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Extremophiles : Life Under Extreme... May 2018A psychrophilic extracellular protease was isolated from the marine bacterium Planococcus sp. M7 found in the deep-sea mud of the Southern Indian Ocean. The mature...
A psychrophilic extracellular protease was isolated from the marine bacterium Planococcus sp. M7 found in the deep-sea mud of the Southern Indian Ocean. The mature protease is about 43 kDa and contains 389 amino acids. Sequence alignment revealed that the protease whose catalytic triad was comprised of Ser224, Lys249, and Gln253 contains a catalytic module belonging to the serralysin-type protease family 41, and displays 46.55% identity with the experimentally verified serine protease from Bacillus subtilis str. 168. The enzyme displayed an alkaline mesophilic preference with an optimum pH of 10.0 and an optimum temperature of 35 °C. The enzyme retained its activity from 5 to 35 °C and was resistant to repeated freezing and thawing, but was completely inactivated at 55 °C. Calcium ions had a protective effect against thermal denaturation. More than 60% of the maximum activity was retained at pH values in the range of 5.0-11.0. Almost no activity loss was detected after 1 h of incubation at pH 8.0-10.0 and 20 °C, or with 1.0% SDS. Most important, this protease also showed good stability and compatibility with the standard enzyme-free detergent, which indicates its special interest for applications in detergent industry.
Topics: Bacterial Proteins; Enzyme Stability; Freezing; Peptide Hydrolases; Planococcus Bacteria; Protein Denaturation
PubMed: 29497843
DOI: 10.1007/s00792-018-1010-2 -
Life (Basel, Switzerland) Jan 2021(1) Background: Future missions to potentially habitable places in the Solar System require biochemistry-independent methods for detecting potential alien life forms....
(1) Background: Future missions to potentially habitable places in the Solar System require biochemistry-independent methods for detecting potential alien life forms. The technology was not advanced enough for onboard machine analysis of microscopic observations to be performed in past missions, but recent increases in computational power make the use of automated in-situ analyses feasible. (2) Methods: Here, we present a semi-automated experimental setup, capable of distinguishing the movement of abiotic particles due to Brownian motion from the motility behavior of the bacteria . Supervised machine learning algorithms were also used to specifically identify these species based on their characteristic motility behavior. (3) Results: While we were able to distinguish microbial motility from the abiotic movements due to Brownian motion with an accuracy exceeding 99%, the accuracy of the automated identification rates for the selected species does not exceed 82%. (4) Conclusions: Motility is an excellent biosignature, which can be used as a tool for upcoming life-detection missions. This study serves as the basis for the further development of a microscopic life recognition system for upcoming missions to Mars or the ocean worlds of the outer Solar System.
PubMed: 33445805
DOI: 10.3390/life11010044 -
The Science of the Total Environment Apr 2020The response mechanism of wastewater treatment biofilms to salt stress has not yet been fully established. The aim of this study was to reveal the comprehensive...
The response mechanism of wastewater treatment biofilms to salt stress has not yet been fully established. The aim of this study was to reveal the comprehensive biological effects of salinity on biofilm microbial community and metabonomic characteristics. The study assessed performance at a range of sodium chloride (NaCl) concentrations of 0.6, 14 and 20 g/L. Biofilm coverage rate decreased significantly with increasing NaCl concentrations. High NaCl concentrations resulted in more compact and smoother biofilm morphologies. NaCl concentrations affected bacterial community variation at the class and genus level, with Gammaproteobacteria being the most dominant Proteobacteria, exhibiting NaCl tolerance at concentrations ranging from 0 to 20 g/L. Also, NaCl sensitive or tolerant species were identified, such as Pseudomonas and Planococcus, respectively. Dominant metabolites in wastewater treatment biofilms belonging to nucleotide, lipid, vitamin, amino acid and carbohydrate metabolism pathways decreased with increasing NaCl concentrations. High concentrations of NaCl regulated cell motility, transcription and membrane transport functions. In particular, the activity of ABC transporters were up-regulated at NaCl concentrations of 0.6 g/L and down-regulated at higher salinity concentrations. In addition, transcription machinery were inhibited under the stress of 14 g/L NaCl. These findings further our understanding of the short-term adaption mechanisms of wastewater treatment biofilms to high NaCl concentration environments.
