Bioprospecting of Microorganism-Based Industrial Molecules

Здесь есть возможность читать онлайн «Bioprospecting of Microorganism-Based Industrial Molecules» — ознакомительный отрывок электронной книги совершенно бесплатно, а после прочтения отрывка купить полную версию. В некоторых случаях можно слушать аудио, скачать через торрент в формате fb2 и присутствует краткое содержание. Жанр: unrecognised, на английском языке. Описание произведения, (предисловие) а так же отзывы посетителей доступны на портале библиотеки ЛибКат.

Bioprospecting of Microorganism-Based Industrial Molecules: краткое содержание, описание и аннотация

Предлагаем к чтению аннотацию, описание, краткое содержание или предисловие (зависит от того, что написал сам автор книги «Bioprospecting of Microorganism-Based Industrial Molecules»). Если вы не нашли необходимую информацию о книге — напишите в комментариях, мы постараемся отыскать её.

Discover a comprehensive and current overview of microbial bioprospecting written by leading voices in the field In
, distinguished researchers and authors Sudhir P. Singh and Santosh Kumar Upadhyay deliver global perspectives of bioprospecting of biodiversity. The book covers diverse aspects of bioprospecting of microorganisms demonstrating biomass value of nutraceutical, pharmaceutical, biomedical, and bioenergetic importance.
The authors present an amalgamation of translational research on bioresource utilization and ecological sustainability that will further the reader’s knowledge of the applications of different microbial diversity and reveal new avenues of research investigation.
Readers will also benefit from:
A thorough introduction to microbial biodiversity and bioprospecting An exploration of anti-ageing and skin lightening microbial products and microbial production of anti-cancerous biomolecules A treatment of UV protective compounds from algal biodiversity and polysaccharides from marine microalgal sources Discussions of microbial sources of insect toxic proteins and the role of microbes in bio-surfactants production Perfect for academics, scientists, researchers, graduate and post-graduate students working and studying in the areas of microbiology, food biotechnology, industrial microbiology, plant biotechnology, and microbial biotechnology,
is an indispensable guide for anyone looking for a comprehensive overview of the subject.

Bioprospecting of Microorganism-Based Industrial Molecules — читать онлайн ознакомительный отрывок

Ниже представлен текст книги, разбитый по страницам. Система сохранения места последней прочитанной страницы, позволяет с удобством читать онлайн бесплатно книгу «Bioprospecting of Microorganism-Based Industrial Molecules», без необходимости каждый раз заново искать на чём Вы остановились. Поставьте закладку, и сможете в любой момент перейти на страницу, на которой закончили чтение.

Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

In the second category, surfactants are normally grouped according to the presence or absence of formal electrostatic charges in the hydrophilic moiety of the molecule. Thus, cationic surfactants contain formal positive charges (+) on the polar head of the surfactant molecule and are systematically escorted by negative counterions that neutralize the charges. Anionic surfactants have negative formal charges (−), an example of this latter is represented in Figure 2.1. The third class of ionic surfactants is those species comprising both positive and negative charges in the same body (±). These species are known as inner salts or zwitterions (from German zwitter = hybrid). The last case of this classification is the absence of formal charges in the surfactant molecule, so these are called nonionic surfactants.

Figure 21 3D chemical structure of lauryl sulfate as an example of a - фото 4

Figure 2.1 3D chemical structure of lauryl sulfate as an example of a surfactant molecule. The hydrophilic head of sulfate (SO 4 2−) is surrounded by water molecules, while the lipophilic tail avoids any contact with water.

Source: Based on [1].

Table 2.1 Classification of surfactants by origin, ionic status, and hydrophilic–lipophilic balance.

Category Example
I. Origin Synthetic Nonylphenol ethoxylates
Oleochemical Lauryl alcohol ethoxylates
Biosurfactants Sophorolipids
II. Electrostatic status Oonic Cationic Ammonium salts
Anionic Lauryl sulfates
Zwitterionic Betaines
Nonionic Oxirane and 2‐methyoxirane copolymers
III. Hydrophilic–lipophilic balance 01–03 Antifoaming agents
03–08 w/o emulsifiers
07–10 Wetting agents
08–16 o/w emulsifiers
13–16 Detergents
16–19 Solubilizing agent

Finally, surfactants can be ranked according to their amphiphilic nature, otherwise by their hydrophilic–lipophilic balance (HLB). Although there are a significant number of theoretical and experimental approaches, the most used HLB system is the Griffin’s [3]. In a simplistic way, HLB values are estimated from the division of the mass of the hydrophilic fragment by the mass of the entire molecule, and the resulting quotient is then multiplied by a conventional value of 20. HLB can predict whether a surfactant will behave as an emulsifier, solubilizer, dispersant, or other; therefore, this system has been a useful guide to formulate products containing conventional surfactants for specific applications, and certainly, will be just as convenient for the case of BS. The hydrophilic part of BS is normally constituted by carbohydrates, amino acids, proteins, phosphates, carboxylic acids, or alcohol motifs; and these can be ionic or nonionic. The lipophilic part commonly is long chains of carbon atoms, just as in fatty acids. Both molecular components, hydrophilic and lipophilic, are assembled via linking biochemical functionalities, e.g. ethers (C−O−C), amides (N−C=O), and esters (O−C=O). According to the nature of each moiety hydrophilic and lipophilic, BS are commonly classified in the following groups: (i) glycolipids, (ii) lipopolysaccharides, (iii) lipopeptides, (iv) phospholipids, and (v) fatty acids; each one with specific physicochemical characteristics and physiological roles [4, 5]; for example, Emulsan and other complex lipopolysaccharides are polymeric BS with known emulsification capabilities.

