К пробиотикам относят «живые микроорганизмы, которые при введении в адекватных количествах оказывают положительное влияние на здоровье хозяина» [1]. В то время как применению некоторых из них (Lactobacillus, Bifidobacterium) было уделено много внимания, другие были изучены позже, и их важное лечебное действие становится ясным только сейчас. Одним из пробиотиков является грамположительная палочка Bacillus subtilis (B.subtilis). Большинство бактерий рода Bacillus (включая B.subtilis) не опасны для человека и широко распространены в окружающей среде. Их обнаруживают в почве, воде, воздухе и пищевых продуктах (пшеница, другие зерновые культуры, хлебобулочные изделия, соевые продукты, цельное мясо, сырое и пастеризованное молоко). Как следствие, они постоянно попадают в желудочно-кишечный тракт и дыхательные пути, засевая эти отделы. Количество бацилл в кишечнике может достигать 10 КОЕ/г, что сравнимо с аналогичным показателем у Lactobacillus. В связи с этим ряд исследователей рассматривают бактерии рода Bacillus как один из доминирующих компонентов нормальной микрофлоры кишечника [2]. В то же время лечебное введение B.subtilis позволяет использовать данный микроорганизм в качестве пробиотика по четырем основным направлениям: 1) для защиты от кишечных патогенов; 2) от дыхательных патогенов; 3) для устранения дисбактериоза при антибиотикотерапии; 4) для усиления переваривания и продвижения пищи. Упрощенная схема пробиотической активности B.subtilis при патологии желудочнокишечного тракта представлена на рис. 1. Таким образом, в научных работах последних десятилетий были сделаны значительные продвижения в выяснении спектра пробиотической активности B.subtilis, что делает данную бактерию одним из наиболее привлекательных пробиотиков для медицинского применения. В настоящем обзоре мы представляем данные соответствующих экспериментальных и клинических исследований, позволяющих составить впечатление о терапевтическом потенциале B.subtilis. УДК 615.331:579.852.1

Bacillus subtilis. (Book Reviews: The Molecular Biology of the Bacilli; Molecular Cloning and Gene Regulation in Bacilli)

As a class of thermal energy-storage materials, phase change materials (PCMs) play an important role in sustainable development of economy and society with a rapid increase in energy demand. Microencapsulation of solid–liquid PCMs has been recognized as a vital technology to protect them from leakage and running off and to give them a shape stability in the liquid state to offer the ease of handling and thus received tremendous attention from fundamental studies to industrial development in recent decades. Aiming to provide the most complete and reliable source of information on recent progress and current development in microencapsulated PCMs, this review focuses on methodologies and technologies for the encapsulation of PCMs with a variety of wall materials from traditional organic polymers to novel inorganic materials to pursue high encapsulation efficiency, excellent thermal energy-storage performance and long-term operation durability. We attempt to clearly summarize the selection of core and wall materials, synthetic methods, formation mechanisms and characteristic performance of microencapsulated PCMs to help scientists better understand their design principles and synthetic mechanisms. This review also highlights the diverse design of bi- and multi-functional PCM-based microcapsules by fabricating various functional shells in a multilayered or hierarchical structure to provide a great potential to meet the growing demand for versatile applications. We also provide insights on the future research and development direction of microencapsulated PCMs with multifunctional applications in energy efficiency, sustainable processes, high-tech energy management and specific physicochemical effectiveness.

Innovative design of microencapsulated phase change materials for thermal energy storage and versatile applications: a review

Thermal spraying has been present for over a century, being greatly refined and optimised during this time, becoming nowadays a reliable and cost-efficient method to deposit thick coatings with a wide variety of feedstock materials and substrates. Thermal sprayed coatings have been successfully applied in fields such as aerospace or electricity production, becoming an essential component of today's industry. To overpass the traditional capabilities of those coatings, new functionalities and coherent responses are being integrated, opening the field of functional and smart coatings. The aim of this paper is to present a comprehensive review of the current state of functional and smart coatings produced using thermal spraying deposition. It will first describe the different thermal spraying technologies, with a focus on how different techniques achieve the thermal and kinetic energy required to form a coating, as well as the environment to which feedstock particles are exposed in terms of temperature and velocity. It will then deal with the state-of-the-art functional and smart coatings applied using thermal spraying techniques, with a discussion on the fundamentals on which the coatings are designed, the efficiency of its performance and the industrial applications, both current and potential. The inherent designing flexibility of thermal sprayed functional and smart coatings has been exploited to explore exciting new possibilities on many different fields. Applications such as anti-bacterial and anti-fouling coatings, superhydrophobic surfaces, electrical and heating devices for functional coatings and self-healing, self-lubricating and sensors for smart coatings are here presented and discussed. All these exciting developments pave the way for the numerous applications that are to come in the next decade, making the field of thermal sprayed coatings a unique opportunity for research.