Topics: Bacteria; Biofilms; Microbiota; Salinity; Wastewater
PubMed: 31812393
DOI: 10.1016/j.scitotenv.2019.134437 -
Current Microbiology Oct 2016Several reports have highlighted that many plant growth-promoting endophytic bacteria (PGPE) can assist their host plants in coping with various biotic and abiotic...
Several reports have highlighted that many plant growth-promoting endophytic bacteria (PGPE) can assist their host plants in coping with various biotic and abiotic stresses. However, information about the PGPE colonizing in the halophytes is still scarce. This study was designed to isolate and characterize PGPE from salt-accumulating halophyte Salicornia europaea grown under extreme salinity and to evaluate in vitro the bacterial mechanisms related to plant growth promotion. A total of 105 isolates were obtained from the surface-sterilized roots, stems, and assimilation twigs of S. europaea. Thirty-two isolates were initially selected for their ability to produce 1-aminocyclopropane-1-carboxylate deaminase as well as other properties such as production of indole-3-acetic acid and phosphate-solubilizing activities. The 16S rRNA gene-sequencing analysis revealed that these isolates belong to 13 different genera and 19 bacterial species. For these 32 strains, seed germination and seedling growth in axenically grown S. europaea seedlings at different NaCl concentrations (50-500 mM) were quantified. Five isolates possessing significant stimulation of the host plant growth were obtained. The five isolates were identified as Bacillus endophyticus, Bacillus tequilensis, Planococcus rifietoensis, Variovorax paradoxus, and Arthrobacter agilis. All the five strains could colonize and can be reisolated from the host plant interior tissues. These results demonstrate that habitat-adapted PGPE isolated from halophyte could enhance plant growth under saline stress conditions.
Topics: Bacteria; Chenopodiaceae; Endophytes; Indoleacetic Acids; Plant Growth Regulators; Plant Roots; Salt-Tolerant Plants; Sodium Chloride
PubMed: 27447799
DOI: 10.1007/s00284-016-1096-7 -
Huan Jing Ke Xue= Huanjing Kexue Sep 2014This research used batch soil column experiment to study the effects of irrigating with reclaimed water and tap water on the soil chemical properties and culturable...
This research used batch soil column experiment to study the effects of irrigating with reclaimed water and tap water on the soil chemical properties and culturable microorganisms. The results indicated that reclaimed water could markedly increase the soil organic material (OM) and total nitrogen (TN) content, but it had no obvious effect on total phosphorus (TP), available phosphorus (AP) and pH value. Reclaimed water irrigation could significantly enhance the amounts of surface soil bacteria and actinomycetes at a depth of 0-20 cm, but it had little effect on the biomass of 20-40 cm and 40-60 cm soil layers. The dominant bacteria in tap water irrigation area was the genus Bacillus whereas that of reclaimed water irrigation area was the genus Acinetobacter. Tap water irrigation area had four endemic genera and reclaimed water irrigation area had six endemic genera. Reclaimed water had no obvious effect on the microbial community Shannon diversity of 0-20 cm soil layer, while it decreased Pielou evenness index, and improved Margalef richness index. Through SPSS 17. 0 correlation analysis between soil microbes quantity and soil chemical properties, it was shown that the soil microbes quantity was positively correlated with OM, TN, TP and AP, but negatively correlated with soil water content (SWC) and pH value. Based on CANOCO 4.5 detrended correspondence analysis (DCA) and redundancy analysis (RDA) between soil microbes species and soil chemical properties, it was shown that AP had the strongest correlation with the microbial community (P = 0.002). TN and TP had larger impact on Streptococcus, Aeromonas and Neisseria. OM and AP had larger impact on Aerococcus, Planococcus and Halobacterium.
