scholarly journals Isolation and Screening of Thermophilic Bacilli from Compost for Electrotransformation and Fermentation: Characterization of Bacillus smithii ET 138 as a New Biocatalyst

2015 ◽  
Vol 81 (5) ◽  
pp. 1874-1883 ◽  
Author(s):  
Elleke F. Bosma ◽  
Antonius H. P. van de Weijer ◽  
Martinus J. A. Daas ◽  
John van der Oost ◽  
Willem M. de Vos ◽  
...  
Keyword(s):  
Organic Acids ◽  
Thermophilic Bacteria ◽  
Culture Collection ◽  
Content Type ◽  
Thermophilic Bacilli ◽  
Bacillus Smithii ◽  
Cost Efficient ◽  
Ph Range ◽  
Production Capacities ◽  
Green Chemicals

ABSTRACTThermophilic bacteria are regarded as attractive production organisms for cost-efficient conversion of renewable resources to green chemicals, but their genetic accessibility is a major bottleneck in developing them into versatile platform organisms. In this study, we aimed to isolate thermophilic, facultatively anaerobic bacilli that are genetically accessible and have potential as platform organisms. From compost, we isolated 267 strains that produced acids from C5and C6sugars at temperatures of 55°C or 65°C. Subsequently, 44 strains that showed the highest production of acids were screened for genetic accessibility by electroporation. TwoGeobacillus thermodenitrificansisolates and oneBacillus smithiiisolate were found to be transformable with plasmid pNW33n. Of these,B. smithiiET 138 was the best-performing strain in laboratory-scale fermentations and was capable of producing organic acids from glucose as well as from xylose. It is an acidotolerant strain able to produce organic acids until a lower limit of approximately pH 4.5. As genetic accessibility ofB. smithiihad not been described previously, six otherB. smithiistrains from the DSMZ culture collection were tested for electroporation efficiencies, and we found the type strain DSM 4216Tand strain DSM 460 to be transformable. The transformation protocol forB. smithiiisolate ET 138 was optimized to obtain approximately 5 × 103colonies per μg plasmid pNW33n. Genetic accessibility combined with robust acid production capacities on C5and C6sugars at a relatively broad pH range makeB. smithiiET 138 an attractive biocatalyst for the production of lactic acid and potentially other green chemicals.

scholarly journals A systematic review of the genera Geobacillus and Parageobacillus: their evolution, current taxonomic status and major applications

Microbiology ◽  
2020 ◽  
Vol 166 (9) ◽  
pp. 800-816
Author(s):  
Ishfaq Nabi Najar ◽  
Nagendra Thakur
Keyword(s):  
Hydrothermal Vents ◽  
Hot Springs ◽  
Thermophilic Bacteria ◽  
Taxonomic Status ◽  
Content Type ◽  
Cellular Fatty Acids ◽  
Link Type ◽  
Characteristic Features ◽  
Ph Range ◽  
Taxonomic Studies

The genus Geobacillus , belonging to the phylum Firmicutes, is one of the most important genera and comprises thermophilic bacteria. The genus Geobacillus was erected with the taxonomic reclassification of various Bacillus species. Taxonomic studies of Geobacillus remain in progress. However, there is no comprehensive review of the characteristic features, taxonomic status and study of various applications of this interesting genus. The main aim of this review is to give a comprehensive account of the genus Geobacillus . At present the genus acomprises 25 taxa, 14 validly published (with correct name), nine validly published (with synonyms) and two not validly published species. We describe only validly published species of the genera Geobacillus and Parageobacillus . Vegetative cells of Geobacillus species are Gram-strain-positive or -variable, rod-shaped, motile, endospore-forming, aerobic or facultatively anaerobic, obligately thermophilic and chemo-organotrophic. Growth occurs in the pH range 6.08.5 and a temperature of 37–75 °C. The major cellular fatty acids are iso-C15:o, iso-C16:0 and iso-C17:o. The main menaquinone type is MK-7. The G­+C content of the DNA ranges between 48.2 and 58 mol%. The genus Geobacillus is widely distributed in nature, being mostly found in many extreme locations such as hot springs, hydrothermal vents, marine trenches, hay composts, etc. Geobacillus species have been widely exploited in various industrial and biotechnological applications, and thus are promising candidates for further studies in the future.