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Beyond traditional coatings, a review on thermal sprayed functional and smart coatings

The impact of corrosion on the oil industry has been viewed in terms of its effect on both capital and operational expenditures (CAPEX and OPEX) and health, safety, and the environment (HSE). To fight against the high cost and the impact of corrosion within the oil industry, an overview of topical research and engineering activities is presented. This covers corrosion and metallurgy issues related to drilling, production, transportation, and refinery activities.

The impact of corrosion on oil and gas industry

Thermal performance of phase change materials (PCM)-enhanced cellulose insulation in passive solar residential building walls

Latent heat storage by silica-coated polymer beads containing organic phase change materials

Microbiologically influenced corrosion (MIC) refers to the influence of microorganisms on the kinetics of corrosion processes of metals and nonmetallic materials, caused by adhering to the interfaces (usually referred to as “biofilms”). The corrosion-relevant microbes like to attach to solids via exopolymeric substances (EPS), which give the main component of the slime and form biofilms at the solid–liquid interface. Not only single stains but also diverse bacterial communities (e.g., iron and manganese and sulfur oxidizers and reducers, slime formers, acid producers, etc.) are able to produce biofilm. There are gradients of microorganisms, oxygen concentrations, and pH values inside the biofilm, which consists mostly of water, microbial metabolites, exopolymeric substances, organic, and inorganic molecules of the aqueous environment. Beneath this biofilm, corrosion initiates and progresses resulting in localized corrosion that can lead, if remained uncontrolled, to pinholes and leaks. This chapter discusses the different microbes responsible for MIC in oil and gas industry, classification of microorganisms, MIC mechanisms, and biofilm development and factors necessary for its formation. Finally the chapter briefly discusses current knowledge gaps in understanding and managing MIC and future research and engineering trends to close these gaps.

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Microbiologically influenced corrosion (MIC)

This chapter deals with traditional and special anti-biofouling coatings used for naval applications. The description starts with the definition of biofouling with an emphasis on its drawbacks and the plants and animals involved in the fouling. After illustration of the undesired action of micro- and macroorganisms, a historical retrospection of antifouling techniques is given. This is followed by a full description of coatings with and without biocides that illustrate those methods when the undesired activity of the organisms is inhibited either by killing them, or repelling from the surfaces that sink in natural waters. Examples are given for polymers, which are able to repel organisms alone or with biocides incorporated, and inorganic and organic additives are introduced as antifouling chemicals. An important section closes the chapter where the most environmentally friend resolutions, i.e., the quorum quenching techniques are discussed.

Smart anti-biofouling composite coatings for naval applications

Microencapsulation of phase change materials (PCMs) is an attractive opportunity for broadening their applications. In this respect, a novel encapsulating polymer, ethyl cellulose (EC) was used to entrap n-hexadecane (HD) PCM by an emulsion-solvent evaporation method. Emulsifiers strongly influenced the size and morphology of the forming EC–HD composite microcapsules, and they also had a great impact on their thermal properties. All of the three emulsifiers were suitable to prepare quasi core–shell microparticles, though the high porosity of shells resulted in serious leakage in composites prepared by Tween 80, and permeability of particles manufactured by poly(vinyl alcohol) (PVA), as can be stated from scanning electron microscopy and differential scanning calorimetry analysis. Interfacial tension measurements and spreading coefficient analysis enabled the prediction of preparation conditions for usable core–shell microcapsules. Volume-weighted mean diameters of the microparticles were 319, 92 and 85 μm formed by Tween 80, PVA and poly(methacrylic acid sodium salt) (PMAA), respectively. A significantly higher HD content and latent heat storage capacity could be achieved using PVA and PMAA than with Tween 80. The thermal cycling test indicated good thermal reliability of microcapsules prepared by PMAA, while the energy-storing capacity of composites prepared by PVA decreased substantially, and a dramatic reduction was found in microparticles using Tween 80.

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László Trif

Papers

Latent heat storage by silica-coated polymer beads containing organic phase change materials

Microbiologically influenced corrosion (MIC)

Smart anti-biofouling composite coatings for naval applications

Microencapsulation of n-hexadecane phase change material by ethyl cellulose polymer

Fully bio-originated latent heat storing calcium alginate microcapsules with high coconut oil loading