Topics: Agricultural Irrigation; Biomass; Environmental Monitoring; Nitrogen; Phosphorus; Soil; Soil Microbiology; Soil Pollutants; Wastewater
PubMed: 25518681
DOI: No ID Found -
Frontiers in Microbiology 2015Many insect species establish mutualistic symbiosis with intracellular bacteria that complement their unbalanced diets. The betaproteobacterium "Candidatus Tremblaya"...
Many insect species establish mutualistic symbiosis with intracellular bacteria that complement their unbalanced diets. The betaproteobacterium "Candidatus Tremblaya" maintains an ancient symbiosis with mealybugs (Hemiptera: Pseudococcidae), which are classified in subfamilies Phenacoccinae and Pseudococcinae. Most Phenacoccinae mealybugs have "Candidatus Tremblaya phenacola" as their unique endosymbiont, while most Pseudococcinae mealybugs show a nested symbiosis (a bacterial symbiont placed inside another one) where every "Candidatus Tremblaya princeps" cell harbors several cells of a gammaproteobacterium. Genomic characterization of the endosymbiotic consortium from Planococcus citri, composed by "Ca. Tremblaya princeps" and "Candidatus Moranella endobia," unveiled several atypical features of the former's genome, including the concerted evolution of paralogous loci. Its comparison with the genome of "Ca. Tremblaya phenacola" PAVE, single endosymbiont of Phenacoccus avenae, suggests that the atypical reductive evolution of "Ca. Tremblaya princeps" could be linked to the acquisition of "Ca. Moranella endobia," which possess an almost complete set of genes encoding proteins involved in homologous recombination. In order to test this hypothesis, we performed comparative genomics between "Ca. Tremblaya phenacola" and "Ca. Tremblaya princeps" and searched for the co-occurrence of concerted evolution and homologous recombination genes in endosymbiotic consortia from four unexplored mealybug species, Dysmicoccus boninsis, Planococcus ficus, Pseudococcus longispinus, and Pseudococcus viburni. Our results support a link between concerted evolution and nested endosymbiosis.
PubMed: 26161080
DOI: 10.3389/fmicb.2015.00642 -
Journal of Industrial Microbiology &... Jun 2017A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from...
A recently developed rapid co-composting of oil palm empty fruit bunch (OPEFB) and palm oil mill effluent (POME) anaerobic sludge is beginning to attract attention from the palm oil industry in managing the disposal of these wastes. However, a deeper understanding of microbial diversity is required for the sustainable practice of the co-compositing process. In this study, an in-depth assessment of bacterial community succession at different stages of the pilot scale co-composting of OPEFB-POME anaerobic sludge was performed using 454-pyrosequencing, which was then correlated with the changes of physicochemical properties including temperature, oxygen level and moisture content. Approximately 58,122 of 16S rRNA gene amplicons with more than 500 operational taxonomy units (OTUs) were obtained. Alpha diversity and principal component analysis (PCoA) indicated that bacterial diversity and distributions were most influenced by the physicochemical properties of the co-composting stages, which showed remarkable shifts of dominant species throughout the process. Species related to Devosia yakushimensis and Desemzia incerta are shown to emerge as dominant bacteria in the thermophilic stage, while Planococcus rifietoensis correlated best with the later stage of co-composting. This study proved the bacterial community shifts in the co-composting stages corresponded with the changes of the physicochemical properties, and may, therefore, be useful in monitoring the progress of co-composting and compost maturity.
Topics: Bacteria; Biodiversity; Composting; Fruit; Industrial Waste; Palm Oil; RNA, Ribosomal, 16S; Sewage
PubMed: 28197796
DOI: 10.1007/s10295-017-1916-1 -
Standards in Genomic Sciences 2018Y42, isolated from the petroleum-contaminated soil of the Qaidam Basin, can use crude oil as its sole source of carbon and energy at 20 °C. The genome of strain Y42...
