Evolution and Ecology ofActinobacteriaand Their Bioenergy Applications

Abstract

The ancient phylum Actinobacteria is composed of phylogenetically and physiologically diverse bacteria that help Earth’s ecosystems function. As free-living organisms and symbionts of herbivorous animals, Actinobacteria contribute to the global carbon cycle through the breakdown of plant biomass. In addition, they mediate community dynamics as producers of small molecules with diverse biological activities. Together, the evolution of high cellulolytic ability and diverse chemistry, shaped by their ecological roles in nature, make Actinobacteria a promising group for the bioenergy industry. Specifically, their enzymes can contribute to industrial-scale breakdown of cellulosic plant biomass into simple sugars that can then be converted into biofuels. Furthermore, harnessing their ability to biosynthesize a range of small molecules has potential for the production of specialty biofuels.

In vivo synergistic activity of a CAZyme cassette from Acidothermus cellulolyticus significantly improves the cellulolytic activity of the C. bescii exoproteome

“…Some members of the GH12 family are also known to be active on xylan and in this architecture the CBM2 could provide binding to xylan (Czjzek et al, ; Lombard et al, ). The GH6 family contains examples of enzymes with both endo‐ and exoglucanase activities, and exoglucanase activity has been detected in both bacterial and fungal enzymes (Berlemont and Martiny, ; Lewin et al, ). We note that the C. bescii genome does not contain either a GH6 or GH12 catalytic domain or a CBM2.…”

Draft Genome Sequences of Two Novel Cellulolytic Streptomyces Strains Isolated from South African Rhizosphere Soil

“…Streptomyces species are known for their diverse metabolic potential, wide range of antibiotic biosynthesis capabilities, and ability to degrade unique compounds, such as lignocellulose, keratin, xylan, pectin, cellulose, lignin, chitin, and styrene (1–4). They also produce various hydrolytic enzymes, such as amylase, lipase, esterase, gelatinase, xylanase, and cellulases.…”

Research Article Characterization and phylogenetic affiliation of Actinobacteria from tropical soils with potential uses for agro-industrial processes.

“…Recently, cellulolytic enzymes of bacterial origin have received special attention of the bioenergy industry due to the higher bacterial growth, sustainability, and environmental impact compared with non-renewable fossil fuel counterparts. However, the industrial-scale breakdown of lignocellulosic plant biomass into simple sugars that can be converted into biofuels is one of the major barriers to the lignocellulosic ethanol production (Lewin et al, 2016).…”

“…Actinobacteria comprise an ecologically diverse group ubiquitously distributed in various natural environments as free-living, pathogens, and endophyte symbionts (Hardoim et al, 2015). They are distinguished as Gram-positive bacteria, normally aerobic, non-acid fast and with a high GC content in their DNA, varying to less than 50% in a few species to more than 70% in some genera (Lewin et al, 2016). …”