scholarly journals Potentiating Effect of Mandelate and Lactate on Chemically Induced Germination in Members of Bacillus cereus Sensu Lato

2017 ◽  
Vol 83 (24) ◽  
Author(s):  
Alistair H. Bishop
Keyword(s):  
Bacillus Cereus ◽  
Large Scale ◽  
Germination Rate ◽  
Dependent Manner ◽  
Clostridium Sporogenes ◽  
Specific Chemical ◽  
Content Type ◽  
Ph Range ◽  
Significant Discovery ◽  
The Impact

ABSTRACT Endospores of the genus Bacillus can be triggered to germinate by a limited number of chemicals. Mandelate had powerful additive effects on the levels and rates of germination produced in non-heat-shocked spores of Bacillus anthracis strain Sterne, Bacillus cereus, and Bacillus thuringiensis when combined with l-alanine and inosine. Mandelate had no germinant effect on its own but was active with these germinants in a dose-dependent manner at concentrations higher than 0.5 mM. The maximum rate and extent of germination were produced in B. anthracis by 100 mM l-alanine with 10 mM inosine; this was equaled by just 25% of these germinants when supplemented with 10 mM mandelate. Half the maximal germination rate was produced by 40% of the optimum germinant concentrations or 15% of them when supplemented with 0.8 mM mandelate. Germination rates in B. thuringiensis were highest around neutrality, but the potentiating effect of mandelate was maintained over a wider pH range than was germination with l-alanine and inosine alone. For all species, lactate also promoted germination in the presence of l-alanine and inosine; this was further increased by mandelate. Ammonium ions also enhanced l-alanine- and inosine-induced germination but only when mandelate was present. In spite of the structural similarities, mandelate did not compete with phenylalanine as a germinant. Mandelate appeared to bind to spores while enhancing germination. There was no effect when mandelate was used in conjunction with nonnutrient germinants. No effect was produced with spores of Bacillus subtilis, Clostridium sporogenes, or C. difficile. IMPORTANCE The number of chemicals that can induce germination in the species related to Bacillus cereus has been defined for many years, and they conform to specific chemical types. Although not a germinant itself, mandelate has a structure that is different from these germination-active compounds, and its addition to this list represents a significant discovery in the fundamental biology of spore germination. This novel activity may also have important applied relevance given the impact of spores of B. cereus in foodborne disease and B. anthracis as a threat agent. The destruction of spores of B. anthracis, for example, particularly over large outdoor areas, poses significant scientific and logistical problems. The addition of mandelate and lactate to the established mixtures of l-alanine and inosine would decrease the amount of the established germinants required and increase the speed and level of germination achieved. The large-scale application of “germinate to decontaminate” strategy may thus become more practicable.

Litorilinea aerophila gen. nov., sp. nov., an aerobic member of the class Caldilineae , phylum Chloroflexi , isolated from an intertidal hot spring

2013 ◽  
Vol 63 (Pt_3) ◽  
pp. 1149-1154 ◽  
Author(s):  
Varsha Kale ◽  
Snædís H. Björnsdóttir ◽  
Ólafur H. Friðjónsson ◽  
Sólveig K. Pétursdóttir ◽  
Sesselja Ómarsdóttir ◽  
...  
Keyword(s):  
Type Species ◽  
Hot Spring ◽  
Sequence Similarity ◽  
Rrna Gene ◽  
Content Type ◽  
Phenotypic Differences ◽  
Link Type ◽  
Fermentative Growth ◽  
Distinct Lineage ◽  
Ph Range

