Extracellular and cell-associated forms of beta-glucosidase in Thermomonospora curvata

The thermophilic actinomycete, Thermomonospora curvata , released 16-times the beta-glucosidase when grown on protein-extracted lucerne fibre compared with growth on cellobiose or purified cellulose. The intracellular and extracellular betaglucosidases had the same mol. wts (66 kD), but the extracellular enzyme had higher affinities for both p -nitrophenyl glucoside and cellobiose and was more resistant to thermal inactivation.     

The importance of sourcing enzymes from non-conventional fungi for metabolic engineering and biomass breakdown

A wealth of fungal enzymes has been identified from nature, which continue to drive strain engineering and bioprocessing for a range of industries. However, while a number of clades have been investigated, the vast majority of the fungal kingdom remains unexplored for industrial applications. Here, we discuss selected classes of fungal enzymes that are currently in biotechnological use, and explore more basal, non-conventional fungi and their underexploited biomass-degrading mechanisms as promising agents in the transition towards a bio-based society. Of special interest are anaerobic fungi like the Neocallimastigomycota, which were recently found to harbor the largest diversity of biomass-degrading enzymes among the fungal kingdom. Enzymes sourced from these basal fungi have been used to metabolically engineer substrate utilization in yeast, and may offer new paths to lignin breakdown and tunneled biocatalysis. We also contrast classic enzymology approaches with emerging ‘omics’-based tools to decipher function within novel fungal isolates and identify new promising enzymes. Recent developments in genome editing are expected to accelerate discovery and metabolic engineering within these systems, yet are still limited by a lack of high-resolution genomes, gene regulatory regions, and even appropriate culture conditions. Finally, we present new opportunities to harness the biomass-degrading potential of undercharacterized fungi via heterologous expression and engineered microbial consortia.     

Green land: Multiple perspectives on green algal evolution and the earliest land plants

Green plants, broadly defined as green algae and the land plants (together, Viridiplantae), constitute the primary eukaryotic lineage that successfully colonized Earth's emergent landscape. Members of various clades of green plants have independently made the transition from fully aquatic to subaerial habitats many times throughout Earth's history. The transition, from unicells or simple filaments to complex multicellular plant bodies with functionally differentiated tissues and organs, was accompanied by innovations built upon a genetic and phenotypic toolkit that have served aquatic green phototrophs successfully for at least a billion years. These innovations opened an enormous array of new, drier places to live on the planet and resulted in a huge diversity of land plants that have dominated terrestrial ecosystems over the past 500 million years. This review examines the greening of the land from several perspectives, from paleontology to phylogenomics, to water stress responses and the genetic toolkit shared by green algae and plants, to the genomic evolution of the sporophyte generation. We summarize advances on disparate fronts in elucidating this important event in the evolution of the biosphere and the lacunae in our understanding of it. We present the process not as a step-by-step advancement from primitive green cells to an inevitable success of embryophytes, but rather as a process of adaptations and exaptations that allowed multiple clades of green plants, with various combinations of morphological and physiological terrestrialized traits, to become diverse and successful inhabitants of the land habitats of Earth.     

A sporulation medium forDiscula destructiva,the dogwood anthracnose fungus

A growth medium incorporating finely ground oak or maple leaf tissue was developed for the purpose of increasing in vitro conidium production by the dogwood anthracnose pathogen,Discula destructiva.     

When Landscaping Goes Bad: The Incipient Invasion of Mahonia bealei in the Southeastern United States

Woodlots are forest islands embedded within an urban matrix, and often represent the only natural areas remaining in suburban areas. Woodlots represent critical conservation areas for native plants, and are important habitat for wildlife in urban areas. Invasion by non-indigenous (NIS) plants can alter ecological structure and function, and may be especially severe in remnant forests where NIS propagule pressure is high. Woody shrubs in the Family Berberidaceae have been well documented as invaders of the forest–urban matrix in North America. Mahonia bealei (Berberidaceae) is a clonal shrub native to China, and is a popular ornamental in the Southeastern United States. Mahoni bealei is listed as “present” on some local and state floras, but almost nothing is known regarding its invasion potential in the United States. We sampled 15 woodlots in Clemson, South Carolina, to assess the invasion of M. bealei and other woody non-indigenous species (NIS). M. bealei invaded 87% of the woodlots surveyed and species richness of NIS on these woodlots varied from 5 to 14. Stepwise-multiple regression indicated that less canopy cover and older M. bealei predicted greater abundance of M. bealei , and that not all subdivisions were equally invaded (P < 0.0001; r² = 0.88). The impact of M. bealei on native flora and fauna may be considerable, and it is likely to continue to spread in the Southeastern United States. M. bealei should be recognized as an aggressive invader in the Southeastern United States, with the potential for negative impacts on native flora and fauna.     

Interference of the detergent Tween 80 in protein assays.

The nonionic detergent Tween 80, which has been widely used to stimulate protein secretion in bacterial and fungal systems, caused interferences in three protein determination methods. The OD595 developed in the Coomassie blue dye-binding assay with a variety of purified proteins in the presence of Tween 80 was 1.6 to 3.4 times greater than that observed without detergent. These differences could not be attributed totally to the rapid color development in the assay with Tween 80 alone. Crude concentrated extracellular bacterial proteins shaken overnight with Tween 80 yielded an altered fractionation pattern on size exclusion chromatography and 10-fold increased color with an absorption spectrum in the dye-binding assay different from that of bacterial proteins shaken without detergent. In the bicinchoninic acid method, the detergent caused a 2- to 3-fold increase in OD562 due largely to contaminating peroxides which could be removed by treatment with catalase. In the Folin phenol method, the detergent caused a slight precipitate, but residual interference was not detectable in filtered assay mixtures.     

Selective adsorption of endoglucanases from Thermomonospora curvata on protein-extracted lucerne fibres

Cellulases of Thermomonospora curvata contain three endoglucanase components. Two of these enzymes (molecular weights of 46 and 106 kD) bound to protein-extracted lucerne fibres. Maximal adsorption occurred within 6 min, followed by a gradual desorption during fibre hydrolysis.     

A socio-ecological test bed

A test bed simulation is described, composed of an individual-based simulation where species co-evolve on a 2D grid. This can generate, in a bottom-up manner, complex ecosystems of individuals. This test bed is designed so that the kind of ecological complexity observed is exhibited in order to be able to assess the longer-term complex dynamics that might occur if humans with different cultural characteristics are introduced. This is compared to Hubbell's ‘Neutral Theory’. A sensitivity analysis is shown. Then an example where “human agents” are introduced half way into the simulation is described. A comprehensive exploration of the impact of introducing ‘human-like’ agents is beyond the scope of this paper, but some indicative results shown, showing both the high impact humans have, but also some of the complexity of the human-ecosystem interaction.