From all the types of BS, glycolipids have the greatest opportunity to be manufactured on a large scale due to the high yield of obtention compared to other BS such as lipoproteins. It is clear that BS produced in higher yields will represent a lower cost for production [6]. This is why glycolipids have captured our attention for this chapter. Glycolipids result from the condensation of aliphatic fatty acids (lipids) and carbohydrates. Their names are taken from the nature of the carbohydrate moiety. Consequently, glycolipids containing sophorose in the hydrophilic segment are called sophorolipids (SL); those containing rhamnose are named rhamnolipids; those with trehalose, trehalose‐lipids, and so on. Of all the glycolipid types, SL and rhamnolipids have been among the most studied [7, 8].

SL ( Figure 2.2) contain the disaccharide sophorose linked to a fatty acid via an ether function. The fatty acid must be previously hydroxylated somewhere in the carbon chain, usually at the other end of the carboxylic acid function. SL can be found as different chemical structures. The most evident and well known is the divergence between open and cyclic arrangements [9]. Open SL are those that have the chemical functionality of carboxylic acid (COOH) at the end of the lipophilic chain, while cyclic arrangements are those having an ester functionality as a result of the condensation between the fatty acid and one of the hydroxyl motifs of the sophorose.

Figure 22 Chemical structures for two species of sophorolipids as a result of - фото 5

Figure 2.2 Chemical structures for two species of sophorolipids as a result of the condensation of sophorose with oleic acid. On the left side, it is shown the open form of carboxylic acid and on the right side, the cyclic form of the lactone.

Cyclic esters are called lactones. Hence, there are two types of SL: the acidic forms and the lactone forms. Other less notable molecular variables are (i) the presence or absence of acetyl groups attached to the hydroxyl moieties on the carbohydrate periphery, (ii) the length of the alkyl chain, (iii) the degree of unsaturation (unsaturation = double or triple bonds), (iv) the position of the hydroxyl group in the alkyl chain, (v) the position of the hydroxyl group of the sophorose that serves to build the ether bond with the fatty alcohol, and (vi) the position of the hydroxyl group of sophorose serves to construct the ester bond with the fatty acid in the lactone forms, inter alia.

Figure 2.2shows the chemical structures of two SL: one in the acid form (left) and one in the lactone form (right). Both species do not contain any acetyl groups but have a fatty acid moiety of 18 carbon atoms with only one unsaturation in position C‐9 with Z geometry. This fatty acid (oleic acid) must have been previously hydroxylated inside the cell by some biochemical β ‐oxidation at position C‐17. This latter allows its association with the free hydroxyl moiety of the anomeric carbon of sophorose, which produces the ether bridge of sophorose‐lipid equally found in both acid and lactone arrangements. Thus, the chemical name for the acid form should be ( S , Z )‐17‐{[(2 S ,3 R ,4 S ,5 S ,6 R )‐4,5‐dihydroxy‐6‐hydroxymethyl‐3‐{[(2 S ,3 R ,4 S ,5 S ,6 R )‐3,4,5‐trihydroxy‐6‐hydroxymethyltetrahydro‐2 H ‐pyran‐2‐yl]oxy}tetrahydro‐2 H ‐pyran‐2‐yl]oxy}octadec‐9‐enoic acid.

In the case of lactone, the carboxylic acid was condensed with the hydroxyl group in C‐5 of the other monosaccharide fragment of sophorose. After imagining the number of possible combinations of structural variations, one would not expect microorganisms to produce unique and pure compounds, but rather a wide variety of many different species. Therefore, the selection of microorganism strain, culture conditions, culture media, and substrates are the first fundamental factors playing a decisive role in the complexity (or simplicity) of obtained mixtures.

Читать дальше
Тёмная тема
Сбросить

Интервал:

Закладка:

Сделать

Похожие книги на «Bioprospecting of Microorganism-Based Industrial Molecules»

Представляем Вашему вниманию похожие книги на «Bioprospecting of Microorganism-Based Industrial Molecules» списком для выбора. Мы отобрали схожую по названию и смыслу литературу в надежде предоставить читателям больше вариантов отыскать новые, интересные, ещё непрочитанные произведения.


Отзывы о книге «Bioprospecting of Microorganism-Based Industrial Molecules»

Обсуждение, отзывы о книге «Bioprospecting of Microorganism-Based Industrial Molecules» и просто собственные мнения читателей. Оставьте ваши комментарии, напишите, что Вы думаете о произведении, его смысле или главных героях. Укажите что конкретно понравилось, а что нет, и почему Вы так считаете.

x