A thermophilic, aerobic, Gram-stain-negative, filamentous bacterium, strain PRI-4131T, was isolated from an intertidal hot spring in Isafjardardjup, NW Iceland. The strain grew chemo-organotrophically on various carbohydrates. The temperature range for growth was 40–65 °C (optimum 55 °C), the pH range was pH 6.5–9.0 (optimum pH 7.0) and the NaCl range was 0–3 % (w/v) (optimum 0.5 %). Phylogenetic analysis based on 16S rRNA gene sequences revealed that strain PRI-4131T represented a distinct lineage within the class Caldilineae of the phylum Chloroflexi. The highest levels of sequence similarity, about 91 %, were with Caldilinea aerophila STL-6-O1T and Caldilinea tarbellica D1-25-10-4T. Fermentative growth was not observed for strain PRI-4131T, which, in addition to other characteristics, distinguished it from the two Caldilinea species. Owing to both phylogenetic and phenotypic differences from the described members of the class Caldilineae , we propose to accommodate strain PRI-4131T in a novel species in a new genus, Litorilinea aerophila gen. nov., sp. nov. The type strain of Litorilinea aerophila is PRI-4131T ( = DSM 25763T  = ATCC BAA-2444T).

scholarly journals Influence of Cations on Growth of Thermophilic Geobacillus spp. and Anoxybacillus flavithermus in Planktonic Culture

2012 ◽  
Vol 78 (7) ◽  
pp. 2477-2481 ◽  
Author(s):  
Ben Somerton ◽  
Jon Palmer ◽  
John Brooks ◽  
Edward Smolinski ◽  
Denise Lindsay ◽  
...  
Keyword(s):  
Optical Density ◽  
Milk Powder ◽  
Manufacturing Plant ◽  
Planktonic Culture ◽  
Content Type ◽  
Free Ions ◽  
Thermophilic Bacilli ◽  
Anoxybacillus Flavithermus ◽  
Powder Manufacturing

ABSTRACTFree ions of Na+, K+, Ca2+, and Mg2+influenced the optical density of planktonic cultures of thermophilic bacilli.Anoxybacillus flavithermusE16 andGeobacillussp. strain F75 (milk powder manufacturing plant isolates) andA. flavithermusDSM 2641 andG. thermoleovoransDSM 5366 were studied. Ca2+and Mg2+were associated with increases in optical density more so than Na+and K+. Overall, it appeared that Ca2+and/or Mg2+was required for the production of protein in thermophilic bacilli, as shown by results obtained withA. flavithermusE16, which was selected for further study.

Banking market structure and efficiency: an assessment of the USA and Canada

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Salah U-Din ◽  
David Tripe
Keyword(s):  
Market Structure ◽  
Market Power ◽  
Negative Impact ◽  
Positive Impact ◽  
Bank Efficiency ◽  
Content Type ◽  
Frontier Analysis ◽  
Banking Market ◽  
Cost Efficient ◽  
The Impact

PurposeThe study aims to analyze the changes in banking market structure and their impact on the bank efficiency.Design/methodology/approachThis study uses a one-stage stochastic frontier analysis (SFA) to compare the impact of the market structure and the GFC on the economic efficiency of the major banks in both countries.FindingsA significant negative impact of the GFC is observed on bank efficiency. Overall, Canadian banks posted better efficiency scores than their American counterparts. Additionally, cost-efficient banks are found to be more resilient to crises and more profit-efficient in the post-GFC period. The authors found that market power had a positive impact on the cost and profit efficiency of banks. Higher levels of equity, market power and concentration helped banks be more cost-efficient.Research limitations/implicationsOnly large banks are selected for study although it represents the majority stake of both banking sectors.Practical implicationsBanking regulators should include more measures to assess the banking market structure and performance.Originality/valueAs per the best knowledge of the authors, it is the first study to assess the change in banking market structure and efficiency of the US and Canadian banking sectors in the post-GFC period.

