels) matched with 28 unique protein models predicted from C. lunatus m118 v.2 genome peptides. Furthermore, C. lunatus secreted peptides via classical and non-classical pathways related to virulence, proteolysis, nucleic acid metabolism, carbohydrate metabolism, heat stress, signal trafficking and some with unidentified catalytic domains. CONCLUSIONS: We have identified a set of 5 soluble candidate effectors of unknown function from C. lunatus secretome weaponries against potato crop at different temperature regimes. Our findings demonstrate that C. lunatus has a repertoire of signature secretome which mediates thermo-pathogenicity and share a leucine rich "CL[xxxx]LHM"-motif. Considering the rapidly evolving temperature dependent-virulence and host diversity of C. lunatus, this data will be useful for designing new protection strategies.

Copper enhanced monooxygenase activity and FT-IR spectroscopic characterisation of biotransformation products in trichloroethylene degrading bacterium: Stenotrophomonas maltophilia PM102.

Stenotrophomonas maltophilia PM102 (NCBI GenBank Acc. no. JQ797560) is capable of growth on trichloroethylene as the sole carbon source. In this paper, we report the purification and characterisation of oxygenase present in the PM102 isolate. Enzyme activity was found to be induced 10.3-fold in presence of 0.7 mM copper with a further increment to 14.96-fold in presence of 0.05 mM NADH. Optimum temperature for oxygenase activity was recorded at 36°C. The reported enzyme was found to have enhanced activity at pH 5 and pH 8, indicating presence of two isoforms. Maximum activity was seen on incubation with benzene compared to other substrates like TCE, chloroform, toluene, hexane, and petroleum benzene. K(m) and V(max) for benzene were 3.8 mM and 340 U/mg/min and those for TCE were 2.1 mM and 170 U/mg/min. The crude enzyme was partially purified by ammonium sulphate precipitation followed by dialysis. Zymogram analysis revealed two isoforms in the 70% purified enzyme fraction. The activity stain was more prominent when the native gel was incubated in benzene as substrate in comparison to TCE. Crude enzyme and purified enzyme fractions were assayed for TCE degradation by the Fujiwara test. TCE biotransformation products were analysed by FT-IR spectroscopy.

Persistent organic pollutants induced protein expression and immunocrossreactivity by Stenotrophomonas maltophilia PM102: a prospective bioremediating candidate.

A novel bacterium capable of growth on trichloroethylene as the sole carbon source was identified as Stenotrophomonas maltophilia PM102 by 16S rDNA sequencing (accession number of NCBI GenBank: JQ797560). In this paper, we report the growth pattern, TCE degradation, and total proteome of this bacterium in presence of various other carbon sources: toluene, phenol, glucose, chloroform, and benzene. TCE degradation was comparatively enhanced in presence of benzene. Densitometric analysis of the intracellular protein profile revealed four proteins of 78.6, 35.14, 26.2, and 20.47 kDa while the extracellular protein profile revealed two distinct bands at 14 kDa and 11 kDa that were induced by TCE, benzene, toluene, and chloroform but absent in the glucose lane. A rabbit was immunised with the total protein extracted from the bacteria grown in 0.2% TCE + 0.2% peptone. Antibody preadsorbed on proteins from peptone grown PM102 cells reacted with a single protein of 35.14 kDa (analysed by MALDI-TOF-mass-spectrometry) from TCE, benzene, toluene, or chloroform grown cells. No reaction was seen for proteins of PM102 grown with glucose. The PM102 strain was immobilised in calcium alginate beads, and TCE degradation by immobilised cells was almost double of that by free cells. The beads could be reused 8 times.

Purification and identification of trichloroethylene induced proteins from Stenotrophomonas maltophilia PM102 by immuno-affinity-chromatography and MALDI-TOF Mass spectrometry.

A novel bacterial isolate capable of growth on trichloroethylene as the sole carbon source was identified as Stenotrophomonas maltophilia PM102 by 16S rDNA sequencing (GenBank Acc.no. JQ797560). Serum was obtained from a rabbit immunized with the total protein extracted from the PM102 isolate grown in 0.2% TCE with 0.2% peptone. Antibodies to the common antigens were removed by preadsorbing the serum antibody on total protein extracted from the PM102 strain grown in 0.2% peptone. Western blot with the preadsorbed antibody reacted to a single band in TCE and TCE with peptone lane. No reaction was seen in peptone lane. This preadsorbed antibody specific for TCE inducible antigens was immobilised on epoxy activated sepharose 6B and total protein from PM102 cells grown in minimal medium with TCE as the sole carbon source was purified through the column. The bound protein fraction was eluted and resolved through 12% SDS PAGE. Four prominent bands observed in the protein profile were analysed by matrix-assisted laser desorption/ionization time of flight-mass spectrometry (MS) and tandem mass spectrometry (MS/MS) after in gel digestion with 25 ng/µl trypsin. A number of mono/di-oxygenases that cometabolise TCE in presence of some other primary carbon source are present in literature but this is the first attempt in identification of TCE induced proteins linked to metabolic activity with oxidoreductase like function, from a bacterial isolate that utilises TCE as the sole carbon source.