Microbiology Blog: The weblog for microbiologists
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Diversity of Polyketide Synthases in Fusarium
from Daren W. Brown and Robert H. Proctor writing in Fusarium: Genomics, Molecular and Cellular Biology:
Fusarium can produce a structurally diverse array of secondary metabolites (SMs) with a range of biological activities, including pigmentation, plant growth regulation, and toxicity to humans and other animals. Contamination of grain-based food and feed with toxic SMs produced by Fusarium is associated with a variety of diseases in plants and animals and results in loss of millions of dollars in grain commodities each year. Many SMs are formed via the activities of a family of large enzymes called polyketide synthases (PKSs) that consist of between five and eight functional domains. This Chapter reviews the structures and functions of Fusarium PKSs present in four species, Fusarium verticillioides, Fusarium graminearum, Fusarium solani and Fusarium oxysporum. Each genome has between 11 and 16 PKS genes. Re-examination of inferred phylogenetic relationships of deduced amino acid sequences provides insight into how this gene family evolved. The geneaologies suggest that collectively the Fusarium PKSs represent 36 distinct sets of PKS homologs, where each set catalyzes synthesis of a structurally distinct polyketide. Variation in Fusarium PKS genes is due to both ancient and recent gene duplications, gene loss events, gain-of-function due to the acquisition of new domains, and of loss-of-function due to nucleotide mutations. The significant number and variety of evolutionary changes reflects a vast biosynthetic potential this gene family provides fungi and that may help them adapt to changing environmental conditions. Understanding how fungal polyketides are synthesized should lead to better methods to control their production and thereby reduce their negative impact on human endevors.
Further reading: Fusarium: Genomics, Molecular and Cellular Biology
Next Generation Sequencing
Written by experts from around the world, this book explores the most recent advances in NGS instrumentation and data analysis. The book begins with a comprehensive description of current NGS platforms, their sequencing chemistries, instrument specifications, and general workflows and procedures. A separate chapter is dedicated to low-quantity, single molecule sequencing technology. Further chapters explore the application of NGS technologies in various fields including polymorphism detection, sRNA research, rare variant detection, large variant detection, exome sequencing, plant development studies, microbial metagenomics, and studies on the human microbiome. Practical and cutting-edge, this volume represents an excellent collection of chapters to aid all scientists who wish to apply these innovative research tools read more ...
 | Edited by: Jianping Xu read more ...ISBN: 978-1-908230-33-1 Publisher: Caister Academic Press Publication Date: March 2014 Cover: hardback |
Myxobacteria
In this book, expert myxobiologists describe important recent advances in understanding the behaviour of these bacteria at a molecular and cellular level. The book covers ecology, genomics and cell biology as well as modelling and simulation on topics including motility, development and their associated genetic regulatory networks. Authors provide the most up-to-date overview on myxobacteria and highlight open questions in the active areas of research. The book will serve as an essential reference for everyone working with myxobacteria. Chapters have been written and structured to be accessible to teachers, graduate and advanced undergraduate students new to myxobacteria, as well as experts in other fields including physical and computational sciences read more ...
 | Edited by: Zhaomin Yang and Penelope I. Higgs read more ...ISBN: 978-1-908230-34-8 Publisher: Caister Academic Press Publication Date: February 2014 Cover: hardback |
Ecology and Taxonomy of Psychrotolerant Bacteria in Artificial Cold Environments
from Isao Yumoto and Koji Yamazaki writing in Cold-Adapted Microorganisms:
A variety of artificial cold environmental conditions exist around human activities. These environments involve several factors that define the kinds of bacteria existing in niches. These environmental factors change with time owing to changes in the environment caused by existing microorganisms and their metabolisms. Namely, the inevitable selection of bacteria occurs in each artificial cold environment and the successive changes in microbiota occur according to changes in environmental factors. Some of the microorganisms in these microbial communities are useful for the degradation of organic matter in cold environments and for food preservation. On the other hand, several microorganisms adapted to artificial cold environments cause food spoilage. The frequently isolated psychrotolerant bacterial genera in artificial cold environments are Pseudomonas, Psychrobacter, Staphylococcus and Photobacterium. Lactic acid bacteria are also frequently detected under anaerobic conditions. To date, it has been reported that these genera are widely distributed in natural as well as artificial cold environments. It is intriguing why these bacterial genera are widely distributed in cold environments and why certain species belonging to these genera are able to survive in artificial cold environments. The frequent detection of members of above-mentioned genera in artificial cold environments suggests that the important factors that define the existence of these genera in cold artificial environments are i) chances of invasion of such cold environments from ambient environments, ii) chances of invasion through their own basic components, iii) ability to rapidly propagate at low temperature and iv) presence or absence of oxygen. It is also considered that these genera are genetically widely diverse, and cold artificial environment adaptation mechanisms of certain species belonging to these genera make their distribution wider not only in natural cold environments but also in artificial cold environments.
Further reading: Cold-Adapted Microorganisms
Effect of Microglial Inflammation in Prion Disease
from Yasuhisa Ano, Akikazu Sakudo and Takashi Onodera writing in Prions: Current Progress in Advanced Research:
Prion diseases are a group of transmissible fatal neurodegenerative disorders. Neuropathological features of prion diseases include neuronal vacuolation, neuronal loss, astrogliosis, and accumulation of activated microglial cells in affected brain areas. Recent studies have indicated that microglia may play a role in the pathogenesis of prion diseases. Chemokine receptor (CXCR3) expressed in microglia and microglial inflammasome activated by prion infection is important in the etiology of CNS pathologies. pathologies. The functions of microglia in this disease are discussed in this review.
Further reading: Prions: Current Progress in Advanced Research
Mollicutes
In this book acknowledged experts critically review the most recent advances in the evolution, genetics and molecular pathogenesis of these important pathogens. Topics covered include: taxonomy; genomic mosaics; molecular genetic tools for mollicutes; identification and characterisation of virulence genes in mycoplasmas; post-translational modification of proteins; multifunctional cytoadherence factors; the glycocalyx; glycosidase activity; phase and antigenic variation in mycoplasmas; spiroplasma transmission from insect to plants; cytoskeletons organization; gliding mechanism of the Mycoplasma pneumoniae subgroup; biofilm formation by mycoplasmas; host immune responses to mycoplasmas; and emerging antimicrobial resistance in mycoplasmas of humans and animals. An essential book for researchers working with mollicutes and recommended reading for everyone interested in bacterial genomics, bacterial pathogenesis and the evolution of bacterial virulence read more ...
 | Edited by: Glenn F. Browning and Christine Citti read more ...ISBN: 978-1-908230-30-0 Publisher: Caister Academic Press Publication Date: January 2014 Cover: hardback |