Rhizobium paknamense sp. nov., isolated from lesser duckweeds (Lemna aequinoctialis)

2013 ◽  
Vol 63 (Pt_10) ◽  
pp. 3823-3828 ◽  
Author(s):  
Chokchai Kittiwongwattana ◽  
Chitti Thawai
Keyword(s):  
Dna Hybridization ◽  
Type Species ◽  
Sequence Similarity ◽  
Housekeeping Genes ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Low Levels ◽  
Sequence Similarity Analysis ◽  
Ph Range

A Gram-stain-negative, rod-shaped bacterium was isolated and designated strain L6-8T during a study of endophytic bacterial communities in lesser duckweed (Lemna aequinoctialis). Cells of strain L6-8T were motile with peritrichous flagella. The analysis of the nearly complete 16S rRNA gene sequence indicated that strain L6-8T was phylogenetically related to species of the genus Rhizobium . Its closest relatives were Rhizobium borbori DN316T (97.6 %), Rhizobium oryzae Alt 505T (97.3 %) and Rhizobium pseudoryzae J3-A127T (97.0 %). The sequence similarity analysis of housekeeping genes recA, glnII, atpD and gyrB showed low levels of sequence similarity (<91.5 %) between strain L6-8T and other species of the genus Rhizobium with validly published names. The pH range for growth was 4.0–9.0 (optimum 6.0–7.0), and the temperature range for growth was 20–45 °C (optimum 30 °C). Strain L6-8T tolerated NaCl up to 2 % (w/v) (optimum 1 % NaCl). The predominant components of cellular fatty acids were C19 : 0 cyclo ω8c (31.32 %), summed feature 8 (C18 : 1ω7c and/or C18 : 1ω6c; 25.39 %) and C16 : 0 (12.03 %). The DNA G+C content of strain L6-8T was 60.4 mol% (T m). nodC and nifH were not amplified in strain L6-8T. DNA–DNA relatedness between strain L6-8T and R. borbori DN316T, R. oryzae Alt505T and R. pseudoryzae J3-A127T was between 11.2 and 18.3 %. Based on the sequence similarity analyses, phenotypic, biochemical and physiological characteristics and DNA–DNA hybridization, strain L6-8T could be readily distinguished from its closest relatives and represents a novel species of the genus Rhizobium , for which the name Rhizobium paknamense sp. nov. is proposed. The type strain is L6-8T ( = NBRC 109338T = BCC 55142T).

scholarly journals Essential Roles of thesppRAFructose-Phosphate Phosphohydrolase Operon in Carbohydrate Metabolism and Virulence Expression byStreptococcus mutans

2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Lin Zeng ◽  
Robert A. Burne
Keyword(s):  
Dental Caries ◽  
Organic Acids ◽  
Streptococcus Mutans ◽  
Biochemical Characterization ◽  
Constitutive Expression ◽  
Extracellular Dna ◽  
Tooth Surface ◽  
Oral Diseases ◽  
Sugar Phosphate ◽  
Content Type