Y42, isolated from the petroleum-contaminated soil of the Qaidam Basin, can use crude oil as its sole source of carbon and energy at 20 °C. The genome of strain Y42 has been sequenced to provide information on its properties. Genomic analysis shows that the genome of strain Y42 contains one circular DNA chromosome with a size of 3,718,896 bp and a GC content of 48.8%, and three plasmids (329,482; 89,073; and 12,282 bp). Although the strain Y42 did not show a remarkably higher ability in degrading crude oil than other oil-degrading bacteria, the existence of strain Y42 played a significant role to reducing the overall environmental impact as an indigenous oil-degrading bacterium. In addition, genome annotation revealed that strain Y42 has many genes responsible for hydrocarbon degradation. Structural features of the genomes might provide a competitive edge for strain Y42 to survive in oil-polluted environments and be worthy of further study in oil degradation for the recovery of crude oil-polluted environments.
PubMed: 30338026
DOI: 10.1186/s40793-018-0328-9 -
IET Nanobiotechnology Aug 2018Here, extracellular synthesis of silver nanoparticles (AgNPs) was carried out by strain BGCC-51 isolated from dye industry effluent soil. The microbes were isolated,...
Here, extracellular synthesis of silver nanoparticles (AgNPs) was carried out by strain BGCC-51 isolated from dye industry effluent soil. The microbes were isolated, screened, and characterised by molecular analysis (accession number KX776160). The optimisation of synthesis of AgNPs to determine the optimum substrate level (1-5 mM), pH (5-9), and temperature (25-55°C) were further carried out. strain BGCC-51 gave best yield of AgNPs at substrate concentration 5 mM, pH 8, and at 35°C. Synthesised AgNPs were characterised by scanning electron microscope and high-resolution transmission electron microscope. The size of synthesised AgNPs was in the range of 20-40 nm having spherical morphology. The AgNPs were found to show antimicrobial activity against bacteria such as (ATCC 25922), (ATCC 27853), and (ATCC 29213).
Topics: Biotechnology; Coloring Agents; Extracellular Space; Metal Nanoparticles; Oxidation-Reduction; Planococcaceae; Silver; Soil Microbiology; Textile Industry
PubMed: 30095422
DOI: 10.1049/iet-nbt.2017.0251 -
Bioresource Technology Jan 2015The present study investigates the impacts of phase separated disintegration through CaCl2 (calcium chloride) mediated biosurfactant producing bacterial pretreatment. In...
The present study investigates the impacts of phase separated disintegration through CaCl2 (calcium chloride) mediated biosurfactant producing bacterial pretreatment. In the initial phase of the study, the flocs were disintegrated (deflocculation) with 0.06g/gSS of CaCl2. In the subsequent phase, the sludge biomass was disintegrated (cell disintegration) through potent biosurfactant producing new novel bacteria, Planococcus jake 01. The pretreatment showed that suspended solids reduction and chemical oxygen demand solubilization for deflocculated - bacterially pretreated sludge was found to be 17.14% and 14.14% which were comparatively higher than flocculated sludge (treated with bacteria alone). The biogas yield potential of deflocculated - bacterially pretreated, flocculated, and control sludges were observed to be 0.322(L/gVS), 0.225(L/gVS) and 0.145(L/gVS) respectively. To our knowledge, this is the first study to present the thorough knowledge of biogas production potential through a novel phase separated biosurfactant bacterial pretreatment.
Topics: Anaerobiosis; Biodegradation, Environmental; Biofuels; Biological Oxygen Demand Analysis; Biomass; Biotechnology; Calcium Chloride; Flocculation; Planococcus Bacteria; Sewage; Surface-Active Agents; Waste Disposal, Fluid
PubMed: 25459848
DOI: 10.1016/j.biortech.2014.10.122