China
Africa
Explore chapters and articles related to this topic
Biological Fundamentals
Published in Roger T. Haug, of Compost Engineering, 2018
Microbes of importance in composting include bacteria and fungi. All other groups are of minor significance. It should be noted that some workers in composting include actinomycetes as a separate group distinct from bacteria and fungi. There appears to be considerable confusion on this point, because actinomycetes have been at times classified as bacteria, fungi, and even a separate phylogenetic line. Actinomycetes are filamentous in form like many of the fungi, but they have a procaryotic cell structure like the bacteria. As a class they are active in degradation of insoluble, high molecular weight organics, such as cellulose, chitin, proteins, waxes, paraffins, and rubber. As such, they should be important in composting systems. For convenience they will be considered along with bacteria, although the difficulty of classification should be recognized.
Alkaliphilic Bacteria and Thermophilic Actinomycetes as New Sources of Antimicrobial Compounds
Published in Devarajan Thangadurai, Jeyabalan Sangeetha, Industrial Biotechnology, 2017
Suchitra B. Borgave, Meghana S. Kulkarni, Pradnya P. Kanekar, Dattatraya G. Naik
Actinomycetes are the most economical and biotechnologically valuable class of prokaryotes producing bioactive secondary metabolites notably antibiotics (Blunt et al., 2006), anti-tumor agents, immunosuppressive agents (Mann, 2001) and enzymes (Strohl, 2004; Berdy, 2005; Cragg and Newman, 2005). Actinomycetes are the main source of clinically important antibiotics, most of which are too complex to be synthesized by combinatorial chemistry, making three quarters of all known products; the Streptomyces are especially prolific, producing around 80% of total antibiotic products (Stach and Bull, 2005; Hoa et al., 2009). Micromonospora is the runner up with less than one-tenth as many as Streptomyces (Lam, 2006). In addition to antibacterial components they also produce secondary metabolites with biological activities of which the Streptomyces spp. amounts for 80% of the total production by actinomycetes (Cragg and Newman, 2005). Since the introduction of antibiotics as therapeutic agents, no other group of microorganisms has contributed so much to this field of human and animal therapy as the actinomycetes. Beginning with actinomycin, announced by Walksman in 1940, a large number of chemical compounds have been isolated from the cultures of these organisms. Streptomycin soon followed and repeated the success story of penicillin. Actinomycetes are known to produce almost two thirds of all known antibiotics of microbial origin.
Cu, 29]
Published in Alina Kabata-Pendias, Barbara Szteke, Trace Elements in Abiotic and Biotic Environments, 2015
Alina Kabata-Pendias, Barbara Szteke
Under microorganisms activities, Cu may be available to plants, even from the remediated soils. Some bacteria, especially in the rhizosphere, may accumulate Cu, and thus control its availability (Wang et al. 2008). Bioremediation of Cu-contaminated soils by actinomycetes, due to their very high resistance and great bioaccumulation abilities is proposed (Amoroso and Abate 2012). Under the impact of some endomycorrhizal fungi, Cu nanoparticles are formed at the soil–root interface and influence its availability (Manceau et al. 2008).
Actinomycetes mediated microwave-assisted synthesis of nanoselenium and its biological activities
Published in Particulate Science and Technology, 2023
V. R. Ranjitha, V. Ravishankar Rai
Despite the various methods (Physical and chemical methods) involved in the synthesis of SeNPs, major drawbacks involve the use of toxic chemicals, high temperatures, non-sustainable protocols, and tedious processes restricting their use in biomedical applications (Habibullah, Viktorova, and Ruml 2021). Green approaches for the synthesis of nanoparticles possess considerable attention these days. One such promising approach in the green synthesis of nanoparticles is microbial-mediated synthesis from actinomycetes. Green synthetic methods for metal nanoparticles synthesis are considered effective synthetic methods, microwave-assisted biosynthesis is considered to be a highly effective synthesis because of the increase in reaction rate and homogenous heating compared to the conventional methods (Sheikhlou et al. 2020). Biosynthesis from the microwave irradiation method provides maximum stability, good particle size distribution, and minimum size (Mellinas, Jiménez, and Garrigós 2019). Microwave synthesis provides a superheating process that results in faster and more efficient heating that allows to complete reactions within a minute. While significant works related to the microwave-assisted synthesis of metal nanoparticles are reported (Singh, Rawat, and Isha 2016; Ashraf et al. 2020). But Actinomycetes mediated synthesis from microwave heating is not reported yet. Actinomycetes are known for the production of intracellular enzymes and diverse secondary metabolites that are of commercial interest (Manimaran and Kannabiran 2017).
Atlantic Forest’s and Caatinga’s semiarid soils and their potential as a source for halothermotolerant actinomycetes and proteolytic enzymes
Published in Environmental Technology, 2023
Marghuel A. Vieira Silveira, Saara M. Batista dos Santos, Débora Noma Okamoto, Itamar Soares de Melo, Maria A. Juliano, Jair Ribeiro Chagas, Suzan P. Vasconcellos
Actinomycetes are Gram-positive bacteria with similar fungal morphology. They are dominant in soils and are considered as a huge source of diverse and bioactive secondary metabolites, able to break down resistant and toxic compounds [8]. Recently, a study by Preethi and Ramesh [9] described the use of a Streptomyces sp. strain to deteriorate genotoxic textile azo dyes in water bodies, showing the functionality and strategic use of such microorganisms in economical and time-saving bioremediation. In addition, Matsumoto and Takahashi [10] conducted a study exploring the potential of endophytic actinomycetes from rhizosphere, soil and plant roots, showing possibilities to find the production of aranciamycins, an antibacterial compound against plant pathogen, that might be useful in agriculture. Furthermore, by harbouring a high commercial value, Actinobacteria is responsible for approximately 50% of all commercial antibiotics, among which a single genus, Streptomyces, contributed to 75% [11].
Actinomycetes mediated synthesis, characterization, and applications of metallic nanoparticles
Published in Inorganic and Nano-Metal Chemistry, 2020
Suman Kumari, Nimisha Tehri, Anjum Gahlaut, Vikas Hooda
Actinomycetes play a significant role in pharmaceuticals and medical field[75] and it also helps in the production of various important antibiotics, for instance, vancomycin, gentamycin, amphotericin, chloramphenicol, neomycin, etc. Hence, this group of microbes is considered as most significant in different manufacturing processes of industry. The various metallic nanoparticles biosynthesized using actinomycetes exhibit a wide spectrum antimicrobial activity as listed in Table 3. NPs interferes with bacterial machinery by effectively disrupting the cell membrane components in the pathogenic organism.[82] The AgNPs biosynthesized from Streptomyces sp. show antibacterial activity against bacterial spps. which are multiple drug resistant.[83] Moreover, AgNPs synthesized from Streptomyces sp. (09 PBT 005) has been reported to show good cytotoxicity and antimicrobial activity.[4] The AgNPs biosynthesized extracellularly using Streptomyces viridochromogenes also depicted exemplary antimicrobial property against gram negative and positive bacteria and yeast like Candida albicans.[56]