ABSTRACTThe dental caries pathogenStreptococcus mutanscan ferment a variety of sugars to produce organic acids. Exposure ofS. mutansto certain nonmetabolizable carbohydrates, such as xylitol, impairs growth and can cause cell death. Recently, the presence of a sugar-phosphate stress inS. mutanswas demonstrated using a mutant lacking 1-phosphofructokinase (FruK) that accumulates fructose-1-phosphate (F-1-P). Here, we studied an operon inS. mutans,sppRA, which was highly expressed in thefruKmutant. Biochemical characterization of a recombinant SppA protein indicated that it possessed hexose-phosphate phosphohydrolase activity, with preferences for F-1-P and, to a lesser degree, fructose-6-phosphate (F-6-P). SppA activity was stimulated by Mg2+and Mn2+but inhibited by NaF. SppR, a DeoR family regulator, repressed the expression of thesppRAoperon to minimum levels in the absence of the fructose-derived metabolite F-1-P and likely also F-6-P. The accumulation of F-1-P, as a result of growth on fructose, not only inducedsppAexpression, but it significantly altered biofilm maturation through increased cell lysis and enhanced extracellular DNA release. Constitutive expression ofsppA, via a plasmid or by deletingsppR, greatly alleviated fructose-induced stress in afruKmutant, enhanced resistance to xylitol, and reversed the effects of fructose on biofilm formation. Finally, by identifying three additional putative phosphatases that are capable of promoting sugar-phosphate tolerance, we show thatS. mutansis capable of mounting a sugar-phosphate stress response by modulating the levels of certain glycolytic intermediates, functions that are interconnected with the ability of the organism to manifest key virulence behaviors.IMPORTANCEStreptococcus mutansis a major etiologic agent for dental caries, primarily due to its ability to form biofilms on the tooth surface and to convert carbohydrates into organic acids. We have discovered a two-gene operon inS. mutansthat regulates fructose metabolism by controlling the levels of fructose-1-phosphate, a potential signaling compound that affects bacterial behaviors. With fructose becoming increasingly common and abundant in the human diet, we reveal the ways that fructose may alter bacterial development, stress tolerance, and microbial ecology in the oral cavity to promote oral diseases.

Kallotenue papyrolyticum gen. nov., sp. nov., a cellulolytic and filamentous thermophile that represents a novel lineage (Kallotenuales ord. nov., Kallotenuaceae fam. nov.) within the class Chloroflexia

2013 ◽  
Vol 63 (Pt_12) ◽  
pp. 4675-4682 ◽  
Author(s):  
Jessica K. Cole ◽  
Brandon A. Gieler ◽  
Devon L. Heisler ◽  
Maryknoll M. Palisoc ◽  
Amanda J. Williams ◽  
...  
Keyword(s):  
Carbon Sources ◽  
Rrna Gene ◽  
Bacterial Strains ◽  
16S Rrna Gene Sequences ◽  
Content Type ◽  
Link Type ◽  
Casamino Acids ◽  
Ph Range ◽  
Dense Liquid ◽  
Cellulose Filter

Several closely related, thermophilic and cellulolytic bacterial strains, designated JKG1T, JKG2, JKG3, JKG4 and JKG5, were isolated from a cellulolytic enrichment (corn stover) incubated in the water column of Great Boiling Spring, NV. Strain JKG1T had cells of diameter 0.7–0.9 µm and length ~2.0 µm that formed non-branched, multicellular filaments reaching >300 µm. Spores were not formed and dense liquid cultures were red. The temperature range for growth was 45–65 °C, with an optimum of 55 °C. The pH range for growth was pH 5.6–9.0, with an optimum of pH 7.5. JKG1T grew as an aerobic heterotroph, utilizing glucose, sucrose, xylose, arabinose, cellobiose, CM-cellulose, filter paper, microcrystalline cellulose, xylan, starch, Casamino acids, tryptone, peptone, yeast extract, acetate, citrate, lactate, pyruvate and glycerol as sole carbon sources, and was not observed to photosynthesize. The cells stained Gram-negative. Phylogenetic analysis using 16S rRNA gene sequences placed the new isolates in the class Chloroflexia , but distant from other cultivated members, with the highest sequence identity of 82.5 % to Roseiflexus castenholzii . The major quinone was menaquinone-9; no ubiquinones were detected. The major cellular fatty acids (>5 %) were C18 : 0, anteiso-C17 : 0, iso-C18 : 0, iso-C17 : 0, C16 : 0, iso-C16 : 0 and C17 : 0. The peptidoglycan amino acids were alanine, ornithine, glutamic acid, serine and asparagine. Whole-cell sugars included mannose, rhamnose, glucose, galactose, ribose, arabinose and xylose. Morphological, phylogenetic and chemotaxonomic results suggest that JKG1T is representative of a new lineage within the class Chloroflexia , which we propose to designate Kallotenue papyrolyticum gen. nov., sp. nov., Kallotenuaceae fam. nov., Kallotenuales ord. nov. The type strain of Kallotenue papyrolyticum gen. nov., sp. nov. is JKG1T ( = DSM 26889T = JCM 19132T).

