Structural diversity and possible functional roles of free fatty acids of the novel soil isolate Streptomyces sp. NP10

Herein, a novel soil bacterium Streptomyces sp. NP10 able to grow outside usual streptomycetes optimum conditions (e.g., at 4 A degrees C, pH 9 and high NaCl concentration), exhibiting atypical hemolytic, DNAse, and cellulolytic activities, is described. This strain produces and excretes into the growth medium large amounts of free long-chain fatty acids (FAs). A concurrent lipidomics study revealed a large structural diversity of FAs with over 50 different n- and branched-chain, (un)saturated, and cyclopropane FAs (C-7-C-30) produced by this strain. Two of these, i-17:0cy9-10 and a-18:0cy9-10, represent new natural products and the first ever identified branched cyclopropane FAs. Both free and bound lipid profiles of Streptomyces sp. NP10 were dominated by saturated branched chain FAs (i-14:0, a-15:0, and i-16:0). Although these free FAs showed only a moderate antimicrobial activity, our results suggest that they could have an ecophysiological role in interspecies signaling with another soil microorganism Pseudomonas aeruginosa. This work represents the first comprehensive report on the structural diversity and complexity of the free FA pool in Streptomyces. A naturally occurring streptomycete, such as Streptomyces sp. NP10, which secretes significant amounts of free long-chain FAs (non-cytotoxic) into the medium, could be useful in microbial biodiesel production.Supplementary material: [http://cherry.chem.bg.ac.rs/handle/123456789/3430

Alkaliphiles : The Versatile Tools in Biotechnology

The extreme environments within the biosphere are inhabited by organisms known as extremophiles. Lately, these organisms are attracting a great deal of interest from researchers and industrialists. The motive behind this attraction is mainly related to the desire for new and efficient products of biotechnological importance and human curiosity of understanding nature. Organisms living in common “human-friendly” environments have served humanity for a very long time, and this has led to exhaustion of the low-hanging “fruits,” a phenomenon witnessed by the diminishing rate of new discoveries. For example, acquiring novel products such as drugs from the traditional sources has become difficult and expensive. Such challenges together with the basic research interest have brought the exploration of previously neglected or unknown groups of organisms. Extremophiles are among these groups which have been brought to focus and garnering a growing importance in biotechnology. In the last few decades, numerous extremophiles and their products have got their ways into industrial, agricultural, environmental, pharmaceutical, and other biotechnological applications. Alkaliphiles, organisms which thrive optimally at or above pH 9, are one of the most important classes of extremophiles. To flourish in their extreme habitats, alkaliphiles evolved impressive structural and functional adaptations. The high pH adaptation gave unique biocatalysts that are operationally stable at elevated pH and several other novel products with immense biotechnological application potential. Advances in the cultivation techniques, success in gene cloning and expression, metabolic engineering, metagenomics, and other related techniques are significantly contributing to expand the application horizon of these remarkable organisms of the ‘bizarre’ world. Studies have shown the enormous potential of alkaliphiles in numerous biotechnological applications. Although it seems just the beginning, some fantastic strides are already made in tapping this potential. This work tries to review some of the prominent applications of alkaliphiles by focusing such as on their enzymes, metabolites, exopolysaccharides, and biosurfactants. Moreover, the chapter strives to assesses the whole-cell applications of alkaliphiles including in biomining, food and feed supplementation, bioconstruction, microbial fuel cell, biofuel production, and bioremediation