The Islamic gold dinar: a hedge against exchange rate volatility

2018 ◽  
Vol 44 (6) ◽  
pp. 722-738 ◽  
Author(s):  
Calvin W.H. Cheong
Keyword(s):  
Management Practices ◽  
Exchange Rate Volatility ◽  
Cost Effective ◽  
Market Volatility ◽  
Content Type ◽  
Sample Country ◽  
Islamic Financial Institutions ◽  
Cost Efficient ◽  
Lower Magnitude ◽  
First Time

Purpose The purpose of this paper is to investigate the ability of the Islamic gold dinar to hedge against two well-established foreign exchange (FX) risk factors namely, the dollar risk factor and global FX volatility innovations. Design/methodology/approach The paper uses a combination of the Markowitz (1952) portfolio optimization, visual data representations and the classic Fama-Macbeth (1973) two-pass procedure regressions. Findings The findings show that the Islamic gold dinar can serve as a hedge against market volatility, outperforms a diversified currency portfolio, and through its inclusions into the diversified currency portfolio, improve said portfolio’s ability to hedge against market volatility. Research limitations/implications Due to the spread of the sample, country-specific factors could not be taken into account. Practical implications The Islamic gold dinar is a cost-efficient, cost-effective, and Shariah-compliant instrument that provides a solid hedge for investors and/or firms that have financial positions denominated in foreign currencies. Should these investors or firms find it costly to maintain a dinar-only portfolio, including the dinar into their currency portfolios also provides the same benefit, albeit at a lower magnitude. Originality/value This study is timely as the Accounting and Auditing Organization for Islamic Financial Institutions has recently for the first time recognized gold as a Shariah-compliant investment. The findings of this study provide the first look as to how investors and firms can benefit through the use of the Islamic gold dinar in their risk management practices.

A multi-objective approach to design strategic supply chains and develop responsiveness- efficiency frontiers

2018 ◽  
Vol 29 (1) ◽  
pp. 365-386 ◽  
Author(s):  
Raed AlHusain ◽  
Reza Khorramshahgol
Keyword(s):  
Supply Chain ◽  
Integer Programming ◽  
Programming Model ◽  
Efficient Frontier ◽  
Decision Makers ◽  
Binary Integer Programming ◽  
Content Type ◽  
Strategic Fit ◽  
Cost Efficient ◽  
Alternative Solutions

Purpose The purpose of this paper is twofold. Initially, a multi-objective binary integer programming model is proposed for designing an appropriate supply chain that takes into consideration both responsiveness and efficiency. Then, a responsiveness-cost efficient frontier is generated for the supply chain design that can help organizations find the right balance between responsiveness and efficiency, and hence achieve a strategic fit between organizational strategy and supply chain capabilities. Design/methodology/approach The proposed SC design model used both cross-functional and logistical SC drivers to build a binary integer programming model. To this end, various alternative solutions that correspond to different SC design portfolios were generated and a responsiveness-cost efficient frontier was constructed. Findings Various alternative solutions that correspond to different SC designs were generated and a responsiveness-cost efficient frontier was constructed to help the decision makers to design SC portfolios to achieve a strategic fit between organizational strategy and SC capabilities. Practical implications The proposed methodology enables the decision makers to incorporate both qualitative and quantitative judgements in SC design. The methodology is easy to use and it can be readily implemented by a software. Originality/value The proposed methodology allows for subjective value judgements of the decision makers to be considered in SC design and the efficiency-responsiveness frontier generated by the methodology provides a trade-off to be used when choosing between speed and cost efficiency in SC design.

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